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Sample records for early drosophila embryo

  1. Stable, precise, and reproducible patterning of bicoid and hunchback molecules in the early Drosophila embryo.

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    Yurie Okabe-Oho

    2009-08-01

    Full Text Available Precise patterning of morphogen molecules and their accurate reading out are of key importance in embryonic development. Recent experiments have visualized distributions of proteins in developing embryos and shown that the gradient of concentration of Bicoid morphogen in Drosophila embryos is established rapidly after fertilization and remains stable through syncytial mitoses. This stable Bicoid gradient is read out in a precise way to distribute Hunchback with small fluctuations in each embryo and in a reproducible way, with small embryo-to-embryo fluctuation. The mechanisms of such stable, precise, and reproducible patterning through noisy cellular processes, however, still remain mysterious. To address these issues, here we develop the one- and three-dimensional stochastic models of the early Drosophila embryo. The simulated results show that the fluctuation in expression of the hunchback gene is dominated by the random arrival of Bicoid at the hunchback enhancer. Slow diffusion of Hunchback protein, however, averages out this intense fluctuation, leading to the precise patterning of distribution of Hunchback without loss of sharpness of the boundary of its distribution. The coordinated rates of diffusion and transport of input Bicoid and output Hunchback play decisive roles in suppressing fluctuations arising from the dynamical structure change in embryos and those arising from the random diffusion of molecules, and give rise to the stable, precise, and reproducible patterning of Bicoid and Hunchback distributions.

  2. Changes in protein synthetic activity in early Drosophila embryos mutant for the segmentation gene Krueppel

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    Bedian, V.; Summers, M.C.; Kauffman, S.A.

    1988-01-01

    We have identified early embryo proteins related to the segmentation gene Krueppel by [35S]methionine pulse labelling and two-dimensional gel electrophoresis. Protein synthesis differences shared by homozygous embryos of two Krueppel alleles when compared to heterozygous and wild-type embryos are reported. The study was extended to syncytial blastoderm stages by pulse labelling and gel analysis of single embryos, using Krueppel-specific proteins from gastrula stages as molecular markers for identifying homozygous Krueppel embryos. Localized expression of interesting proteins was examined in embryo fragments. The earliest differences detected at nuclear migration stages showed unregulated synthesis in mutant embryos of two proteins that have stage specific synthesis in normal embryos. At the cellular blastoderm stage one protein was not synthesized and two proteins showed apparent shifts in isoelectric point in mutant embryos. Differences observed in older embryos included additional proteins with shifted isoelectric points and a number of qualitative and quantitative changes in protein synthesis. Five of the proteins with altered rates of synthesis in mutant embryos showed localized synthesis in normal embryos. The early effects observed are consistent with the hypothesis that the Krueppel product can be a negative or positive regulator of expression of other loci, while blastoderm and gastrula stage shifts in isoelectric point indicate that a secondary effect of Krueppel function may involve post-translational modification of proteins

  3. The Brakeless co-regulator can directly activate and repress transcription in early Drosophila embryos.

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    Crona, Filip; Holmqvist, Per-Henrik; Tang, Min; Singla, Bhumica; Vakifahmetoglu-Norberg, Helin; Fantur, Katrin; Mannervik, Mattias

    2015-11-01

    The Brakeless protein performs many important functions during Drosophila development, but how it controls gene expression is poorly understood. We previously showed that Brakeless can function as a transcriptional co-repressor. In this work, we perform transcriptional profiling of brakeless mutant embryos. Unexpectedly, the majority of affected genes are down-regulated in brakeless mutants. We demonstrate that genomic regions in close proximity to some of these genes are occupied by Brakeless, that over-expression of Brakeless causes a reciprocal effect on expression of these genes, and that Brakeless remains an activator of the genes upon fusion to an activation domain. Together, our results show that Brakeless can both repress and activate gene expression. A yeast two-hybrid screen identified the Mediator complex subunit Med19 as interacting with an evolutionarily conserved part of Brakeless. Both down- and up-regulated Brakeless target genes are also affected in Med19-depleted embryos, but only down-regulated targets are influenced in embryos depleted of both Brakeless and Med19. Our data provide support for a Brakeless activator function that regulates transcription by interacting with Med19. We conclude that the transcriptional co-regulator Brakeless can either activate or repress transcription depending on context. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. No significant regulation of bicoid mRNA by Pumilio or Nanos in the early Drosophila embryo.

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    Wharton, Tammy H; Nomie, Krystle J; Wharton, Robin P

    2018-01-01

    Drosophila Pumilio (Pum) is a founding member of the conserved Puf domain class of RNA-binding translational regulators. Pum binds with high specificity, contacting eight nucleotides, one with each of the repeats in its RNA-binding domain. In general, Pum is thought to block translation in collaboration with Nanos (Nos), which exhibits no binding specificity in isolation but is recruited jointly to regulatory sequences containing a Pum binding site in the 3'-UTRs of target mRNAs. Unlike Pum, which is ubiquitous in the early embryo, Nos is tightly restricted to the posterior, ensuring that repression of its best-characterized target, maternal hunchback (hb) mRNA, takes place exclusively in the posterior. An exceptional case of Nos-independent regulation by Pum has been described-repression of maternal bicoid (bcd) mRNA at the anterior pole of the early embryo, dependent on both Pum and conserved Pum binding sites in the 3'-UTR of the mRNA. We have re-investigated regulation of bcd in the early embryo; our experiments reveal no evidence of a role for Pum or its conserved binding sites in regulation of the perdurance of bcd mRNA or protein. Instead, we find that Pum and Nos control the accumulation of bcd mRNA in testes.

  5. The presence of nuclear cactus in the early Drosophila embryo may extend the dynamic range of the dorsal gradient.

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    Michael D O'Connell

    2015-04-01

    Full Text Available In a developing embryo, the spatial distribution of a signaling molecule, or a morphogen gradient, has been hypothesized to carry positional information to pattern tissues. Recent measurements of morphogen distribution have allowed us to subject this hypothesis to rigorous physical testing. In the early Drosophila embryo, measurements of the morphogen Dorsal, which is a transcription factor responsible for initiating the earliest zygotic patterns along the dorsal-ventral axis, have revealed a gradient that is too narrow to pattern the entire axis. In this study, we use a mathematical model of Dorsal dynamics, fit to experimental data, to determine the ability of the Dorsal gradient to regulate gene expression across the entire dorsal-ventral axis. We found that two assumptions are required for the model to match experimental data in both Dorsal distribution and gene expression patterns. First, we assume that Cactus, an inhibitor that binds to Dorsal and prevents it from entering the nuclei, must itself be present in the nuclei. And second, we assume that fluorescence measurements of Dorsal reflect both free Dorsal and Cactus-bound Dorsal. Our model explains the dynamic behavior of the Dorsal gradient at lateral and dorsal positions of the embryo, the ability of Dorsal to regulate gene expression across the entire dorsal-ventral axis, and the robustness of gene expression to stochastic effects. Our results have a general implication for interpreting fluorescence-based measurements of signaling molecules.

  6. Comparative gene expression analysis of Dtg, a novel target gene of Dpp signaling pathway in the early Drosophila melanogaster embryo.

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    Hodar, Christian; Zuñiga, Alejandro; Pulgar, Rodrigo; Travisany, Dante; Chacon, Carlos; Pino, Michael; Maass, Alejandro; Cambiazo, Verónica

    2014-02-10

    In the early Drosophila melanogaster embryo, Dpp, a secreted molecule that belongs to the TGF-β superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. Here, we examined the expression pattern and transcriptional regulation of Dtg, a new target gene of Dpp signaling pathway that is required for proper amnioserosa differentiation. We showed that the expression of Dtg was controlled by Dpp and characterized a 524-bp enhancer that mediated expression in the dorsal midline, as well as, in the differentiated amnioserosa in transgenic reporter embryos. This enhancer contained a highly conserved region of 48-bp in which bioinformatic predictions and in vitro assays identified three Mad binding motifs. Mutational analysis revealed that these three motifs were necessary for proper expression of a reporter gene in transgenic embryos, suggesting that short and highly conserved genomic sequences may be indicative of functional regulatory regions in D. melanogaster genes. Dtg orthologs were not detected in basal lineages of Dipterans, which unlike D. melanogaster develop two extra-embryonic membranes, amnion and serosa, nevertheless Dtg orthologs were identified in the transcriptome of Musca domestica, in which dorsal ectoderm patterning leads to the formation of a single extra-embryonic membrane. These results suggest that Dtg was recruited as a new component of the network that controls dorsal ectoderm patterning in the lineage leading to higher Cyclorrhaphan flies, such as D. melanogaster and M. domestica. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Spatial Reorganization of the Endoplasmic Reticulum during Mitosis Relies on Mitotic Kinase Cyclin A in the Early Drosophila Embryo

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    Bergman, Zane J.; Mclaurin, Justin D.; Eritano, Anthony S.; Johnson, Brittany M.; Sims, Amanda Q.; Riggs, Blake

    2015-01-01

    Mitotic cyclin-dependent kinase with their cyclin partners (cyclin:Cdks) are the master regulators of cell cycle progression responsible for regulating a host of activities during mitosis. Nuclear mitotic events, including chromosome condensation and segregation have been directly linked to Cdk activity. However, the regulation and timing of cytoplasmic mitotic events by cyclin:Cdks is poorly understood. In order to examine these mitotic cytoplasmic events, we looked at the dramatic changes in the endoplasmic reticulum (ER) during mitosis in the early Drosophila embryo. The dynamic changes of the ER can be arrested in an interphase state by inhibition of either DNA or protein synthesis. Here we show that this block can be alleviated by micro-injection of Cyclin A (CycA) in which defined mitotic ER clusters gathered at the spindle poles. Conversely, micro-injection of Cyclin B (CycB) did not affect spatial reorganization of the ER, suggesting CycA possesses the ability to initiate mitotic ER events in the cytoplasm. Additionally, RNAi-mediated simultaneous inhibition of all 3 mitotic cyclins (A, B and B3) blocked spatial reorganization of the ER. Our results suggest that mitotic ER reorganization events rely on CycA and that control and timing of nuclear and cytoplasmic events during mitosis may be defined by release of CycA from the nucleus as a consequence of breakdown of the nuclear envelope. PMID:25689737

  8. Global regulation of mRNA translation and stability in the early Drosophila embryo by the Smaug RNA-binding protein.

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    Chen, Linan; Dumelie, Jason G; Li, Xiao; Cheng, Matthew Hk; Yang, Zhiyong; Laver, John D; Siddiqui, Najeeb U; Westwood, J Timothy; Morris, Quaid; Lipshitz, Howard D; Smibert, Craig A

    2014-01-07

    Smaug is an RNA-binding protein that induces the degradation and represses the translation of mRNAs in the early Drosophila embryo. Smaug has two identified direct target mRNAs that it differentially regulates: nanos and Hsp83. Smaug represses the translation of nanos mRNA but has only a modest effect on its stability, whereas it destabilizes Hsp83 mRNA but has no detectable effect on Hsp83 translation. Smaug is required to destabilize more than one thousand mRNAs in the early embryo, but whether these transcripts represent direct targets of Smaug is unclear and the extent of Smaug-mediated translational repression is unknown. To gain a panoramic view of Smaug function in the early embryo, we identified mRNAs that are bound to Smaug using RNA co-immunoprecipitation followed by hybridization to DNA microarrays. We also identified mRNAs that are translationally repressed by Smaug using polysome gradients and microarrays. Comparison of the bound mRNAs to those that are translationally repressed by Smaug and those that require Smaug for their degradation suggests that a large fraction of Smaug's target mRNAs are both translationally repressed and degraded by Smaug. Smaug directly regulates components of the TRiC/CCT chaperonin, the proteasome regulatory particle and lipid droplets, as well as many metabolic enzymes, including several glycolytic enzymes. Smaug plays a direct and global role in regulating the translation and stability of a large fraction of the mRNAs in the early Drosophila embryo, and has unanticipated functions in control of protein folding and degradation, lipid droplet function and metabolism.

  9. Drosophila brakeless interacts with atrophin and is required for tailless-mediated transcriptional repression in early embryos.

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    Haecker, Achim; Qi, Dai; Lilja, Tobias; Moussian, Bernard; Andrioli, Luiz Paulo; Luschnig, Stefan; Mannervik, Mattias

    2007-06-01

    Complex gene expression patterns in animal development are generated by the interplay of transcriptional activators and repressors at cis-regulatory DNA modules (CRMs). How repressors work is not well understood, but often involves interactions with co-repressors. We isolated mutations in the brakeless gene in a screen for maternal factors affecting segmentation of the Drosophila embryo. Brakeless, also known as Scribbler, or Master of thickveins, is a nuclear protein of unknown function. In brakeless embryos, we noted an expanded expression pattern of the Krüppel (Kr) and knirps (kni) genes. We found that Tailless-mediated repression of kni expression is impaired in brakeless mutants. Tailless and Brakeless bind each other in vitro and interact genetically. Brakeless is recruited to the Kr and kni CRMs, and represses transcription when tethered to DNA. This suggests that Brakeless is a novel co-repressor. Orphan nuclear receptors of the Tailless type also interact with Atrophin co-repressors. We show that both Drosophila and human Brakeless and Atrophin interact in vitro, and propose that they act together as a co-repressor complex in many developmental contexts. We discuss the possibility that human Brakeless homologs may influence the toxicity of polyglutamine-expanded Atrophin-1, which causes the human neurodegenerative disease dentatorubral-pallidoluysian atrophy (DRPLA).

  10. Cortical movement of Bicoid in early Drosophila embryos is actin- and microtubule-dependent and disagrees with the SDD diffusion model.

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    Xiaoli Cai

    Full Text Available The Bicoid (Bcd protein gradient in Drosophila serves as a paradigm for gradient formation in textbooks. The SDD model (synthesis, diffusion, degradation was proposed to explain the formation of the gradient. The SDD model states that the bcd mRNA is located at the anterior pole of the embryo at all times and serves a source for translation of the Bicoid protein, coupled with diffusion and uniform degradation throughout the embryo. Recently, the ARTS model (active RNA transport, synthesis challenged the SDD model. In this model, the mRNA is transported at the cortex along microtubules to form a mRNA gradient which serves as template for the production of Bcd, hence little Bcd movement is involved. To test the validity of the SDD model, we developed a sensitive assay to monitor the movement of Bcd during early nuclear cycles. We observed that Bcd moved along the cortex and not in a broad front towards the posterior as the SDD model would have predicted. We subjected embryos to hypoxia where the mRNA remained strictly located at the tip at all times, while the protein was allowed to move freely, thus conforming to an ideal experimental setup to test the SDD model. Unexpectedly, Bcd still moved along the cortex. Moreover, cortical Bcd movement was sparse, even under longer hypoxic conditions. Hypoxic embryos treated with drugs compromising microtubule and actin function affected Bcd cortical movement and stability. Vinblastine treatment allowed the simulation of an ideal SDD model whereby the protein moved throughout the embryo in a broad front. In unfertilized embryos, the Bcd protein followed the mRNA which itself was transported into the interior of the embryo utilizing a hitherto undiscovered microtubular network. Our data suggest that the Bcd gradient formation is probably more complex than previously anticipated.

  11. Manipulating early pig embryos.

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    Niemann, H; Reichelt, B

    1993-01-01

    On the basis of established surgical procedures for embryo recovery and transfer, the early pig embryo can be subjected to various manipulations aimed at a long-term preservation of genetic material, the generation of identical multiplets, the early determination of sex or the alteration of the genetic make-up. Most of these procedures are still at an experimental stage and despite recent considerable progress are far from practical application. Normal piglets have been obtained after cryopreservation of pig blastocysts hatched in vitro, whereas all attempts to freeze embryos with intact zona pellucida have been unsuccessful. Pig embryos at the morula and blastocyst stage can be bisected microsurgically and the resulting demi-embryos possess a high developmental potential in vitro, whereas their development in vivo is impaired. Pregnancy rates are similar (80%) but litter size is reduced compared with intact embryos and twinning rate is approximately 2%. Pig blastomeres isolated from embryos up to the 16-cell stage can be grown in culture and result in normal blastocysts. Normal piglets have been born upon transfer of blastocysts derived from isolated eight-cell blastomeres, clearly underlining the totipotency of this developmental stage. Upon nuclear transfer the developmental capacity of reconstituted pig embryos is low and culture. Sex determination can be achieved either by separation of X and Y chromosome bearing spermatozoa by flow cytometry or by analysing the expression of the HY antigen in pig embryos from the eight-cell to morula stage. Microinjection of foreign DNA has been successfully used to alter growth and development of transgenic pigs, and to produce foreign proteins in the mammary gland or in the bloodstream, indicating that pigs can be used as donors for valuable human pharmaceutical proteins. Another promising area of gene transfer is the increase of disease resistance in transgenic lines of pigs. Approximately 30% of pig spermatozoa bind

  12. Single molecule transcription factor dynamics in the syncytial Drosophila embryo

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    Darzacq, Xavier

    During early development in the Drosophila embryo, cell fates are determined over the course of just 2 hours with exquisite spatio-temoral precision. One of the key regulators of this process is the transcription factor Bicoid which forms a concentration gradient across the long axis of the embryo. Although Bicoids' primary role is activation at the anterior, where concentrations are highest, it is also known to play a role in the posterior where there are only 100s of molecules per nucleus. Understanding how Bicoid can find its target at such low concentrations has remained intractable, largely due to the inability to perform single molecule imaging in the context of the developing embryo. Here we use lattice light sheet microscopy to overcome the technical barriers of sample thickness and auto-fluorescence to characterize the single molecule dynamics of Bicoid. We find that off-rates do not vary across the embryo and that instead the on-rates are modulated through the formation of clusters that enrich local concentration. This data is contrary to the current concentration dependent model of Bicoid function since local concentration within the nucleus is now a regulated parameter and suggests a previously unknown mechanism for regulation at extremely low concentrations.

  13. Effect of localized hypoxia on Drosophila embryo development.

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    Zhinan Wang

    Full Text Available Environmental stress, such as oxygen deprivation, affects various cellular activities and developmental processes. In this study, we directly investigated Drosophila embryo development in vivo while cultured on a microfluidic device, which imposed an oxygen gradient on the developing embryos. The designed microfluidic device enabled both temporal and spatial control of the local oxygen gradient applied to the live embryos. Time-lapse live cell imaging was used to monitor the morphology and cellular migration patterns as embryos were placed in various geometries relative to the oxygen gradient. Results show that pole cell movement and tail retraction during Drosophila embryogenesis are highly sensitive to oxygen concentrations. Through modeling, we also estimated the oxygen permeability across the Drosophila embryonic layers for the first time using parameters measured on our oxygen control device.

  14. Parallel imaging of Drosophila embryos for quantitative analysis of genetic perturbations of the Ras pathway

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    Yogesh Goyal

    2017-07-01

    Full Text Available The Ras pathway patterns the poles of the Drosophila embryo by downregulating the levels and activity of a DNA-binding transcriptional repressor Capicua (Cic. We demonstrate that the spatiotemporal pattern of Cic during this signaling event can be harnessed for functional studies of mutations in the Ras pathway in human diseases. Our approach relies on a new microfluidic device that enables parallel imaging of Cic dynamics in dozens of live embryos. We found that although the pattern of Cic in early embryos is complex, it can be accurately approximated by a product of one spatial profile and one time-dependent amplitude. Analysis of these functions of space and time alone reveals the differential effects of mutations within the Ras pathway. Given the highly conserved nature of Ras-dependent control of Cic, our approach provides new opportunities for functional analysis of multiple sequence variants from developmental abnormalities and cancers.

  15. Gene expression profiling of brakeless mutant Drosophila embryos.

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    Crona, Filip; Singla, Bhumica; Mannervik, Mattias

    2015-12-01

    The transcriptional co-regulator Brakeless performs many important functions during Drosophila development, but few target genes have been identified. Here we use Affymetrix microarrays to identify Brakeless-regulated genes in 2-4 h old Drosophila embryos. Robust multi-array analysis (RMA) and statistical tests revealed 240 genes that changed their expression more than 1.5 fold. We find that up- and down-regulated genes fall into distinct gene ontology categories. In our associated study [2] we demonstrate that both up- and down-regulated genes can be direct Brakeless targets. Our results indicate that the co-repressor and co-activator activities of Brakeless may result in distinct biological responses. The microarray data complies with MIAME guidelines and is deposited in GEO under accession number GSE60048.

  16. Drosophila embryos as model to assess cellular and developmental toxicity of multi-walled carbon nanotubes (MWCNT in living organisms.

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    Boyin Liu

    Full Text Available Different toxicity tests for carbon nanotubes (CNT have been developed to assess their impact on human health and on aquatic and terrestrial animal and plant life. We present a new model, the fruit fly Drosophila embryo offering the opportunity for rapid, inexpensive and detailed analysis of CNTs toxicity during embryonic development. We show that injected DiI labelled multi-walled carbon nanotubes (MWCNTs become incorporated into cells in early Drosophila embryos, allowing the study of the consequences of cellular uptake of CNTs on cell communication, tissue and organ formation in living embryos. Fluorescently labelled subcellular structures showed that MWCNTs remained cytoplasmic and were excluded from the nucleus. Analysis of developing ectodermal and neural stem cells in MWCNTs injected embryos revealed normal division patterns and differentiation capacity. However, an increase in cell death of ectodermal but not of neural stem cells was observed, indicating stem cell-specific vulnerability to MWCNT exposure. The ease of CNT embryo injections, the possibility of detailed morphological and genomic analysis and the low costs make Drosophila embryos a system of choice to assess potential developmental and cellular effects of CNTs and test their use in future CNT based new therapies including drug delivery.

  17. Sample Preparation and Mounting of Drosophila Embryos for Multiview Light Sheet Microscopy.

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    Schmied, Christopher; Tomancak, Pavel

    2016-01-01

    Light sheet fluorescent microscopy (LSFM), and in particular its most widespread flavor Selective Plane Illumination Microscopy (SPIM), promises to provide unprecedented insights into developmental dynamics of entire living systems. By combining minimal photo-damage with high imaging speed and sample mounting tailored toward the needs of the specimen, it enables in toto imaging of embryogenesis with high spatial and temporal resolution. Drosophila embryos are particularly well suited for SPIM imaging because the volume of the embryo does not change from the single cell embryo to the hatching larva. SPIM microscopes can therefore image Drosophila embryos embedded in rigid media, such as agarose, from multiple angles every few minutes from the blastoderm stage until hatching. Here, we describe sample mounting strategies to achieve such a recording. We also provide detailed protocols to realize multiview, long-term, time-lapse recording of Drosophila embryos expressing fluorescent markers on the commercially available Zeiss Lightsheet Z.1 microscope and the OpenSPIM.

  18. The preparation of Drosophila embryos for live-imaging using the hanging drop protocol.

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    Reed, Bruce H; McMillan, Stephanie C; Chaudhary, Roopali

    2009-03-13

    Green fluorescent protein (GFP)-based timelapse live-imaging is a powerful technique for studying the genetic regulation of dynamic processes such as tissue morphogenesis, cell-cell adhesion, or cell death. Drosophila embryos expressing GFP are readily imaged using either stereoscopic or confocal microscopy. A goal of any live-imaging protocol is to minimize detrimental effects such as dehydration and hypoxia. Previous protocols for preparing Drosophila embryos for live-imaging analysis have involved placing dechorionated embryos in halocarbon oil and sandwiching them between a halocarbon gas-permeable membrane and a coverslip. The introduction of compression through mounting embryos in this manner represents an undesirable complication for any biomechanical-based analysis of morphogenesis. Our method, which we call the hanging drop protocol, results in excellent viability of embryos during live imaging and does not require that embryos be compressed. Briefly, the hanging drop protocol involves the placement of embryos in a drop of halocarbon oil that is suspended from a coverslip, which is, in turn, fixed in position over a humid chamber. In addition to providing gas exchange and preventing dehydration, this arrangement takes advantage of the buoyancy of embryos in halocarbon oil to prevent them from drifting out of position during timelapse acquisition. This video describes in detail how to collect and prepare Drosophila embryos for live imaging using the hanging drop protocol. This protocol is suitable for imaging dechorionated embryos using stereomicroscopy or any upright compound fluorescence microscope.

  19. A modifier screen for Bazooka/PAR-3 interacting genes in the Drosophila embryo epithelium.

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    Wei Shao

    2010-04-01

    Full Text Available The development and homeostasis of multicellular organisms depends on sheets of epithelial cells. Bazooka (Baz; PAR-3 localizes to the apical circumference of epithelial cells and is a key hub in the protein interaction network regulating epithelial structure. We sought to identify additional proteins that function with Baz to regulate epithelial structure in the Drosophila embryo.The baz zygotic mutant cuticle phenotype could be dominantly enhanced by loss of known interaction partners. To identify additional enhancers, we screened molecularly defined chromosome 2 and 3 deficiencies. 37 deficiencies acted as strong dominant enhancers. Using deficiency mapping, bioinformatics, and available single gene mutations, we identified 17 interacting genes encoding known and predicted polarity, cytoskeletal, transmembrane, trafficking and signaling proteins. For each gene, their loss of function enhanced adherens junction defects in zygotic baz mutants during early embryogenesis. To further evaluate involvement in epithelial polarity, we generated GFP fusion proteins for 15 of the genes which had not been found to localize to the apical domain previously. We found that GFP fusion proteins for Drosophila ASAP, Arf79F, CG11210, Septin 5 and Sds22 could be recruited to the apical circumference of epithelial cells. Nine of the other proteins showed various intracellular distributions, and one was not detected.Our enhancer screen identified 17 genes that function with Baz to regulate epithelial structure in the Drosophila embryo. Our secondary localization screen indicated that some of the proteins may affect epithelial cell polarity by acting at the apical cell cortex while others may act through intracellular processes. For 13 of the 17 genes, this is the first report of a link to baz or the regulation of epithelial structure.

  20. Glassfrog embryos hatch early after parental desertion.

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    Delia, Jesse R J; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-06-22

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations.

  1. Glassfrog embryos hatch early after parental desertion

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    Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-01-01

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations. PMID:24789892

  2. The Atg1-Tor pathway regulates yolk catabolism in Drosophila embryos.

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    Kuhn, Hallie; Sopko, Richelle; Coughlin, Margaret; Perrimon, Norbert; Mitchison, Tim

    2015-11-15

    Yolk provides an important source of nutrients during the early development of oviparous organisms. It is composed mainly of vitellogenin proteins packed into membrane-bound compartments called yolk platelets. Catabolism of yolk is initiated by acidification of the yolk platelet, leading to the activation of Cathepsin-like proteinases, but it is unknown how this process is triggered. Yolk catabolism initiates at cellularization in Drosophila melanogaster embryos. Using maternal shRNA technology we found that yolk catabolism depends on the Tor pathway and on the autophagy-initiating kinase Atg1. Whereas Atg1 was required for a burst of spatially regulated autophagy during late cellularization, autophagy was not required for initiating yolk catabolism. We propose that the conserved Tor metabolic sensing pathway regulates yolk catabolism, similar to Tor-dependent metabolic regulation on the lysosome. © 2015. Published by The Company of Biologists Ltd.

  3. Mitochondrial DNA polymerase from embryos of Drosophila melanogaster: purification, subunit structure, and partial characterization

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    Wernette, C.M.; Kaguni, L.S.

    1986-01-01

    The mitochondrial DNA polymerase has been purified to near-homogeneity from early embryos of Drosophila melanogaster. Sodium dodecyl sulfate gel electrophoresis of the highly purified enzyme reveals two polypeptides with molecular masses of 125,000 and 35,000 daltons, in a ratio of 1:1. The enzyme has a sedimentation coefficient of 7.6 S and a stokes radius of 51 A. Taken together, the data suggest that the D. melanogaster DNA polymerase γ is a heterodimer. DNA polymerase activity gel analysis has allowed the assignment of the DNA polymerization function to the large subunit. The DNA polymerase exhibits a remarkable ability to utilize efficiently a variety of template-primers including gapped DNA, poly(rA).oligo(dT) and singly primed phiX174 DNA. Both the crude and the highly purified enzymes are stimulated by KCl, and inhibited by dideoxythymidine triphosphate and by N-ethylmaleimide. Thus, the catalytic properties of the near-homogeneous Drosophila enzyme are consistent with those of DNA polymerase γ as partially purified from several vertebrates

  4. Overlapping functions of argonaute proteins in patterning and morphogenesis of Drosophila embryos.

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    Wibke J Meyer

    2006-08-01

    Full Text Available Argonaute proteins are essential components of the molecular machinery that drives RNA silencing. In Drosophila, different members of the Argonaute family of proteins have been assigned to distinct RNA silencing pathways. While Ago1 is required for microRNA function, Ago2 is a crucial component of the RNA-induced silencing complex in siRNA-triggered RNA interference. Drosophila Ago2 contains an unusual amino-terminus with two types of imperfect glutamine-rich repeats (GRRs of unknown function. Here we show that the GRRs of Ago2 are essential for the normal function of the protein. Alleles with reduced numbers of GRRs cause specific disruptions in two morphogenetic processes associated with the midblastula transition: membrane growth and microtubule-based organelle transport. These defects do not appear to result from disruption of siRNA-dependent processes but rather suggest an interference of the mutant Ago2 proteins in an Ago1-dependent pathway. Using loss-of-function alleles, we further demonstrate that Ago1 and Ago2 act in a partially redundant manner to control the expression of the segment-polarity gene wingless in the early embryo. Our findings argue against a strict separation of Ago1 and Ago2 functions and suggest that these proteins act in concert to control key steps of the midblastula transition and of segmental patterning.

  5. Mid-embryo patterning and precision in Drosophila segmentation: Krüppel dual regulation of hunchback.

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    David M Holloway

    Full Text Available In early development, genes are expressed in spatial patterns which later define cellular identities and tissue locations. The mechanisms of such pattern formation have been studied extensively in early Drosophila (fruit fly embryos. The gap gene hunchback (hb is one of the earliest genes to be expressed in anterior-posterior (AP body segmentation. As a transcriptional regulator for a number of downstream genes, the spatial precision of hb expression can have significant effects in the development of the body plan. To investigate the factors contributing to hb precision, we used fine spatial and temporal resolution data to develop a quantitative model for the regulation of hb expression in the mid-embryo. In particular, modelling hb pattern refinement in mid nuclear cleavage cycle 14 (NC14 reveals some of the regulatory contributions of simultaneously-expressed gap genes. Matching the model to recent data from wild-type (WT embryos and mutants of the gap gene Krüppel (Kr indicates that a mid-embryo Hb concentration peak important in thoracic development (at parasegment 4, PS4 is regulated in a dual manner by Kr, with low Kr concentration activating hb and high Kr concentration repressing hb. The processes of gene expression (transcription, translation, transport are intrinsically random. We used stochastic simulations to characterize the noise generated in hb expression. We find that Kr regulation can limit the positional variability of the Hb mid-embryo border. This has been recently corroborated in experimental comparisons of WT and Kr- mutant embryos. Further, Kr regulation can decrease uncertainty in mid-embryo hb expression (i.e. contribute to a smooth Hb boundary and decrease between-copy transcriptional variability within nuclei. Since many tissue boundaries are first established by interactions between neighbouring gene expression domains, these properties of Hb-Kr dynamics to diminish the effects of intrinsic expression noise may

  6. Global sensitivity analysis of a dynamic model for gene expression in Drosophila embryos

    Science.gov (United States)

    McCarthy, Gregory D.; Drewell, Robert A.

    2015-01-01

    It is well known that gene regulation is a tightly controlled process in early organismal development. However, the roles of key processes involved in this regulation, such as transcription and translation, are less well understood, and mathematical modeling approaches in this field are still in their infancy. In recent studies, biologists have taken precise measurements of protein and mRNA abundance to determine the relative contributions of key factors involved in regulating protein levels in mammalian cells. We now approach this question from a mathematical modeling perspective. In this study, we use a simple dynamic mathematical model that incorporates terms representing transcription, translation, mRNA and protein decay, and diffusion in an early Drosophila embryo. We perform global sensitivity analyses on this model using various different initial conditions and spatial and temporal outputs. Our results indicate that transcription and translation are often the key parameters to determine protein abundance. This observation is in close agreement with the experimental results from mammalian cells for various initial conditions at particular time points, suggesting that a simple dynamic model can capture the qualitative behavior of a gene. Additionally, we find that parameter sensitivites are temporally dynamic, illustrating the importance of conducting a thorough global sensitivity analysis across multiple time points when analyzing mathematical models of gene regulation. PMID:26157608

  7. Fluorescently labeled inhibitors detect localized serine protease activities in Drosophila melanogaster pole cells, embryos, and ovarian egg chambers

    DEFF Research Database (Denmark)

    Jakobsen, Rasmus Kragh; Ono, S.; Powers, J. C.

    2005-01-01

    processes that they mediate. Until only recently, the tools to conveniently address the question of where and when serine proteases are active within complex tissues have been lacking. In order to detect spatially restricted serine protease activities in Drosophila embryos and ovaries we introduce...... activity localized to the oocyte-somatic follicle cell interface of the developing egg chamber. Our results suggest that this technique holds promise to identify new spatially restricted activities in adult Drosophila tissues and developing embryos....

  8. Repair of lesions provoked by X-rays in embryos of Drosophila (D. melanogaster Meig)

    International Nuclear Information System (INIS)

    Ghelelovitch, S.

    1975-01-01

    The sensitivity of Drosophila eggs to the lethal action of X-rays did not remain constant during embryogenesis. The X-ray doses used in the present investigation may have retarded the hatching of the larvae but did not block development immediately after irradiation. A fraction of the damage induced in young embryos was repaired during gastrulation. The amount of repair was independent of the X-ray dose but was influenced by the temperature. The damage could be repaired even after the cells of the embryo had undergone many mitotic cycles. (author)

  9. Drosophila MOF controls Checkpoint protein2 and regulates genomic stability during early embryogenesis.

    Science.gov (United States)

    Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Chowdhury, Debabani Roy; Bhadra, Utpal; Pal-Bhadra, Manika

    2013-01-24

    In Drosophila embryos, checkpoints maintain genome stability by delaying cell cycle progression that allows time for damage repair or to complete DNA synthesis. Drosophila MOF, a member of MYST histone acetyl transferase is an essential component of male X hyperactivation process. Until recently its involvement in G2/M cell cycle arrest and defects in ionizing radiation induced DNA damage pathways was not well established. Drosophila MOF is highly expressed during early embryogenesis. In the present study we show that haplo-insufficiency of maternal MOF leads to spontaneous mitotic defects like mitotic asynchrony, mitotic catastrophe and chromatid bridges in the syncytial embryos. Such abnormal nuclei are eliminated and digested in the yolk tissues by nuclear fall out mechanism. MOF negatively regulates Drosophila checkpoint kinase 2 tumor suppressor homologue. In response to DNA damage the checkpoint gene Chk2 (Drosophila mnk) is activated in the mof mutants, there by causing centrosomal inactivation suggesting its role in response to genotoxic stress. A drastic decrease in the fall out nuclei in the syncytial embryos derived from mof¹/+; mnkp⁶/+ females further confirms the role of DNA damage response gene Chk2 to ensure the removal of abnormal nuclei from the embryonic precursor pool and maintain genome stability. The fact that mof mutants undergo DNA damage has been further elucidated by the increased number of single and double stranded DNA breaks. mof mutants exhibited genomic instability as evidenced by the occurance of frequent mitotic bridges in anaphase, asynchronous nuclear divisions, disruption of cytoskeleton, inactivation of centrosomes finally leading to DNA damage. Our findings are consistent to what has been reported earlier in mammals that; reduced levels of MOF resulted in increased genomic instability while total loss resulted in lethality. The study can be further extended using Drosophila as model system and carry out the interaction of MOF

  10. Drosophila MOF controls Checkpoint protein2 and regulates genomic stability during early embryogenesis

    Directory of Open Access Journals (Sweden)

    Pushpavalli Sreerangam NCVL

    2013-01-01

    Full Text Available Abstract Background In Drosophila embryos, checkpoints maintain genome stability by delaying cell cycle progression that allows time for damage repair or to complete DNA synthesis. Drosophila MOF, a member of MYST histone acetyl transferase is an essential component of male X hyperactivation process. Until recently its involvement in G2/M cell cycle arrest and defects in ionizing radiation induced DNA damage pathways was not well established. Results Drosophila MOF is highly expressed during early embryogenesis. In the present study we show that haplo-insufficiency of maternal MOF leads to spontaneous mitotic defects like mitotic asynchrony, mitotic catastrophe and chromatid bridges in the syncytial embryos. Such abnormal nuclei are eliminated and digested in the yolk tissues by nuclear fall out mechanism. MOF negatively regulates Drosophila checkpoint kinase 2 tumor suppressor homologue. In response to DNA damage the checkpoint gene Chk2 (Drosophila mnk is activated in the mof mutants, there by causing centrosomal inactivation suggesting its role in response to genotoxic stress. A drastic decrease in the fall out nuclei in the syncytial embryos derived from mof1/+; mnkp6/+ females further confirms the role of DNA damage response gene Chk2 to ensure the removal of abnormal nuclei from the embryonic precursor pool and maintain genome stability. The fact that mof mutants undergo DNA damage has been further elucidated by the increased number of single and double stranded DNA breaks. Conclusion mof mutants exhibited genomic instability as evidenced by the occurance of frequent mitotic bridges in anaphase, asynchronous nuclear divisions, disruption of cytoskeleton, inactivation of centrosomes finally leading to DNA damage. Our findings are consistent to what has been reported earlier in mammals that; reduced levels of MOF resulted in increased genomic instability while total loss resulted in lethality. The study can be further extended using

  11. Determination of gene expression patterns using high-throughput RNA in situ hybridizaion to whole-mount Drosophila embryos

    Energy Technology Data Exchange (ETDEWEB)

    Weiszmann, R.; Hammonds, A.S.; Celniker, S.E.

    2009-04-09

    We describe a high-throughput protocol for RNA in situ hybridization (ISH) to Drosophila embryos in a 96-well format. cDNA or genomic DNA templates are amplified by PCR and then digoxigenin-labeled ribonucleotides are incorporated into antisense RNA probes by in vitro transcription. The quality of each probe is evaluated before ISH using a RNA probe quantification (dot blot) assay. RNA probes are hybridized to fixed, mixed-staged Drosophila embryos in 96-well plates. The resulting stained embryos can be examined and photographed immediately or stored at 4oC for later analysis. Starting with fixed, staged embryos, the protocol takes 6 d from probe template production through hybridization. Preparation of fixed embryos requires a minimum of 2 weeks to collect embryos representing all stages. The method has been used to determine the expression patterns of over 6,000 genes throughout embryogenesis.

  12. Stochastic model for gene transcription on Drosophila melanogaster embryos

    Science.gov (United States)

    Prata, Guilherme N.; Hornos, José Eduardo M.; Ramos, Alexandre F.

    2016-02-01

    We examine immunostaining experimental data for the formation of stripe 2 of even-skipped (eve) transcripts on D. melanogaster embryos. An estimate of the factor converting immunofluorescence intensity units into molecular numbers is given. The analysis of the eve dynamics at the region of stripe 2 suggests that the promoter site of the gene has two distinct regimes: an earlier phase when it is predominantly activated until a critical time when it becomes mainly repressed. That suggests proposing a stochastic binary model for gene transcription on D. melanogaster embryos. Our model has two random variables: the transcripts number and the state of the source of mRNAs given as active or repressed. We are able to reproduce available experimental data for the average number of transcripts. An analysis of the random fluctuations on the number of eves and their consequences on the spatial precision of stripe 2 is presented. We show that the position of the anterior or posterior borders fluctuate around their average position by ˜1 % of the embryo length, which is similar to what is found experimentally. The fitting of data by such a simple model suggests that it can be useful to understand the functions of randomness during developmental processes.

  13. [Association of human chorionic gonadotropin level in embryo culture media with early embryo development].

    Science.gov (United States)

    Wang, Haiying; Zhang, Renli; Han, Dong; Liu, Caixia; Cai, Jiajie; Bi, Yanling; Wen, Anmin; Quan, Song

    2014-06-01

    To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development. Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed. In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02). ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful marker for embryo selection in IVF-ET procedure.

  14. Lethality of radioisotopes in early mouse embryos

    International Nuclear Information System (INIS)

    Macqueen, H.A.

    1979-01-01

    The development of pre-implantation mouse embryos was found to be prevented by exposure of the embryos to [ 35 S]methionine, but not to [ 3 H]methionine. Such embryos have also been shown to be highly sensitive to [ 3 H]thymidine. These observations are discussed with reference to the path lengths and energies of electrons emitted from the different radioisotopes. (author)

  15. Cdk1 and Okadaic Acid-sensitive Phosphatases Control Assembly of Nuclear Pore Complexes in Drosophila EmbryosV⃞

    OpenAIRE

    Onischenko, Evgeny A.; Gubanova, Natalia V.; Kiseleva, Elena V.; Hallberg, Einar

    2005-01-01

    Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat...

  16. Glassfrog embryos hatch early after parental desertion

    OpenAIRE

    Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-01-01

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested th...

  17. File list: Pol.Emb.10.AllAg.Early_embryo [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Emb.10.AllAg.Early_embryo ce10 RNA polymerase Embryo Early embryo SRX495119,SRX...495120,SRX043866,SRX043864,SRX043865,SRX043863 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Pol.Emb.10.AllAg.Early_embryo.bed ...

  18. File list: Pol.Emb.20.AllAg.Early_embryo [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Emb.20.AllAg.Early_embryo ce10 RNA polymerase Embryo Early embryo SRX495120,SRX...495119,SRX043864,SRX043866,SRX043863,SRX043865 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Pol.Emb.20.AllAg.Early_embryo.bed ...

  19. Origin and specification of type II neuroblasts in the Drosophila embryo.

    Science.gov (United States)

    Álvarez, José-Andrés; Díaz-Benjumea, Fernando J

    2018-04-05

    In Drosophila , neural stem cells or neuroblasts (NBs) acquire different identities according to their site of origin in the embryonic neuroectoderm. Their identity determines the number of times they will divide and the types of daughter cells they will generate. All NBs divide asymmetrically, with type I NBs undergoing self-renewal and generating another cell that will divide only once more. By contrast, a small set of NBs in the larval brain, type II NBs, divides differently, undergoing self-renewal and generating an intermediate neural progenitor (INP) that continues to divide asymmetrically several more times, generating larger lineages. In this study, we have analysed the origin of type II NBs and how they are specified. Our results indicate that these cells originate in three distinct clusters in the dorsal protocerebrum during stage 12 of embryonic development. Moreover, it appears that their specification requires the combined action of EGFR signalling and the activity of the related genes buttonhead and Drosophila Sp1 In addition, we also show that the INPs generated in the embryo enter quiescence at the end of embryogenesis, resuming proliferation during the larval stage. © 2018. Published by The Company of Biologists Ltd.

  20. A biomechanical analysis of ventral furrow formation in the Drosophila melanogaster embryo.

    Directory of Open Access Journals (Sweden)

    Vito Conte

    Full Text Available The article provides a biomechanical analysis of ventral furrow formation in the Drosophila melanogaster embryo. Ventral furrow formation is the first large-scale morphogenetic movement in the fly embryo. It involves deformation of a uniform cellular monolayer formed following cellularisation, and has therefore long been used as a simple system in which to explore the role of mechanics in force generation. Here we use a quantitative framework to carry out a systematic perturbation analysis to determine the role of each of the active forces observed. The analysis confirms that ventral furrow invagination arises from a combination of apical constriction and apical-basal shortening forces in the mesoderm, together with a combination of ectodermal forces. We show that the mesodermal forces are crucial for invagination: the loss of apical constriction leads to a loss of the furrow, while the mesodermal radial shortening forces are the primary cause of the internalisation of the future mesoderm as the furrow rises. Ectodermal forces play a minor but significant role in furrow formation: without ectodermal forces the furrow is slower to form, does not close properly and has an aberrant morphology. Nevertheless, despite changes in the active mesodermal and ectodermal forces lead to changes in the timing and extent of furrow, invagination is eventually achieved in most cases, implying that the system is robust to perturbation and therefore over-determined.

  1. Acute drug treatment in the early C. elegans embryo.

    Directory of Open Access Journals (Sweden)

    Ana Carvalho

    Full Text Available Genetic and genome-wide RNAi approaches available in C. elegans, combined with tools for visualizing subcellular events with high-resolution, have led to increasing adoption of the early C. elegans embryo as a model for mechanistic and functional genomic analysis of cellular processes. However, a limitation of this system has been the impermeability of the embryo eggshell, which has prevented the routine use of small molecule inhibitors. Here, we present a method to permeabilize and immobilize embryos for acute inhibitor treatment in conjunction with live imaging. To identify a means to permeabilize the eggshell, we used a dye uptake assay to screen a set of 310 candidate genes defined by a combination of bioinformatic criteria. This screen identified 20 genes whose inhibition resulted in >75% eggshell permeability, and 3 that permeabilized embryos with minimal deleterious effects on embryo production and early embryonic development. To mount permeabilized embryos for acute drug addition in conjunction with live imaging, we combined optimized inhibition of one of these genes with the use of a microfabricated chamber that we designed. We demonstrate that these two developments enable the temporally controlled introduction of inhibitors for mechanistic studies. This method should also open new avenues of investigation by allowing profiling and specificity-testing of inhibitors through comparison with genome-wide phenotypic datasets.

  2. Abnormal early cleavage events predict early embryo demise: sperm oxidative stress and early abnormal cleavage.

    Science.gov (United States)

    Burruel, Victoria; Klooster, Katie; Barker, Christopher M; Pera, Renee Reijo; Meyers, Stuart

    2014-10-13

    Human embryos resulting from abnormal early cleavage can result in aneuploidy and failure to develop normally to the blastocyst stage. The nature of paternal influence on early embryo development has not been directly demonstrated although many studies have suggested effects from spermatozoal chromatin packaging, DNA damage, centriolar and mitotic spindle integrity, and plasma membrane integrity. The goal of this study was to determine whether early developmental events were affected by oxidative damage to the fertilizing sperm. Survival analysis was used to compare patterns of blastocyst formation based on P2 duration. Kaplan-Meier survival curves demonstrate that relatively few embryos with short (P2 times reached blastocysts, and the two curves diverged beginning on day 4, with nearly all of the embryos with longer P2 times reaching blastocysts by day 6 (p < .01). We determined that duration of the 2nd to 3rd mitoses were sensitive periods in the presence of spermatozoal oxidative stress. Embryos that displayed either too long or too short cytokineses demonstrated an increased failure to reach blastocyst stage and therefore survive for further development. Although paternal-derived gene expression occurs later in development, this study suggests a specific role in early mitosis that is highly influenced by paternal factors.

  3. Notch and PKC Are Involved in Formation of the Lateral Region of the Dorso-Ventral Axis in Drosophila Embryos

    OpenAIRE

    Tremmel, Daniel M.; Resad, Sedat; Little, Christopher J.; Wesley, Cedric S.

    2013-01-01

    The Notch gene encodes an evolutionarily conserved cell surface receptor that generates regulatory signals based on interactions between neighboring cells. In Drosophila embryos it is normally expressed at a low level due to strong negative regulation. When this negative regulation is abrogated neurogenesis in the ventral region is suppressed, the development of lateral epidermis is severely disrupted, and the dorsal aminoserosa is expanded. Of these phenotypes only the anti-neurogenic phenot...

  4. High dose progesterone effects the growth of early chick embryo

    International Nuclear Information System (INIS)

    Iqbal, I.; Qamar, K.

    2014-01-01

    Objective: To find out the effect of high dose progesterone on the development of early chick embryo. Study Design: Lab based randomized controlled trial. Place and Duration of study: This study was carried out in Army Medical College and Post Graduate Institute of Poultry Sciences, Rawalpindi from June 2010 - December 2010. Material and Methods: Forty five specific pathogen free, fertile, eggs of Fyoumi species of chick were selected at zero hour of incubation. They were incubated at 37.5oC and 75% relative humidity for 26 hrs until the embryos reached stage 8 of the development. Then on stage 8 the eggs were divided into three groups consisting of 15 eggs per group. The first group (GI) was incubated without any operation. The second (G2) and third groups (G3) were injected with two and twenty times more than physiologic does of progesterone respectively. After 48 hours of incvbation, all embryos were examined for their development under light microscopy. Results: All the embryos of G1 and G2 showed normal development according to their stage of development, while 4 out of 11 embryos of G3 were under developed and their survival rate was also less. Conclusion: Exogenous progesterone at levels twenty times above its physiologic range effects the development of chick embryos. Further studies are needed to explain the mechanisms of this effect. (author)

  5. Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

    Science.gov (United States)

    González-Gutiérrez, Alejandra G; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín

    2014-01-01

    Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

  6. The Early Stages of Heart Development: Insights from Chicken Embryos

    Directory of Open Access Journals (Sweden)

    Johannes G. Wittig

    2016-04-01

    Full Text Available The heart is the first functioning organ in the developing embryo and a detailed understanding of the molecular and cellular mechanisms involved in its formation provides insights into congenital malformations affecting its function and therefore the survival of the organism. Because many developmental mechanisms are highly conserved, it is possible to extrapolate from observations made in invertebrate and vertebrate model organisms to humans. This review will highlight the contributions made through studying heart development in avian embryos, particularly the chicken. The major advantage of chick embryos is their accessibility for surgical manipulation and functional interference approaches, both gain- and loss-of-function. In addition to experiments performed in ovo, the dissection of tissues for ex vivo culture, genomic, or biochemical approaches is straightforward. Furthermore, embryos can be cultured for time-lapse imaging, which enables tracking of fluorescently labeled cells and detailed analysis of tissue morphogenesis. Owing to these features, investigations in chick embryos have led to important discoveries, often complementing genetic studies in mice and zebrafish. As well as including some historical aspects, we cover here some of the crucial advances made in understanding early heart development using the chicken model.

  7. Interdependence of macrophage migration and ventral nerve cord development in Drosophila embryos.

    Science.gov (United States)

    Evans, Iwan R; Hu, Nan; Skaer, Helen; Wood, Will

    2010-05-01

    During embryonic development, Drosophila macrophages (haemocytes) undergo a series of stereotypical migrations to disperse throughout the embryo. One major migratory route is along the ventral nerve cord (VNC), where haemocytes are required for the correct development of this tissue. We show, for the first time, that a reciprocal relationship exists between haemocytes and the VNC and that defects in nerve cord development prevent haemocyte migration along this structure. Using live imaging, we demonstrate that the axonal guidance cue Slit and its receptor Robo are both required for haemocyte migration, but signalling is not autonomously required in haemocytes. We show that the failure of haemocyte migration along the VNC in slit mutants is not due to a lack of chemotactic signals within this structure, but rather to a failure in its detachment from the overlying epithelium, creating a physical barrier to haemocyte migration. This block of haemocyte migration in turn disrupts the formation of the dorsoventral channels within the VNC, further highlighting the importance of haemocyte migration for correct neural development. This study illustrates the important role played by the three-dimensional environment in directing cell migration in vivo and reveals an intriguing interplay between the developing nervous system and the blood cells within the fly, demonstrating that their development is both closely coupled and interdependent.

  8. Maternal Nanos-Dependent RNA Stabilization in the Primordial Germ Cells of Drosophila Embryos.

    Science.gov (United States)

    Sugimori, Seiko; Kumata, Yuji; Kobayashi, Satoru

    2018-01-01

    Nanos (Nos) is an evolutionary conserved protein expressed in the germline of various animal species. In Drosophila, maternal Nos protein is essential for germline development. In the germline progenitors, or the primordial germ cells (PGCs), Nos binds to the 3' UTR of target mRNAs to repress their translation. In contrast to this prevailing role of Nos, here we report that the 3' UTR of CG32425 mRNA mediates Nos-dependent RNA stabilization in PGCs. We found that the level of mRNA expressed from a reporter gene fused to the CG32425 3' UTR was significantly reduced in PGCs lacking maternal Nos (nos PGCs) as compared with normal PGCs. By deleting the CG32425 3' UTR, we identified the region required for mRNA stabilization, which includes Nos-binding sites. In normal embryos, CG32425 mRNA was maternally supplied into PGCs and remained in this cell type during embryogenesis. However, as expected from our reporter assay, the levels of CG32425 mRNA and its protein product expressed in nos PGCs were lower than in normal PGCs. Thus, we propose that Nos protein has dual functions in translational repression and stabilization of specific RNAs to ensure proper germline development. © 2017 Japanese Society of Developmental Biologists.

  9. [Specification of cell destiny in early Caenorhabditis elegans embryo].

    Science.gov (United States)

    Schierenberg, E

    1997-02-01

    Embryogenesis of the nematode Caenorhabditis elegans has been described completely on a cell-by-cell basis and found to be essentially invariant. With this knowledge in hands, micromanipulated embryos and mutants have been analyzed for cell lineage defects and the distribution of specific gene products. The results challenge the classical view of cell-autonomous development in nematodes and indicate that the early embryo of C. elegans is a highly dynamic system. A network of inductive events between neighboring cells is being revealed, which is necessary to assign different developmental programs to blastomeres. In those cases where molecules involved in these cell-cell interactions have been identified, homologies to cell surface receptors, ligands and transcription factors found in other systems have become obvious.

  10. Protein O-Mannosyltransferases Affect Sensory Axon Wiring and Dynamic Chirality of Body Posture in the Drosophila Embryo.

    Science.gov (United States)

    Baker, Ryan; Nakamura, Naosuke; Chandel, Ishita; Howell, Brooke; Lyalin, Dmitry; Panin, Vladislav M

    2018-02-14

    Genetic defects in protein O-mannosyltransferase 1 (POMT1) and POMT2 underlie severe muscular dystrophies. POMT genes are evolutionarily conserved in metazoan organisms. In Drosophila , both male and female POMT mutants show a clockwise rotation of adult abdominal segments, suggesting a chirality of underlying pathogenic mechanisms. Here we described and analyzed a similar phenotype in POMT mutant embryos that shows left-handed body torsion. Our experiments demonstrated that coordinated muscle contraction waves are associated with asymmetric embryo rolling, unveiling a new chirality marker in Drosophila development. Using genetic and live-imaging approaches, we revealed that the torsion phenotype results from differential rolling and aberrant patterning of peristaltic waves of muscle contractions. Our results demonstrated that peripheral sensory neurons are required for normal contractions that prevent the accumulation of torsion. We found that POMT mutants show abnormal axonal connections of sensory neurons. POMT transgenic expression limited to sensory neurons significantly rescued the torsion phenotype, axonal connectivity defects, and abnormal contractions in POMT mutant embryos. Together, our data suggested that protein O-mannosylation is required for normal sensory feedback to control coordinated muscle contractions and body posture. This mechanism may shed light on analogous functions of POMT genes in mammals and help to elucidate the etiology of neurological defects in muscular dystrophies. SIGNIFICANCE STATEMENT Protein O-mannosyltransferases (POMTs) are evolutionarily conserved in metazoans. Mutations in POMTs cause severe muscular dystrophies associated with pronounced neurological defects. However, neurological functions of POMTs remain poorly understood. We demonstrated that POMT mutations in Drosophila result in abnormal muscle contractions and cause embryo torsion. Our experiments uncovered a chirality of embryo movements and a unique POMT -dependent

  11. Cdk1 and okadaic acid-sensitive phosphatases control assembly of nuclear pore complexes in Drosophila embryos.

    Science.gov (United States)

    Onischenko, Evgeny A; Gubanova, Natalia V; Kiseleva, Elena V; Hallberg, Einar

    2005-11-01

    Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat germ agglutinin (WGA) or in fixed embryos using electron microscopy and immunostaining techniques. We found that in live embryos Cdk1 activity was necessary and sufficient to induce disassembly of NPCs as well as their cytoplasmic mimics: annulate lamellae pore complexes (ALPCs). Cdk1 activity was also required for keeping NPCs and ALPCs disassembled during mitosis. In agreement recombinant Cdk1/cyclin B was able to induce phosphorylation and dissociation of nucleoporins from the NPCs in vitro. Conversely, reassembly of NPCs and ALPCs was dependent on the activity of protein phosphatases, sensitive to okadaic acid (OA). Our findings suggest a model where mitotic disassembly/reassembly of the NPCs is regulated by a dynamic equilibrium of Cdk1 and OA-sensitive phosphatase activities and provide evidence that mitotic phosphorylation mediates disassembly of the NPC.

  12. Embryo density and medium volume effects on early murine embryo development.

    Science.gov (United States)

    Canseco, R S; Sparks, A E; Pearson, R E; Gwazdauskas, F C

    1992-10-01

    One-cell mouse embryos were used to determine the effects of drop size and number of embryos per drop for optimum development in vitro. Embryos were collected from immature C57BL6 female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by CD1 males. Groups of 1, 5, 10, or 20 embryos were cultured in 5-, 10-, 20-, or 40-microliters drops of CZB under silicon oil at 37.5 degrees C in a humidified atmosphere of 5% CO2 and 95% air. Development score for embryos cultured in 10 microliters was higher than that of embryos cultured in 20 or 40 microliters. Embryos cultured in groups of 5, 10, or 20 had higher development scores than embryos cultured singly. The highest development score was obtained by the combination of 5 embryos per 10-microliters drop. The percentage of live embryos in 20 or 40 microliters was lower than that of embryos cultured in 10 microliters. Additionally, the percentage of live embryos cultured singly was lower than that of embryos cultured in groups. Our results suggest that a stimulatory interaction occurs among embryos possibly exerted through the secretion of growth factors. This effect can be diluted if the embryos are cultured in large drops or singly.

  13. Notch and PKC are involved in formation of the lateral region of the dorso-ventral axis in Drosophila embryos.

    Science.gov (United States)

    Tremmel, Daniel M; Resad, Sedat; Little, Christopher J; Wesley, Cedric S

    2013-01-01

    The Notch gene encodes an evolutionarily conserved cell surface receptor that generates regulatory signals based on interactions between neighboring cells. In Drosophila embryos it is normally expressed at a low level due to strong negative regulation. When this negative regulation is abrogated neurogenesis in the ventral region is suppressed, the development of lateral epidermis is severely disrupted, and the dorsal aminoserosa is expanded. Of these phenotypes only the anti-neurogenic phenotype could be linked to excess canonical Notch signaling. The other phenotypes were linked to high levels of Notch protein expression at the surface of cells in the lateral regions indicating that a non-canonical Notch signaling activity normally functions in these regions. Results of our studies reported here provide evidence. They show that Notch activities are inextricably linked to that of Pkc98E, the homolog of mammalian PKCδ. Notch and Pkc98E up-regulate the levels of the phosphorylated form of IκBCactus, a negative regulator of Toll signaling, and Mothers against dpp (MAD), an effector of Dpp signaling. Our data suggest that in the lateral regions of the Drosophila embryos Notch activity, in conjunction with Pkc98E activity, is used to form the slopes of the opposing gradients of Toll and Dpp signaling that specify cell fates along the dorso-ventral axis.

  14. Notch and PKC are involved in formation of the lateral region of the dorso-ventral axis in Drosophila embryos.

    Directory of Open Access Journals (Sweden)

    Daniel M Tremmel

    Full Text Available The Notch gene encodes an evolutionarily conserved cell surface receptor that generates regulatory signals based on interactions between neighboring cells. In Drosophila embryos it is normally expressed at a low level due to strong negative regulation. When this negative regulation is abrogated neurogenesis in the ventral region is suppressed, the development of lateral epidermis is severely disrupted, and the dorsal aminoserosa is expanded. Of these phenotypes only the anti-neurogenic phenotype could be linked to excess canonical Notch signaling. The other phenotypes were linked to high levels of Notch protein expression at the surface of cells in the lateral regions indicating that a non-canonical Notch signaling activity normally functions in these regions. Results of our studies reported here provide evidence. They show that Notch activities are inextricably linked to that of Pkc98E, the homolog of mammalian PKCδ. Notch and Pkc98E up-regulate the levels of the phosphorylated form of IκBCactus, a negative regulator of Toll signaling, and Mothers against dpp (MAD, an effector of Dpp signaling. Our data suggest that in the lateral regions of the Drosophila embryos Notch activity, in conjunction with Pkc98E activity, is used to form the slopes of the opposing gradients of Toll and Dpp signaling that specify cell fates along the dorso-ventral axis.

  15. Characterization of the onset of embryonic control and early development in the bovine embryo

    International Nuclear Information System (INIS)

    Barnes, F.L.

    1988-01-01

    Bovine embryos were used to determine if morphological and molecular features of early development are similar to in vivo recovered bovine embryos and to determine at what level early bovine development is regulated. Radiolabeling of IVP embryos and in vivo recovered embryos with 35 S-methionine for SDS-polyacrylamide gel electrophoresis reveals that these embryos are equivalent. Few differences in protein profiles are observed between 1- and early 4-cell embryos. A change in protein profiles begins at the mid 4-cell stage and continues into the 8-cell stage. Few differences in protein profiles are observed between 1- and early 4-cell embryos. A change in protein profiles begins at the mid 4-cell stage and continues into the 8-cell stage. Few differences in protein profiles are observed between late 8-cells and morulae. This transition is α-amanitin sensitive therefore due to de novo embryonic transcription. Embryonic transcription is partially responsible for terminating the post-transcriptionally regulated period of early bovine development. Argentophillic nucleolar organizing regions (Ag-NORs) indicate onset of nucleolar activation. Ag-NORs were absent in 2- and 4-cell IVP embryos and rarely occurred in 8-cell IVP embryos cultured in vitro. IVP 1- and 2-cell embryos cultured to blastocysts in sheep oviducts demonstrated Ag-NORs. Thus the lack of nucleolar activation of IVP embryos cultured in vitro is culture induced between the 2- and 8-cell stage

  16. The effect of flurbiprofen on the development of anencephaly in early stage chicken embryos.

    Science.gov (United States)

    Özeren, Ersin; Er, Uygur; Güvenç, Yahya; Demirci, Adnan; Arıkök, Ata Türker; Şenveli, Engin; Ergün, Rüçhan Behzat

    2015-04-01

    The study investigated the effect of flurbiprofen on the development of anencephaly in early stage chicken embryos. We looked at four groups with a total of 36 embryos. There was a control group, a normal saline group, a normal-dose group and a high-dose group with ten, ten, eight and eight eggs with embryo respectively. Two embryos in the control group, studied with light microscopy at 48 h, were consistent with 28-29 hours' incubation in the Hamburger-Hamilton System. They had open neural tubes. The other embryos in this group were considered normal. One embryo in the normal saline group was on the occlusion stage at 48 h. One embryo showed an open neural tube. They were compatible with 28-29 hours' incubation in the Hamburger-Hamilton system. The remaining eight embryos showed normal development. In the normal dose group, one embryo showed underdevelopment of the embryonic disc and the embryo was dead. In four embryos, the neural tubes were open. One cranial malformation was found that was complicated with anencephaly in one embryo. In two embryos the neural tubes were closed, as they showed normal development, and they reached their expected stages according to the Hamburger-Hamilton classification. There was no malformation or growth retardation. Four experimental embryos were anencephalic in the high dose group, and three embryos had open neural tubes. One embryo exhibited both anencephaly and a neural tube closure defect. None of the embryos in this group showed normal development. Even the usual therapeutic doses of flurbiprofen increased the risk of neural tube defect. Flurbiprofen was found to significantly increase the risk of anencephaly. The provision of improved technical materials and studies with larger sample sizes will reveal the stage of morphological disruption during the development of embryos.

  17. The effect of unilateral ovariectomy on early embryonic survival and embryo development in rabbits

    Directory of Open Access Journals (Sweden)

    R. Peiró

    2014-06-01

    Full Text Available Unilateral ovariectomy can be used to study uterine capacity in rabbits because an overcrowding of the functional uterine horn is produced. Due to the uterus duplex, the rabbit is the ideal model for such studies. However, this technique may affect embryo survival. The aim of this work is to study the effect of unilateral ovariectomy on early embryo survival and development in rabbit. A total of 101 unilateral ovariectomised females and 52 intact females were compared after slaughter at 30 h post-mating. Early embryo survival was estimated as the ratio between number of embryo recovered and ovulation rate. No differences were found between intact and unilaterally ovariectomised females in this trait. Unilateral ovariectomy did not change embryo development, measured as the number of embryo cells. Variability of embryo development was not affected either. At 30 h post-mating, the majority of embryos (86.2% were 4-cell stage. Embryo quality was evaluated according to morphological criteria. No difference in embryo quality between intact and unilaterally ovariectomised females was found. Therefore, unilateral ovariectomy performed before puberty in rabbit does not modify early embryo survival and development.

  18. Ultrastructural changes in goat interspecies and intraspecies reconstructed early embryos

    DEFF Research Database (Denmark)

    Tao, Yong; Gheng, Lizi; Zhang, Meiling

    2008-01-01

    and dispered gradually from the 4-cell period. The nucleolus of GC and GG embryos changed from electron dense to a fibrillo-granular meshwork at the 16-cell stage, showing that nucleus function in the reconstructed embryos was activated. The broken nuclear envelope and multiple nucleoli in one blastomere......- and intraspecies reconstructed embryos have a similar pattern of developmental change to that of in vivo-produced embryos for ZP, rough ER, Gi and nucleolus, but differ for mitochondria, LD, vesicles, nucleus and gap junction development. In particular, the interspecies cloned embryos showed more severe...

  19. Early Cambrian pentamerous cubozoan embryos from South China.

    Directory of Open Access Journals (Sweden)

    Jian Han

    Full Text Available BACKGROUND: Extant cubozoans are voracious predators characterized by their square shape, four evenly spaced outstretched tentacles and well-developed eyes. A few cubozoan fossils are known from the Middle Cambrian Marjum Formation of Utah and the well-known Carboniferous Mazon Creek Formation of Illinois. Undisputed cubozoan fossils were previously unknown from the early Cambrian; by that time probably all representatives of the living marine phyla, especially those of basal animals, should have evolved. METHODS: Microscopic fossils were recovered from a phosphatic limestone in the Lower Cambrian Kuanchuanpu Formation of South China using traditional acetic-acid maceration. Seven of the pre-hatched pentamerous cubozoan embryos, each of which bears five pairs of subumbrellar tentacle buds, were analyzed in detail through computed microtomography (Micro-CT and scanning electron microscopy (SEM without coating. RESULTS: The figured microscopic fossils are unequivocal pre-hatching embryos based on their spherical fertilization envelope and the enclosed soft-tissue that has preserved key anatomical features arranged in perfect pentaradial symmetry, allowing detailed comparison with modern cnidarians, especially medusozoans. A combination of features, such as the claustrum, gonad-lamella, suspensorium and velarium suspended by the frenula, occur exclusively in the gastrovascular system of extant cubozoans, indicating a cubozoan affinity for these fossils. Additionally, the interior anatomy of these embryonic cubozoan fossils unprecedentedly exhibits the development of many new septum-derived lamellae and well-partitioned gastric pockets unknown in living cubozoans, implying that ancestral cubozoans had already evolved highly specialized structures displaying unexpected complexity at the dawn of the Cambrian. The well-developed endodermic lamellae and gastric pockets developed in the late embryonic stages of these cubozoan fossils are comparable with

  20. Early Olfactory Processing in Drosophila: Mechanisms and Principles

    OpenAIRE

    Wilson, Rachel I.

    2013-01-01

    In the olfactory system of Drosophila melanogaster, it is relatively straightforward to make in vivo measurements of activity in neurons corresponding to targeted processing. This, together with the numerical simplicity of the Drosophila olfactory system, has produced rapid gains in our understanding of Drosophila olfaction. This review summarizes the neurophysiology of the first two layers of this system: the peripheral olfactory receptor neurons and their postsynaptic targets in the antenna...

  1. A multicenter prospective study to assess the effect of early cleavage on embryo quality, implantation, and live-birth rate.

    Science.gov (United States)

    de los Santos, Maria José; Arroyo, Gemma; Busquet, Ana; Calderón, Gloria; Cuadros, Jorge; Hurtado de Mendoza, Maria Victoria; Moragas, Marta; Herrer, Raquel; Ortiz, Agueda; Pons, Carme; Ten, Jorge; Vilches, Miguel Angel; Figueroa, Maria José

    2014-04-01

    To investigate the impact of early cleavage (EC) on embryo quality, implantation, and live-birth rates. Prospective cross-sectional study. Multicenter study. Seven hundred embryo transfers and 1,028 early-stage human embryos. None. Implantation according to the presence of EC and embryo quality. The presence of EC is associated with embryo quality, especially in cycles with autologous oocytes. However, the use of EC as an additional criterion for selecting an embryo for transfer does not appear to significantly improve likelihood of implantation. Furthermore, embryos that presented EC had live-birth rates per implanted embryo similar to those that did not show any sign of cleavage. At least for conventional embryo culture and morphologic evaluations, the additional evaluation of EC in embryos may not be valuable to improve embryo implantation. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  2. Loss of PTB or negative regulation of Notch mRNA reveals distinct zones of Notch and actin protein accumulation in Drosophila embryo.

    Directory of Open Access Journals (Sweden)

    Cedric S Wesley

    Full Text Available Polypyrimidine Tract Binding (PTB protein is a regulator of mRNA processing and translation. Genetic screens and studies of wing and bristle development during the post-embryonic stages of Drosophila suggest that it is a negative regulator of the Notch pathway. How PTB regulates the Notch pathway is unknown. Our studies of Drosophila embryogenesis indicate that (1 the Notch mRNA is a potential target of PTB, (2 PTB and Notch functions in the dorso-lateral regions of the Drosophila embryo are linked to actin regulation but not their functions in the ventral region, and (3 the actin-related Notch activity in the dorso-lateral regions might require a Notch activity at or near the cell surface that is different from the nuclear Notch activity involved in cell fate specification in the ventral region. These data raise the possibility that the Drosophila embryo is divided into zones of different PTB and Notch activities based on whether or not they are linked to actin regulation. They also provide clues to the almost forgotten role of Notch in cell adhesion and reveal a role for the Notch pathway in cell fusions.

  3. Loss of PTB or Negative Regulation of Notch mRNA Reveals Distinct Zones of Notch and Actin Protein Accumulation in Drosophila Embryo

    Science.gov (United States)

    Wesley, Cedric S.; Guo, Heng; Chaudhry, Kanita A.; Thali, Markus J.; Yin, Jerry C.; Clason, Todd; Wesley, Umadevi V.

    2011-01-01

    Polypyrimidine Tract Binding (PTB) protein is a regulator of mRNA processing and translation. Genetic screens and studies of wing and bristle development during the post-embryonic stages of Drosophila suggest that it is a negative regulator of the Notch pathway. How PTB regulates the Notch pathway is unknown. Our studies of Drosophila embryogenesis indicate that (1) the Notch mRNA is a potential target of PTB, (2) PTB and Notch functions in the dorso-lateral regions of the Drosophila embryo are linked to actin regulation but not their functions in the ventral region, and (3) the actin-related Notch activity in the dorso-lateral regions might require a Notch activity at or near the cell surface that is different from the nuclear Notch activity involved in cell fate specification in the ventral region. These data raise the possibility that the Drosophila embryo is divided into zones of different PTB and Notch activities based on whether or not they are linked to actin regulation. They also provide clues to the almost forgotten role of Notch in cell adhesion and reveal a role for the Notch pathway in cell fusions. PMID:21750738

  4. The p66(Shc adaptor protein controls oxidative stress response in early bovine embryos.

    Directory of Open Access Journals (Sweden)

    Dean H Betts

    Full Text Available The in vitro production of mammalian embryos suffers from high frequencies of developmental failure due to excessive levels of permanent embryo arrest and apoptosis caused by oxidative stress. The p66Shc stress adaptor protein controls oxidative stress response of somatic cells by regulating intracellular ROS levels through multiple pathways, including mitochondrial ROS generation and the repression of antioxidant gene expression. We have previously demonstrated a strong relationship with elevated p66Shc levels, reduced antioxidant levels and greater intracellular ROS generation with the high incidence of permanent cell cycle arrest of 2-4 cell embryos cultured under high oxygen tensions or after oxidant treatment. The main objective of this study was to establish a functional role for p66Shc in regulating the oxidative stress response during early embryo development. Using RNA interference in bovine zygotes we show that p66Shc knockdown embryos exhibited increased MnSOD levels, reduced intracellular ROS and DNA damage that resulted in a greater propensity for development to the blastocyst stage. P66Shc knockdown embryos were stress resistant exhibiting significantly reduced intracellular ROS levels, DNA damage, permanent 2-4 cell embryo arrest and diminished apoptosis frequencies after oxidant treatment. The results of this study demonstrate that p66Shc controls the oxidative stress response in early mammalian embryos. Small molecule inhibition of p66Shc may be a viable clinical therapy to increase the developmental potential of in vitro produced mammalian embryos.

  5. Genetic and proteomic evidence for roles of Drosophila SUMO in cell cycle control, Ras signaling, and early pattern formation.

    Directory of Open Access Journals (Sweden)

    Minghua Nie

    2009-06-01

    Full Text Available SUMO is a protein modifier that is vital for multicellular development. Here we present the first system-wide analysis, combining multiple approaches, to correlate the sumoylated proteome (SUMO-ome in a multicellular organism with the developmental roles of SUMO. Using mass-spectrometry-based protein identification, we found over 140 largely novel SUMO conjugates in the early Drosophila embryo. Enriched functional groups include proteins involved in Ras signaling, cell cycle, and pattern formation. In support of the functional significance of these findings, sumo germline clone embryos exhibited phenotypes indicative of defects in these same three processes. Our cell culture and immunolocalization studies further substantiate roles for SUMO in Ras signaling and cell cycle regulation. For example, we found that SUMO is required for efficient Ras-mediated MAP kinase activation upstream or at the level of Ras activation. We further found that SUMO is dynamically localized during mitosis to the condensed chromosomes, and later also to the midbody. Polo kinase, a SUMO substrate found in our screen, partially colocalizes with SUMO at both sites. These studies show that SUMO coordinates multiple regulatory processes during oogenesis and early embryogenesis. In addition, our database of sumoylated proteins provides a valuable resource for those studying the roles of SUMO in development.

  6. Early events in speciation: Polymorphism for hybrid male sterility in Drosophila

    OpenAIRE

    Reed, Laura K.; Markow, Therese A.

    2004-01-01

    Capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. We have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. Specifically, we show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, Drosophila arizonae, is controlled by factors p...

  7. Embryo mortality and early post-oestrous cycle embryonic death ...

    African Journals Online (AJOL)

    Department of Animal Science, University of Natal, P.O. Box 375, ... An estimate of embryo mortality (cycles longer than 28 days) was obtained from milk progesterone analysis and .... test, these differences were significant (P < 0,001). It.

  8. Pipe-dependent ventral processing of Easter by Snake is the defining step in Drosophila embryo DV axis formation.

    Science.gov (United States)

    Cho, Yong Suk; Stevens, Leslie M; Stein, David

    2010-06-22

    The establishment of Drosophila embryonic dorsal-ventral (DV) polarity relies on serine proteolytic activity in the perivitelline space between the embryonic membrane and the eggshell. Gastrulation Defective cleaves and activates Snake, which processes and activates Easter, which cleaves Spätzle to form the activating ligand for the Toll receptor. Ventral restriction of ligand formation depends on the Pipe sulfotransferase, which is expressed in ventral cells of the follicular epithelium surrounding the developing oocyte. Pipe modifies components of the developing eggshell to produce a ventral cue embedded in the vitelline membrane. This ventral cue is believed to promote one or more of the proteolysis steps in the perivitelline space. By examining the processing of transgenic, tagged versions of the perivitelline proteins during DV patterning, we find that the proteolysis of Easter by Snake is the first Pipe-dependent step and therefore the key ventrally restricted event in the protease cascade. We also find that Snake and Easter associate together in a complex in both wild-type and pipe mutant-derived embryos. This observation suggests a mechanism in which the sulfated target of Pipe promotes a productive interaction between Snake and Easter, perhaps by facilitating conformational changes in a complex containing the two proteins. Copyright 2010 Elsevier Ltd. All rights reserved.

  9. The L1-type cell adhesion molecule Neuroglian is necessary for maintenance of sensory axon advance in the Drosophila embryo

    Directory of Open Access Journals (Sweden)

    Martin Veronica

    2008-04-01

    Full Text Available Abstract Background Cell adhesion molecules have long been implicated in the regulation of axon growth, but the precise cellular roles played by individual cell adhesion molecules and the molecular basis for their action are still not well understood. We have used the sensory system of the Drosophila embryo to shed light on the mechanism by which the L1-type cell adhesion molecule Neuroglian regulates axon growth. Results We have found a highly penetrant sensory axon stalling phenotype in neuroglian mutant embryos. Axons stalled at a variety of positions along their normal trajectory, but most commonly in the periphery some distance along the peripheral nerve. All lateral and dorsal cluster sensory neurons examined, except for the dorsal cluster neuron dbd, showed stalling. Sensory axons were never seen to project along inappropriate pathways in neuroglian mutants and stalled axons showed normal patterns of fasciculation within nerves. The growth cones of stalled axons possessed a simple morphology, similar to their appearance in wild-type embryos when advancing along nerves. Driving expression of the wild-type form of Neuroglian in sensory neurons alone rescued the neuroglian mutant phenotype of both pioneering and follower neurons. A partial rescue was achieved by expressing the Neuroglian extracellular domain. Over/mis-expression of Neuroglian in all neurons, oenocytes or trachea had no apparent effect on sensory axon growth. Conclusion We conclude that Neuroglian is necessary to maintain axon advance along axonal substrates, but is not required for initiation of axon outgrowth, axon fasciculation or recognition of correct growth substrates. Expression of Neuroglian in sensory neurons alone is sufficient to promote axon advance and the intracellular region of the molecule is largely dispensable for this function. It is unlikely, therefore, that Nrg acts as a molecular 'clutch' to couple adhesion of F-actin within the growth cone to the

  10. Chronology of early embryonic development and embryo uterine migration in alpacas.

    Science.gov (United States)

    Picha, Y; Tibary, A; Memon, M; Kasimanickam, R; Sumar, J

    2013-03-01

    The objectives were to: (1) describe the chronology of early embryonic development from ovulation to entry into the uterus; and (2) to determine the timing of embryo migration to the left uterine horn when ovulation occurred from the right ovary. The experiment was conducted in Peru. Females (n = 132) were randomly assigned to 15 experimental groups. All females were mated to an intact male, given 50 μg GnRH im (Cystorelin) and ovulation time determined by transrectal ultrasonography, conducted every 6 hours, starting 24 hours postmating. Animals were slaughtered at a specific intervals postovulation and reproductive tracts were recovered and subjected to oviductal and uterine flushing for females slaughtered between 1 and 6 days postovulation (dpo; Day 0 = ovulation) and uterine flushing for females slaughtered from 7 to 15 dpo for recovery of oocytes/embryos. Season of mating did not influence the interval from mating to ovulation (winter: 29 ± 6 hours vs. summer: 30 ± 6 hours; P = 0.49). Ovulation rates for females mated during winter and summer were 92% versus 100%, respectively (P = 0.05). Fertilization rates for winter and summer mated females were 72% and 82% (P = 0.29). Unfertilized ova were not retained in the uterine tube. All embryos collected were in the uterine tube ipsilateral to the side of ovulation between 1 and 5 dpo. Embryos reached the uterus on 6 dpo. Embryos began to elongate on 9 dpo; at this time, 83% of embryos derived from right-ovary ovulations were collected from the left uterine horn. Embryos occupied the entire uterine cavity by 10 dpo. In conclusion, we characterized early embryo development and location of embryo during its early developmental stages in alpaca. This was apparently the first report regarding chronology of embryo development and migration to the left horn in alpaca which merits further investigation regarding its role in maternal recognition of pregnancy. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Transcriptomic profiling of bovine IVF embryos revealed candidate genes and pathways involved in early embryonic development

    Directory of Open Access Journals (Sweden)

    Yandell Brian S

    2010-01-01

    Full Text Available Abstract Background Early embryonic loss is a large contributor to infertility in cattle. Although genetic factors are known to affect early embryonic development, the discovery of such factors has been a serious challenge. The objective of this study was to identify genes differentially expressed between blastocysts and degenerative embryos at early stages of development. Results Using microarrays, genome-wide RNA expression was profiled and compared for in vitro fertilization (IVF - derived blastocysts and embryos undergoing degenerative development up to the same time point. Surprisingly similar transcriptomic profiles were found in degenerative embryos and blastocysts. Nonetheless, we identified 67 transcripts that significantly differed between these two groups of embryos at a 15% false discovery rate, including 33 transcripts showing at least a two-fold difference. Several signaling and metabolic pathways were found to be associated with the developmental status of embryos, among which were previously known important steroid biosynthesis and cell communication pathways in early embryonic development. Conclusions This study presents the first direct and comprehensive comparison of transcriptomes between IVF blastocysts and degenerative embryos, providing important information for potential genes and pathways associated with early embryonic development.

  12. Metabolic and mitochondrial dysfunction in early mouse embryos following maternal dietary protein intervention.

    Science.gov (United States)

    Mitchell, Megan; Schulz, Samantha L; Armstrong, David T; Lane, Michelle

    2009-04-01

    Dietary supply of nutrients, both periconception and during pregnancy, influence the growth and development of the fetus and offspring and their health into adult life. Despite the importance of research efforts surrounding the developmental origins of health and disease hypothesis, the biological mechanisms involved remain elusive. Mitochondria are of major importance in the oocyte and early embryo, particularly as a source of ATP generation, and perturbations in their function have been related to reduced embryo quality. The present study examined embryo development following periconception exposure of females to a high-protein diet (HPD) or a low-protein diet (LPD) relative to a medium-protein diet (MPD; control), and we hypothesized that perturbed mitochondrial metabolism in the mouse embryo may be responsible for the impaired embryo and fetal development reported by others. Although the rate of development to the blastocyst stage did not differ between diets, both the HPD and LPD reduced the number of inner cell mass cells in the blastocyst-stage embryo. Furthermore, mitochondrial membrane potential was reduced and mitochondrial calcium levels increased in the 2-cell embryo. Embryos from HPD females had elevated levels of reactive oxygen species and ADP concentrations, indicative of metabolic stress and, potentially, the uncoupling of oxidative phosphorylation, whereas embryos from LPD females had reduced mitochondrial clustering around the nucleus, suggestive of an overall quietening of metabolism. Thus, although periconception dietary supply of different levels of protein is permissive of development, mitochondrial metabolism is altered in the early embryo, and the nature of the perturbation differs between HPD and LPD exposure.

  13. MiRNA-mediated regulation of cell signaling and homeostasis in the early mouse embryo.

    Science.gov (United States)

    Pernaute, Barbara; Spruce, Thomas; Rodriguez, Tristan A; Manzanares, Miguel

    2011-02-15

    At the time of implantation the mouse embryo is composed of three tissues the epiblast, trophectoderm and primitive endoderm. As development progresses the epiblast goes on to form the foetus whilst the trophectoderm and primitive endoderm give rise to extra-embryonic structures with important roles in embryo patterning and nutrition. Dramatic changes in gene expression occur during early embryo development and these require regulation at different levels. miRNAs are small non coding RNAs that have emerged over the last decade as important post-transcriptional repressors of gene expression. The roles played by miRNAs during early mammalian development are only starting to be elucidated. In order to gain insight into the function of miRNAs in the different lineages of the early mouse embryo we have analysed in depth the phenotype of embryos and extra-embryonic stem cells mutant for the miRNA maturation protein Dicer. This study revealed that miRNAs are involved in regulating cell signaling and homeostasis in the early embryo. Specifically, we identified a role for miRNAs in regulating the Erk signaling pathway in the extra-embryonic endoderm, cell cycle progression in extra-embryonic tissues and apoptosis in the epiblast.

  14. Early detection and staging of spontaneous embryo resorption by ultrasound biomicroscopy in murine pregnancy.

    Science.gov (United States)

    Flores, Luis E; Hildebrandt, Thomas B; Kühl, Anja A; Drews, Barbara

    2014-05-10

    Embryo resorption is a major problem in human medicine, agricultural animal production and in conservation breeding programs. Underlying mechanisms have been investigated in the well characterised mouse model. However, post mortem studies are limited by the rapid disintegration of embryonic structures. A method to reliably identify embryo resorption in alive animals has not been established yet. In our study we aim to detect embryos undergoing resorption in vivo at the earliest possible stage by ultra-high frequency ultrasound. In a longitudinal study, we monitored 30 pregnancies of wild type C57BI/6 mice using ultra-high frequency ultrasound (30-70 MHz), so called ultrasound biomicroscopy (UBM). We compared the sonoembryology of mouse conceptuses under spontaneous resorption and neighbouring healthy conceptuses and correlated the live ultrasound data with the respective histology. The process of embryo resorption comprised of four stages: first, the conceptus exhibited growth retardation, second, bradycardia and pericardial edema were observed, third, further development ceased and the embryo died, and finally embryo remnants were resorbed by maternal immune cells. In early gestation (day 7 and 8), growth retardation was characterized by a small embryonic cavity. The embryo and its membranes were ill defined or did not develop at all. The echodensity of the embryonic fluid increased and within one to two days, the embryo and its cavity disappeared and was transformed into echodense tissue surrounded by fluid filled caverns. In corresponding histologic preparations, fibrinoid material interspersed with maternal granulocytes and lacunae filled with maternal blood were observed. In later stages (day 9-11) resorption prone embryos were one day behind in their development compared to their normal siblings. The space between Reichert's membrane and inner yolk sac membrane was enlarged The growth retarded embryos exhibited bradycardia and ultimately cessation of heart

  15. Effects of helium ions of an early embryo on postembryonic leaf development in Brassica napus L.

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Noboru [Tokyo Metropolitan Industrial Technology Research Institute, Tokyo (Japan); Minami, Harufumi [Tokyo Metropolitan Agricultural Experiment Station, Tachikawa, Tokyo (Japan); Shikazono, Naoya; Tanaka, Atsushi; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-12-01

    We examined postembryonic effects after helium ion and gamma ray irradiation of an isolated whole flower (a flower with pedicel) of Brassica napus through a flower organ culture, and estimated the effects of irradiation on embryogenesis in sexual reproductive stages. The whole flowers were irradiated with 30 Gy of helium ions and gamma rays in the early globular embryo and/or torpedo embryo stages. The helium ion and gamma ray irradiation of early globular embryos caused some drastic malformations in the first true leaves. Those malformations were classified into four types: cup-shaped, funnel-shaped, shrunk and the other varied leaves. The types were observed in 40% of plants that developed first true leaves. Both cup-shaped and funnel-shaped types were observed in over 15%. On the other hand, the irradiation of gamma rays of torpedo embryos caused sectors lacking chlorophyll in first true leaves. (author)

  16. The early-stage diagnosis of albinic embryos by applying optical coherence tomography

    Science.gov (United States)

    Yang, Bor-Wen; Wang, Shih-Yuan; Wang, Yu-Yen; Cai, Jyun-Jhang; Chang, Chung-Hao

    2013-09-01

    Albinism is a kind of congenital disease of abnormal metabolism. Poecilia reticulata (guppy fish) is chosen as the model to study the development of albinic embryos as it is albinic, ovoviviparous and with short life period. This study proposed an imaging method for penetrative embryo investigation using optical coherence tomography. By imaging through guppy mother’s reproduction purse, we found the embryo’s eyes were the early-developed albinism features. As human’s ocular albinism typically appear at about four weeks old, it is the time to determine if an embryo will grow into an albino.

  17. The Influence of Interspecies Somatic Cell Nuclear Transfer on Epigenetic Enzymes Transcription in Early Embryos

    DEFF Research Database (Denmark)

    Morovic, Martin; Murin, Matej; Strejcek, Frantisek

    2016-01-01

    in oocytes and early embryos of several species including bovine and porcine zygotes is species-dependent process and the incomplete DNA methylation correlates with the nuclear transfer failure rate in mammals. In this study the transcription of DNA methyltransferase 1 and 3a (DNMT1, DNMT3a) genes in early......One of the main reason for the incorrect development of embryos derived from somatic cell nuclear transfer is caused by insufficient demethylation of injected somatic chromatin to a state comparable with an early embryonic nucleus. It is already known that the epigenetic enzymes transcription....... In spite of the detection of ooplasmic DNA methyltransferases, the somatic genes for DNMT1 and DNMT3a enzymes were not expressed and the development of intergeneric embryos stopped at the 4-cell stage. Our results indicate that the epigenetic reprogramming during early mammalian development is strongly...

  18. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Protein nutrition and metabolism during early development of the chick embryo

    International Nuclear Information System (INIS)

    Klein, N.W.

    1976-01-01

    Cultures of intact early chick embryos have been used as a model system in which to study the nutrition and metabolism of proteins during early embryonic development. Previous studies have shown that these embryos require nutrient proteins for growth and development. The protein requirement was found to be specific in that at least two proteins were essential; one a transferrin (either conalbumin or yolk transferrin) and the other either ovalbumin or lipovitellin. Variations in the quantity or type of protein provided in the medium altered the growth of embryo regions through regionally specific changes in protein breakdown. This was confirmed through protein synthetic studies with isolated polyribosomes. More recently such variations in protein nutrition have been shown also to affect the actual patterns of proteins synthesized by regions of the embryo. These observed responses to protein nutrition have been difficult to reconcile with our observation that proteins as such did not reach the embryo proper but were first degraded to amine acids within the yolk-sac membrane. Studies on the synthesis of serum proteins by the yolk-sac membrane have provided a possible explanation in that the relative synthesis of individual serum proteins was dramatically influenced by the protein composition of the culture medium. We are currently attempting to demonstrate that serum proteins are indeed the mediators of the response of embryos to protein nutrition. (author)

  20. Early bovine embryos regulate oviduct epithelial cell gene expression during in vitro co-culture.

    Science.gov (United States)

    Schmaltz-Panneau, Barbara; Cordova, Amanda; Dhorne-Pollet, Sophie; Hennequet-Antier, Christelle; Uzbekova, Sveltlana; Martinot, Emmanuelle; Doret, Sarah; Martin, Patrice; Mermillod, Pascal; Locatelli, Yann

    2014-10-01

    In mammals, the oviduct may participate to the regulation of early embryo development. In vitro co-culture of early bovine embryos with bovine oviduct epithelial cells (BOEC) has been largely used to mimic the maternal environment. However, the mechanisms of BOEC action have not been clearly elucidated yet. The aim of this study was to determine the response of BOEC cultures to the presence of developing bovine embryos. A 21,581-element bovine oligonucleotide array was used compare the gene expression profiles of confluent BOEC cultured for 8 days with or without embryos. This study revealed 34 differentially expressed genes (DEG). Of these 34 genes, IFI6, ISG15, MX1, IFI27, IFI44, RSAD2, IFITM1, EPSTI1, USP18, IFIT5, and STAT1 expression increased to the greatest extent due to the presence of embryos with a major impact on antiviral and immune response. Among the mRNAs at least 25 are already described as induced by interferons. In addition, transcript levels of new candidate genes involved in the regulation of transcription, modulation of the maternal immune system and endometrial remodeling were found to be increased. We selected 7 genes and confirmed their differential expression by quantitative RT-PCR. The immunofluorescence imaging of cellular localization of STAT1 protein in BOEC showed a nuclear translocation in the presence of embryos, suggesting the activation of interferon signaling pathway. This first systematic study of BOEC transcriptome changes in response to the presence of embryos in cattle provides some evidences that these cells are able to adapt their transcriptomic profile in response to embryo signaling. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Type II cytokeratin gene expression is indicative of early cell differentiation in the chick embryo

    International Nuclear Information System (INIS)

    Charlebois, T.S.

    1988-01-01

    Embryonic development in vertebrates appears to involve a series of inductive tissue interactions that lead to regional specializations, which eventually become elaborated in the basic body plan of the embryo. The inductive interactions leading to early regionalization of the embryo are often particularly difficult to evaluate because of the absence of available morphological or biochemical evidence that such events have occurred. In the 36 hour chick embryo, the regional subdivision of the early ectoderm is evidence by a marked lens-forming bias in the head ectoderm, which is absent in the presumptive dorsal epidermis of the trunk region. As a strategy for isolating genes whose differential expression might reflect this regional subdivision, a cDNA library from 36 hour embryos was prepared and screened for differential hybridization to [ 32 P]cDNA probes synthesized using template RNA isolated from 36 hour head ectoderm and trunk ectoderm. A cDNA clone (T4) was isolated which hybridizes to transcripts present at much higher levels in trunk ectoderm than in head ectoderm. Partial nucleotide and deduced amino acid sequences of this clone indicate that it represents a gene encoding a type II cytokeratin. The distribution of transcripts complementary to the T4 probe was evaluated in early embryos using RNA gel blot analysis and in situ hybridization to tissue sections

  2. Global gene expression profiling of individual human oocytes and embryos demonstrates heterogeneity in early development.

    Directory of Open Access Journals (Sweden)

    Lisa Shaw

    Full Text Available Early development in humans is characterised by low and variable embryonic viability, reflected in low fecundity and high rates of miscarriage, relative to other mammals. Data from assisted reproduction programmes provides additional evidence that this is largely mediated at the level of embryonic competence and is highly heterogeneous among embryos. Understanding the basis of this heterogeneity has important implications in a number of areas including: the regulation of early human development, disorders of pregnancy, assisted reproduction programmes, the long term health of children which may be programmed in early development, and the molecular basis of pluripotency in human stem cell populations. We have therefore investigated global gene expression profiles using polyAPCR amplification and microarray technology applied to individual human oocytes and 4-cell and blastocyst stage embryos. In order to explore the basis of any variability in detail, each developmental stage is replicated in triplicate. Our data show that although transcript profiles are highly stage-specific, within each stage they are relatively variable. We describe expression of a number of gene families and pathways including apoptosis, cell cycle and amino acid metabolism, which are variably expressed and may be reflective of embryonic developmental competence. Overall, our data suggest that heterogeneity in human embryo developmental competence is reflected in global transcript profiles, and that the vast majority of existing human embryo gene expression data based on pooled oocytes and embryos need to be reinterpreted.

  3. Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice.

    Science.gov (United States)

    Glenn, David R J; McClure, Neil; Cosby, S Louise; Stevenson, Michael; Lewis, Sheena E M

    2009-03-01

    To determine the effects of sildenafil citrate, a cyclic monophosphate-specific type 5 phosphodiesterase inhibitor known to affect sperm function, on fertilization and early embryo cleavage. This acute mammal study included male and female mice assigned randomly, the females sacrificed after mating and their oocytes/embryos evaluated at four time periods after treatment. Academic research environment. Male and female CBAB(6) mice. Female mice were injected intraperitoneally with 5 IU gonadotropin (hCG) to stimulate follicular growth and induce ovulation. They were each caged with a male that had been gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. After 12, 36, 60, and 84 h, females were killed, their oviducts were dissected out, and retrieved embryos were assessed for blastomere number and quality. Fertilization rates and numbers of embryos were evaluated after treatment. Fertilization rates (day 1) were markedly reduced (-33%) in matings where the male had taken sildenafil citrate. Over days 2-4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance. The impairments to fertility caused by sildenafil citrate have important implications for infertility centers and for couples who are using this drug precoitally while attempting to conceive.

  4. Expression of voltage-activated calcium channels in the early zebrafish embryo.

    Science.gov (United States)

    Sanhueza, Dayán; Montoya, Andro; Sierralta, Jimena; Kukuljan, Manuel

    2009-05-01

    Increases in cytosolic calcium concentrations regulate many cellular processes, including aspects of early development. Calcium release from intracellular stores and calcium entry through non-voltage-gated channels account for signalling in non-excitable cells, whereas voltage-gated calcium channels (CaV) are important in excitable cells. We report the expression of multiple transcripts of CaV, identified by its homology to other species, in the early embryo of the zebrafish, Danio rerio, at stages prior to the differentiation of excitable cells. CaV mRNAs and proteins were detected as early as the 2-cell stages, which indicate that they arise from both maternal and zygotic transcription. Exposure of embryos to pharmacological blockers of CaV does not perturb early development significantly, although late effects are appreciable. These results suggest that CaV may have a role in calcium homeostasis and control of cellular process during early embryonic development.

  5. Changes in oscillatory dynamics in the cell cycle of early Xenopus laevis embryos.

    Directory of Open Access Journals (Sweden)

    Tony Y-C Tsai

    2014-02-01

    Full Text Available During the early development of Xenopus laevis embryos, the first mitotic cell cycle is long (∼85 min and the subsequent 11 cycles are short (∼30 min and clock-like. Here we address the question of how the Cdk1 cell cycle oscillator changes between these two modes of operation. We found that the change can be attributed to an alteration in the balance between Wee1/Myt1 and Cdc25. The change in balance converts a circuit that acts like a positive-plus-negative feedback oscillator, with spikes of Cdk1 activation, to one that acts like a negative-feedback-only oscillator, with a shorter period and smoothly varying Cdk1 activity. Shortening the first cycle, by treating embryos with the Wee1A/Myt1 inhibitor PD0166285, resulted in a dramatic reduction in embryo viability, and restoring the length of the first cycle in inhibitor-treated embryos with low doses of cycloheximide partially rescued viability. Computations with an experimentally parameterized mathematical model show that modest changes in the Wee1/Cdc25 ratio can account for the observed qualitative changes in the cell cycle. The high ratio in the first cycle allows the period to be long and tunable, and decreasing the ratio in the subsequent cycles allows the oscillator to run at a maximal speed. Thus, the embryo rewires its feedback regulation to meet two different developmental requirements during early development.

  6. A technique for sexing fully developed embryos and early-instar larvae of the gypsy moth

    Science.gov (United States)

    Gilbert Levesque

    1963-01-01

    Because variation in sex ratio is an important factor in the population dynamics of the gypsy moth (Porthetria dispar), it is necessary to have some means of determining the ratio of males to females in a population at the beginning of the larval period as well as in the later stages. For determining the sex of fully developed embryos and early-...

  7. Coordinated development of muscles and tendon-like structures: early interactions in the Drosophila leg

    Directory of Open Access Journals (Sweden)

    cedric esoler

    2016-02-01

    Full Text Available The formation of the musculoskeletal system is a remarkable example of tissue assembly. In both vertebrates and invertebrates, precise connectivity between muscles and skeleton (or exoskeleton via tendons or equivalent structures is fundamental for movement and stability of the body. The molecular and cellular processes underpinning muscle formation are well established and significant advances have been made in understanding tendon development. However, the mechanisms contributing to proper connection between these two tissues have received less attention. Observations of coordinated development of tendons and muscles suggest these tissues may interact during the different steps in their development. There is growing evidence that, depending on animal model and muscle type, these interactions can take place from progenitor induction to the final step of the formation of the musculoskeletal system. Here we briefly review and compare the mechanisms behind muscle and tendon interaction throughout the development of vertebrates and Drosophila before going on to discuss our recent findings on the coordinated development of muscles and tendon-like structures in Drosophila leg. By altering apodeme formation (the functional Drosophila equivalent of tendons in vertebrates during the early steps of leg development, we affect the spatial localisation of subsequent myoblasts. These findings provide the first evidence of the developmental impact of early interactions between muscle and tendon-like precursors, and confirm the appendicular Drosophila muscle system as a valuable model for studying these processes.

  8. Immunological mechanisms to establish embryo tolerance in early bovine pregnancy.

    Science.gov (United States)

    Groebner, A E; Schulke, K; Schefold, J C; Fusch, G; Sinowatz, F; Reichenbach, H D; Wolf, E; Meyer, H H D; Ulbrich, S E

    2011-01-01

    A well-balanced immunological interaction between mother and the semi-allogenic embryo is of particular importance. The objective of the present study was to analyse mechanisms of immune tolerance in bovine pregnancy during peri-implantation. Simmental heifers inseminated with either cryopreserved spermatozoa or seminal plasma were killed 12, 15 or 18 days after oestrus. Uteri were flushed for the recovery of conceptuses and the ipsilateral intercaruncular endometrium was sampled for gene expression analysis. Indoleamine 2,3-dioxygenase (IDO) mRNA, coding for the initial enzyme of the kynurenine pathway, was 18-fold (P < 0.001) more abundant in the endometrium of Day 18 pregnant v. non-pregnant animals. Tandem mass spectrometry revealed a decrease of endometrial l-tryptophan (P = 0.0008), but an increase of l-kynurenine concentration (P = 0.005) from Day 12 to Day 18, suggesting increasing IDO activity (P < 0.03). An in vitro coculture model of endometrial cells showed an induction of IDO expression following interferon-τ exposure primarily in stroma cells, which was confirmed by in situ hybridisation localising IDO mRNA mainly in deep stroma cells. Immunohistochemical analysis revealed fewer CD45-positive leucocytes in the zona basalis of pregnant animals. Elevated IDO activity may reduce the presence of leucocytes in the pregnant endometrium, providing a possible mechanism for protecting the semi-allogenic conceptus from maternal rejection.

  9. Nuclear and cellular expression data from the whole 16-cell stage Arabidopsis thaliana embryo and a cell type-specific expression atlas of the early Arabidopsis embryo

    NARCIS (Netherlands)

    Palovaara, J.P.J.

    2017-01-01

    SuperSeries contain expression data from the nuclei of cell types involved in patterning events, with focus on root apical stem cell formation, at 16-cell stage, early globular stage and late globular stage in the early Arabidopsis embryo (atlas). Expression data comparing nuclear and cellular RNA

  10. Regional localization of suspensor mRNAs during early embryo development.

    Science.gov (United States)

    Weterings, K; Apuya, N R; Bi, Y; Fischer, R L; Harada, J J; Goldberg, R B

    2001-11-01

    We investigated gene activity within the giant embryos of the scarlet runner bean (Phaseolus coccineus) to gain understanding of the processes by which the apical and basal cells become specified to follow different developmental pathways after division of the zygote. We identified two mRNAs, designated G564 and C541, that accumulate specifically within the suspensor of globular-stage embryos. G564 mRNA accumulates uniformly throughout the suspensor, whereas C541 mRNA accumulates to a higher level within the large basal cells of the suspensor that anchor the embryo to the surrounding seed tissue. Both G564 and C541 mRNAs begin to accumulate shortly after fertilization and are present within the two basal cells of embryos at the four-cell stage. In contrast, at the same stage, these mRNAs are not detectable within the two descendants of the apical cell. Nor are they detectable within cells of the embryo sac before fertilization, including the egg cell. We used a G564/beta-glucuronidase reporter gene to show that the G564 promoter is activated specifically within the basal region and suspensor of preglobular tobacco embryos. Analysis of the G564 promoter identified a sequence domain required for transcription within the suspensor that contains several copies of a conserved motif. These results show that derivatives of the apical and basal cells transcribe different genes as early as the four-cell stage of embryo development and suggest that the apical and basal cells are specified at the molecular level after division of the zygote.

  11. Regional Localization of Suspensor mRNAs during Early Embryo Development

    Science.gov (United States)

    Weterings, Koen; Apuya, Nestor R.; Bi, Yuping; Fischer, Robert L.; Harada, John J.; Goldberg, Robert B.

    2001-01-01

    We investigated gene activity within the giant embryos of the scarlet runner bean (Phaseolus coccineus) to gain understanding of the processes by which the apical and basal cells become specified to follow different developmental pathways after division of the zygote. We identified two mRNAs, designated G564 and C541, that accumulate specifically within the suspensor of globular-stage embryos. G564 mRNA accumulates uniformly throughout the suspensor, whereas C541 mRNA accumulates to a higher level within the large basal cells of the suspensor that anchor the embryo to the surrounding seed tissue. Both G564 and C541 mRNAs begin to accumulate shortly after fertilization and are present within the two basal cells of embryos at the four-cell stage. In contrast, at the same stage, these mRNAs are not detectable within the two descendants of the apical cell. Nor are they detectable within cells of the embryo sac before fertilization, including the egg cell. We used a G564/β-glucuronidase reporter gene to show that the G564 promoter is activated specifically within the basal region and suspensor of preglobular tobacco embryos. Analysis of the G564 promoter identified a sequence domain required for transcription within the suspensor that contains several copies of a conserved motif. These results show that derivatives of the apical and basal cells transcribe different genes as early as the four-cell stage of embryo development and suggest that the apical and basal cells are specified at the molecular level after division of the zygote. PMID:11701878

  12. Nucleolus Precursor Bodies and Ribosome Biogenesis in Early Mammalian Embryos: Old Theories and New Discoveries.

    Science.gov (United States)

    Fulka, Helena; Aoki, Fugaku

    2016-06-01

    In mammals, mature oocytes and early preimplantation embryos contain transcriptionally inactive structures termed nucleolus precursor bodies instead of the typical fibrillo-granular nucleoli. These nuclear organelles are essential and strictly of maternal origin. If they are removed from oocytes, the resulting embryos are unable to replace them and consequently fail to develop. Historically, nucleolus precursor bodies have been perceived as a passive repository site of nucleolar proteins that are required for embryos to form fully functional nucleoli. Recent results, however, contradict this long-standing dogma and show that these organelles are dispensable for nucleologenesis and ribosome biogenesis. In this article, we discuss the possible roles of nucleolus precursor bodies and propose how they might be involved in embryogenesis. Furthermore, we argue that these organelles are essential only shortly after fertilization and suggest that they might actively participate in centromeric chromatin establishment. © 2016 by the Society for the Study of Reproduction, Inc.

  13. Early events in speciation: polymorphism for hybrid male sterility in Drosophila.

    Science.gov (United States)

    Reed, Laura K; Markow, Therese A

    2004-06-15

    Capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. We have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. Specifically, we show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, Drosophila arizonae, is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, we show that hybrid male sterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring. Because male sterility factors in hybrids between these species are not yet fixed within D. mojavensis, this system provides an invaluable opportunity to characterize the genetics of reproductive isolation at an early stage.

  14. Effect of culture medium volume and embryo density on early mouse embryonic development: tracking the development of the individual embryo.

    Science.gov (United States)

    Dai, Shan-Jun; Xu, Chang-Long; Wang, Jeffrey; Sun, Ying-Pu; Chian, Ri-Cheng

    2012-07-01

    To determine the optimal volume or density of embryos for the well-of-the-well (WOW) system in order to track the development of individual embryos and to determine whether the WOW system can reverse the negative impact of culturing embryos singly. (1) Mouse embryos (groups of nine at the 2-cell stage) were cultured in 6.25 μl, 12.50 μl, 25.00 μl and 50.00 μl of droplets of culture medium under paraffin oil; (2) Groups of three, six, nine and twelve embryos at the 2-cell stage were cultured in 50 μl of droplet of culture medium under paraffin oil; (3) Groups of nine embryos at the 2-cell stage were cultured in 50 μl of droplet under paraffin oil with or without nine micro-wells made on the bottom of the Petri dish into each of which were placed one of the nine embryos (WOW system). Also single 2-cell stage embryos was cultured individually in 5.5 μl of droplet of culture medium under paraffin oil with or without a single micro-well made on the bottom of the Petri dish (WOW system for single culture). At the end of culture, the percentages of blastocyst development, hatching and hatched blastocysts were compared in each group. The blastocysts were fixed for differential staining. The blastocyst development was significantly higher (P WOW system. The blastocyst development was not improved when single embryo cultured individually in a micro-well was compared to single embryo cultured individually without micro-well. The total cell numbers of blastocysts were significantly higher in group embryo culture than single embryo culture regardless of whether the WOW system was used. In addition, the total cell numbers of blastocysts were significantly higher (P WOW system than without. Group embryo culture is superior to single embryo culture for blastocyst development. The WOW system with 50 μl of droplet of culture medium can be used to track the individual development of embryo cultured in groups while preserving good embryonic development. The reduced

  15. A novel function for the IκB inhibitor Cactus in promoting Dorsal nuclear localization and activity in the Drosophila embryo.

    Science.gov (United States)

    Cardoso, Maira Arruda; Fontenele, Marcio; Lim, Bomyi; Bisch, Paulo Mascarello; Shvartsman, Stanislav Y; Araujo, Helena Marcolla

    2017-08-15

    The evolutionarily conserved Toll signaling pathway controls innate immunity across phyla and embryonic patterning in insects. In the Drosophila embryo, Toll is required to establish gene expression domains along the dorsal-ventral axis. Pathway activation induces degradation of the IκB inhibitor Cactus, resulting in a ventral-to-dorsal nuclear gradient of the NFκB effector Dorsal. Here, we investigate how cactus modulates Toll signals through its effects on the Dorsal gradient and on Dorsal target genes. Quantitative analysis using a series of loss- and gain-of-function conditions shows that the ventral and lateral aspects of the Dorsal gradient can behave differently with respect to Cactus fluctuations. In lateral and dorsal embryo domains, loss of Cactus allows more Dorsal to translocate to the nucleus. Unexpectedly, cactus loss-of-function alleles decrease Dorsal nuclear localization ventrally, where Toll signals are high. Overexpression analysis suggests that this ability of Cactus to enhance Toll stems from the mobilization of a free Cactus pool induced by the Calpain A protease. These results indicate that Cactus acts to bolster Dorsal activation, in addition to its role as a NFκB inhibitor, ensuring a correct response to Toll signals. © 2017. Published by The Company of Biologists Ltd.

  16. Redundant roles of Sox17 and Sox18 in early cardiovascular development of mouse embryos

    International Nuclear Information System (INIS)

    Sakamoto, Youhei; Hara, Kenshiro; Kanai-Azuma, Masami; Matsui, Toshiyasu; Miura, Yutaroh; Tsunekawa, Naoki; Kurohmaru, Masamichi; Saijoh, Yukio; Koopman, Peter; Kanai, Yoshiakira

    2007-01-01

    Sox7, -17 and -18 constitute the Sox subgroup F (SoxF) of HMG box transcription factor genes, which all are co-expressed in developing vascular endothelial cells in mice. Here we characterized cardiovascular phenotypes of Sox17/Sox18-double and Sox17-single null embryos during early-somite stages. Whole-mount PECAM staining demonstrated the aberrant heart looping, enlarged cardinal vein and mild defects in anterior dorsal aorta formation in Sox17 single-null embryos. The Sox17/Sox18 double-null embryos showed more severe defects in formation of anterior dorsal aorta and head/cervical microvasculature, and in some cases, aberrant differentiation of endocardial cells and defective fusion of the endocardial tube. However, the posterior dorsal aorta and allantoic microvasculature was properly formed in all of the Sox17/Sox18 double-null embryos. The anomalies in both anterior dorsal aorta and head/cervical vasculature corresponded with the weak Sox7 expression sites. This suggests the region-specific redundant activities of three SoxF members along the anteroposterior axis of embryonic vascular network

  17. Neural stem cell-encoded temporal patterning delineates an early window of malignant susceptibility in Drosophila.

    Science.gov (United States)

    Narbonne-Reveau, Karine; Lanet, Elodie; Dillard, Caroline; Foppolo, Sophie; Chen, Ching-Huan; Parrinello, Hugues; Rialle, Stéphanie; Sokol, Nicholas S; Maurange, Cédric

    2016-06-14

    Pediatric neural tumors are often initiated during early development and can undergo very rapid transformation. However, the molecular basis of this early malignant susceptibility remains unknown. During Drosophila development, neural stem cells (NSCs) divide asymmetrically and generate intermediate progenitors that rapidly differentiate in neurons. Upon gene inactivation, these progeny can dedifferentiate and generate malignant tumors. Here, we find that intermediate progenitors are prone to malignancy only when born during an early window of development while expressing the transcription factor Chinmo, and the mRNA-binding proteins Imp/IGF2BP and Lin-28. These genes compose an oncogenic module that is coopted upon dedifferentiation of early-born intermediate progenitors to drive unlimited tumor growth. In late larvae, temporal transcription factor progression in NSCs silences the module, thereby limiting mitotic potential and terminating the window of malignant susceptibility. Thus, this study identifies the gene regulatory network that confers malignant potential to neural tumors with early developmental origins.

  18. Shorter exposures to harder X-rays trigger early apoptotic events in Xenopus laevis embryos.

    Directory of Open Access Journals (Sweden)

    JiaJia Dong

    Full Text Available BACKGROUND: A long-standing conventional view of radiation-induced apoptosis is that increased exposure results in augmented apoptosis in a biological system, with a threshold below which radiation doses do not cause any significant increase in cell death. The consequences of this belief impact the extent to which malignant diseases and non-malignant conditions are therapeutically treated and how radiation is used in combination with other therapies. Our research challenges the current dogma of dose-dependent induction of apoptosis and establishes a new parallel paradigm to the photoelectric effect in biological systems. METHODOLOGY/PRINCIPAL FINDINGS: We explored how the energy of individual X-ray photons and exposure time, both factors that determine the total dose, influence the occurrence of cell death in early Xenopus embryo. Three different experimental scenarios were analyzed and morphological and biochemical hallmarks of apoptosis were evaluated. Initially, we examined cell death events in embryos exposed to increasing incident energies when the exposure time was preset. Then, we evaluated the embryo's response when the exposure time was augmented while the energy value remained constant. Lastly, we studied the incidence of apoptosis in embryos exposed to an equal total dose of radiation that resulted from increasing the incoming energy while lowering the exposure time. CONCLUSIONS/SIGNIFICANCE: Overall, our data establish that the energy of the incident photon is a major contributor to the outcome of the biological system. In particular, for embryos exposed under identical conditions and delivered the same absorbed dose of radiation, the response is significantly increased when shorter bursts of more energetic photons are used. These results suggest that biological organisms display properties similar to the photoelectric effect in physical systems and provide new insights into how radiation-mediated apoptosis should be understood and

  19. Direct evidence that radiation induced micronuclei of early embryos require a mitosis for expression

    International Nuclear Information System (INIS)

    Mueller, W.U.; Schlusen, I.; Streffer, C.

    1991-01-01

    The naturally synchronous development of early mouse embryos was exploited to address the question, whether micronuclei require a mitosis for expression or whether they can be expressed in the same cell cycle, in which exposure to X-rays or caffeine took place. Experiments with 2-cell and with 4-cell embryos showed that micronulcei are expressed only if a mitosis is completed. There was no indication, even after doses up to 20 Gy, that micronuclei can be expressed before the mitosis was reached, which followed exposure. Furthermore, no nuclear fragmentation pointing to apoptosis could be detected in the cycle, in which cells were exposed. The same results were obtained when caffeine (5 mM) was used as micronucleus inducing agent. (orig.)

  20. Imidacloprid Exposure Suppresses Neural Crest Cells Generation during Early Chick Embryo Development.

    Science.gov (United States)

    Wang, Chao-Jie; Wang, Guang; Wang, Xiao-Yu; Liu, Meng; Chuai, Manli; Lee, Kenneth Ka Ho; He, Xiao-Song; Lu, Da-Xiang; Yang, Xuesong

    2016-06-15

    Imidacloprid is a neonicotinoid pesticide that is widely used in the control pests found on crops and fleas on pets. However, it is still unclear whether imidacloprid exposure could affect early embryo development-despite some studies having been conducted on the gametes. In this study, we demonstrated that imidacloprid exposure could lead to abnormal craniofacial osteogenesis in the developing chick embryo. Cranial neural crest cells (NCCs) are the progenitor cells of the chick cranial skull. We found that the imidacloprid exposure retards the development of gastrulating chick embryos. HNK-1, PAX7, and Ap-2α immunohistological stainings indicated that cranial NCCs generation was inhibited after imidacloprid exposure. Double immunofluorescent staining (Ap-2α and PHIS3 or PAX7 and c-Caspase3) revealed that imidacloprid exposure inhibited both NCC proliferation and apoptosis. In addition, it inhibited NCCs production by repressing Msx1 and BMP4 expression in the developing neural tube and by altering expression of EMT-related adhesion molecules (Cad6B, E-Cadherin, and N-cadherin) in the developing neural crests. We also determined that imidacloprid exposure suppressed cranial NCCs migration and their ability to differentiate. In sum, we have provided experimental evidence that imidacloprid exposure during embryogenesis disrupts NCCs development, which in turn causes defective cranial bone development.

  1. Rapid DNA Synthesis During Early Drosophila Embryogenesis Is Sensitive to Maternal Humpty Dumpty Protein Function.

    Science.gov (United States)

    Lesly, Shera; Bandura, Jennifer L; Calvi, Brian R

    2017-11-01

    Problems with DNA replication cause cancer and developmental malformations. It is not fully understood how DNA replication is coordinated with development and perturbed in disease. We had previously identified the Drosophila gene humpty dumpty ( hd ), and showed that null alleles cause incomplete DNA replication, tissue undergrowth, and lethality. Animals homozygous for the missense allele, hd 272-9 , were viable, but adult females had impaired amplification of eggshell protein genes in the ovary, resulting in the maternal effects of thin eggshells and embryonic lethality. Here, we show that expression of an hd transgene in somatic cells of the ovary rescues amplification and eggshell synthesis but not embryo viability. The germline of these mothers remain mutant for the hd 272-9 allele, resulting in reduced maternal Hd protein and embryonic arrest during mitosis of the first few S/M nuclear cleavage cycles with chromosome instability and chromosome bridges. Epistasis analysis of hd with the rereplication mutation plutonium indicates that the chromosome bridges of hd embryos are the result of a failed attempt to segregate incompletely replicated sister chromatids. This study reveals that maternally encoded Humpty dumpty protein is essential for DNA replication and genome integrity during the little-understood embryonic S/M cycles. Moreover, the two hd 272-9 maternal-effect phenotypes suggest that ovarian gene amplification and embryonic cleavage are two time periods in development that are particularly sensitive to mild deficits in DNA replication function. This last observation has broader relevance for interpreting why mild mutations in the human ortholog of humpty dumpty and other DNA replication genes cause tissue-specific malformations of microcephalic dwarfisms. Copyright © 2017 by the Genetics Society of America.

  2. DOT1L inhibitor improves early development of porcine somatic cell nuclear transfer embryos

    DEFF Research Database (Denmark)

    Tao, Jia; Zhang, Yu; Zuo, Xiaoyuan

    2017-01-01

    Incomplete epigenetic reprogramming of the genome of donor cells causes poor early and full-term developmental efficiency of somatic cell nuclear transfer (SCNT) embryos. Previous research indicate that inhibition of the histone H3 K79 methyltransferase DOT1L, using a selective pharmacological...... inhibitor EPZ004777 (EPZ), significantly improved reprogramming efficiency during the generation of mouse induced pluripotent stem cells. However, the roles of DOT1L in porcine nuclear transfer-mediated cellular reprogramming are not yet known. Here we showed that DOT1L inhibition via 0.5 nM EPZ treatment...

  3. Modification and standardization of the culture of early postimplantation embryos for toxicological studies

    Energy Technology Data Exchange (ETDEWEB)

    Klug, S.; Lewandowski, C.; Neubert, D.

    1985-12-01

    The method of culturing ''whole'' rat embryos (days 9.5-11.5 of gestation, i.e. at the early stage of organogenesis) as modified and standardized in our laboratory is presented. We have succeeded in using bovine serum as culture medium instead of rat serum as recommended in the original procedure. Experimental conditions are described for obtaining reproducible results. An improved scoring system was developed which, in connection with a computerized documentation, greatly facilitates the evaluation of the data.

  4. Transcriptome analyses of rhesus monkey preimplantation embryos reveal a reduced capacity for DNA double-strand break repair in primate oocytes and early embryos

    Science.gov (United States)

    Wang, Xinyi; Liu, Denghui; He, Dajian; Suo, Shengbao; Xia, Xian; He, Xiechao; Han, Jing-Dong J.; Zheng, Ping

    2017-01-01

    Preimplantation embryogenesis encompasses several critical events including genome reprogramming, zygotic genome activation (ZGA), and cell-fate commitment. The molecular basis of these processes remains obscure in primates in which there is a high rate of embryo wastage. Thus, understanding the factors involved in genome reprogramming and ZGA might help reproductive success during this susceptible period of early development and generate induced pluripotent stem cells with greater efficiency. Moreover, explaining the molecular basis responsible for embryo wastage in primates will greatly expand our knowledge of species evolution. By using RNA-seq in single and pooled oocytes and embryos, we defined the transcriptome throughout preimplantation development in rhesus monkey. In comparison to archival human and mouse data, we found that the transcriptome dynamics of monkey oocytes and embryos were very similar to those of human but very different from those of mouse. We identified several classes of maternal and zygotic genes, whose expression peaks were highly correlated with the time frames of genome reprogramming, ZGA, and cell-fate commitment, respectively. Importantly, comparison of the ZGA-related network modules among the three species revealed less robust surveillance of genomic instability in primate oocytes and embryos than in rodents, particularly in the pathways of DNA damage signaling and homology-directed DNA double-strand break repair. This study highlights the utility of monkey models to better understand the molecular basis for genome reprogramming, ZGA, and genomic stability surveillance in human early embryogenesis and may provide insights for improved homologous recombination-mediated gene editing in monkey. PMID:28223401

  5. Post-Transcriptional Control of Gene Expression in Mouse Early Embryo Development: A View from the Tip of the Iceberg

    Directory of Open Access Journals (Sweden)

    Claudio Sette

    2011-04-01

    Full Text Available Fertilization is a very complex biological process that requires the perfect cooperation between two highly specialized cells: the male and female gametes. The oocyte provides the physical space where this process takes place, most of the energetic need, and half of the genetic contribution. The spermatozoon mostly contributes the other half of the chromosomes and it is specialized to reach and to penetrate the oocyte. Notably, the mouse oocyte and early embryo are transcriptionally inactive. Hence, they fully depend on the maternal mRNAs and proteins stored during oocyte maturation to drive the onset of development. The new embryo develops autonomously around the four-cell stage, when maternal supplies are exhausted and the zygotic genome is activated in mice. This oocyte-to-embryo transition needs an efficient and tightly regulated translation of the maternally-inherited mRNAs, which likely contributes to embryonic genome activation. Full understanding of post-transcriptional regulation of gene expression in early embryos is crucial to understand the reprogramming of the embryonic genome, it might help driving reprogramming of stem cells in vitro and will likely improve in vitro culturing of mammalian embryos for assisted reproduction. Nevertheless, the knowledge of the mechanism(s underlying this fundamental step in embryogenesis is still scarce, especially if compared to other model organisms. We will review here the current knowledge on the post-transcriptional control of gene expression in mouse early embryos and discuss some of the unanswered questions concerning this fascinating field of biology.

  6. Causality analysis detects the regulatory role of maternal effect genes in the early Drosophila embryo

    Directory of Open Access Journals (Sweden)

    Zara Ghodsi

    2017-03-01

    Full Text Available In developmental studies, inferring regulatory interactions of segmentation genetic network play a vital role in unveiling the mechanism of pattern formation. As such, there exists an opportune demand for theoretical developments and new mathematical models which can result in a more accurate illustration of this genetic network. Accordingly, this paper seeks to extract the meaningful regulatory role of the maternal effect genes using a variety of causality detection techniques and to explore whether these methods can suggest a new analytical view to the gene regulatory networks. We evaluate the use of three different powerful and widely-used models representing time and frequency domain Granger causality and convergent cross mapping technique with the results being thoroughly evaluated for statistical significance. Our findings show that the regulatory role of maternal effect genes is detectable in different time classes and thereby the method is applicable to infer the possible regulatory interactions present among the other genes of this network.

  7. HNK-1 immunoreactivity during early morphogenesis of the head region in a nonmodel vertebrate, crocodile embryo

    Science.gov (United States)

    Kundrát, Martin

    2008-11-01

    The present study examines HNK-1 immunoidentification of a population of the neural crest (NC) during early head morphogenesis in the nonmodel vertebrate, the crocodile ( Crocodylus niloticus) embryos. Although HNK-1 is not an exclusive NC marker among vertebrates, temporospatial immunoreactive patterns found in the crocodile are almost consistent with NC patterns derived from gene expression studies known in birds (the closest living relatives of crocodiles) and mammals. In contrast to birds, the HNK-1 epitope is immunoreactive in NC cells at the neural fold level in crocodile embryos and therefore provides sufficient base to assess early migratory events of the cephalic NC. I found that crocodile NC forms three classic migratory pathways in the head: mandibular, hyoid, and branchial. Further, I demonstrate that, besides this classic phenotype, there is also a forebrain-derived migratory population, which consolidates into a premandibular stream in the crocodile. In contrast to the closely related chick model, crocodilian premandibular and mandibular NC cells arise from the open neural tube suggesting that species-specific heterochronic behavior of NC may be involved in the formation of different vertebrate facial phenotypes.

  8. Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Joseph Landry

    2008-10-01

    Full Text Available We have characterized the biological functions of the chromatin remodeling protein Bptf (Bromodomain PHD-finger Transcription Factor, the largest subunit of NURF (Nucleosome Remodeling Factor in a mammal. Bptf mutants manifest growth defects at the post-implantation stage and are reabsorbed by E8.5. Histological analyses of lineage markers show that Bptf(-/- embryos implant but fail to establish a functional distal visceral endoderm. Microarray analysis at early stages of differentiation has identified Bptf-dependent gene targets including homeobox transcriptions factors and genes essential for the development of ectoderm, mesoderm, and both definitive and visceral endoderm. Differentiation of Bptf(-/- embryonic stem cell lines into embryoid bodies revealed its requirement for development of mesoderm, endoderm, and ectoderm tissue lineages, and uncovered many genes whose activation or repression are Bptf-dependent. We also provide functional and physical links between the Bptf-containing NURF complex and the Smad transcription factors. These results suggest that Bptf may co-regulate some gene targets of this pathway, which is essential for establishment of the visceral endoderm. We conclude that Bptf likely regulates genes and signaling pathways essential for the development of key tissues of the early mouse embryo.

  9. Early ontogeny of the central benzodiazepine receptor in human embryos and fetuses

    Energy Technology Data Exchange (ETDEWEB)

    Hebebrand, J.; Hofmann, D.; Reichelt, R.; Schnarr, S.; Knapp, M.; Propping, P.; Foedisch, H.J.

    1988-01-01

    The early ontogeny of the central benzodiazepine receptor (BZR) was investigated in human embryos and fetuses between 7 and 26 weeks of gestation. Brain tissue was gained from terminated pregnancies or spontaneous abortions. Binding studies, which were performed with /sup 3/H-flunitrazepam (FNZ), revealed that specific benzodiazepine binding is already detectable at an embryonal age of 7 weeks post conception. Binding at this early stage can be displaced potently by clonazepam and the inverse agonist ..beta..-CCE. Additionally, /sup 3/H-FNZ binding is enhanced by GABA. Thus, benzodiazepine binding is of the central type. Receptor density increases steeply in whole brain between weeks 8 and 11 of gestation. In frontal cortex receptor density increases gradually between weeks 12 and 26 of gestation. No specific fetal disease entity (including trisomy 21) was consistently associated with exceptionally high or low B/sub max/-values.

  10. Induction of the early-late Ddc gene during Drosophila metamorphosis by the ecdysone receptor.

    Science.gov (United States)

    Chen, Li; Reece, Christian; O'Keefe, Sandra L; Hawryluk, Gregory W L; Engstrom, Monica M; Hodgetts, Ross B

    2002-06-01

    During Drosophila metamorphosis, the 'early-late' genes constitute a unique class regulated by the steroid hormone 20-hydroxyecdysone. Their induction is comprised of both a primary and a secondary response to ecdysone. Previous work has suggested that the epidermal expression of the dopa decarboxylase gene (Ddc) is likely that of a typical early-late gene. Accumulation of the Ddc transcript is rapidly initiated in the absence of protein synthesis, which implies that the ecdysone receptor plays a direct role in induction. However, full Ddc expression requires the participation of one of the transcription factors encoded by the Broad-Complex. In this paper, we characterize an ecdysone response element (EcRE) that contributes to the primary response. Using gel mobility shift assays and transgenic assays, we identified a single functional EcRE, located at position -97 to -83 bp relative to the transcription initiation site. This is the first report of an EcRE associated with an early-late gene in Drosophila. Competition experiments indicated that the affinity of the Ddc EcRE for the ecdysone receptor complex was at least four-fold less than that of the canonical EcRE of the hsp27 gene. Using in vitro mutagenesis, we determined that the reduced affinity of the EcRE resided at two positions where the nucleotides differed from those found in the canonical sequence. The ecdysone receptor, acting through this EcRE, releases Ddc from a silencing mechanism, whose cis-acting domain we have mapped to the 5'-upstream region between -2067 and -1427 bp. Deletion of this repressive element resulted in precocious expression of Ddc in both epidermis and imaginal discs. Thus, epidermal Ddc induction at pupariation is under the control of an extended genomic region that contains both positive and negative regulatory elements. Copyright 2002 Elsevier Science Ireland Ltd.

  11. Toxicity and cardiac effects of carbaryl in early developing zebrafish (Danio rerio) embryos

    International Nuclear Information System (INIS)

    Lin, C.C.; Hui, Michelle N.Y.; Cheng, S.H.

    2007-01-01

    Carbaryl, an acetylcholinesterase inhibitor, is known to be moderately toxic to adult zebrafish and has been reported to cause heart malformations and irregular heartbeat in medaka. We performed experiments to study the toxicity of carbaryl, specifically its effects on the heart, in early developing zebrafish embryos. LC50 and EC50 values for carbaryl at 28 h post-fertilization were 44.66 μg/ml and 7.52 μg/ml, respectively, and 10 μg/ml carbaryl was used in subsequent experiments. After confirming acetylcholinesterase inhibition by carbaryl using an enzymatic method, we observed red blood cell accumulation, delayed hatching and pericardial edema, but not heart malformation as described in some previous reports. Our chronic exposure data also demonstrated carbaryl-induced bradycardia, which is a common effect of acetylcholinesterase inhibitors due to the accumulation of acetylcholine, in embryos from 1 day post-fertilization (dpf) to 5 dpf. The distance between the sinus venosus, the point where blood enters the atrium, and the bulbus arteriosus, the point where blood leaves the ventricle, indicated normal looping of the heart tube. Immunostaining of myosin heavy chains with the ventricle-specific antibody MF20 and the atrium-specific antibody S46 showed normal development of heart chambers. At the same time, acute exposure resulted in carbaryl-induced bradycardia. Heart rate dropped significantly after a 10-min exposure to 100 μg/ml carbaryl but recovered when carbaryl was removed. The novel observation of carbaryl-induced bradycardia in 1- and 2-dpf embryos suggested that carbaryl affected cardiac function possibly through an alternative mechanism other than acetylcholinesterase inhibition such as inhibition of calcium ion channels, since acetylcholine receptors in zebrafish are not functional until 3 dpf. However, the exact nature of this mechanism is currently unknown, and thus further studies are required

  12. Peptone and tomato extract induced early stage of embryo development of Dendrobium phalaenopsis Orchid

    Directory of Open Access Journals (Sweden)

    Nintya Setiari

    2017-04-01

    Full Text Available Germination and growth of orchid seeds can be accelerated by the addition of organic supplement and plant extract in culture medium. The objective of this study was to determine the effect of peptone and tomato extract on early stage of embryo development of Dendrobium phalaenopsis orchids. Orchid seeds were sown on NP and VW medium with addition of 10% of CW (NPCW and VWCW.  Five weeks after seed germination, about 58.03% seed germination was observed on VWCW medium, and only 37.45% seed germination on NPCW. Tomato extract and peptone were added in VWCW, resulting VWCWTP medium. After 4-8 weeks on VWCWTP, 94.42% seeds was germinated into plantlet, but only 67.30% germinated seeds on VWCW. To get optimal growth and development of  D.  phalaenopsis orchids embryos in the in vitro condition, supplement of 100 ml.L-1 coconut water, 100 mg.L-1 tomato extract and 2 mg.L-1 peptone into VW basic medium is required.

  13. Copper induces expression and methylation changes of early development genes in Crassostrea gigas embryos.

    Science.gov (United States)

    Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Rivière, Guillaume

    2018-03-01

    Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L -1 Cu 2+ ) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval bioassay at the D-larva stage 24 h post fertilization (hpf) and genotoxicity at gastrulation 7 hpf. In parallel, the relative expression of 15 genes encoding putative homeotic, biomineralization and DNA methylation proteins was measured at three developmental stages (3 hpf morula stage, 7 hpf gastrula stage, 24 hpf D-larvae stage) using RT-qPCR. Global DNA content in methylcytosine and hydroxymethylcytosine were measured by HPLC and gene-specific DNA methylation levels were monitored using MeDIP-qPCR. A significant increase in larval abnormalities was observed from copper concentrations of 10 μg L -1 , while significant genotoxic effects were detected at 1 μg L -1 and above. All the selected genes presented a stage-dependent expression pattern, which was impaired for some homeobox and DNA methylation genes (Notochord, HOXA1, HOX2, Lox5, DNMT3b and CXXC-1) after copper exposure. While global DNA methylation (5-methylcytosine) at gastrula stage didn't show significant changes between experimental conditions, 5-hydroxymethylcytosine, its degradation product, decreased upon copper treatment. The DNA methylation of exons and the transcript levels were correlated in control samples for HOXA1 but such

  14. ULTRASTRUCTURAL MODIFICATIONS INDUCED BY DIRECT ACTION OF CU2+ UPON EARLY CHICK EMBRYO

    Directory of Open Access Journals (Sweden)

    Delia Checiu

    2003-01-01

    Full Text Available Teratological testing of sulphonate phtalocyanine (an alimentary blue dye synthetized by the Center of Chemisty, Timisoara, shown a strong malformative effect of this compound upon early chick embryo (48 hours of incubation, (Sandor, Checiu, Prelipceanu, 1985. Dye administration on day 2 of incubation (44-48 hours revealed a high rate of embryo mortality and abnormal modification of caudal segment or even a total absence of caudal tail bud. Living embryos until day 7 of incubation showed a normal development of the anterior body part (head and trunk in contrast with posterior body part which presented an abnormal position of posterior limbs, tail and trunk aplasia. The dye with the some name produced in Germany did not show (in the some experimental conditions a malformative effect. The only difference between the two dyes was the presence of Cu2+ in our compound. It is well known that chemicals and physics factors (X rayes, insuline, hypoxy, D-Actinomycine, sucrose, etc. are noxious, inducing malformations of caudal segment (tail bud, urogenital and anorectal abnormalities associated with cardiac, facial and SNC malformations (Landauer 1953, Shepard 1973. Abnormalities of esophagus, urogenital and anorectal region associated with those of caudal axial skeleton and posterior limb buds are involved in caudal dysplasia syndrome (Duhamel 1961 cited by Roux and Martinet 1962. This syndrome is frequent (1:1000 in children of diabetic mothers (Warkany 1971. Experimental works on mice suggested implication of genetic factors in pathogenesis of this syndrome (Frye et all.1964 cited by Warkany 1971. Previous investigations (Checiu et all. 1966 revealed a caudal malformative syndrome in chick embryos induced by Cu2+. It is well known capacity of some heavy metal ions to affect the formation and desintegration reaction of free radicals. The aim of this paper is to present a morphological study of caudal malformative syndrome (Checiu et all. 1999 and an

  15. Disparities in reproductive outcomes according to the endometrial preparation protocol in frozen embryo transfer : The risk of early pregnancy loss in frozen embryo transfer cycles.

    Science.gov (United States)

    Hatoum, I; Bellon, L; Swierkowski, N; Ouazana, M; Bouba, S; Fathallah, K; Paillusson, B; Bailly, M; Boitrelle, F; Alter, L; Bergère, M; Selva, J; Wainer, R

    2018-03-01

    The purpose of this study was to determine the effect of stimulated and artificial endometrial preparation protocols on reproductive outcomes in frozen embryo transfer (FET) cycles. We performed a retrospective study of 1926 FET cycles over a 3.5-year period in the Fertility Unit at a University Hospital. Stimulated and artificial protocols were used for endometrial preparation. The embryos for FET were obtained from either in vitro fertilization or intracytoplasmic sperm injection cycles. Live birth rate and early pregnancy loss rates were retrospectively compared. In artificial protocols, oral or vaginal administration of oestradiol 2 mg two or three times a day was followed by vaginal supplementation with progesterone 200 mg two or three times a day. In stimulated protocols, recombinant follicle-stimulating hormone was administered from day 4 onward. Vaginal ultrasound was used for endometrial and ovarian monitoring. A pregnancy test was performed 14 days after FET. If it was positive, oestradiol and progesterone were administered up until the 12th week of gestation in artificial cycles. We defined early pregnancy losses as biochemical pregnancies (preclinical losses) and miscarriages. Data on 865 artificial cycles (45% of the total) and 1061 stimulated cycles (55%) were collected. Early pregnancy loss rate was significantly lower for stimulated cycles (34.2%) than for artificial cycles (56.9%), and the live birth rate was significantly higher for stimulated cycles (59.7%) than for artificial cycles (29.1%). In frozen embryo transfer, artificial cycles were associated with more early pregnancy loss and lower live birth rate than stimulated cycles.

  16. Prediction of in-vitro developmental competence of early cleavage-stage mouse embryos with compact time-lapse equipment.

    Science.gov (United States)

    Pribenszky, Csaba; Losonczi, Eszter; Molnár, Miklós; Lang, Zsolt; Mátyás, Szabolcs; Rajczy, Klára; Molnár, Katalin; Kovács, Péter; Nagy, Péter; Conceicao, Jason; Vajta, Gábor

    2010-03-01

    Single blastocyst transfer is regarded as an efficient way to achieve high pregnancy rates and to avoid multiple pregnancies. Risk of cancellation of transfer due to a lack of available embryos may be reduced by early prediction of blastocyst development. Time-lapse investigation of mouse embryos shows that the time of the first and second cleavage (to the 2- and 3-cell stages, respectively) has a strong predictive value for further development in vitro, while cleavage from the 3-cell to the 4-cell stage has no predictive value. In humans, embryo fragmentation during preimplantation development has been associated with lower pregnancy rates and a higher incidence of developmental abnormalities. Analysis of time-lapse records shows that most fragmentation is reversible in the mouse and is resorbed in an average of 9 h. Daily or bi-daily microscopic checks of embryo development, applied routinely in human IVF laboratories, would fail to detect 36 or 72% of these fragmentations, respectively. Fragmentation occurring in a defined time frame has a strong predictive value for in-vitro embryo development. The practical compact system used in the present trial, based on the 'one camera per patient' principle, has eliminated the usual disadvantages of time-lapse investigations and is applicable for the routine follow-up of in-vitro embryo development. Copyright 2009 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  17. Early embryo mortality in natural human reproduction: What the data say [version 2; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Gavin E. Jarvis

    2017-06-01

    Full Text Available How many human embryos die between fertilisation and birth under natural conditions? It is widely accepted that natural human embryo mortality is high, particularly during the first weeks after fertilisation, with total prenatal losses of 70% and higher frequently claimed. However, the first external sign of pregnancy occurs two weeks after fertilisation with a missed menstrual period, and establishing the fate of embryos before this is challenging. Calculations are additionally hampered by a lack of data on the efficiency of fertilisation under natural conditions. Four distinct sources are used to justify quantitative claims regarding embryo loss: (i a hypothesis published by Roberts & Lowe in The Lancet  is widely cited but has no practical quantitative value; (ii life table analyses give consistent assessments of clinical pregnancy loss, but cannot illuminate losses at earlier stages of development; (iii studies that measure human chorionic gonadotrophin (hCG reveal losses in the second week of development and beyond, but not before; and (iv the classic studies of Hertig and Rock offer the only direct insight into the fate of human embryos from fertilisation under natural conditions. Re-examination of Hertig’s data demonstrates that his estimates for fertilisation rate and early embryo loss are highly imprecise and casts doubt on the validity of his numerical analysis. A recent re-analysis of hCG study data concluded that approximately 40-60% of embryos may be lost between fertilisation and birth, although this will vary substantially between individual women. In conclusion, natural human embryo mortality is lower than often claimed and widely accepted. Estimates for total prenatal mortality of 70% or higher are exaggerated and not supported by the available data.

  18. [Establishment of sprouting embryoid body model mimicking early embryonic vasculogenesis in human embryo].

    Science.gov (United States)

    Jiang, Hua; Feng, You-Ji; Xie, Yi; Han, Jin-Lan; Wang, Zack; Chen, Tong

    2008-10-14

    To establish a sprouting embryoid body model mimicking early embryonic vasculogenesis in human embryo. Human embryonic stem were (hESCs) were cultured on the mouse embryo fibroblasts and then were induced to differentiate to form three-dimensional EB. The hEBs were cultured in media containing various angiogenesis-related factors: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), endostatin, angiostatin, and platelet factor (PF)-4 of different concentrations for 3 days to observe the sprouting of the hEBs. 3, 3, 3', 3'-tetramethylindo-carbocyanine perchlorate labeled acetylated low density lipoprotein (Dil-AcLDL) was added onto the hEBs foe 4 h Immunofluorescence assay was used to observe if Dil-AcLDL was absorbed and if CD31 was expressed so as to determine the existence of embryonic endothelial cells in the sprouting structures. The ideal culturing condition was analyzed. The differentiated EBs formed sprouting structures in the collagen I matrix containing VEGF and FGF. The sprouts among individual EBs were able to link to each other and form vascular network-like structures. In the presence of VEGF and FGF, the sprouts branching from the EBs assimilated Dil-AcLDL, expressed CD31 and formed a 3-dimensional cylindrical organization. The concentrations of growth factors ideally stimulating sprouting growth were 100 ng/ml of VEGF and 50 ng/ml of FGF. The networks among the EBs were abolished by the angiostatin, endostatin, and PF4. The sprouting from hEBs accumulates embryonic endothelial cells and the sprouting network-like structures are indeed endothelial in nature. Inducing of sprouting EBs is an ideal model that mimics early embryonic vasculogenesis in humans.

  19. Oviduct-on-a-chip : Creating an in vitro oviduct to study bovine gamete interaction and early embryo development

    NARCIS (Netherlands)

    de Almeida Monteiro Melo Ferraz, M.

    2018-01-01

    The oviduct is host to the period in which the early embryo undergoes complete reprogramming of its (epi)genome in preparation for the reacquisition of epigenetic marks as differentiation proceeds. This reprogramming period is vulnerable to changes in environmental conditions, such as compromised

  20. Estimation of the {beta}+ dose to the embryo resulting from {sup 18}F-FDG administration during early pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Zanotti-Fregonara, P.; Trebossen, R.; Maroy, R. [CEA, DSV, I2BM, SHFJ, LIME, Orsay (France); Champion, C. [Univ Paul Verlaine Metz, Inst Phys, Lab Phys Mol et Collis, Metz (France); Hindie, E. [Univ Paris 07, IUH, Ecole Doctorale B2T, Paris (France); Hindie, E. [Hop St Louis, AP-HP, Nucl Med Serv, F-75475 Paris 10 (France)

    2008-07-01

    Although {sup 18}F-FDG examinations are widely used, data are lacking on the dose to human embryo tissues in cases of exposure in early pregnancy. Although the photon component can easily be estimated from available data on the pharmacokinetics of {sup 18}F-FDG in female organs and from phantom measurements (considering the uterus as the target organ), the intensity of embryo tissue uptake, which is essential for deriving the {beta}+ dose, is not known. We report the case of a patient who underwent {sup 18}F-FDG PET/CT for tumor surveillance and who was later found to have been pregnant at the time of the examination(embryo age, 8 wk). Methods: The patient received 320 MBq of {sup 18}F-FDG. Imaging started with an unenhanced CT scan 1 h after the injection, followed by PET acquisition. PET images were used to compute the total number of {beta}+ emissions in embryo tissues per unit of injected activity, from standardized uptake value (SUV) measurements corrected for partial-volume effects. A Monte Carlo track structure code was then used to derive the {beta}+ self-dose and the {beta}+ cross-dose from amniotic fluid. The photon and CT doses were added to obtain the final dose received by the embryo. Results: The mean SUV in embryo tissues was 2.7, after correction for the partial-volume effect. The mean corrected SUV of amniotic fluid was 1.1. Monte Carlo simulation showed that the {beta}+ dose to the embryo (self-dose plus cross-dose from amniotic fluid) was 1.8 E-2 mGy per MBq of injected {sup 18}F-FDG. Based on MIRD data for the photon dose to the uterus, the estimated photon dose to the embryo was 1.5 E-2 mGy/MBq. Thus, the specific {sup 18}F-FDG dose to the embryo was 3.3 E-2 mGy/MBq (10.6 mGy in this patient). The CT scan added a further 8.3 mGy. Conclusion: The dose to the embryo is 3.3 E-2 mGy/MBq of {sup 18}F-FDG. The {beta}+ dose contributes 55% of the total dose. This value is higher than previous estimates in late nonhuman-primate pregnancies. (authors)

  1. Proteomic analysis of the early bovine yolk sac fluid and cells from the day 13 ovoid and elongated preimplatation embryos

    DEFF Research Database (Denmark)

    Jensen, Pernille L.; Beck, Hans Christian; Petersen, Tonny S.

    2014-01-01

    differentiate into the hypoblast and epiblast, which remain surrounded by the trophectoderm. The formation of the hypoblast epithelium is also accompanied by a change in the fluid within the embryo, i.e., the blastocoel fluid gradually alters to become the primitive yolk sac (YS) fluid. Our previous research......The bovine blastocyst hatches 8 to 9 days after fertilization, and this is followed by several days of preimplantation development during which the embryo transforms from a spherical over an ovoid to an elongated shape. As the spherical embryo enlarges, the cells of the inner cell mass...... describes the protein composition of human and bovine blastocoel fluid, which is surrounded by the trophectoderm and undifferentiated cells of the inner cell mass. In this study, we further examine the changes in the protein composition in both the primitive YS fluid and the embryonic cells during early...

  2. Gene Expression Associated with Early and Late Chronotypes in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Mirko ePegoraro

    2015-05-01

    Full Text Available The circadian clock provides the temporal framework for rhythmic behavioural and metabolic functions. In the modern era of industrialization, work and social pressures, the clock function is often jeopardized, resulting in adverse and chronic effects on health. Understanding circadian clock function, particularly individual variation in diurnal phase preference (chronotype, and the molecular mechanisms underlying such chronotypes may lead to interventions that could abrogate clock dysfunction and improve human (and animal health and welfare. Our preliminary studies suggested that fruitflies, like humans, can be classified as early rising ‘larks’ or late rising ‘owls’, providing a convenient model system for these types of studies. We have identified strains of flies showing increased preference for morning emergence (Early or E from the pupal case, or more pronounced preference for evening emergence (Late or L. We have sampled pupae the day before eclosion (4th day after pupariation at 4 h intervals in the E and L strains, and examined differences in gene expression by RNAseq. We have identified differentially expressed transcripts between the E and L strains which provide candidate genes for studies of Drosophila chronotypes and their human orthologues.

  3. Autoradiographic study of transcription during early germination of Zea mays embryos maintained in situ

    International Nuclear Information System (INIS)

    Deltour, Roger

    1979-01-01

    Recovery of RNA synthesis was studied by autoradiography in primary root of Zea mays embryos germinating at 16 0 C. [H 3 ] uridine was provided to embryos maintained in situ. During the first 4hrs of germination the cell radioactivity is located almost exclusively in the extranucleolar chromatin. These observations agree well with previous results obtained when [H 3 ] uridine was provided to isolated embryos [fr

  4. Early aberrations in chromatin dynamics in embryos produced under In vitro conditions

    DEFF Research Database (Denmark)

    Deshmukh, Rahul Shahaji; Østrup, Olga; Strejcek, Frantisek

    2012-01-01

    standard to that of embryos produced by IVF, parthenogenetic activation (PA), or SCNT. In contrast to IV embryos, chromatin spatial and temporal dynamics in PA, IVF, and SCNT embryos were altered; starting with aberrant chromatin-nuclear envelope interactions at the two-cell stage, delayed chromatin...... decondensation and nucleolar development at the four-cell stage, and ultimately culminating in failure of proper first lineage segregation at the blastocyst stage, demonstrated by poorly defined inner cell mass. Interestingly, in vitro produced (IVP) embryos also lacked a heterochromatin halo around nucleolar...

  5. Early embryo development in a sequential versus single medium: a randomized study

    Directory of Open Access Journals (Sweden)

    D'Hooghe Thomas M

    2010-07-01

    Full Text Available Abstract Background The success of in vitro fertilization techniques is defined by multiple factors including embryo culture conditions, related to the composition of the culture medium. In view of the lack of solid scientific data and in view of the current general belief that sequential media are superior to single media, the aim of this randomized study was to compare the embryo quality in two types of culture media. Methods In this study, the embryo quality on day 3 was measured as primary outcome. In total, 147 patients younger than 36 years treated with IVF/ICSI during the first or second cycle were included in this study. Embryos were randomly cultured in a sequential (group A or a single medium (group B to compare the embryo quality on day 1, day 2 and day 3. The embryo quality was compared in both groups using a Chi-square test with a significance level of 0.05. Results At day 1, the percentage of embryos with a cytoplasmic halo was higher in group B (46% than in group A (32%. At day 2, number of blastomeres, degree of fragmentation and the percentage of unequally sized blastomeres were higher in group B than in group A. At day 3, a higher percentage of embryos had a higher number of blastomeres and unequally sized blastomeres in group B. The number of good quality embryos (GQE was comparable in both groups. The embryo utilization rate was higher in group B (56% compared to group A (49%. Conclusions Although, no significant difference in the number of GQE was found in both media, the utilization rate was significantly higher when the embryos were cultured in the single medium compared to the sequential medium. The results of this study have a possible positive effect on the cumulative cryo-augmented pregnancy rate. Trial registration number NCT01094314

  6. Early expression of hypocretin/orexin in the chick embryo brain.

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    Kyle E Godden

    Full Text Available Hypocretin/Orexin (H/O neuropeptides are released by a discrete group of neurons in the vertebrate hypothalamus which play a pivotal role in the maintenance of waking behavior and brain state control. Previous studies have indicated that the H/O neuronal development differs between mammals and fish; H/O peptide-expressing cells are detectable during the earliest stages of brain morphogenesis in fish, but only towards the end of brain morphogenesis (by ∼ 85% of embryonic development in rats. The developmental emergence of H/O neurons has never been previously described in birds. With the goal of determining whether the chick developmental pattern was more similar to that of mammals or of fish, we investigated the emergence of H/O-expressing cells in the brain of chick embryos of different ages using immunohistochemistry. Post-natal chick brains were included in order to compare the spatial distribution of H/O cells with that of other vertebrates. We found that H/O-expressing cells appear to originate from two separate places in the region of the diencephalic proliferative zone. These developing cells express the H/O neuropeptide at a comparatively early age relative to rodents (already visible at 14% of the way through fetal development, thus bearing a closer resemblance to fish. The H/O-expressing cell population proliferates to a large number of cells by a relatively early embryonic age. As previously suggested, the distribution of H/O neurons is intermediate between that of mammalian and non-mammalian vertebrates. This work suggests that, in addition to its roles in developed brains, the H/O peptide may play an important role in the early embryonic development of non-mammalian vertebrates.

  7. The methyltransferase Setdb1 is essential for meiosis and mitosis in mouse oocytes and early embryos.

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    Eymery, Angeline; Liu, Zichuan; Ozonov, Evgeniy A; Stadler, Michael B; Peters, Antoine H F M

    2016-08-01

    Oocytes develop the competence for meiosis and early embryogenesis during their growth. Setdb1 is a histone H3 lysine 9 (H3K9) methyltransferase required for post-implantation development and has been implicated in the transcriptional silencing of genes and endogenous retroviral elements (ERVs). To address its role in oogenesis and pre-implantation development, we conditionally deleted Setdb1 in growing oocytes. Loss of Setdb1 expression greatly impaired meiosis. It delayed meiotic resumption, altered the dynamics of chromatin condensation, and impaired kinetochore-spindle interactions, bipolar spindle organization and chromosome segregation in more mature oocytes. The observed phenotypes related to changes in abundance of specific transcripts in mutant oocytes. Setdb1 maternally deficient embryos arrested during pre-implantation development and showed comparable defects during cell cycle progression and in chromosome segregation. Finally, transcriptional profiling data indicate that Setdb1 downregulates rather than silences expression of ERVK and ERVL-MaLR retrotransposons and associated chimearic transcripts during oogenesis. Our results identify Setdb1 as a newly discovered meiotic and embryonic competence factor safeguarding genome integrity at the onset of life. © 2016. Published by The Company of Biologists Ltd.

  8. Lack of miRNA misregulation at early pathological stages in Drosophila neurodegenerative disease models

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    Anita eReinhardt

    2012-10-01

    Full Text Available Late onset neurodegenerative diseases represent a major public health concern as the population in many countries ages. Both frequent diseases such as Alzheimer disease (AD, 14% incidence for 80-84 year old Europeans or Parkinson disease (PD, 1.4% prevalence for > 55 years old share, with other low-incidence neurodegenerative pathologies such as spinocerebellar ataxias (SCAs, 0.01% prevalence and frontotemporal lobar degeneration (FTLD, 0.02% prevalence, a lack of efficient treatment in spite of important research efforts. Besides significant progress, studies with animal models have revealed unexpected complexities in the degenerative process, emphasizing a need to better understand the underlying pathological mechanisms. Recently, microRNAs, a class of small regulatory non-coding RNAs, have been implicated in some neurodegenerative diseases. The current data supporting a role of miRNAs in PD, tauopathies, dominant ataxias and FTLD will first be discussed to emphasize the different levels of the pathological processes which may be affected by miRNAs. To investigate a potential involvement of miRNA dysregulation in the early stages of these neurodegenerative diseases we have used Drosophila models for 7 diseases (PD, 3 FTLD, 3 dominant ataxias that recapitulate many features of the human diseases. We performed deep sequencing of head small RNAs after 3 days of pathological protein expression in the fly head neurons. We found no evidence for a statistically significant difference in miRNA expression in this early stage of the pathological process. In addition, we could not identify small non coding CAG repeat RNAs (sCAG in polyQ disease models. Thus our data suggest that transcriptional deregulation of miRNAs or sCAG is unlikely to play a significant role in the initial stages of neurodegenerative diseases.

  9. Increased expression of heat shock protein 105 in rat uterus of early pregnancy and its significance in embryo implantation

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    Hu Zhao-Yuan

    2009-03-01

    Full Text Available Abstract Background Heat shock proteins (Hsps are a set of highly conserved proteins, Hsp105, has been suggested to play a role in reproduction. Methods Spatio-temporal expression of Hsp105 in rat uterus during peri-implantation period was examined by immunohistochemistry and Western blot, pseudopregnant uterus was used as control. Injection of antisense oligodeoxynucleotides to Hsp105 into pregnant rat uteri was carried out to look at effect of Hsp105 on embryo implantation. Results Expression of Hsp105 was mainly in the luminal epithelium on day 1 of pregnancy, and reached a peak level on day 5, whereas in stroma cells, adjacent to the implanting embryo, the strongest expression of Hsp105 was observed on day 6. The immunostaining profile in the uterus was consistent with that obtained by Western blot in the early pregnancy. In contrast, no obvious peak level of Hsp105 was observed in the uterus of pseudopregnant rat on day 5 or day 6. Furthermore, injection of antisense oligodeoxynucleotides to Hsp105 into the rat uterine horn on day 3 of pregnancy obviously suppressed the protein expression as expected and reduced number of the implanted embryos as compared with the control. Conclusion Temporal and spatial changes in Hsp105 expression in pregnant rat uterus may play a physiological role in regulating embryo implantation.

  10. Specific and spatial labeling of P0-Cre versus Wnt1-Cre in cranial neural crest in early mouse embryos.

    Science.gov (United States)

    Chen, Guiqian; Ishan, Mohamed; Yang, Jingwen; Kishigami, Satoshi; Fukuda, Tomokazu; Scott, Greg; Ray, Manas K; Sun, Chenming; Chen, Shi-You; Komatsu, Yoshihiro; Mishina, Yuji; Liu, Hong-Xiang

    2017-06-01

    P0-Cre and Wnt1-Cre mouse lines have been widely used in combination with loxP-flanked mice to label and genetically modify neural crest (NC) cells and their derivatives. Wnt1-Cre has been regarded as the gold standard and there have been concerns about the specificity of P0-Cre because it is not clear about the timing and spatial distribution of the P0-Cre transgene in labeling NC cells at early embryonic stages. We re-visited P0-Cre and Wnt1-Cre models in the labeling of NC cells in early mouse embryos with a focus on cranial NC. We found that R26-lacZ Cre reporter responded to Cre activity more reliably than CAAG-lacZ Cre reporter during early embryogenesis. Cre immunosignals in P0-Cre and reporter (lacZ and RFP) activity in P0-Cre/R26-lacZ and P0-Cre/R26-RFP embryos was detected in the cranial NC and notochord regions in E8.0-9.5 (4-19 somites) embryos. P0-Cre transgene expression was observed in migrating NC cells and was more extensive in the forebrain and hindbrain but not apparent in the midbrain. Differences in the Cre distribution patterns of P0-Cre and Wnt1-Cre were profound in the midbrain and hindbrain regions, that is, extensive in the midbrain of Wnt1-Cre and in the hindbrain of P0-Cre embryos. The difference between P0-Cre and Wnt1-Cre in labeling cranial NC may provide a better explanation of the differential distributions of their NC derivatives and of the phenotypes caused by Cre-driven genetic modifications. © 2017 Wiley Periodicals, Inc.

  11. Improvement of porcine cloning efficiency by trichostain A through early-stage induction of embryo apoptosis.

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    Ji, Qianqian; Zhu, Kongju; Liu, Zhiguo; Song, Zhenwei; Huang, Yuankai; Zhao, Haijing; Chen, Yaosheng; He, Zuyong; Mo, Delin; Cong, Peiqing

    2013-03-15

    Trichostain A (TSA), an inhibitor of histone deacetylases, improved developmental competence of SCNT embryos in many species, apparently by improved epigenetic reprogramming. The objective of the present study was to determine the effects of TSA-induced apoptosis in cloned porcine embryos. At various developmental stages, a comet assay and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining were used to detect apoptosis, and real-time polymerase chain reaction was used to assess expression of genes related to apoptosis and pluripotency. In this study, TSA significantly induced apoptosis (in a dose-dependent manner) at the one-, two-, and four-cell stages. However, in blastocyst stage embryos, TSA decreased the apoptotic index (P < 0.05). Expression levels of Caspase 3 were higher in TSA-treated versus control embryos at the two-cell stage (not statistically significant). The expression ratio of antiapoptotic Bcl-xl gene to proapoptotic Bax gene, an indicator of antiapoptotic potential, was higher in TSA-treated groups at the one-, two-, and four-cell and blastocyst stages. Furthermore, expression levels of pluripotency-related genes, namely, Oct4 and Nanog, were elevated at the morula stage (P < 0.05) in TSA treatment groups. We concluded that inducing apoptosis might be a mechanism by which TSA promotes development of reconstructed embryos. At the initial stage of apoptosis induction, abnormal cells were removed, thereby enhancing proliferation of healthy cells and improving embryo quality. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Three-Dimensional High-Frequency Ultrasonography for Early Detection and Characterization of Embryo Implantation Site Development in the Mouse.

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    Mary C Peavey

    Full Text Available Ultrasonography is a powerful tool to non-invasively monitor in real time the development of the human fetus in utero. Although genetically engineered mice have served as valuable in vivo models to study both embryo implantation and pregnancy progression, such studies usually require sacrifice of parous mice for subsequent phenotypic analysis. To address this issue, we used three-dimensional (3-D reconstruction in silico of high-frequency ultrasound (HFUS imaging data for early detection and characterization of murine embryo implantation sites and their development in utero. With HFUS imaging followed by 3-D reconstruction, we were able to precisely quantify embryo implantation site number and embryonic developmental progression in pregnant C57BL6J/129S mice from as early as 5.5 days post coitus (d.p.c. through to 9.5 d.p.c. using a VisualSonics Vevo 2100 (MS550S transducer. In addition to measurements of implantation site number, location, volume and spacing, embryo viability via cardiac activity monitoring was also achieved. A total of 12 dams were imaged with HFUS with approximately 100 embryos examined per embryonic day. For the post-implantation period (5.5 to 8.5 d.p.c., 3-D reconstruction of the gravid uterus in mesh or solid overlay format enabled visual representation in silico of implantation site location, number, spacing distances, and site volume within each uterine horn. Therefore, this short technical report describes the feasibility of using 3-D HFUS imaging for early detection and analysis of post-implantation events in the pregnant mouse with the ability to longitudinally monitor the development of these early pregnancy events in a non-invasive manner. As genetically engineered mice continue to be used to characterize female reproductive phenotypes, we believe this reliable and non-invasive method to detect, quantify, and characterize early implantation events will prove to be an invaluable investigative tool for the study of

  13. The effect of UV irradiation on the early development of silkworm embryos, (2)

    International Nuclear Information System (INIS)

    Kobayashi, Yoshihiro

    1981-01-01

    The development of silkworm eggs irradiated with UV was compared with that of normal eggs. When the eggs were irradiated with UV from the lateral side immediately after oviposition, development was decelerated, but the germ band was produced. The side of the germ band that was irradiated with UV was abnormal with holes, but the opposite side was hole-free and normal. The normal half of the germ band splits longitudinally, but developed along with the abnormal half to form various malformations. When the eggs were irradiated from the ventral side, the ventral part of the germ band was abnormal at the early stage, the germ band did not concentrate to one place, and produced the half-embryos longitudinally divided by the median line. The UV irradiation at the beginning of the blastoderm stage produced similar results. In the areas irradiated by UV, cleavage nuclei invaded into the surrounding protoplasm, and mitotic figures were observed, but the cell number did not increase even with the advance of development unlike normal cells, whereas the sizes of the cells, their nuclei and nucleoli were enlarged, and intercellular space widened so that the cells were no longer in close contact. The germ band cells produced in the non-irradiated area were normal. The above results suggest that when either the protoplasm or the nucleus of a silkworm egg is damaged by UV, the effect first appears as the inhibition of cell division in the germ band, and as the enlargement of the cell, nucleus and nucleoli. It is presumed that this induces the subsequent inhibition of cell differentiation or abnormalities. (Kaihara, S.)

  14. Effect of UV irradiation on the early development of silkworm embryos, (2). Development of irradiated eggs

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Y. (Hokkaido Univ., Sapporo (Japan). Faculty of Agriculture)

    1981-02-01

    The development of silkworm eggs irradiated with UV was compared with that of normal eggs. When the eggs were irradiated with UV from the lateral side immediately after oviposition, development was decelerated, but the germ band was produced. The side of the germ band that was irradiated with UV was abnormal with holes, but the opposite side was hole-free and normal. The normal half of the germ band splits longitudinally, but developed along with the abnormal half to form various malformations. When the eggs were irradiated from the ventral side, the ventral part of the germ band was abnormal at the early stage, the germ band did not concentrate to one place, and produced the half-embryos longitudinally divided by the median line. The UV irradiation at the beginning of the blastoderm stage produced similar results. In the areas irradiated by UV, cleavage nuclei invaded into the surrounding protoplasm, and mitotic figures were observed, but the cell number did not increase even with the advance of development unlike normal cells, whereas the sizes of the cells, their nuclei and nucleoli were enlarged, and intercellular space widened so that the cells were no longer in close contact. The germ band cells produced in the non-irradiated area were normal. The above results suggest that when either the protoplasm or the nucleus of a silkworm egg is damaged by UV, the effect first appears as the inhibition of cell division in the germ band, and as the enlargement of the cell, nucleus and nucleoli. It is presumed that this induces the subsequent inhibition of cell differentiation or abnormalities.

  15. The impact of high-salt exposure on cardiovascular development in the early chick embryo.

    Science.gov (United States)

    Wang, Guang; Zhang, Nuan; Wei, Yi-Fan; Jin, Yi-Mei; Zhang, Shi-Yao; Cheng, Xin; Ma, Zheng-Lai; Zhao, Shu-Zhu; Chen, You-Peng; Chuai, Manli; Hocher, Berthold; Yang, Xuesong

    2015-11-01

    In this study, we show that high-salt exposure dramatically increases chick mortality during embryo development. As embryonic mortality at early stages mainly results from defects in cardiovascular development, we focused on heart formation and angiogenesis. We found that high-salt exposure enhanced the risk of abnormal heart tube looping and blood congestion in the heart chamber. In the presence of high salt, both ventricular cell proliferation and apoptosis increased. The high osmolarity induced by high salt in the ventricular cardiomyocytes resulted in incomplete differentiation, which might be due to reduced expression of Nkx2.5 and GATA4. Blood vessel density and diameter were suppressed by exposure to high salt in both the yolk sac membrane (YSM) and chorioallantoic membrane models. In addition, high-salt-induced suppression of angiogenesis occurred even at the vasculogenesis stage, as blood island formation was also inhibited by high-salt exposure. At the same time, cell proliferation was repressed and cell apoptosis was enhanced by high-salt exposure in YSM tissue. Moreover, the reduction in expression of HIF2 and FGF2 genes might cause high-salt-suppressed angiogenesis. Interestingly, we show that high-salt exposure causes excess generation of reactive oxygen species (ROS) in the heart and YSM tissues, which could be partially rescued through the addition of antioxidants. In total, our study suggests that excess generation of ROS might play an important role in high-salt-induced defects in heart and angiogenesis. © 2015. Published by The Company of Biologists Ltd.

  16. Optimization of CRISPR/Cas9 genome editing for loss-of-function in the early chick embryo.

    Science.gov (United States)

    Gandhi, Shashank; Piacentino, Michael L; Vieceli, Felipe M; Bronner, Marianne E

    2017-12-01

    The advent of CRISPR/Cas9 has made genome editing possible in virtually any organism, including those not previously amenable to genetic manipulations. Here, we present an optimization of CRISPR/Cas9 for application to early avian embryos with improved efficiency via a three-fold strategy. First, we employed Cas9 protein flanked with two nuclear localization signal sequences for improved nuclear localization. Second, we used a modified guide RNA (gRNA) scaffold that obviates premature termination of transcription and unstable Cas9-gRNA interactions. Third, we used a chick-specific U6 promoter that yields 4-fold higher gRNA expression than the previously utilized human U6. For rapid screening of gRNAs for in vivo applications, we also generated a chicken fibroblast cell line that constitutively expresses Cas9. As proof of principle, we performed electroporation-based loss-of-function studies in the early chick embryo to knock out Pax7 and Sox10, key transcription factors with known functions in neural crest development. The results show that CRISPR/Cas9-mediated deletion causes loss of their respective proteins and transcripts, as well as predicted downstream targets. Taken together, the results reveal the utility of this optimized CRISPR/Cas9 method for targeted gene knockout in chicken embryos in a manner that is reproducible, robust and specific. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Drosophila Kismet regulates histone H3 lysine 27 methylation and early elongation by RNA polymerase II.

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    Shrividhya Srinivasan

    2008-10-01

    Full Text Available Polycomb and trithorax group proteins regulate cellular pluripotency and differentiation by maintaining hereditable states of transcription. Many Polycomb and trithorax group proteins have been implicated in the covalent modification or remodeling of chromatin, but how they interact with each other and the general transcription machinery to regulate transcription is not well understood. The trithorax group protein Kismet-L (KIS-L is a member of the CHD subfamily of chromatin-remodeling factors that plays a global role in transcription by RNA polymerase II (Pol II. Mutations in CHD7, the human counterpart of kis, are associated with CHARGE syndrome, a developmental disorder affecting multiple tissues and organs. To clarify how KIS-L activates gene expression and counteracts Polycomb group silencing, we characterized defects resulting from the loss of KIS-L function in Drosophila. These studies revealed that KIS-L acts downstream of P-TEFb recruitment to stimulate elongation by Pol II. The presence of two chromodomains in KIS-L suggested that its recruitment or function might be regulated by the methylation of histone H3 lysine 4 by the trithorax group proteins ASH1 and TRX. Although we observed significant overlap between the distributions of KIS-L, ASH1, and TRX on polytene chromosomes, KIS-L did not bind methylated histone tails in vitro, and loss of TRX or ASH1 function did not alter the association of KIS-L with chromatin. By contrast, loss of kis function led to a dramatic reduction in the levels of TRX and ASH1 associated with chromatin and was accompanied by increased histone H3 lysine 27 methylation-a modification required for Polycomb group repression. A similar increase in H3 lysine 27 methylation was observed in ash1 and trx mutant larvae. Our findings suggest that KIS-L promotes early elongation and counteracts Polycomb group repression by recruiting the ASH1 and TRX histone methyltransferases to chromatin.

  18. Radiosensitive target in the early mouse embryo exposed to very low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Wiley, Lynn M.; Raabe, Otto G.; Khan, Rakhshi; Straume, Tore

    1994-01-01

    We exposed mouse preimplantation embryos in vitro to either tritiated water (HTO) or tritiated thymidine (TdR) to determine whether the radiosensitive target was nuclear or extranuclear for embryonic cell proliferation disadvantage in the mouse embryo chimera assay. 8-cell embryos were incubated in either HTO or TdR for 2 h and paired with non-irradiated control embryos to form chimeras. Chimeras were cultured for an average of 20.2 h to allow for 2-3 cell cycles and then partially dissociated to obtain the number of progeny cells contributed by the two partner embryos for each chimera. These values were expressed as a 'proliferation ratio' (number of cells from the irradiated embryo: total number of cells in the chimera). A ratio significantly less than 0.50 indicates that the experimental embryo expressed an embryonic cell proliferation disadvantage, which is the endpoint of this assay. The activity concentrations of HTO and TdR were adjusted so that both would deliver comparable mean absorbed nuclear doses during the combined initial 2-h irradiation incubation and subsequent 20.2 h chimera incubation periods. Although nuclear doses were comparable under these conditions, the extranuclear dose delivered by the uniformly distributed HTO was about 100 times greater than the extranuclear dose delivered by TdR for each given nuclear dose. Consequently, obtaining mean TdR proliferation ratios≤mean HTO proliferation ratios would be evidence for a nuclear target while obtaining mean HTO proliferation ratios< mean TdR proliferation ratios would be evidence for an extranuclear target. TdR consistently produced lower mean proliferation ratios over a range of doses from 0.14 Gy to 0.43 Gy. Therefore, we conclude that the radiosensitive target for this endpoint is nuclear

  19. The Effect of Cirata Reservoir Sediment on Early Developmental Stage of Common Carp (Cyprinus carpio Embryo

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    Yuni Pujihastuti

    2009-07-01

    Full Text Available Sedimentation at Cirata reservoir may directly and indirectly influence fish particularly fish which have an adhesive characteristic at its early developmental stage such as common carp (Cyprinus carpio. Sample of sediment was collected from Cirata reservoir using Eikmand dredge at a depth of 80 m. The sample was subsequently centrifuged at 5500 rpm for 10 min. The supernatant obtained was then used for toxicity test on common carp at early developmental stage. In this test, four treatments were applied based on the concentration of sediment supernatant, namely: 0, 8.33, 16.60 and 24.90 %. The results showed that a higher sediment supernatant concentration resulted in lower egg yolk absorption rate, lower relative growth rate in length, lower egg yolk efficiency and higher egg and larval abnormality.  Higher sediment supernatant concentration also resulted in lower hatching percentage of common carp larva. The damage of eggs and larval morphologies in treatments with sediment supernatant was likely caused by the presence Pb and organic matters which act in synergy. Keywords :  sediment, Cirata, embryo, common carp   ABSTRAK Sedimentasi di Waduk Cirata secara langsung dan tidak langsung akan berpengaruh terhadap kehidupan ikan khususnya tahap awal perkembangan ikan yang bersifat adhesiveseperti ikan mas (Cyprinus carpio.  Sampel sedimen waduk Cirata diambil dengan Eikmand dredge pada kedalaman 80 m.  Hasil ekstrak di sentrifugasi dengan kecepatan 5500 rpm selama 10 menit untuk diambil air pori sedimennya.  Air pori digunakan sebagai bahan uji toksisitas terhadap perkembangan awal ikan mas dengan perlakuan 0; 8,33; 16,60 dan 24,90 %. Hasil uji toksisitas diperoleh bahwa semakin tinggi konsentrasi air pori dari sediment maka semakin rendah laju penyerapan kuning telur Laju pertumbuhan relatif panjang embrio pada berbagai konsentrasi juga diperoleh bahwa semakin tinggi konsentrasi air sedimen maka semakin rendah laju pertumbuhan relatif

  20. Quantitative imaging of lipids in live mouse oocytes and early embryos using CARS microscopy

    Science.gov (United States)

    Bradley, Josephine; Pope, Iestyn; Masia, Francesco; Sanusi, Randa; Langbein, Wolfgang; Borri, Paola

    2016-01-01

    Mammalian oocytes contain lipid droplets that are a store of fatty acids, whose metabolism plays a substantial role in pre-implantation development. Fluorescent staining has previously been used to image lipid droplets in mammalian oocytes and embryos, but this method is not quantitative and often incompatible with live cell imaging and subsequent development. Here we have applied chemically specific, label-free coherent anti-Stokes Raman scattering (CARS) microscopy to mouse oocytes and pre-implantation embryos. We show that CARS imaging can quantify the size, number and spatial distribution of lipid droplets in living mouse oocytes and embryos up to the blastocyst stage. Notably, it can be used in a way that does not compromise oocyte maturation or embryo development. We have also correlated CARS with two-photon fluorescence microscopy simultaneously acquired using fluorescent lipid probes on fixed samples, and found only a partial degree of correlation, depending on the lipid probe, clearly exemplifying the limitation of lipid labelling. In addition, we show that differences in the chemical composition of lipid droplets in living oocytes matured in media supplemented with different saturated and unsaturated fatty acids can be detected using CARS hyperspectral imaging. These results demonstrate that CARS microscopy provides a novel non-invasive method of quantifying lipid content, type and spatial distribution with sub-micron resolution in living mammalian oocytes and embryos. PMID:27151947

  1. Determination of Relative Biological Efficacy (RBE) and Oxygen Enhancement Ratio (OER) for the entire negative and positive pion beam profile using Vicia faba roots and Drosophila embryos as biological model systems

    International Nuclear Information System (INIS)

    Baarli, J.; Bianchi, M.; Keusch, F.; Mindek, G.; Sullivan, A.H.

    As an introduction to preclinical studies, pilot studies of pion beams are planned with relatively simple biological model systems that can be quickly evaluated and that yield indicative data for further action. Inhibition of growth was studied in Vicia faba roots, a biological system excellently suited for RBE and OER studies. For comparison there are already results from a low-intensity pion irradiation. A second system used Drosophila embryos 1 and 4 hours old, which are especially well suited for LET studies. The unambiguous criterion will be failure to slip out of the oolemma. The smallness of the objects (their beam sensitivity) will make it possible to determine empirically the peak region and to determine Gain factors; furthermore, the known dependency of RBE on the development stage promises highly informative results

  2. Use of Early Ripening Cultivars to Avoid Infestation and Mass Trapping to Manage Drosophila suzukii (Diptera: Drosophilidae) in Vaccinium corymbosum (Ericales: Ericaceae).

    Science.gov (United States)

    Hampton, Emily; Koski, Carissa; Barsoian, Olivia; Faubert, Heather; Cowles, Richard S; Alm, Steven R

    2014-10-01

    Use of early ripening highbush blueberry cultivars to avoid infestation and mass trapping were evaluated for managing spotted wing drosophila, Drosophila suzukii (Matsumura). Fourteen highbush blueberry cultivars were sampled for spotted wing drosophila infestation. Most 'Earliblue', 'Bluetta', and 'Collins' fruit were harvested before spotted wing drosophila oviposition commenced, and so escaped injury. Most fruit from 'Bluejay', 'Blueray', and 'Bluehaven' were also harvested before the first week of August, after which spotted wing drosophila activity led to high levels of blueberry infestation. In a separate experiment, damage to cultivars was related to the week in which fruit were harvested, with greater damage to fruit observed as the season progressed. Attractant traps placed within blueberry bushes increased nearby berry infestation by 5%, irrespective of cultivar and harvest date. The significant linear reduction in infestation with increasing distance from the attractant trap suggests that traps are influencing fly behavior to at least 5.5 m. Insecticides applied to the exterior of traps, compared with untreated traps, revealed that only 10-30% of flies visiting traps enter the traps and drown. Low trap efficiency may jeopardize surrounding fruits by increasing local spotted wing drosophila activity. To protect crops, traps for mass trapping should be placed in a perimeter outside fruit fields and insecticides need to be applied to the surface of traps or on nearby fruit to function as an attract-and-kill strategy. © 2014 Entomological Society of America.

  3. Inactivation of the Huntington's disease gene (Hdh impairs anterior streak formation and early patterning of the mouse embryo

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    Conlon Ronald A

    2005-08-01

    Full Text Available Abstract Background Huntingtin, the HD gene encoded protein mutated by polyglutamine expansion in Huntington's disease, is required in extraembryonic tissues for proper gastrulation, implicating its activities in nutrition or patterning of the developing embryo. To test these possibilities, we have used whole mount in situ hybridization to examine embryonic patterning and morphogenesis in homozygous Hdhex4/5 huntingtin deficient embryos. Results In the absence of huntingtin, expression of nutritive genes appears normal but E7.0–7.5 embryos exhibit a unique combination of patterning defects. Notable are a shortened primitive streak, absence of a proper node and diminished production of anterior streak derivatives. Reduced Wnt3a, Tbx6 and Dll1 expression signify decreased paraxial mesoderm and reduced Otx2 expression and lack of headfolds denote a failure of head development. In addition, genes initially broadly expressed are not properly restricted to the posterior, as evidenced by the ectopic expression of Nodal, Fgf8 and Gsc in the epiblast and T (Brachyury and Evx1 in proximal mesoderm derivatives. Despite impaired posterior restriction and anterior streak deficits, overall anterior/posterior polarity is established. A single primitive streak forms and marker expression shows that the anterior epiblast and anterior visceral endoderm (AVE are specified. Conclusion Huntingtin is essential in the early patterning of the embryo for formation of the anterior region of the primitive streak, and for down-regulation of a subset of dynamic growth and transcription factor genes. These findings provide fundamental starting points for identifying the novel cellular and molecular activities of huntingtin in the extraembryonic tissues that govern normal anterior streak development. This knowledge may prove to be important for understanding the mechanism by which the dominant polyglutamine expansion in huntingtin determines the loss of neurons in

  4. Inactivation of the Huntington's disease gene (Hdh) impairs anterior streak formation and early patterning of the mouse embryo.

    Science.gov (United States)

    Woda, Juliana M; Calzonetti, Teresa; Hilditch-Maguire, Paige; Duyao, Mabel P; Conlon, Ronald A; MacDonald, Marcy E

    2005-08-18

    Huntingtin, the HD gene encoded protein mutated by polyglutamine expansion in Huntington's disease, is required in extraembryonic tissues for proper gastrulation, implicating its activities in nutrition or patterning of the developing embryo. To test these possibilities, we have used whole mount in situ hybridization to examine embryonic patterning and morphogenesis in homozygous Hdh(ex4/5) huntingtin deficient embryos. In the absence of huntingtin, expression of nutritive genes appears normal but E7.0-7.5 embryos exhibit a unique combination of patterning defects. Notable are a shortened primitive streak, absence of a proper node and diminished production of anterior streak derivatives. Reduced Wnt3a, Tbx6 and Dll1 expression signify decreased paraxial mesoderm and reduced Otx2 expression and lack of headfolds denote a failure of head development. In addition, genes initially broadly expressed are not properly restricted to the posterior, as evidenced by the ectopic expression of Nodal, Fgf8 and Gsc in the epiblast and T (Brachyury) and Evx1 in proximal mesoderm derivatives. Despite impaired posterior restriction and anterior streak deficits, overall anterior/posterior polarity is established. A single primitive streak forms and marker expression shows that the anterior epiblast and anterior visceral endoderm (AVE) are specified. Huntingtin is essential in the early patterning of the embryo for formation of the anterior region of the primitive streak, and for down-regulation of a subset of dynamic growth and transcription factor genes. These findings provide fundamental starting points for identifying the novel cellular and molecular activities of huntingtin in the extraembryonic tissues that govern normal anterior streak development. This knowledge may prove to be important for understanding the mechanism by which the dominant polyglutamine expansion in huntingtin determines the loss of neurons in Huntington's disease.

  5. Effect of early addition of bone morphogenetic protein 5 (BMP5) to embryo culture medium on in vitro development and expression of developmentally important genes in bovine preimplantation embryos.

    Science.gov (United States)

    García, Elina V; Miceli, Dora C; Rizo, Gabriela; Valdecantos, Pablo A; Barrera, Antonio D

    2015-09-01

    Previous studies have reported that bone morphogenetic protein 5 (BMP5) is differentially expressed in the isthmus of bovine oviducts and it is present in the oviductal fluid. However, the specific action of this factor is unknown. To evaluate whether BMP5 exerts some effect during early bovine embryo development, gene expression of BMP5, BMP receptors, and the effect of exogenous BMP5 on in vitro development and expression of developmentally important genes were assessed. In experiment 1, pools of embryos at two-cell, four-cell, eight-cell, and blastocyst stages, derived from in vitro fertilization, were collected for analysis of BMP5 and BMP receptors (BMPR1A, BMPR1B, and BMPR2) messenger RNA (mRNA) expression. On the basis of previous results, in experiment 2, presumptive zygotes were cultured for the first 48 hours after insemination in CR1aa medium assaying three different treatments: (1) control (CR1aa); (2) vehicle control (CR1aa + 0.04 mM HCl), and (3) BMP5 treatment (CR1aa + 100 ng/mL of BMP5). The cleavage rate was evaluated 48 hours after insemination (Day 2), and then, embryos were transferred to CR1aa + 10% fetal bovine serum. The blastocyst rate was determined on Day 7. In experiment 3, pools of embryos at two-cell, four-cell, eight-cell, and blastocyst stages, derived from control and BMP5-treated groups, were collected for analysis of ID2 (BMP target gene), OCT4, NANOG, and SOX2 (pluripotency genes) mRNA expression. BMP5 transcripts were not detectable in any of the embryonic stages examined, whereas the relative mRNA abundance of the three BMP receptors analyzed was greater in early embryo development stages before maternal-embryonic transition, raising the possibility of a direct effect of exogenous BMPs on the embryo during the first developmental period. Although early addition of 100 ng/mL of BMP5 to the embryo culture medium had no effect on the cleavage rate, a significantly higher proportion of cleaved embryos developed to the

  6. Development of the embryonic heat shock response and the impact of repeated thermal stress in early stage lake whitefish (Coregonus clupeaformis) embryos.

    Science.gov (United States)

    Whitehouse, Lindy M; McDougall, Chance S; Stefanovic, Daniel I; Boreham, Douglas R; Somers, Christopher M; Wilson, Joanna Y; Manzon, Richard G

    2017-10-01

    Lake whitefish (Coregonus clupeaformis) embryos were exposed to thermal stress (TS) at different developmental stages to determine when the heat shock response (HSR) can be initiated and if it is altered by exposure to repeated TS. First, embryos were subject to one of three different TS temperatures (6, 9, or 12°C above control) at 4 points in development (21, 38, 60 and 70 days post-fertilisation (dpf)) for 2h followed by a 2h recovery to understand the ontogeny of the HSR. A second experiment explored the effects of repeated TS on the HSR in embryos from 15 to 75 dpf. Embryos were subjected to one of two TS regimes; +6°C TS for 1h every 6 days or +9°C TS for 1h every 6 days. Following a 2h recovery, a subset of embryos was sampled. Our results show that embryos could initiate a HSR via upregulation of heat shock protein 70 (hsp70) mRNA at all developmental ages studied, but that this response varied with age and was only observed with a TS of +9 or +12°C. In comparison, when embryos received multiple TS treatments, hsp70 was not induced in response to the 1h TS and 2h recovery, and a downregulation was observed at 39 dpf. Downregulation of hsp47 and hsp90α mRNA was also observed in early age embryos. Collectively, these data suggest that embryos are capable of initiating a HSR at early age and throughout embryogenesis, but that repeated TS can alter the HSR, and may result in either reduced responsiveness or a downregulation of inducible hsps. Our findings warrant further investigation into both the short- and long-term effects of repeated TS on lake whitefish development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Selective loss of mouse embryos due to the expression of transgenic major histocompatibility class I molecules early in embryogenesis.

    Science.gov (United States)

    Aït-Azzouzene, D; Langkopf, A; Cohen, J; Bleux, C; Gendron, M C; Kanellopoulos-Langevin, C

    1998-05-01

    Among the numerous hypotheses proposed to explain the absence of fetal rejection by the mother in mammals, it has been suggested that regulation of expression of the polymorphic major histocompatibility complex (MHC) at the fetal-maternal interface plays a major role. In addition to a lack of MHC gene expression in the placenta throughout gestation, the absence of polymorphic MHC molecules on the early embryo, as well as their low level of expression after midgestation, could contribute to this important biologic phenomenon. In order to test this hypothesis, we have produced transgenic mice able to express polymorphic MHC class I molecules early in embryogenesis. We have placed the MHC class la gene H-2Kb under the control of a housekeeping gene promoter, the hydroxy-methyl-glutaryl coenzyme A reductase (HMG) gene minimal promoter. This construct has been tested for functionality after transfection into mouse fibroblast L cells. The analysis of three founder transgenic mice and their progeny suggested that fetoplacental units that could express the H-2Kb heavy chains are unable to survive in utero beyond midgestation. We have shown further that a much higher resorption rate, on days 11 to 13 of embryonic development, is observed among transgenic embryos developing from eggs microinjected at the one-cell stage with the pHMG-Kb construct than in control embryos. This lethality is not due to immune phenomena, since it is observed in histocompatible combinations between mother and fetus. These results are discussed in the context of what is currently known about the regulation of MHC expression at the fetal-maternal interface and in various transgenic mouse models.

  8. Early molecular events involved in Pinus pinaster Ait. somatic embryo development under reduced water availability: transcriptomic and proteomic analyses.

    Science.gov (United States)

    Morel, Alexandre; Teyssier, Caroline; Trontin, Jean-François; Eliášová, Kateřina; Pešek, Bedřich; Beaufour, Martine; Morabito, Domenico; Boizot, Nathalie; Le Metté, Claire; Belal-Bessai, Leila; Reymond, Isabelle; Harvengt, Luc; Cadene, Martine; Corbineau, Françoise; Vágner, Martin; Label, Philippe; Lelu-Walter, Marie-Anne

    2014-09-01

    Maritime pine somatic embryos (SEs) require a reduction in water availability (high gellan gum concentration in the maturation medium) to reach the cotyledonary stage. This key switch, reported specifically for pine species, is not yet well understood. To facilitate the use of somatic embryogenesis for mass propagation of conifers, we need a better understanding of embryo development. Comparison of both transcriptome (Illumina RNA sequencing) and proteome [two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with mass spectrometry (MS) identification] of immature SEs, cultured on either high (9G) or low (4G) gellan gum concentration, was performed, together with analysis of water content, fresh and dry mass, endogenous abscisic acid (ABA; gas chromatography-MS), soluble sugars (high-pressure liquid chromatography), starch and confocal laser microscope observations. This multiscale, integrated analysis was used to unravel early molecular and physiological events involved in SE development. Under unfavorable conditions (4G), the glycolytic pathway was enhanced, possibly in relation to cell proliferation that may be antagonistic to SE development. Under favorable conditions (9G), SEs adapted to culture constraint by activating specific protective pathways, and ABA-mediated molecular and physiological responses promoting embryo development. Our results suggest that on 9G, germin-like protein and ubiquitin-protein ligase could be used as predictive markers of SE development, whereas protein phosphatase 2C could be a biomarker for culture adaptive responses. This is the first characterization of early molecular mechanisms involved in the development of pine SEs following an increase in gellan gum concentration in the maturation medium, and it is also the first report on somatic embryogenesis in conifers combining transcriptomic and proteomic datasets. © 2014 Scandinavian Plant Physiology Society.

  9. Casein kinase 1 alpha regulates chromosome congression and separation during mouse oocyte meiotic maturation and early embryo development.

    Directory of Open Access Journals (Sweden)

    Lu Wang

    Full Text Available Casein kinase I alpha (CK1α is a member of serine/threonine protein kinase, generally present in all eukaryotes. In mammals, CK1α regulates the transition from interphase to metaphase in mitosis. However, little is known about its role in meiosis. Here we examined Ck1α mRNA and protein expression, as well as its subcellular localization in mouse oocytes from germinal vesicle to the late 1-cell stage. Our results showed that the expression level of CK1α was increased in metaphase. Immunostaining results showed that CK1α colocalized with condensed chromosomes during oocyte meiotic maturation and early embryo development. We used the loss-of-function approach by employing CK1α specific morpholino injection to block the function of CK1α. This functional blocking leads to failure of polar body 1 (PB1 extrusion, chromosome misalignment and MII plate incrassation. We further found that D4476, a specific and efficient CK1 inhibitor, decreased the rate of PB1 extrusion. Moreover, D4476 resulted in giant polar body extrusion, oocyte pro-MI arrest, chromosome congression failure and impairment of embryo developmental potential. In addition, we employed pyrvinium pamoate (PP, an allosteric activator of CK1α, to enhance CK1α activity in oocytes. Supplementation of PP induced oocyte meiotic maturation failure, severe congression abnormalities and misalignment of chromosomes. Taken together, our study for the first time demonstrates that CK1α is required for chromosome alignment and segregation during oocyte meiotic maturation and early embryo development.

  10. Generating different genetic expression patterns in the early embryo: insights from the mouse model

    Czech Academy of Sciences Publication Activity Database

    Bruce, Alexander

    2013-01-01

    Roč. 27, č. 6 (2013), s. 586-592 ISSN 1472-6483 Grant - others:Marie Curie Career Integration Grant(CZ) IDNOVCELFAT2011; Czech Science Foundation(CZ) 13-032955 Institutional support: RVO:60077344 Keywords : cell fate * preimplantation embryo * probabilistic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.980, year: 2013 http://www.sciencedirect.com/science/article/pii/S1472648313002435

  11. Ultrastructural dynamics of human reproduction, from ovulation to fertilization and early embryo development.

    Science.gov (United States)

    Familiari, Giuseppe; Heyn, Rosemarie; Relucenti, Michela; Nottola, Stefania A; Sathananthan, A Henry

    2006-01-01

    This study describes the updated, fine structure of human gametes, the human fertilization process, and human embryos, mainly derived from assisted reproductive technology (ART). As clearly shown, the ultrastructure of human reproduction is a peculiar multistep process, which differs in part from that of other mammalian models, having some unique features. Particular attention has been devoted to the (1) sperm ultrastructure, likely "Tygerberg (Kruger) strict morphology criteria"; (2) mature oocyte, in which the MII spindle is barrel shaped, anastral, and lacking centrioles; (3) three-dimensional microarchitecture of the zona pellucida with its unique supramolecular filamentous organization; (4) sperm-egg interactions with the peculiarity of the sperm centrosome that activates the egg and organizes the sperm aster and mitotic spindles of the embryo; and (5) presence of viable cumulus cells whose metabolic activity is closely related to egg and embryo behavior in in vitro as well as in vivo conditions, in a sort of extraovarian "microfollicular unit." Even if the ultrastructural morphodynamic features of human fertilization are well understood, our knowledge about in vivo fertilization is still very limited and the complex sequence of in vivo biological steps involved in human reproduction is only partially reproduced in current ART procedures.

  12. Metabolome analysis of Drosophila melanogaster during embryogenesis.

    Science.gov (United States)

    An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

    2014-01-01

    The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos' metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo.

  13. Early miscarriage rate in lean polycystic ovary syndrome women after euploid embryo transfer - a matched-pair study.

    Science.gov (United States)

    Luo, Lu; Gu, Fang; Jie, Huying; Ding, Chenhui; Zhao, Qiang; Wang, Qiong; Zhou, Canquan

    2017-11-01

    The early miscarriage rate is reported to be higher in patients with polycystic ovary syndrome (PCOS) compared with non-PCOS patients. However, whether PCOS is an independent risk factor for early miscarriage is still controversial; to what extent embryonic aneuploidy accounts for miscarriages of PCOS is still unknown. In this 1:3 matched-pair study, 67 lean PCOS patients and 201 controls matched for age, body mass index (BMI) and embryo scores undergoing a single euploid blastocyst transfer in vitrified-warmed cycles were analysed. Clinical pregnancy, early miscarriage and live birth rates were compared. Logistic regression analysis was performed to further evaluate the factors associated with early miscarriage and live birth. Clinical pregnancy rates were 50.7% in PCOS and 55.2% in control groups. Early miscarriage rate was significantly (P = 0.029) increased in the PCOS group compared with controls; non-PCOS patients had a significantly higher live birth rate than PCOS patients, P PCOS was significantly associated with a higher risk of early miscarriage and decreased chance of live birth. In conclusion, PCOS in women undergoing pre-implantation genetic diagnosis may, independently from BMI and karyotype, increase the risk of miscarriage. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  14. The First Human Cloned Embryo.

    Science.gov (United States)

    Cibelli, Jose B.; Lanza, Robert P.; West, Michael D.; Ezzell, Carol

    2002-01-01

    Describes a process known as parthenogenesis which produces cloned, early-stage embryos and human embryos generated only from eggs. Speculates that this technology puts therapeutic cloning within reach. (DDR)

  15. Mei-p26 cooperates with Bam, Bgcn and Sxl to promote early germline development in the Drosophila ovary.

    Directory of Open Access Journals (Sweden)

    Yun Li

    Full Text Available In the Drosophila female germline, spatially and temporally specific translation of mRNAs governs both stem cell maintenance and the differentiation of their progeny. However, the mechanisms that control and coordinate different modes of translational repression within this lineage remain incompletely understood. Here we present data showing that Mei-P26 associates with Bam, Bgcn and Sxl and nanos mRNA during early cyst development, suggesting that this protein helps to repress the translation of nanos mRNA. Together with recently published studies, these data suggest that Mei-P26 mediates both GSC self-renewal and germline differentiation through distinct modes of translational repression depending on the presence of Bam.

  16. Mei-P26 Cooperates with Bam, Bgcn and Sxl to Promote Early Germline Development in the Drosophila Ovary

    Science.gov (United States)

    Li, Yun; Zhang, Qiao; Carreira-Rosario, Arnaldo; Maines, Jean Z.; McKearin, Dennis M.; Buszczak, Michael

    2013-01-01

    In the Drosophila female germline, spatially and temporally specific translation of mRNAs governs both stem cell maintenance and the differentiation of their progeny. However, the mechanisms that control and coordinate different modes of translational repression within this lineage remain incompletely understood. Here we present data showing that Mei-P26 associates with Bam, Bgcn and Sxl and nanos mRNA during early cyst development, suggesting that this protein helps to repress the translation of nanos mRNA. Together with recently published studies, these data suggest that Mei-P26 mediates both GSC self-renewal and germline differentiation through distinct modes of translational repression depending on the presence of Bam. PMID:23526974

  17. Tissue-specific direct microtransfer of nanomaterials into Drosophila embryos as a versatile in vivo test bed for nanomaterial toxicity assessment

    Directory of Open Access Journals (Sweden)

    Vega-Alvarez S

    2014-04-01

    Full Text Available Sasha Vega-Alvarez,1 Adriana Herrera,2 Carlos Rinaldi,2–4 Franklin A Carrero-Martínez1,5 1Department of Biology, 2Department of Chemical Engineering, University of Puerto Rico-Mayagüez, Mayagüez, Puerto Rico; 3J Crayton Pruitt Family Department of Biomedical Engineering, 4Department of Chemical Engineering, University of Florida, Gainesville, FL, USA; 5Department of Anatomy and Neuroscience, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico Abstract: Nanomaterials are the subject of intense research, focused on their synthesis, modification, and biomedical applications. Increased nanomaterial production and their wide range of applications imply a higher risk of human and environmental exposure. Unfortunately, neither environmental effects nor toxicity of nanomaterials to organisms are fully understood. Cost-effective, rapid toxicity assays requiring minimal amounts of materials are needed to establish both their biomedical potential and environmental safety standards. Drosophila exemplifies an efficient and cost-effective model organism with a vast repertoire of in vivo tools and techniques, all with high-throughput scalability and screening feasibility throughout its life cycle. Here we report tissue specific nanomaterial assessment through direct microtransfer into target tissues. We tested several nanomaterials with potential biomedical applications such as single-wall carbon nanotubes, multiwall carbon nanotubes, silver, gold, titanium dioxide, and iron oxide nanoparticles. Assessment of nanomaterial toxicity was conducted by evaluating progression through developmental morphological milestones in Drosophila. This cost-effective assessment method is amenable to high-throughput screening. Keywords: nanotoxicity, Drosophila, microtransfer, nanoparticle, iron oxide, silver, gold, titanium dioxide, carbon nanotube

  18. Tet protein function during Drosophila development.

    Directory of Open Access Journals (Sweden)

    Fei Wang

    Full Text Available The TET (Ten-eleven translocation 1, 2 and 3 proteins have been shown to function as DNA hydroxymethylases in vertebrates and their requirements have been documented extensively. Recently, the Tet proteins have been shown to also hydroxylate 5-methylcytosine in RNA. 5-hydroxymethylcytosine (5hmrC is enriched in messenger RNA but the function of this modification has yet to be elucidated. Because Cytosine methylation in DNA is barely detectable in Drosophila, it serves as an ideal model to study the biological function of 5hmrC. Here, we characterized the temporal and spatial expression and requirement of Tet throughout Drosophila development. We show that Tet is essential for viability as Tet complete loss-of-function animals die at the late pupal stage. Tet is highly expressed in neuronal tissues and at more moderate levels in somatic muscle precursors in embryos and larvae. Depletion of Tet in muscle precursors at early embryonic stages leads to defects in larval locomotion and late pupal lethality. Although Tet knock-down in neuronal tissue does not cause lethality, it is essential for neuronal function during development through its affects upon locomotion in larvae and the circadian rhythm of adult flies. Further, we report the function of Tet in ovarian morphogenesis. Together, our findings provide basic insights into the biological function of Tet in Drosophila, and may illuminate observed neuronal and muscle phenotypes observed in vertebrates.

  19. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Elmore, Logan R [ORNL; McCracken, Kitty [ORNL

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the

  20. Early events in speciation: Cryptic species of Drosophila aldrichi.

    Science.gov (United States)

    Castro Vargas, Cynthia; Richmond, Maxi Polihronakis; Ramirez Loustalot Laclette, Mariana; Markow, Therese Ann

    2017-06-01

    Understanding the earliest events in speciation remains a major challenge in evolutionary biology. Thus identifying species whose populations are beginning to diverge can provide useful systems to study the process of speciation. Drosophila aldrichi , a cactophilic fruit fly species with a broad distribution in North America, has long been assumed to be a single species owing to its morphological uniformity. While previous reports either of genetic divergence or reproductive isolation among different D. aldrichi strains have hinted at the existence of cryptic species, the evolutionary relationships of this species across its range have not been thoroughly investigated. Here we show that D. aldrichi actually is paraphyletic with respect to its closest relative, Drosophila wheeleri , and that divergent D. aldrichi lineages show complete hybrid male sterility when crossed. Our data support the interpretation that there are at least two species of D. aldrichi, making these flies particularly attractive for studies of speciation in an ecological and geographical context.

  1. Contributions to the tooth morphology in early embryos of three species of hammerhead sharks (Elasmobranchii: Sphyrnidae) and their evolutionary implications.

    Science.gov (United States)

    Mello, Waldiney; Brito, Paulo Marques Machado

    2013-09-01

    The tooth types in the embryos of the hammerhead sharks Sphyrna tiburo, Sphyrna tudes and Eusphyra blochii are here described in labial and lingual views, and, in some cases, in additional views. The presence of cusplets was observed in the anterior teeth of S. tiburo and S. tudes, which is secondarily lost after early embryonic stages. Many aligned root foramina were detected in the sphyrnids, which, as the cusplets, are shared by many phylogenetic-related carcharhinids. Other anatomic features, related to the root and central cusp, are presented for the first time. Such characters represent the first step to compare the teeth of extant and fossil species. Copyright © 2013. Published by Elsevier SAS.

  2. Detecting cardiac contractile activity in the early mouse embryo using multiple modalities

    Directory of Open Access Journals (Sweden)

    Chiann-mun eChen

    2015-01-01

    Full Text Available The heart is one of the first organs to develop during mammalian embryogenesis. In the mouse, it starts to form shortly after gastrulation, and is derived primarily from embryonic mesoderm. The embryonic heart is unique in having to perform a mechanical contractile function while undergoing complex morphogenetic remodelling. Approaches to imaging the morphogenesis and contractile activity of the developing heart are important in understanding not only how this remodelling is controlled but also the origin of congenital heart defects. Here, we describe approaches for visualising contractile activity in the developing mouse embryo, using brightfield time lapse microscopy and confocal microscopy of calcium transients. We describe an algorithm for enhancing this image data and quantifying contractile activity from it. Finally we describe how atomic force microscopy can be used to record contractile activity prior to it being microscopically visible.

  3. A rapid method for whole mount preparations of mammalian oocytes and early embryos.

    Science.gov (United States)

    Moses, R M; Masui, Y

    1994-05-01

    Whole mounts of mouse oocytes and embryos are useful for observing intracellular structures while preserving morphological integrity. This method is inconvenient for rapid processing of a large number of specimens because washing each specimen in a protein-free solution is required prior to transfer into the fixative. We have developed a new fixative which does not cause protein precipitation which can be added directly to the culture medium. Specimens can be preserved in culture dishes for at least one month, and processed for cytological observation at a convenient time. When stained with hematoxylin, details of cellular structures such as nuclei, nucleoli, chromosomes and spindle microtubules can be observed while maintaining the organization of the organelles.

  4. Embryo splitting

    Directory of Open Access Journals (Sweden)

    Karl Illmensee

    2010-04-01

    Full Text Available Mammalian embryo splitting has successfully been established in farm animals. Embryo splitting is safely and efficiently used for assisted reproduction in several livestock species. In the mouse, efficient embryo splitting as well as single blastomere cloning have been developed in this animal system. In nonhuman primates embryo splitting has resulted in several pregnancies. Human embryo splitting has been reported recently. Microsurgical embryo splitting under Institutional Review Board approval has been carried out to determine its efficiency for blastocyst development. Embryo splitting at the 6–8 cell stage provided a much higher developmental efficiency compared to splitting at the 2–5 cell stage. Embryo splitting may be advantageous for providing additional embryos to be cryopreserved and for patients with low response to hormonal stimulation in assisted reproduction programs. Social and ethical issues concerning embryo splitting are included regarding ethics committee guidelines. Prognostic perspectives are presented for human embryo splitting in reproductive medicine.

  5. Asymmetric distribution of hypoxia-inducible factor α regulates dorsoventral axis establishment in the early sea urchin embryo.

    Science.gov (United States)

    Chang, Wei-Lun; Chang, Yi-Cheng; Lin, Kuan-Ting; Li, Han-Ru; Pai, Chih-Yu; Chen, Jen-Hao; Su, Yi-Hsien

    2017-08-15

    Hypoxia signaling is an ancient pathway by which animals can respond to low oxygen. Malfunction of this pathway disturbs hypoxic acclimation and can result in various diseases, including cancers. The role of hypoxia signaling in early embryogenesis remains unclear. Here, we show that in the blastula of the sea urchin Strongylocentrotus purpuratus , hypoxia-inducible factor α (HIFα), the downstream transcription factor of the hypoxia pathway, is localized and transcriptionally active on the future dorsal side. This asymmetric distribution is attributable to its oxygen-sensing ability. Manipulations of the HIFα level entrained the dorsoventral axis, as the side with the higher level of HIFα tends to develop into the dorsal side. Gene expression analyses revealed that HIFα restricts the expression of nodal to the ventral side and activates several genes encoding transcription factors on the dorsal side. We also observed that intrinsic hypoxic signals in the early embryos formed a gradient, which was disrupted under hypoxic conditions. Our results reveal an unprecedented role of the hypoxia pathway in animal development. © 2017. Published by The Company of Biologists Ltd.

  6. Time-lapse culture with morphokinetic embryo selection improves pregnancy and live birth chances and reduces early pregnancy loss: a meta-analysis.

    Science.gov (United States)

    Pribenszky, Csaba; Nilselid, Anna-Maria; Montag, Markus

    2017-11-01

    Embryo evaluation and selection is fundamental in clinical IVF. Time-lapse follow-up of embryo development comprises undisturbed culture and the application of the visual information to support embryo evaluation. A meta-analysis of randomized controlled trials was carried out to study whether time-lapse monitoring with the prospective use of a morphokinetic algorithm for selection of embryos improves overall clinical outcome (pregnancy, early pregnancy loss, stillbirth and live birth rate) compared with embryo selection based on single time-point morphology in IVF cycles. The meta-analysis of five randomized controlled trials (n = 1637) showed that the application of time-lapse monitoring was associated with a significantly higher ongoing clinical pregnancy rate (51.0% versus 39.9%), with a pooled odds ratio of 1.542 (P loss (15.3% versus 21.3%; OR: 0.662; P = 0.019) and a significantly increased live birth rate (44.2% versus 31.3%; OR 1.668; P = 0.009). Difference in stillbirth was not significant between groups (4.7% versus 2.4%). Quality of the evidence was moderate to low owing to inconsistencies across the studies. Selective application and variability were also limitations. Although time-lapse is shown to significantly improve overall clinical outcome, further high-quality evidence is needed before universal conclusions can be drawn. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  7. Embryo-maternal communication

    DEFF Research Database (Denmark)

    Østrup, Esben; Hyttel, Poul; Østrup, Olga

    2011-01-01

    Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms dire...... directing the placentation. An increasing knowledge of the embryo-maternal communication might not only help to improve the fertility of our farm animals but also our understanding of human health and reproduction.......Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms...

  8. Autoradiographic study of protein synthesis recovery in root cells of Zea mays embryos during early stages of germination

    International Nuclear Information System (INIS)

    Deltour, Roger

    1977-01-01

    Recovery of protein synthesis was studied in primary root of germinating Zea mays embryos. [H 3 ] leucine or [H 3 ] lysine was provided for two hours at 16 0 C to embryos excised from kernels at various times after the beginning of germination. Protein synthesis (probably dependent on long-lived mRNA stocked in dormant embryo root cells) resumed during the first two hours of seed imbibition [fr

  9. Autoradiographic study of protein synthesis recovery in root cells of Zea mays embryos during early stages of germination

    Energy Technology Data Exchange (ETDEWEB)

    Deltour, R [Liege Univ. (Belgium)

    1977-05-02

    Recovery of protein synthesis was studied in primary root of germinating Zea mays embryos. (H/sup 3/) leucine or (H/sup 3/) lysine was provided for two hours at 16/sup 0/C to embryos excised from kernels at various times after the beginning of germination. Protein synthesis (probably dependent on long-lived mRNA stocked in dormant embryo root cells) resumed during the first two hours of seed imbibition.

  10. Effects of lipopolysaccharide (LPS) induced inflammatory response on early embryo survival in ewes

    Science.gov (United States)

    Early pregnant ewes were used to determine the effects of endogenous (through LPS activation) and exogenous TNF-alpha tumor necrosis factor-alpha (TNF-alpha) on embryonic loss. Thirty-eight Dorset x Texel ewes were synchronized for estrus and bred to fertile rams (d0). On d5/6, ewes were assigned t...

  11. DNA repair efficiency in germ cells and early mouse embryos and consequences for radiation-induced transgenerational genomic damage

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, Francesco; Wyrobek, Andrew J.

    2009-01-18

    Exposure to ionizing radiation and other environmental agents can affect the genomic integrity of germ cells and induce adverse health effects in the progeny. Efficient DNA repair during gametogenesis and the early embryonic cycles after fertilization is critical for preventing transmission of DNA damage to the progeny and relies on maternal factors stored in the egg before fertilization. The ability of the maternal repair machinery to repair DNA damage in both parental genomes in the fertilizing egg is especially crucial for the fertilizing male genome that has not experienced a DNA repair-competent cellular environment for several weeks prior to fertilization. During the DNA repair-deficient period of spermatogenesis, DNA lesions may accumulate in sperm and be carried into the egg where, if not properly repaired, could result in the formation of heritable chromosomal aberrations or mutations and associated birth defects. Studies with female mice deficient in specific DNA repair genes have shown that: (i) cell cycle checkpoints are activated in the fertilized egg by DNA damage carried by the sperm; and (ii) the maternal genotype plays a major role in determining the efficiency of repairing genomic lesions in the fertilizing sperm and directly affect the risk for abnormal reproductive outcomes. There is also growing evidence that implicates DNA damage carried by the fertilizing gamete as a mediator of postfertilization processes that contribute to genomic instability in subsequent generations. Transgenerational genomic instability most likely involves epigenetic mechanisms or error-prone DNA repair processes in the early embryo. Maternal and embryonic DNA repair processes during the early phases of mammalian embryonic development can have far reaching consequences for the genomic integrity and health of subsequent generations.

  12. Early-onset sleep defects in Drosophila models of Huntington's disease reflect alterations of PKA/CREB signaling

    Science.gov (United States)

    Gonzales, Erin D.; Tanenhaus, Anne K.; Zhang, Jiabin; Chaffee, Ryan P.; Yin, Jerry C.P.

    2016-01-01

    Huntington's disease (HD) is a progressive neurological disorder whose non-motor symptoms include sleep disturbances. Whether sleep and activity abnormalities are primary molecular disruptions of mutant Huntingtin (mutHtt) expression or result from neurodegeneration is unclear. Here, we report Drosophila models of HD exhibit sleep and activity disruptions very early in adulthood, as soon as sleep patterns have developed. Pan-neuronal expression of full-length or N-terminally truncated mutHtt recapitulates sleep phenotypes of HD patients: impaired sleep initiation, fragmented and diminished sleep, and nighttime hyperactivity. Sleep deprivation of HD model flies results in exacerbated sleep deficits, indicating that homeostatic regulation of sleep is impaired. Elevated PKA/CREB activity in healthy flies produces patterns of sleep and activity similar to those in our HD models. We were curious whether aberrations in PKA/CREB signaling were responsible for our early-onset sleep/activity phenotypes. Decreasing signaling through the cAMP/PKA pathway suppresses mutHtt-induced developmental lethality. Genetically reducing PKA abolishes sleep/activity deficits in HD model flies, restores the homeostatic response and extends median lifespan. In vivo reporters, however, show dCREB2 activity is unchanged, or decreased when sleep/activity patterns are abnormal, suggesting dissociation of PKA and dCREB2 occurs early in pathogenesis. Collectively, our data suggest that sleep defects may reflect a primary pathological process in HD, and that measurements of sleep and cAMP/PKA could be prodromal indicators of disease, and serve as therapeutic targets for intervention. PMID:26604145

  13. Uterine-embryonic interaction in pit : activin, follistatin, and activin receptor II in uterus and embryo during early gestation

    NARCIS (Netherlands)

    Pavert, van de S.A.; Boerjan, M.L.; Stroband, H.W.J.; Taverne, M.A.M.; Hurk, van der R.

    2001-01-01

    The mRNA expression patterns of activin A and follistatin in the uterus and embryo, the mRNA expression of the activin receptor II in the embryo, and the localization in the uterus of the immunoreactive activin A and the receptor II proteins in the uterus were examined at gestation days 7-12 after

  14. Imaging of Norway spruce early somatic embryos with the ESEM, Cryo-SEM and laser scanning microscope.

    Science.gov (United States)

    Neděla, Vilém; Hřib, Jiří; Havel, Ladislav; Hudec, Jiří; Runštuk, Jiří

    2016-05-01

    This article describes the surface structure of Norway spruce early somatic embryos (ESEs) as a typical culture with asynchronous development. The microstructure of extracellular matrix covering ESEs were observed using the environmental scanning electron microscope as a primary tool and using the scanning electron microscope with cryo attachment and laser electron microscope as a complementary tool allowing our results to be proven independently. The fresh samples were observed in conditions of the air environment of the environmental scanning electron microscope (ESEM) with the pressure from 550Pa to 690Pa and the low temperature of the sample from -18°C to -22°C. The samples were studied using two different types of detector to allow studying either the thin surface structure or material composition. The scanning electron microscope with cryo attachment was used for imaging frozen extracellular matrix microstructure with higher resolution. The combination of both electron microscopy methods was suitable for observation of "native" plant samples, allowing correct evaluation of our results, free of error and artifacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Myoblast fusion in Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Haralalka, Shruti [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Abmayr, Susan M., E-mail: sma@stowers.org [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, MO 66160 (United States)

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  16. Myoblast fusion in Drosophila

    International Nuclear Information System (INIS)

    Haralalka, Shruti; Abmayr, Susan M.

    2010-01-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  17. Spermidine is bound to a unique protein in early sea urchin embryos

    International Nuclear Information System (INIS)

    Canellakis, Z.N.; Bondy, P.K.; Infante, A.A.

    1985-01-01

    Spermidine is rapidly taken up and becomes bound to protein during the very early hours of sea urchin embryogenesis. During the first 6 hr after fertilization of freshly obtained sea urchin eggs (Strongylocentrotus purpuratus), which are incubated in the presence of exogenous [ 3 H]-spermidine, up to 7% of the total cell-associated spermidine appears uniquely as spermidine bound in macromolecular form. This unique protein containing spermidine migrates as a single radioactive band in gel electrophoresis. It has a Mr of approximately equal to 30,000 and is readily distinguishable from the protein initiation factor eIF-4D, which has a Mr of 18,000, the only other identifiable protein known to date to be posttranslationally modified by polyamines

  18. Multi-instrumental Investigation of Affecting of Early Somatic Embryos of Spruce by Cadmium(II) and Lead(II) Ions

    Czech Academy of Sciences Publication Activity Database

    Šupálková, V.; Petřek, J.; Baloun, J.; Adam, V.; Bartušek, Karel; Trnková, L.; Beklová, M.; Diopan, V.; Havel, L.; Kizek, R.

    2007-01-01

    Roč. 7, 5 (2007), s. 743-759 ISSN 1424-8220 R&D Projects: GA ČR(CZ) GA102/07/0389 Institutional research plan: CEZ:AV0Z20650511 Keywords : early somatic embryos of spruces * glutathione * heavy metals * plant cells * esterase activity * fluorescence detection Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.573, year: 2007

  19. Intra- and interobserver analysis in the morphological assessment of early stage embryos during an IVF procedure: a multicentre study

    Directory of Open Access Journals (Sweden)

    Devroe Johanna

    2011-09-01

    Full Text Available Abstract Background Quality control programs are necessary to maintain good clinical practice. Embryo grading has been described as one of the external quality assurance schemes. Although the evaluation of embryos is based on the assessment of morphological characteristics, considerable intra- and inter-observer variability has been described. In this multicentre study, the variability in the embryo evaluation has been evaluated using morphological characteristics on day 1, day 2 and day 3 of embryo development. Methods Five embryologists of four different IVF centers participated in this study. Multilevel images of embryos were presented on a website at different time points to evaluate intra-and inter-observer agreement in the assessment of embryo morphology. The embryos were evaluated on day 1, day 2 and day 3 of their development and each embryologist had to decide if the embryo had to be transferred, cryopreserved or discarded. Results Both intra-observer agreement and inter-observer agreement were good to excellent for the position of the pronuclei on day 1, the number of blastomeres on day 2 and day 3 and the clinical decision (transfer, cryopreservation, discard. For all other characteristics (size of pronuclei, presence of cytoplasomic halo, degree of fragmentation and size of blastomeres the intra- and inter-observer agreement was moderate to very poor. Conclusions Mono- or multicentre quality control on embryo scoring by morphological assessment can easily be performed through the design of a simple website. In the future the website design can be adapted to generate statistical feedback upon scoring and can even include a training module.

  20. DNA damage and apoptosis of endometrial cells cause loss of the early embryo in mice exposed to carbon disulfide

    International Nuclear Information System (INIS)

    Zhang, Bingzhen; Shen, Chunzi; Yang, Liu; Li, Chunhui; Yi, Anji; Wang, Zhiping

    2013-01-01

    Carbon disulfide (CS 2 ) may lead to spontaneous abortion and very early pregnancy loss in women exposed in the workplace, but the mechanism remains unclear. We designed an animal model in which gestating Kunming strain mice were exposed to CS 2 via i.p. on gestational day 4 (GD4). We found that the number of implanted blastocysts on GD8 was significantly reduced by each dose of 0.1 LD 50 (157.85 mg/kg), 0.2 LD 50 (315.7 mg/kg) and 0.4 LD 50 (631.4 mg/kg). In addition, both the level of DNA damage and apoptosis rates of endometrial cells on GD4.5 were increased, showed definite dose–response relationships, and inversely related to the number of implanted blastocysts. The expressions of mRNA and protein for the Bax and caspase-3 genes in the uterine tissues on GD4.5 were up-regulated, while the expressions of mRNA and protein for the Bcl-2 gene were dose-dependently down-regulated. Our results indicated that DNA damage and apoptosis of endometrial cells were important reasons for the loss of implanted blastocysts induced by CS 2 . - Highlights: • We built an animal model of CS2 exposure during blastocyst implantation. • Endometrial cells were used in the comet assay to detect DNA damage. • CS2 exposure caused DNA damage and endometrial cell apoptosis. • DNA damage and endometrial cell apoptosis were responsible for embryo loss

  1. DNA damage and apoptosis of endometrial cells cause loss of the early embryo in mice exposed to carbon disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingzhen [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China); Shen, Chunzi [Centers for Disease Control and Prevention, Zibo (China); Yang, Liu; Li, Chunhui; Yi, Anji [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China); Wang, Zhiping, E-mail: zhipingw@sdu.edu.cn [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China)

    2013-12-01

    Carbon disulfide (CS{sub 2}) may lead to spontaneous abortion and very early pregnancy loss in women exposed in the workplace, but the mechanism remains unclear. We designed an animal model in which gestating Kunming strain mice were exposed to CS{sub 2} via i.p. on gestational day 4 (GD4). We found that the number of implanted blastocysts on GD8 was significantly reduced by each dose of 0.1 LD{sub 50} (157.85 mg/kg), 0.2 LD{sub 50} (315.7 mg/kg) and 0.4 LD{sub 50} (631.4 mg/kg). In addition, both the level of DNA damage and apoptosis rates of endometrial cells on GD4.5 were increased, showed definite dose–response relationships, and inversely related to the number of implanted blastocysts. The expressions of mRNA and protein for the Bax and caspase-3 genes in the uterine tissues on GD4.5 were up-regulated, while the expressions of mRNA and protein for the Bcl-2 gene were dose-dependently down-regulated. Our results indicated that DNA damage and apoptosis of endometrial cells were important reasons for the loss of implanted blastocysts induced by CS{sub 2}. - Highlights: • We built an animal model of CS2 exposure during blastocyst implantation. • Endometrial cells were used in the comet assay to detect DNA damage. • CS2 exposure caused DNA damage and endometrial cell apoptosis. • DNA damage and endometrial cell apoptosis were responsible for embryo loss.

  2. Lipid metabolic perturbation is an early-onset phenotype in adult spinster mutants: a Drosophila model for lysosomal storage disorders.

    Science.gov (United States)

    Hebbar, Sarita; Khandelwal, Avinash; Jayashree, R; Hindle, Samantha J; Chiang, Yin Ning; Yew, Joanne Y; Sweeney, Sean T; Schwudke, Dominik

    2017-12-15

    Intracellular accumulation of lipids and swollen dysfunctional lysosomes are linked to several neurodegenerative diseases, including lysosomal storage disorders (LSD). Detailed characterization of lipid metabolic changes in relation to the onset and progression of neurodegeneration is currently missing. We systematically analyzed lipid perturbations in spinster (spin) mutants, a Drosophila model of LSD-like neurodegeneration. Our results highlight an imbalance in brain ceramide and sphingosine in the early stages of neurodegeneration, preceding the accumulation of endomembranous structures, manifestation of altered behavior, and buildup of lipofuscin. Manipulating levels of ceramidase and altering these lipids in spin mutants allowed us to conclude that ceramide homeostasis is the driving force in disease progression and is integral to spin function in the adult nervous system. We identified 29 novel physical interaction partners of Spin and focused on the lipid carrier protein, Lipophorin (Lpp). A subset of Lpp and Spin colocalize in the brain and within organs specialized for lipid metabolism (fat bodies and oenocytes). Reduced Lpp protein was observed in spin mutant tissues. Finally, increased levels of lipid metabolites produced by oenocytes in spin mutants allude to a functional interaction between Spin and Lpp, underscoring the systemic nature of lipid perturbation in LSD. © 2017 Hebbar et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  3. Bovine oocytes and early embryos express mRNA encoding glycerol kinase but addition of glycerol to the culture media interferes with oocyte maturation.

    Science.gov (United States)

    Okawara, Sumika; Hamano, Seizo; Tetsuka, Masafumi

    2009-04-01

    Glycerol plays multi-functional roles in cellular physiology. Other than forming the backbone molecule for glycerophospholipid and triglyceride (TG), glycerol acts as an energy substrate for glycolysis. Spermatozoa are known to utilize glycerol for energy production, but there are no reports of this in oocytes. In this study, the value of glycerol as an energy substrate for bovine oocyte maturation (Exp. 1) and the gene expression of glycerol kinase (GK), an enzyme crucial for cellular glycerol utilization, in bovine oocytes and early embryos (Exp. 2) were examined. In Exp. 1, in vitro maturation (IVM) was conducted using synthetic oviduct fluid supplemented with/without glucose (1.5 mM) and/or glycerol (1.0 mM), and maturation rate, degree of cumulus expansion, glucose consumption and lactate production by cumulus-oocyte complexes (COC) were examined. In Exp. 2, to examine the developmental expression of GK mRNA, cumulus cells, oocytes and embryos at the 2-, 8- and 16-cell, morula, expanded blastocyst and hatched blastocyst stages were obtained in separate experiments, and the expression of GK mRNA was quantified using a real-time PCR. Glycerol did not support oocyte maturation or cumulus expansion. Addition of glycerol to glucose-supplemented media significantly decreased the maturation rate. Expression of GK mRNA was very low in cumulus cells, whereas an appreciable level of the transcript was observed in the oocytes. GK mRNA was detected in embryos at all the stages examined, and its expression significantly increased at the morula stage. These results indicate that glycerol, at least at the present concentration, is not beneficial as a constituent of the medium for bovine oocyte maturation. However, the appreciable levels of GK mRNA found in the oocyte and embryo imply a physiological role for glycerol in bovine oocyte maturation and embryo development.

  4. Myosin-1 inhibition by PClP affects membrane shape, cortical actin distribution and lipid droplet dynamics in early Zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Prabuddha Gupta

    Full Text Available Myosin-1 (Myo1 represents a mechanical link between the membrane and actin-cytoskeleton in animal cells. We have studied the effect of Myo1 inhibitor PClP in 1-8 cell Zebrafish embryos. Our results indicate a unique involvement of Myo1 in early development of Zebrafish embryos. Inhibition of Myo1 (by PClP and Myo2 (by Blebbistatin lead to arrest in cell division. While Myo1 isoforms appears to be important for both the formation and the maintenance of cleavage furrows, Myo2 is required only for the formation of furrows. We found that the blastodisc of the embryo, which contains a thick actin cortex (~13 μm, is loaded with cortical Myo1. Myo1 appears to be crucial for maintaining the blastodisc morphology and the actin cortex thickness. In addition to cell division and furrow formation, inhibition of Myo1 has a drastic effect on the dynamics and distribution of lipid droplets (LDs in the blastodisc near the cleavage furrow. All these results above are effects of Myo1 inhibition exclusively; Myo2 inhibition by blebbistatin does not show such phenotypes. Therefore, our results demonstrate a potential role for Myo1 in the maintenance and formation of furrow, blastodisc morphology, cell-division and LD organization within the blastodisc during early embryogenesis.

  5. Mechanisms of gap gene expression canalization in the Drosophila blastoderm

    Directory of Open Access Journals (Sweden)

    Samsonova Maria G

    2011-07-01

    Full Text Available Abstract Background Extensive variation in early gap gene expression in the Drosophila blastoderm is reduced over time because of gap gene cross regulation. This phenomenon is a manifestation of canalization, the ability of an organism to produce a consistent phenotype despite variations in genotype or environment. The canalization of gap gene expression can be understood as arising from the actions of attractors in the gap gene dynamical system. Results In order to better understand the processes of developmental robustness and canalization in the early Drosophila embryo, we investigated the dynamical effects of varying spatial profiles of Bicoid protein concentration on the formation of the expression border of the gap gene hunchback. At several positions on the anterior-posterior axis of the embryo, we analyzed attractors and their basins of attraction in a dynamical model describing expression of four gap genes with the Bicoid concentration profile accounted as a given input in the model equations. This model was tested against a family of Bicoid gradients obtained from individual embryos. These gradients were normalized by two independent methods, which are based on distinct biological hypotheses and provide different magnitudes for Bicoid spatial variability. We showed how the border formation is dictated by the biological initial conditions (the concentration gradient of maternal Hunchback protein being attracted to specific attracting sets in a local vicinity of the border. Different types of these attracting sets (point attractors or one dimensional attracting manifolds define several possible mechanisms of border formation. The hunchback border formation is associated with intersection of the spatial gradient of the maternal Hunchback protein and a boundary between the attraction basins of two different point attractors. We demonstrated how the positional variability for hunchback is related to the corresponding variability of the

  6. The specification and global reprogramming of histone epigenetic marks during gamete formation and early embryo development in C. elegans.

    Directory of Open Access Journals (Sweden)

    Mark Samson

    2014-10-01

    Full Text Available In addition to the DNA contributed by sperm and oocytes, embryos receive parent-specific epigenetic information that can include histone variants, histone post-translational modifications (PTMs, and DNA methylation. However, a global view of how such marks are erased or retained during gamete formation and reprogrammed after fertilization is lacking. To focus on features conveyed by histones, we conducted a large-scale proteomic identification of histone variants and PTMs in sperm and mixed-stage embryo chromatin from C. elegans, a species that lacks conserved DNA methylation pathways. The fate of these histone marks was then tracked using immunostaining. Proteomic analysis found that sperm harbor ∼2.4 fold lower levels of histone PTMs than embryos and revealed differences in classes of PTMs between sperm and embryos. Sperm chromatin repackaging involves the incorporation of the sperm-specific histone H2A variant HTAS-1, a widespread erasure of histone acetylation, and the retention of histone methylation at sites that mark the transcriptional history of chromatin domains during spermatogenesis. After fertilization, we show HTAS-1 and 6 histone PTM marks distinguish sperm and oocyte chromatin in the new embryo and characterize distinct paternal and maternal histone remodeling events during the oocyte-to-embryo transition. These include the exchange of histone H2A that is marked by ubiquitination, retention of HTAS-1, removal of the H2A variant HTZ-1, and differential reprogramming of histone PTMs. This work identifies novel and conserved features of paternal chromatin that are specified during spermatogenesis and processed in the embryo. Furthermore, our results show that different species, even those with diverged DNA packaging and imprinting strategies, use conserved histone modification and removal mechanisms to reprogram epigenetic information.

  7. Uterine responses to early pre-attachment embryos in the domestic dog and comparisons with other domestic animal species.

    Science.gov (United States)

    Graubner, Felix R; Gram, Aykut; Kautz, Ewa; Bauersachs, Stefan; Aslan, Selim; Agaoglu, Ali R; Boos, Alois; Kowalewski, Mariusz P

    2017-08-01

    In the dog, there is no luteolysis in the absence of pregnancy. Thus, this species lacks any anti-luteolytic endocrine signal as found in other species that modulate uterine function during the critical period of pregnancy establishment. Nevertheless, in the dog an embryo-maternal communication must occur in order to prevent rejection of embryos. Based on this hypothesis, we performed microarray analysis of canine uterine samples collected during pre-attachment phase (days 10-12) and in corresponding non-pregnant controls, in order to elucidate the embryo attachment signal. An additional goal was to identify differences in uterine responses to pre-attachment embryos between dogs and other mammalian species exhibiting different reproductive patterns with regard to luteolysis, implantation, and preparation for placentation. Therefore, the canine microarray data were compared with gene sets from pigs, cattle, horses, and humans. We found 412 genes differentially regulated between the two experimental groups. The functional terms most strongly enriched in response to pre-attachment embryos related to extracellular matrix function and remodeling, and to immune and inflammatory responses. Several candidate genes were validated by semi-quantitative PCR. When compared with other species, best matches were found with human and equine counterparts. Especially for the pig, the majority of overlapping genes showed opposite expression patterns. Interestingly, 1926 genes did not pair with any of the other gene sets. Using a microarray approach, we report the uterine changes in the dog driven by the presence of embryos and compare these results with datasets from other mammalian species, finding common-, contrary-, and exclusively canine-regulated genes. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction.

  8. Identification of ER Proteins Involved in the Functional Organisation of the Early Secretory Pathway in Drosophila Cells by a Targeted RNAi Screen

    Science.gov (United States)

    Kondylis, Vangelis; Tang, Yang; Fuchs, Florian; Boutros, Michael; Rabouille, Catherine

    2011-01-01

    Background In Drosophila, the early secretory apparatus comprises discrete paired Golgi stacks in close proximity to exit sites from the endoplasmic reticulum (tER sites), thus forming tER-Golgi units. Although many components involved in secretion have been identified, the structural components sustaining its organisation are less known. Here we set out to identify novel ER resident proteins involved in the of tER-Golgi unit organisation. Results To do so, we designed a novel screening strategy combining a bioinformatics pre-selection with an RNAi screen. We first selected 156 proteins exhibiting known or related ER retention/retrieval signals from a list of proteins predicted to have a signal sequence. We then performed a microscopy-based primary and confirmation RNAi screen in Drosophila S2 cells directly scoring the organisation of the tER-Golgi units. We identified 49 hits, most of which leading to an increased number of smaller tER-Golgi units (MG for “more and smaller Golgi”) upon depletion. 16 of them were validated and characterised, showing that this phenotype was not due to an inhibition in secretion, a block in G2, or ER stress. Interestingly, the MG phenotype was often accompanied by an increase in the cell volume. Out of 6 proteins, 4 were localised to the ER. Conclusions This work has identified novel proteins involved in the organisation of the Drosophila early secretory pathway. It contributes to the effort of assigning protein functions to gene annotation in the secretory pathway, and analysis of the MG hits revealed an enrichment of ER proteins. These results suggest a link between ER localisation, aspects of cell metabolism and tER-Golgi structural organisation. PMID:21383842

  9. Comparison of commercial lures and food baits for early detection of fruit infestation risk by Drosophila suzukii

    Science.gov (United States)

    Drosophila suzukii is one of the most serious invasive pests of berries and cherries worldwide. Several adult monitoring systems are available to time foliar application of insecticides with the expectation of detecting the presence of D.suzukii before they infest susceptible crops. We tested this b...

  10. ABA Inhibits Embryo Cell Expansion and Early Cell Division Events During Coffee (Coffea arabica 'Rubi') Seed Germination

    NARCIS (Netherlands)

    Silva, da E.A.A.; Toorop, P.E.; Lammeren, van A.A.M.; Hilhorst, H.W.M.

    2008-01-01

    Background and Aims: Coffee seed germination represents an interplay between the embryo and the surrounding endosperm. A sequence of events in both parts of the seed determines whether germination will be successful or not. Following previous studies, the aim here was to further characterize the

  11. A Baculovirus immediate-early gene, ie1, promoter drives efficient expression of a transgene in both Drosophila melanogaster and Bombyx mori.

    Directory of Open Access Journals (Sweden)

    Mika Masumoto

    Full Text Available Many promoters have been used to drive expression of heterologous transgenes in insects. One major obstacle in the study of non-model insects is the dearth of useful promoters for analysis of gene function. Here, we investigated whether the promoter of the immediate-early gene, ie1, from the Bombyx mori nucleopolyhedrovirus (BmNPV could be used to drive efficient transgene expression in a wide variety of insects. We used a piggyBac-based vector with a 3xP3-DsRed transformation marker to generate a reporter construct; this construct was used to determine the expression patterns driven by the BmNPV ie1 promoter; we performed a detailed investigation of the promoter in transgene expression pattern in Drosophila melanogaster and in B. mori. Drosophila and Bombyx belong to different insect orders (Diptera and Lepidoptera, respectively; however, and to our surprise, ie1 promoter-driven expression was evident in several tissues (e.g., prothoracic gland, midgut, and tracheole in both insects. Furthermore, in both species, the ie1 promoter drove expression of the reporter gene from a relatively early embryonic stage, and strong ubiquitous ie1 promoter-driven expression continued throughout the larval, pupal, and adult stages by surface observation. Therefore, we suggest that the ie1 promoter can be used as an efficient expression driver in a diverse range of insect species.

  12. Early embryo achievement through isolated microspore culture in Citrus clementina Hort. ex Tan., cvs. ‘Monreal Rosso’ and ‘Nules’

    Directory of Open Access Journals (Sweden)

    Benedetta eChiancone

    2015-06-01

    Full Text Available Microspore embryogenesis is a method of achieving complete homozygosity from plants. It is particularly useful for woody species, like Citrus, characterized by long juvenility, a high degree of heterozygosity and often self-incompatibility. Anther culture is currently the method of choice for microspore embryogenesis in many crops. However, isolated microspore culture is a better way to investigate the processes at the cellular, physiological, biochemical and molecular levels as it avoids the influence of somatic anther tissue. To exploit the potential of this technique, it is important to separate the key factors affecting the process and, among them, culture medium composition and particularly the plant growth regulators and their concentration, as they can greatly enhance regeneration efficiency. To our knowledge, the ability of meta-Topolin, a naturally occurring aromatic cytokinin, to induce gametic embryogenesis in isolated microspores of Citrus has never been investigated. In this study, the effect of two concentrations of meta-Topolin instead of benzyladenine or zeatin in the culture medium was investigated in isolated microspore culture of two genotypes of Citrus. After eleven months of isolated microspore culture, for both genotypes and for all the four tested media, the microspore reprogramming and their sporophytic development was observed by the presence of multinucleated calli and microspore-derived embryos at different stages. Microsatellite analysis of parental and embryo samples was performed to determine the embryo alleles constitution of early embryos produced in all tested media, confirming their origin from microspores.To our knowledge, this is the first successful report of Citrus microspore embryogenesis with isolated microspore culture in Citrus, and in particular in Citrus clementina Hort. ex Tan, cvs. ‘Monreal Rosso’ and ‘Nules’.

  13. Insulin and branched-chain amino acid depletion during mouse preimplantation embryo culture programmes body weight gain and raised blood pressure during early postnatal life.

    Science.gov (United States)

    Velazquez, Miguel A; Sheth, Bhavwanti; Smith, Stephanie J; Eckert, Judith J; Osmond, Clive; Fleming, Tom P

    2018-02-01

    Mouse maternal low protein diet exclusively during preimplantation development (Emb-LPD) is sufficient to programme altered growth and cardiovascular dysfunction in offspring. Here, we use an in vitro model comprising preimplantation culture in medium depleted in insulin and branched-chain amino acids (BCAA), two proposed embryo programming inductive factors from Emb-LPD studies, to examine the consequences for blastocyst organisation and, after embryo transfer (ET), postnatal disease origin. Two-cell embryos were cultured to blastocyst stage in defined KSOM medium supplemented with four combinations of insulin and BCAA concentrations. Control medium contained serum insulin and uterine luminal fluid amino acid concentrations (including BCAA) found in control mothers from the maternal diet model (N-insulin+N-bcaa). Experimental medium (three groups) contained 50% reduction in insulin and/or BCAA (L-insulin+N-bcaa, N-insulin+L-bcaa, and L-insulin+N-bcaa). Lineage-specific cell numbers of resultant blastocysts were not affected by treatment. Following ET, a combined depletion of insulin and BCAA during embryo culture induced a non sex-specific increase in birth weight and weight gain during early postnatal life. Furthermore, male offspring displayed relative hypertension and female offspring reduced heart/body weight, both characteristics of Emb-LPD offspring. Combined depletion of metabolites also resulted in a strong positive correlation between body weight and glucose metabolism that was absent in the control group. Our results support the notion that composition of preimplantation culture medium can programme development and associate with disease origin affecting postnatal growth and cardiovascular phenotypes and implicate two important nutritional mediators in the inductive mechanism. Our data also have implications for human assisted reproductive treatment (ART) practice. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. TGF-β/Smad2/3 signaling directly regulates several miRNAs in mouse ES cells and early embryos.

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    Nicholas Redshaw

    Full Text Available The Transforming Growth Factor-β (TGF-β signaling pathway is one of the major pathways essential for normal embryonic development and tissue homeostasis, with anti-tumor but also pro-metastatic properties in cancer. This pathway directly regulates several target genes that mediate its downstream functions, however very few microRNAs (miRNAs have been identified as targets. miRNAs are modulators of gene expression with essential roles in development and a clear association with diseases including cancer. Little is known about the transcriptional regulation of the primary transcripts (pri-miRNA, pri-miR from which several mature miRNAs are often derived. Here we present the identification of miRNAs regulated by TGF-β signaling in mouse embryonic stem (ES cells and early embryos. We used an inducible ES cell system to maintain high levels of the TGF-β activated/phosphorylated Smad2/3 effectors, which are the transcription factors of the pathway, and a specific inhibitor that blocks their activation. By performing short RNA deep-sequencing after 12 hours Smad2/3 activation and after 16 hours inhibition, we generated a database of responsive miRNAs. Promoter/enhancer analysis of a subset of these miRNAs revealed that the transcription of pri-miR-181c/d and the pri-miR-341∼3072 cluster were found to depend on activated Smad2/3. Several of these miRNAs are expressed in early mouse embryos, when the pathway is known to play an essential role. Treatment of embryos with TGF-β inhibitor caused a reduction of their levels confirming that they are targets of this pathway in vivo. Furthermore, we showed that pri-miR-341∼3072 transcription also depends on FoxH1, a known Smad2/3 transcription partner during early development. Together, our data show that miRNAs are regulated directly by the TGF-β/Smad2/3 pathway in ES cells and early embryos. As somatic abnormalities in functions known to be regulated by the TGF-β/Smad2/3 pathway underlie tumor

  15. Heterologous expression of mammalian Plk1 in Drosophila reveals divergence from Polo during late mitosis

    International Nuclear Information System (INIS)

    Pearson, John; Godinho, Susana A.; Tavares, Alvaro; Glover, David M.

    2006-01-01

    Drosophila Polo kinase is the founder member of a conserved kinase family required for multiple stages of mitosis. We assessed the ability of mouse Polo-like kinase 1 (Plk1) to perform the multiple mitotic functions of Polo kinase, by expressing a Plk1-GFP fusion in Drosophila. Consistent with the previously reported localization of Polo kinase, Plk1-GFP was strongly localized to centrosomes and recruited to the centromeric regions of condensing chromosomes during early mitosis. However, in contrast to a functional Polo-GFP fusion, Plk1-GFP failed to localize to the central spindle midzone in both syncytial embryo mitosis and the conventional mitoses of cellularized embryos and S2 cells. Moreover, unlike endogenous Polo kinase and Polo-GFP, Plk1-GFP failed to associate with the contractile ring. Expression of Plk1-GFP enhanced the lethality of hypomorphic polo mutants and disrupted the organization of the actinomyosin cytoskeleton in a dominant-negative manner. Taken together, our results suggest that endogenous Polo kinase has specific roles in regulating actinomyosin rearrangements during Drosophila mitoses that its mammalian counterpart, Plk1, cannot fulfill. Consistent with this hypothesis, we observed defects in the cortical recruitment of myosin and myosin regulatory light chain in Polo deficient cells

  16. Ubiquitous overexpression of a transgene encoding the extracellular portion of the Drosophila roughest-irregular chiasm C protein induces early embryonic lethality.

    Science.gov (United States)

    Moda, L; Machado, R C; Ramos, R G

    2000-09-01

    The cell adhesion molecule Rst-irreC is a transmembrane glycoprotein of the immunoglobulin superfamily involved in several important developmental processes in Drosophila, including axonal pathfinding in the optic lobe and programmed cell death and pigment cell differentiation in the pupal retina. As an initial step towards the "in vivo" functional analysis of this protein we have generated transgenic fly stocks carrying a truncated cDNA construct encoding only the extracellular domain of Rst-IrreC under the transcriptional control of the heat shock inducible promoter hsp70. We show that heat-shocking embryos bearing the transgene during the first 8hs of development lead to a 3-4 fold reduction in their viability compared to wild type controls. The embryonic lethality can already be produced by applying the heat pulse in the first 3hs of embryonic development, does not seem to be suppressed in the absence of wildtype product and is progressively reduced as the heat treatment is applied later in embryogenesis. These results are compatible with the hypothesis of the lethal phenotype being primarily due to heterophilic interactions between Rst-IrreC extracellular domain and an yet unknown ligand.

  17. Mouse Embryo Compaction.

    Science.gov (United States)

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

  18. Immunolocalization and expression of Na(+)/K(+) -ATPase in embryos, early larval stages and adults of the freshwater shrimp Palaemonetes argentinus (Decapoda, Caridea, Palaemonidae).

    Science.gov (United States)

    Ituarte, Romina Belén; Lignot, Jehan-Hervé; Charmantier, Guy; Spivak, Eduardo; Lorin-Nebel, Catherine

    2016-06-01

    The euryhaline shrimp Palaemonetes argentinus exemplifies an evolutionary transition from brackish to freshwater habitats that requires adequate osmoregulatory capacities. Hyperosmoregulation is functional at hatching and it likely begins during the embryonic phase allowing this species to develop entirely in fresh water. Here, we investigated the Na(+)/K(+)-ATPase α-subunit gene (nka-α) expression using quantitative real-time PCR and localized Na(+)/K(+)-ATPase (NKA) in ion-transporting epithelia through immunofluorescence microscopy. We reared shrimps from spawning to juvenile stages at two salinities (1, 15 ‰) and maintained adults for 3 weeks at three salinity treatments (1, 15, 25 ‰). nka-α gene expression was measured in: (1) embryos at an early (SI), intermediate (SII) and late (SIII) stage of embryonic development; (2) newly hatched larvae (Zoea I, ZI); and (3) isolated gill tissue of adults. The nka-α expression was low in SI and SII embryos and reached maximum levels prior to hatching (SIII), which were similar to expression levels detected in the ZI. The nka-α expression in SIII and ZI was highest at 15 ‰, whereas salinity did not affect expression in earlier embryos. In SIII, in ZI and in a later zoeal stage ZIV, NKA was localized in epithelial cells of pleurae, in the inner-side epithelium of branchiostegite and in the antennal glands. Gills appeared in the ZIV but NKA immunolabeling of the cells of the gill shaft occurred in a subsequent developmental larval stage, the decapodid. Extrabranchial organs constitute the main site of osmoregulation in early ontogenetic stages of this freshwater shrimp.

  19. The type of GnRH analogue used during controlled ovarian stimulation influences early embryo developmental kinetics

    DEFF Research Database (Denmark)

    Muñoz, Manuel; Cruz, María; Humaidan, Peter

    2013-01-01

    in the Instituto Valenciano de Infertilidad (IVI) Alicante and the Instituto Universitario-IVI Valencia, Spain, 2817 embryos deriving from 400 couples undergoing oocyte donation were analysed. After controlled ovarian stimulation and IVF/intracytoplamic sperm injection, the timing of embryonic cleavages......OBJECTIVE: To explore if the GnRH analogue used for controlled ovarian stimulation (COS) and the ovulation triggering factor (GnRH agonist+hCG triggering versus GnRH antagonist+GnRH agonist triggering) affect embryo development and kinetics. STUDY DESIGN: In a retrospective cohort study...... was assessed by a video time-lapse system. The results were analysed using Student's t test for comparison of timings (hours) and Chi-squared test for comparison of proportions. A p-value...

  20. The developmental transcriptome of Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    University of Connecticut; Graveley, Brenton R.; Brooks, Angela N.; Carlson, Joseph W.; Duff, Michael O.; Landolin, Jane M.; Yang, Li; Artieri, Carlo G.; van Baren, Marijke J.; Boley, Nathan; Booth, Benjamin W.; Brown, James B.; Cherbas, Lucy; Davis, Carrie A.; Dobin, Alex; Li, Renhua; Lin, Wei; Malone, John H.; Mattiuzzo, Nicolas R.; Miller, David; Sturgill, David; Tuch, Brian B.; Zaleski, Chris; Zhang, Dayu; Blanchette, Marco; Dudoit, Sandrine; Eads, Brian; Green, Richard E.; Hammonds, Ann; Jiang, Lichun; Kapranov, Phil; Langton, Laura; Perrimon, Norbert; Sandler, Jeremy E.; Wan, Kenneth H.; Willingham, Aarron; Zhang, Yu; Zou, Yi; Andrews, Justen; Bicke, Peter J.; Brenner, Steven E.; Brent, Michael R.; Cherbas, Peter; Gingeras, Thomas R.; Hoskins, Roger A.; Kaufman, Thomas C.; Oliver, Brian; Celniker, Susan E.

    2010-12-02

    . Whereas, 20% of Drosophila genes are annotated as encoding alternatively spliced premRNAs, splice-junction microarray experiments indicate that this number is at least 40% (ref. 7). Determining the diversity of mRNAs generated by alternative promoters, alternative splicing and RNA editing will substantially increase the inferred protein repertoire. Non-coding RNA genes (ncRNAs) including short interfering RNAs (siRNAs) and microRNAS (miRNAs) (reviewed in ref. 10), and longer ncRNAs such as bxd (ref. 11) and rox (ref. 12), have important roles in gene regulation, whereas others such as small nucleolar RNAs (snoRNAs)and small nuclear RNAs (snRNAs) are important components of macromolecular machines such as the ribosome and spliceosome. The transcription and processing of these ncRNAs must also be fully documented and mapped. As part of the modENCODE project to annotate the functional elements of the D. melanogaster and Caenorhabditis elegans genomes, we used RNA-Seq and tiling microarrays to sample the Drosophila transcriptome at unprecedented depth throughout development from early embryo to ageing male and female adults. We report on a high-resolution view of the discovery, structure and dynamic expression of the D. melanogaster transcriptome.

  1. Drosophila S2 cells are non-permissive for vaccinia virus DNA replication following entry via low pH-dependent endocytosis and early transcription.

    Directory of Open Access Journals (Sweden)

    Zain Bengali

    Full Text Available Vaccinia virus (VACV, a member of the chordopox subfamily of the Poxviridae, abortively infects insect cells. We have investigated VACV infection of Drosophila S2 cells, which are useful for protein expression and genome-wide RNAi screening. Biochemical and electron microscopic analyses indicated that VACV entry into Drosophila S2 cells depended on the VACV multiprotein entry-fusion complex but appeared to occur exclusively by a low pH-dependent endocytic mechanism, in contrast to both neutral and low pH entry pathways used in mammalian cells. Deep RNA sequencing revealed that the entire VACV early transcriptome, comprising 118 open reading frames, was robustly expressed but neither intermediate nor late mRNAs were made. Nor was viral late protein synthesis or inhibition of host protein synthesis detected by pulse-labeling with radioactive amino acids. Some reduction in viral early proteins was noted by Western blotting. Nevertheless, synthesis of the multitude of early proteins needed for intermediate gene expression was demonstrated by transfection of a plasmid containing a reporter gene regulated by an intermediate promoter. In addition, expression of a reporter gene with a late promoter was achieved by cotransfection of intermediate genes encoding the late transcription factors. The requirement for transfection of DNA templates for intermediate and late gene expression indicated a defect in viral genome replication in VACV-infected S2 cells, which was confirmed by direct analysis. Furthermore, VACV-infected S2 cells did not support the replication of a transfected plasmid, which occurs in mammalian cells and is dependent on all known viral replication proteins, indicating a primary restriction of DNA synthesis.

  2. From stem cell to embryo without centrioles.

    Science.gov (United States)

    Stevens, Naomi R; Raposo, Alexandre A S F; Basto, Renata; St Johnston, Daniel; Raff, Jordan W

    2007-09-04

    Centrosome asymmetry plays a key role in ensuring the asymmetric division of Drosophila neural stem cells (neuroblasts [NBs]) and male germline stem cells (GSCs) [1-3]. In both cases, one centrosome is anchored close to a specific cortical region during interphase, thus defining the orientation of the spindle during the ensuing mitosis. To test whether asymmetric centrosome behavior is a general feature of stem cells, we have studied female GSCs, which divide asymmetrically, producing another GSC and a cystoblast. The cystoblast then divides and matures into an oocyte, a process in which centrosomes exhibit a series of complex behaviors proposed to play a crucial role in oogenesis [4-6]. We show that the interphase centrosome does not define spindle orientation in female GSCs and that DSas-4 mutant GSCs [7], lacking centrioles and centrosomes, invariably divide asymmetrically to produce cystoblasts that proceed normally through oogenesis-remarkably, oocyte specification, microtubule organization, and mRNA localization are all unperturbed. Mature oocytes can be fertilized, but embryos that cannot support centriole replication arrest very early in development. Thus, centrosomes are dispensable for oogenesis but essential for early embryogenesis. These results reveal that asymmetric centrosome behavior is not an essential feature of stem cell divisions.

  3. Toxicity of glyphosate as Glypro and LI700 to red-eared slider (trachemys scripta elegans) embryos and early hatchlings.

    Science.gov (United States)

    Sparling, Donald W; Matson, Cole; Bickham, John; Doelling-Brown, Paige

    2006-10-01

    More than 8.2 billion ha of cropland, gardens, and forests are treated with the herbicide glyphosate each year. Whereas the toxicity of glyphosate and associated adjuvants has been measured in other vertebrates, few, if any, studies have looked at their effects in reptiles. In some instances, management of turtle habitat requires control of successional stages through application of herbicides. Adults and juvenile turtles may be exposed directly, whereas embryos may contact the chemicals through the soil. In the present study, we exposed eggs of red-eared sliders (Trachemys scripta elegans) to single applications of herbicide ranging from 0 to 11,206 ppm wet weight of glyphosate in Glypro and 0 to 678 ppm of the surfactant, LI700. Hatching success at the highest concentration was significantly lower (73%) than in other treatments (80-100%). At hatch, turtles at the highest concentration weighed less than those at other concentrations. During a 14-d holding period, we observed dose-response relationships in the ability of hatchlings to right themselves when turned on their backs. At the end of the holding period, hatchlings at the highest dose level were still lighter, and somatic indices were lower, than those in other treatments. Genetic damage, as measured by flow cytometry, increased with treatment concentration except for the highest dose. We conclude that because of the high concentrations needed to produce effects and the protection offered by several centimeters of soil or sediment, glyphosate with LI700 poses low levels of risk to red-eared slider embryos under normal field operations with regards to the endpoints measured in the present study. Carelessness in handling glyphosate or failure to follow label directions may produce adverse effects. There also is a risk that the health of turtle embryos may be affected in ways not measured in the present study.

  4. Molecular cloning, functional expression, and gene silencing of two Drosophila receptors for the Drosophila neuropeptide pyrokinin-2

    DEFF Research Database (Denmark)

    Rosenkilde, Carina; Cazzamali, Giuseppe; Williamson, Michael

    2003-01-01

    The database of the Drosophila Genome Project contains the sequences of two genes, CG8784 and CG8795, predicted to code for two structurally related G protein-coupled receptors. We have cloned these genes and expressed their coding parts in Chinese hamster ovary cells. We found that both receptors...... can be activated by low concentrations of the Drosophila neuropeptide pyrokinin-2 (CG8784, EC(50) for pyrokinin-2, 1x10(-9)M; CG8795, EC(50) for pyrokinin-2, 5 x 10(-10)M). The precise role of Drosophila pyrokinin-2 (SVPFKPRLamide) in Drosophila is unknown, but in other insects, pyrokinins have...... embryos and first instar larvae. In addition to the two Drosophila receptors, we also identified two probable pyrokinin receptors in the genomic database from the malaria mosquito Anopheles gambiae. The two Drosophila pyrokinin receptors are, to our knowledge, the first invertebrate pyrokinin receptors...

  5. A software tool to model genetic regulatory networks. Applications to the modeling of threshold phenomena and of spatial patterning in Drosophila.

    Directory of Open Access Journals (Sweden)

    Rui Dilão

    Full Text Available We present a general methodology in order to build mathematical models of genetic regulatory networks. This approach is based on the mass action law and on the Jacob and Monod operon model. The mathematical models are built symbolically by the Mathematica software package GeneticNetworks. This package accepts as input the interaction graphs of the transcriptional activators and repressors of a biological process and, as output, gives the mathematical model in the form of a system of ordinary differential equations. All the relevant biological parameters are chosen automatically by the software. Within this framework, we show that concentration dependent threshold effects in biology emerge from the catalytic properties of genes and its associated conservation laws. We apply this methodology to the segment patterning in Drosophila early development and we calibrate the genetic transcriptional network responsible for the patterning of the gap gene proteins Hunchback and Knirps, along the antero-posterior axis of the Drosophila embryo. In this approach, the zygotically produced proteins Hunchback and Knirps do not diffuse along the antero-posterior axis of the embryo of Drosophila, developing a spatial pattern due to concentration dependent thresholds. This shows that patterning at the gap genes stage can be explained by the concentration gradients along the embryo of the transcriptional regulators.

  6. Developmental defects and genomic instability after x-irradiation of wild-type and genetically modified mouse pre-implantation and early post-implantation embryos

    International Nuclear Information System (INIS)

    Jacquet, P

    2012-01-01

    Results obtained from the end of the 1950s suggested that ionizing radiation could induce foetal malformations in some mouse strains when administered during early pre-implantation stages. Starting in 1989, data obtained in Germany also showed that radiation exposure during that period could lead to a genomic instability in the surviving foetuses. Furthermore, the same group reported that both malformations and genomic instability could be transmitted to the next generation foetuses after exposure of zygotes to relatively high doses of radiation. As such results were of concern for radiation protection, we investigated this in more detail during recent years, using mice with varying genetic backgrounds including mice heterozygous for mutations involved in important cellular processes like DNA repair, cell cycle regulation or apoptosis. The main parameters which were investigated included morphological development, genomic instability and gene expression in the irradiated embryos or their own progeny. The aim of this review is to critically reassess the results obtained in that field in the different laboratories and to try to draw general conclusions on the risks of developmental defects and genomic instability from an exposure of early embryos to moderate doses of ionizing radiation. Altogether and in the range of doses normally used in diagnostic radiology, the risk of induction of embryonic death and of congenital malformation following the irradiation of a newly fertilised egg is certainly very low when compared to the ‘spontaneous’ risks for such effects. Similarly, the risk of radiation induction of a genomic instability under such circumstances seems to be very small. However, this is not a reason to not apply some precaution principles when possible. One way of doing this is to restrict the use of higher dose examinations on all potentially pregnant women to the first ten days of their menstrual cycle when conception is very unlikely to have occurred

  7. Rearing the Fruit Fly Drosophila melanogaster Under Axenic and Gnotobiotic Conditions.

    Science.gov (United States)

    Koyle, Melinda L; Veloz, Madeline; Judd, Alec M; Wong, Adam C-N; Newell, Peter D; Douglas, Angela E; Chaston, John M

    2016-07-30

    The influence of microbes on myriad animal traits and behaviors has been increasingly recognized in recent years. The fruit fly Drosophila melanogaster is a model for understanding microbial interactions with animal hosts, facilitated by approaches to rear large sample sizes of Drosophila under microorganism-free (axenic) conditions, or with defined microbial communities (gnotobiotic). This work outlines a method for collection of Drosophila embryos, hypochlorite dechorionation and sterilization, and transfer to sterile diet. Sterilized embryos are transferred to sterile diet in 50 ml centrifuge tubes, and developing larvae and adults remain free of any exogenous microbes until the vials are opened. Alternatively, flies with a defined microbiota can be reared by inoculating sterile diet and embryos with microbial species of interest. We describe the introduction of 4 bacterial species to establish a representative gnotobiotic microbiota in Drosophila. Finally, we describe approaches for confirming bacterial community composition, including testing if axenic Drosophila remain bacteria-free into adulthood.

  8. Bruchpilot in ribbon-like axonal agglomerates, behavioral defects, and early death in SRPK79D kinase mutants of Drosophila.

    Directory of Open Access Journals (Sweden)

    Vanessa Nieratschker

    2009-10-01

    Full Text Available Defining the molecular structure and function of synapses is a central theme in brain research. In Drosophila the Bruchpilot (BRP protein is associated with T-shaped ribbons ("T-bars" at presynaptic active zones (AZs. BRP is required for intact AZ structure and normal evoked neurotransmitter release. By screening for mutations that affect the tissue distribution of Bruchpilot, we have identified a P-transposon insertion in gene CG11489 (location 79D which shows high homology to mammalian genes for SR protein kinases (SRPKs. SRPKs phosphorylate serine-arginine rich splicing factors (SR proteins. Since proteins expressed from CG11489 cDNAs phosphorylate a peptide from a human SR protein in vitro, we name CG11489 the Drosophila Srpk79D gene. We have characterized Srpk79D transcripts and generated a null mutant. Mutation of the Srpk79D gene causes conspicuous accumulations of BRP in larval and adult nerves. At the ultrastructural level, these correspond to extensive axonal agglomerates of electron-dense ribbons surrounded by clear vesicles. Basic synaptic structure and function at larval neuromuscular junctions appears normal, whereas life expectancy and locomotor behavior of adult mutants are significantly impaired. All phenotypes of the mutant can be largely or completely rescued by panneural expression of SRPK79D isoforms. Isoform-specific antibodies recognize panneurally overexpressed GFP-tagged SRPK79D-PC isoform co-localized with BRP at presynaptic active zones while the tagged -PB isoform is found in spots within neuronal perikarya. SRPK79D concentrations in wild type apparently are too low to be revealed by these antisera. We propose that the Drosophila Srpk79D gene characterized here may be expressed at low levels throughout the nervous system to prevent the assembly of BRP containing agglomerates in axons and maintain intact brain function. The discovery of an SR protein kinase required for normal BRP distribution calls for the

  9. The Drosophila Pericentrin-like-protein (PLP cooperates with Cnn to maintain the integrity of the outer PCM

    Directory of Open Access Journals (Sweden)

    Jennifer H. Richens

    2015-08-01

    Full Text Available Centrosomes comprise a pair of centrioles surrounded by a matrix of pericentriolar material (PCM. In vertebrate cells, Pericentrin plays an important part in mitotic PCM assembly, but the Drosophila Pericentrin-like protein (PLP appears to have a more minor role in mitotic fly cells. Here we investigate the function of PLP during the rapid mitotic cycles of the early Drosophila embryo. Unexpectedly, we find that PLP is specifically enriched in the outer-most regions of the PCM, where it largely co-localizes with the PCM scaffold protein Cnn. In the absence of PLP the outer PCM appears to be structurally weakened, and it rapidly disperses along the centrosomal microtubules (MTs. As a result, centrosomal MTs are subtly disorganized in embryos lacking PLP, although mitosis is largely unperturbed and these embryos develop and hatch at near-normal rates. Y2H analysis reveals that PLP can potentially form multiple interactions with itself and with the PCM recruiting proteins Asl, Spd-2 and Cnn. A deletion analysis suggests that PLP participates in a complex network of interactions that ultimately help to strengthen the PCM.

  10. Shaped 3D Singular Spectrum Analysis for Quantifying Gene Expression, with Application to the Early Zebrafish Embryo

    Directory of Open Access Journals (Sweden)

    Alex Shlemov

    2015-01-01

    Full Text Available Recent progress in microscopy technologies, biological markers, and automated processing methods is making possible the development of gene expression atlases at cellular-level resolution over whole embryos. Raw data on gene expression is usually very noisy. This noise comes from both experimental (technical/methodological and true biological sources (from stochastic biochemical processes. In addition, the cells or nuclei being imaged are irregularly arranged in 3D space. This makes the processing, extraction, and study of expression signals and intrinsic biological noise a serious challenge for 3D data, requiring new computational approaches. Here, we present a new approach for studying gene expression in nuclei located in a thick layer around a spherical surface. The method includes depth equalization on the sphere, flattening, interpolation to a regular grid, pattern extraction by Shaped 3D singular spectrum analysis (SSA, and interpolation back to original nuclear positions. The approach is demonstrated on several examples of gene expression in the zebrafish egg (a model system in vertebrate development. The method is tested on several different data geometries (e.g., nuclear positions and different forms of gene expression patterns. Fully 3D datasets for developmental gene expression are becoming increasingly available; we discuss the prospects of applying 3D-SSA to data processing and analysis in this growing field.

  11. Distribution of some Glycoconjugates in the Notochord and Developing Gut during Early Morphogenesis in Balb/c Mouse Embryos

    Directory of Open Access Journals (Sweden)

    Mohammad M. Hassanzadeh-Taheri

    2012-03-01

    Full Text Available Background: Embryonic endoderm germinal layer, affected by notochord inductions, forms the primary gut epithelium and parenchyma of its derived organs. This study aims to determine some expressed glycoconjugates and their potential function in notochord and developing gut.Materials and Methods : In this descriptive-analytical study, 9 and 10 embryonic days (ED of Balb/c mouse embryos were fixed in formalin and microscopic sections were prepared from them. These sections were processed for histochemical studies and then they were incubated with 6 different HRP conjugated lectins, including VVA, SBA, and PNA specific to identify terminal sugar (N-acetylgalactosamine (GalNac and lectins of GSA1-B4, LTA and WGA were respectively to identify the terminal sugars of galactose, fructose and sialic acid.Results: The study results showed that the reactions of notochord and developing gut to VVA lectin were moderate on the 9ED and on the 10ED, they showed a significant difference (p < 0.001 from the day before and were severely assessed. Other GalNac specific lectins react severely and almost similarly to notochord and developing gut on the studied days. The other lectins in these two organs did not react similarly.Conclusion: According to the findings of this study, it seems that glycoconjugates with GalNac-terminal sugar probably have played a key role in differentiations of notochord and developing gut and may be involved in the interactions between these two organs.

  12. Molecular Basis of Meiotic Maturation and Apoptosis of Oocytes, Sperm-Oocyte Interactions and Early Cleavage of Embryos in Mice, Role of Phosphatidylinositol 3-Kinase, Mos, Fas-Fas Ligand, Integrinα6 and MAP Kinase

    OpenAIRE

    Yumi Hoshino; Ken-ichi Yamanaka; Ikuo Tomioka; Noritaka Fukunaga; Mehdi Abbasi; Eimei Sato

    2005-01-01

    The interaction between molecular biology and embryology made an extensive progress in the research on gametogenesis, fertilization and early embryogenesis in mice. In this article, molecules involving in meiotic maturation and apoptosis of oocytes, sperm-oocyte interactions and early cleavage of fertilized embryos in mice are described including our recent following experiments. 1) Phosphatidylinositol 3-kinase and Akt participate in the follicle stimulating hormone-induced meiotic maturatio...

  13. Development of the Early Axon Scaffold in the Rostral Brain of the Small Spotted Cat Shark (Scyliorhinus canicula) Embryo

    OpenAIRE

    Ware, Michelle; Waring, Colin P.; Schubert, Frank R.

    2014-01-01

    International audience; The cat shark is increasingly used as a model for Chondrichthyes, an evolutionarily important sister group of the bony vertebrates that include teleosts and tetrapods. In the bony vertebrates, the first axon tracts form a highly conserved early axon scaffold. The corresponding structure has not been well characterised in cat shark and will prove a useful model for comparative studies. Using pan-neural markers, the early axon scaffold of the cat shark, Scyliorhinus cani...

  14. Requirement of the Combination of Mushroom Body ? Lobe and a/ß Lobes for the Retrieval of Both Aversive and Appetitive Early Memories in "Drosophila"

    Science.gov (United States)

    Xie, Zhiyong; Huang, Cheng; Ci, Bo; Lianzhang, Wang; Zhong, Yi

    2013-01-01

    Extensive studies of "Drosophila" mushroom body in formation and retrieval of olfactory memories allow us to delineate the functional logic for memory storage and retrieval. Currently, there is a questionable disassociation of circuits for memory storage and retrieval during "Drosophila" olfactory memory processing. Formation…

  15. Effect of microinjections of subunits of cAMP-dependent protein kinase on development, proliferation, and RNA synthesis in early embryos of the loach Misgurnus fossilis L

    International Nuclear Information System (INIS)

    Glukhov, A.I.; Benyumov, A.O.; Nesterova, M.V.; Severin, E.S.; Gazaryan, K.G.

    1986-01-01

    The effect of the catalytic and regulatory subunits of cAMP-dependent protein kinase type II on development, proliferation, and RNA synthesis was studied in loach embryos. It was found that injection of the catalytic subunit in a physiological concentration leads to a disturbance in the course of development and inhibits proliferation and RNA synthesis in the embryos. An increase in the concentration of this protein above the physiological level leads to death of the embryos in the first hours of development. Injection of the regulatory subunit stimulated the incorporation of labeled uridine into the acid-insoluble fraction of the embryos, beginning with the gastrula stage. The cell nuclei of loach embryos injected with subunits of protein kinase type II were transplanted into activated loach egg cells: subunits of protein kinase type I had no effect on the ability of nuclei of undetermined loach embryo cells to provide de novo development and their effect was reversible

  16. Hormonal Signaling Cascade during an Early-Adult Critical Period Required for Courtship Memory Retention in Drosophila.

    Science.gov (United States)

    Lee, Sang Soo; Ding, Yike; Karapetians, Natalie; Rivera-Perez, Crisalejandra; Noriega, Fernando Gabriel; Adams, Michael E

    2017-09-25

    Formation and expression of memories are critical for context-dependent decision making. In Drosophila, a courting male rejected by a mated female subsequently courts less avidly when paired with a virgin female, a behavioral modification attributed to "courtship memory." Here we show the critical role of hormonal state for maintenance of courtship memory. Ecdysis-triggering hormone (ETH) is essential for courtship memory through regulation of juvenile hormone (JH) levels in adult males. Reduction of JH levels via silencing of ETH signaling genes impairs short-term courtship memory, a phenotype rescuable by the JH analog methoprene. JH-deficit-induced memory impairment involves rapid decay rather than failure of memory acquisition. A critical period governs memory performance during the first 3 days of adulthood. Using sex-peptide-expressing "pseudo-mated" trainers, we find that robust courtship memory elicited in the absence of aversive chemical mating cues also is dependent on ETH-JH signaling. Finally, we find that JH acts through dopaminergic neurons and conclude that an ETH-JH-dopamine signaling cascade is required during a critical period for promotion of social-context-dependent memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Serotonin signaling is a very early step in patterning of the left-right axis in chick and frog embryos

    NARCIS (Netherlands)

    Fukumoto, T; Kema, IP; Levin, M

    2005-01-01

    Background: Consistent left-right (LR) asymmetry is a fascinating problem in developmental and evolutionary biology. Conservation of early LR patterning steps among vertebrates as well as involvement of nonprotein small-molecule messengers are very poorly understood. Serotonin (5-HT) is a key

  18. Cell cycle accumulation of the proliferating cell nuclear antigen PCN-1 transitions from continuous in the adult germline to intermittent in the early embryo of C. elegans.

    Science.gov (United States)

    Kocsisova, Zuzana; Kornfeld, Kerry; Schedl, Tim

    2018-05-30

    The proliferating cell nuclear antigen (PCNA or PCN-1 in C. elegans), an essential processivity factor for DNA polymerase δ, has been widely used as a marker of S-phase. In C. elegans early embryos, PCN-1 accumulation is cyclic, localizing to the nucleus during S-phase and the cytoplasm during the rest of the cell cycle. The C. elegans larval and adult germline is an important model systems for studying cell cycle regulation, and it was observed that the cell cycle regulator cyclin E (CYE-1 in C. elegans) displays a non-cyclic, continuous accumulation pattern in this tissue. The accumulation pattern of PCN-1 has not been well defined in the larval and adult germline, and the objective of this study was to determine if the accumulation pattern is cyclic, as in other cells and organisms, or continuous, similar to cyclin E. To study the larval and adult germline accumulation of PCN-1 expressed from its native locus, we used CRISPR/Cas9 technology to engineer a novel allele of pcn-1 that encodes an epitope-tagged protein. S-phase nuclei were labeled using EdU nucleotide incorporation, and FLAG::PCN-1 was detected by antibody staining. All progenitor zone nuclei, including those that were not in S-phase (as they were negative for EdU staining) showed PCN-1 accumulation, indicating that PCN-1 accumulated during all cell cycle phases in the germline progenitor zone. The same result was observed with a GFP::PCN-1 fusion protein expressed from a transgene. pcn-1 loss-of-function mutations were analyzed, and pcn-1 was necessary for robust fertility and embryonic development. In the C. elegans early embryo as well as other organisms, PCN-1 accumulates in nuclei only during S-phase. By contrast, in the progenitor zone of the germline of C. elegans, PCN-1 accumulated in nuclei during all cell cycle stages. This pattern is similar to accumulation pattern of cyclin E. These observations support the model that mitotic cell cycle regulation in the germline stem and progenitor

  19. PH Domain-Arf G Protein Interactions Localize the Arf-GEF Steppke for Cleavage Furrow Regulation in Drosophila.

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    Donghoon M Lee

    Full Text Available The recruitment of GDP/GTP exchange factors (GEFs to specific subcellular sites dictates where they activate small G proteins for the regulation of various cellular processes. Cytohesins are a conserved family of plasma membrane GEFs for Arf small G proteins that regulate endocytosis. Analyses of mammalian cytohesins have identified a number of recruitment mechanisms for these multi-domain proteins, but the conservation and developmental roles for these mechanisms are unclear. Here, we report how the pleckstrin homology (PH domain of the Drosophila cytohesin Steppke affects its localization and activity at cleavage furrows of the early embryo. We found that the PH domain is necessary for Steppke furrow localization, and for it to regulate furrow structure. However, the PH domain was not sufficient for the localization. Next, we examined the role of conserved PH domain amino acid residues that are required for mammalian cytohesins to bind PIP3 or GTP-bound Arf G proteins. We confirmed that the Steppke PH domain preferentially binds PIP3 in vitro through a conserved mechanism. However, disruption of residues for PIP3 binding had no apparent effect on GFP-Steppke localization and effects. Rather, residues for binding to GTP-bound Arf G proteins made major contributions to this Steppke localization and activity. By analyzing GFP-tagged Arf and Arf-like small G proteins, we found that Arf1-GFP, Arf6-GFP and Arl4-GFP, but not Arf4-GFP, localized to furrows. However, analyses of embryos depleted of Arf1, Arf6 or Arl4 revealed either earlier defects than occur in embryos depleted of Steppke, or no detectable furrow defects, possibly because of redundancies, and thus it was difficult to assess how individual Arf small G proteins affect Steppke. Nonetheless, our data show that the Steppke PH domain and its conserved residues for binding to GTP-bound Arf G proteins have substantial effects on Steppke localization and activity in early Drosophila embryos.

  20. Early gene Broad complex plays a key role in regulating the immune response triggered by ecdysone in the Malpighian tubules of Drosophila melanogaster.

    Science.gov (United States)

    Verma, Puja; Tapadia, Madhu G

    2015-08-01

    In insects, humoral response to injury is accomplished by the production of antimicrobial peptides (AMPs) which are secreted in the hemolymph to eliminate the pathogen. Drosophila Malpighian tubules (MTs), however, are unique immune organs that show constitutive expression of AMPs even in unchallenged conditions and the onset of immune response is developmental stage dependent. Earlier reports have shown ecdysone positively regulates immune response after pathogenic challenge however, a robust response requires prior potentiation by the hormone. Here we provide evidence to show that MTs do not require prior potentiation with ecdysone hormone for expression of AMPs and they respond to ecdysone very fast even without immune challenge, although the different AMPs Diptericin, Cecropin, Attacin, Drosocin show differential expression in response to ecdysone. We show that early gene Broad complex (BR-C) could be regulating the IMD pathway by activating Relish and physically interacting with it to activate AMPs expression. BR-C depletion from Malpighian tubules renders the flies susceptible to infection. We also show that in MTs ecdysone signaling is transduced by EcR-B1 and B2. In the absence of ecdysone signaling the IMD pathway associated genes are down regulated and activation and translocation of transcription factor Relish is also affected. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. [Molecular cloning, expression of rat Msx-1 and Msx-2 during early embryo genesis and roles for mandibular chondrogenesis].

    Science.gov (United States)

    Ishiguro, S

    1999-03-01

    Quail-chick chimera experiments have shown a contribution of carnial neural crest cells to the craniofacial skeletal elements. Moreover, tissue interactions between epithelial-mesenchymal interaction during early facial process development are required for both skeletal differentiation and morphogenesis. In this study, it was observed that Msx homeobox containing genes expressed in the facial process were important molecules of cartilage morphogenesis. Rat cDNAs were isolated and encoded by Msx-1 and -2, and then the expression patterns using in situ hybridization were investigated during early rat face development. These genes were correlatively expressed in the cranial neural crest forming area (E 9.5 dpc) and the facial process (E 12.5 dpc). Antisence inhibition of Msx genes in the E 12.5 mandibular process exhibited the alteration of their gene expression and cartilage patterns. Antisence inhibition of Msx-1 induced lack of the medial portion of cartilage, and antisence inhibition of Msx-2 enhanced chondrogenesis of mandibular process under the organ culture condition. Thus it was concluded that expression of Msx genes during mandibular process development comprises important signals of chondrogenesis.

  2. P element excision in drosophila melanogaster and related drosophilids

    Science.gov (United States)

    The frequency of P element excision and the structure of the resulting excision products were determined in three drosophilid species, Drosophila melanogaster, D. virilis, and Chymomyza procnemis. A transient P element mobility assay was conducted in the cells of developing insect embryos, but unlik...

  3. Growth attenuation with developmental schedule progression in embryos and early larvae of Sterechinus neumayeri raised under elevated CO2.

    Directory of Open Access Journals (Sweden)

    Pauline C Yu

    Full Text Available The Southern Ocean, a region that will be an ocean acidification hotspot in the near future, is home to a uniquely adapted fauna that includes a diversity of lightly-calcified invertebrates. We exposed the larvae of the echinoid Sterechinus neumayeri to environmental levels of CO(2 in McMurdo Sound (control: 410 µatm, Ω = 1.35 and mildly elevated pCO(2 levels, both near the level of the aragonite saturation horizon (510 µatm pCO(2, Ω = 1.12, and to under-saturating conditions (730 µatm, Ω = 0.82. Early embryological development was normal under these conditions with the exception of the hatching process, which was slightly delayed. Appearance of the initial calcium carbonate (CaCO(3 spicule nuclei among the primary mesenchyme cells of the gastrulae was synchronous between control and elevated pCO(2 treatments. However, by prism (7 days after the initial appearance of the spicule nucleus, elongating arm rod spicules were already significantly shorter in the highest CO(2 treatment. Unfed larvae in the 730 µatm pCO(2 treatment remained significantly smaller than unfed control larvae at days 15-30, and larvae in the 510 µatm treatment were significantly smaller at day 20. At day 30, the arm lengths were more differentiated between 730 µatm and control CO(2 treatments than were body lengths as components of total length. Arm length is the most plastic morphological aspect of the echinopluteus, and appears to exhibit the greatest response to high pCO(2/low pH/low carbonate, even in the absence of food. Thus, while the effects of elevated pCO(2 representative of near future climate scenarios are proportionally minor on these early developmental stages, the longer term effects on these long-lived invertebrates is still unknown.

  4. Theory about the Embryo Cryo-Treatment.

    Science.gov (United States)

    Vladimirov, Iavor K; Tacheva, Desislava; Diez, Antonio

    2017-04-01

    To create hypothesis, which can give a logical explanation related to the benefits of freezing/thawing embryos. Cryopreservation is not only a technology used for storing embryos, but also a method of embryo treatment that can potentially improve the success rate in infertile couples. From the analysis of multiple results in assisted reproductive technology, which have no satisfactory explanation to date, we found evidence to support a 'therapeutic' effect of the freezing/thawing of embryos on the process of recovery of the embryo and its subsequent implantation. Freezing/thawing is a way to activate the endogenous survival and repair responses in preimplantation embryos. Several molecular mechanisms can explain the higher success rate of ET using thawed embryos compared to fresh ET in women of advanced reproductive age, the higher miscarriage rate in cases of thawed blastocyst ET compared to thawed ET at early cleavage embryo, and the higher perinatal parameters of born children after thawed ET. Embryo thawing induces a stress. Controlled stress is not necessarily detrimental, because it generates a phenomenon that is counteracted by several known biological responses aimed to repair mitochondrial damage of membrane and protein misfolding. The term for favorable biological responses to low exposures to stress is called hormesis. This thesis will summarize the role of cryopreservation in the activation of a hormetic response, preserving the mitochondrial function, improving survival, and having an impact on the process of implantation, miscarriage, and the development of pregnancy.

  5. The presence of acylated ghrelin during in vitro maturation of bovine oocytes induces cumulus cell DNA damage and apoptosis, and impairs early embryo development.

    Science.gov (United States)

    Sirini, Matias A; Anchordoquy, Juan Mateo; Anchordoquy, Juan Patricio; Pascua, Ana M; Nikoloff, Noelia; Carranza, Ana; Relling, Alejandro E; Furnus, Cecilia C

    2017-10-01

    The aim of this study was to investigate the effects of acylated ghrelin supplementation during in vitro maturation (IVM) of bovine oocytes. IVM medium was supplemented with 20, 40 or 60 pM acylated ghrelin concentrations. Cumulus expansion area and oocyte nuclear maturation were studied as maturation parameters. Cumulus-oocyte complexes (COC) were assessed with the comet, apoptosis and viability assays. The in vitro effects of acylated ghrelin on embryo developmental capacity and embryo quality were also evaluated. Results demonstrated that acylated ghrelin did not affect oocyte nuclear maturation and cumulus expansion area. However, it induced cumulus cell (CC) death, apoptosis and DNA damage. The damage increased as a function of the concentration employed. Additionally, the percentages of blastocyst yield, hatching and embryo quality decreased with all acylated ghrelin concentrations tested. Our study highlights the importance of acylated ghrelin in bovine reproduction, suggesting that this metabolic hormone could function as a signal that prevents the progress to reproductive processes.

  6. Rapid and highly accurate detection of Drosophila suzukii, spotted wing Drosophila (Diptera: Drosophilidae) by loop-mediated isothermal amplification assays

    Science.gov (United States)

    Drosophila suzukii, the spotted wing drosophila (SWD), is currently a major pest that causes severe economic losses to thin-skinned, small fruit growers in North America and Europe. The monitoring and early detection of SWD in the field is of the utmost importance for its proper management. Althou...

  7. Histone gene expression in early development of Xenopus laevis. Analysis of histone mRNA in oocytes and embryos by blot-hybridization and cell-free translation

    NARCIS (Netherlands)

    van Dongen, W. M.; Moorman, A. F.; Destrée, O. H.

    1983-01-01

    This study comprises the hybridization analysis of electrophoretically separated histone mRNAs from oocytes and embryos of Xenopus laevis, and analysis of in vitro translation products of these mRNAs on polyacrylamide gels containing sodium dodecyl sulfate (SDS) or Triton X-100. In oocytes and

  8. In vitro production of bovine embryos: cumulus/granulosa cell gene expression patterns point to early atresia as beneficial for oocyte competence

    DEFF Research Database (Denmark)

    Mazzoni, Gianluca; Razza, Eduardo; Pedersen, Hanne S.

    2017-01-01

    In vitro production (IW) of bovine embryos has become widespread technology implemented in cattle breeding and production. Here, we review novel data on cumulus/granulosa cell gene expression, as determined by RNAseq on cellular material from pooled follicular fluids at the single animal level...

  9. Detection of nuclei in 4D Nomarski DIC microscope images of early Caenorhabditis elegans embryos using local image entropy and object tracking

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    Hamahashi Shugo

    2005-05-01

    Full Text Available Abstract Background The ability to detect nuclei in embryos is essential for studying the development of multicellular organisms. A system of automated nuclear detection has already been tested on a set of four-dimensional (4D Nomarski differential interference contrast (DIC microscope images of Caenorhabditis elegans embryos. However, the system needed laborious hand-tuning of its parameters every time a new image set was used. It could not detect nuclei in the process of cell division, and could detect nuclei only from the two- to eight-cell stages. Results We developed a system that automates the detection of nuclei in a set of 4D DIC microscope images of C. elegans embryos. Local image entropy is used to produce regions of the images that have the image texture of the nucleus. From these regions, those that actually detect nuclei are manually selected at the first and last time points of the image set, and an object-tracking algorithm then selects regions that detect nuclei in between the first and last time points. The use of local image entropy makes the system applicable to multiple image sets without the need to change its parameter values. The use of an object-tracking algorithm enables the system to detect nuclei in the process of cell division. The system detected nuclei with high sensitivity and specificity from the one- to 24-cell stages. Conclusion A combination of local image entropy and an object-tracking algorithm enabled highly objective and productive detection of nuclei in a set of 4D DIC microscope images of C. elegans embryos. The system will facilitate genomic and computational analyses of C. elegans embryos.

  10. Ca²⁺ influx-linked protein kinase C activity regulates the β-catenin localization, micromere induction signalling and the oral-aboral axis formation in early sea urchin embryos.

    Science.gov (United States)

    Yazaki, Ikuko; Tsurugaya, Toko; Santella, Luigia; Chun, Jong Tai; Amore, Gabriele; Kusunoki, Shinichiro; Asada, Akiko; Togo, Tatsuru; Akasaka, Koji

    2015-06-01

    Sea urchin embryos initiate cell specifications at the 16-cell stage by forming the mesomeres, macromeres and micromeres according to the relative position of the cells in the animal-vegetal axis. The most vegetal cells, micromeres, autonomously differentiate into skeletons and induce the neighbouring macromere cells to become mesoendoderm in the β-catenin-dependent Wnt8 signalling pathway. Although the underlying molecular mechanism for this progression is largely unknown, we have previously reported that the initial events might be triggered by the Ca2+ influxes through the egg-originated L-type Ca2+ channels distributed asymmetrically along the animal-vegetal axis and through the stretch-dependent Ca2+channels expressed specifically in the micromere at the 4th cleavage. In this communication, we have examined whether one of the earliest Ca2+ targets, protein kinase C (PKC), plays a role in cell specification upstream of β-catenin. To this end, we surveyed the expression pattern of β-catenin in early embryos in the presence or absence of the specific peptide inhibitor of Hemicentrotus pulcherrimus PKC (HpPKC-I). Unlike previous knowledge, we have found that the initial nuclear entrance of β-catenin does not take place in the micromeres, but in the macromeres at the 16-cell stage. Using the HpPKC-I, we have demonstrated further that PKC not only determines cell-specific nucleation of β-catenin, but also regulates a variety of cell specification events in the early sea urchin embryos by modulating the cell adhesion structures, actin dynamics, intracellular Ca2+ signalling, and the expression of key transcription factors.

  11. Lethals induced by γ-radiation in drosophila somatic cells

    International Nuclear Information System (INIS)

    Ivanov, A.I.

    1989-01-01

    Exposure of 3-hour drosophila male embryos to γ-radiation during the topographic segregation of the germ anlage nuclei caused recessive sex-linked lethals in somatic cells only. The selectivity of the screening was determined by the ratio of mutation frequencies induced in embryos and adult males. Analysis of lethal mutations shows that a minimal rate of the divergence between germinal and somatic patterns of the cell development is observed in the embryogenesis, the 3d instar larva and prepupa, and maximal in the 1st and 2nd larva and pupa

  12. Wolbachia-induced cytoplasmic incompatibility is associated with decreased Hira expression in male Drosophila.

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    Ya Zheng

    Full Text Available BACKGROUND: Wolbachia are obligate endosymbiotic bacteria that infect numerous species of arthropods and nematodes. Wolbachia can induce several reproductive phenotypes in their insect hosts including feminization, male-killing, parthenogenesis and cytoplasmic incompatibility (CI. CI is the most common phenotype and occurs when Wolbachia-infected males mate with uninfected females resulting in no or very low numbers of viable offspring. However, matings between males and females infected with the same strain of Wolbachia result in viable progeny. Despite substantial scientific effort, the molecular mechanisms underlying CI are currently unknown. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression studies were undertaken in Drosophila melanogaster and D. simulans which display differential levels of CI using quantitative RT-PCR. We show that Hira expression is correlated with the induction of CI and occurs in a sex-specific manner. Hira expression is significantly lower in males which induce strong CI when compared to males inducing no CI or Wolbachia-uninfected males. A reduction in Hira expression is also observed in 1-day-old males that induce stronger CI compared to 5-day-old males that induce weak or no CI. In addition, Hira mutated D. melanogaster males mated to uninfected females result in significantly decreased hatch rates comparing with uninfected crosses. Interestingly, wMel-infected females may rescue the hatch rates. An obvious CI phenotype with chromatin bridges are observed in the early embryo resulting from Hira mutant fertilization, which strongly mimics the defects associated with CI. CONCLUSIONS/SIGNIFICANCE: Our results suggest Wolbachia-induced CI in Drosophila occurs due to a reduction in Hira expression in Wolbachia-infected males leading to detrimental effects on sperm fertility resulting in embryo lethality. These results may help determine the underlying mechanism of CI and provide further insight in to the important role

  13. Protein phosphorylation during coconut zygotic embryo development

    International Nuclear Information System (INIS)

    Islas-Flores, I.; Oropeza, C.; Hernandez-Sotomayor, S.M.T.

    1998-01-01

    Evidence was obtained on the occurrence of protein threonine, serine, and tyrosine (Tyr) kinases in developing coconut (Cocos nucifera L.) zygotic embryos, based on in vitro phosphorylation of proteins in the presence of [gamma-32P]ATP, alkaline treatment, and thin-layer chromatography analysis, which showed the presence of [32P]phosphoserine, [32P]phosphothreonine, and [32P]phosphotyrosine in [32P]-labeled protein hydrolyzates. Tyr kinase activity was further confirmed in extracts of embryos at different stages of development using antiphosphotyrosine monoclonal antibodies and the synthetic peptide derived from the amino acid sequence surrounding the phosphorylation site in pp60src (RR-SRC), which is specific for Tyr kinases. Anti-phosphotyrosine western blotting revealed a changing profile of Tyr-phosphorylated proteins during embryo development. Tyr kinase activity, as assayed using RR-SRC, also changed during embryo development, showing two peaks of activity, one during early and another during late embryo development. In addition, the use of genistein, a Tyr kinase inhibitor, diminished the ability of extracts to phosphorylate RR-SRC. Results presented here show the occurrence of threonine, serine, and Tyr kinases in developing coconut zygotic embryos, and suggest that protein phosphorylation, and the possible inference of Tyr phosphorylation in particular, may play a role in the coordination of the development of embryos in this species

  14. Embryos, individuals, and persons: an argument against embryo creation and research.

    Science.gov (United States)

    Tollefsen, C

    2001-01-01

    One strategy for arguing that it should be legally permissible to create human embryos, or to use spare human embryos, for scientific research purposes involves the claim that such embryos cannot be persons because they are not human individuals while twinning may yet take place. Being a human individual is considered to be by most people a necessary condition for being a human person. I argue first that such an argument against the personhood of embryos must be rationally conclusive if their destruction in public places such as laboratories is to be countenanced. I base this argument on a popular understanding of the role that the notion of privacy plays in abortion laws. I then argue that such arguments against personhood are not rationally conclusive. The claim that the early embryos is not a human individual is not nearly as obvious as some assert.

  15. Maternal control of the Drosophila dorsal–ventral body axis

    Science.gov (United States)

    Stein, David S.; Stevens, Leslie M.

    2016-01-01

    The pathway that generates the dorsal–ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. PMID:25124754

  16. High-dose irradiation induces cell cycle arrest, apoptosis, and developmental defects during Drosophila oogenesis.

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    Hee Jin Shim

    Full Text Available Ionizing radiation (IR treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis.

  17. Characterization of the Drosophila ortholog of the human Usher Syndrome type 1G protein sans.

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    Fabio Demontis

    Full Text Available BACKGROUND: The Usher syndrome (USH is the most frequent deaf-blindness hereditary disease in humans. Deafness is attributed to the disorganization of stereocilia in the inner ear. USH1, the most severe subtype, is associated with mutations in genes encoding myosin VIIa, harmonin, cadherin 23, protocadherin 15, and sans. Myosin VIIa, harmonin, cadherin 23, and protocadherin 15 physically interact in vitro and localize to stereocilia tips in vivo, indicating that they form functional complexes. Sans, in contrast, localizes to vesicle-like structures beneath the apical membrane of stereocilia-displaying hair cells. How mutations in sans result in deafness and blindness is not well understood. Orthologs of myosin VIIa and protocadherin 15 have been identified in Drosophila melanogaster and their genetic analysis has identified essential roles in auditory perception and microvilli morphogenesis, respectively. PRINCIPAL FINDINGS: Here, we have identified and characterized the Drosophila ortholog of human sans. Drosophila Sans is expressed in tubular organs of the embryo, in lens-secreting cone cells of the adult eye, and in microvilli-displaying follicle cells during oogenesis. Sans mutants are viable, fertile, and mutant follicle cells appear to form microvilli, indicating that Sans is dispensable for fly development and microvilli morphogenesis in the follicle epithelium. In follicle cells, Sans protein localizes, similar to its vertebrate ortholog, to intracellular punctate structures, which we have identified as early endosomes associated with the syntaxin Avalanche. CONCLUSIONS: Our work is consistent with an evolutionary conserved function of Sans in vesicle trafficking. Furthermore it provides a significant basis for further understanding of the role of this Usher syndrome ortholog in development and disease.

  18. Somatic Embryos in Catharanthus roseus: A Scanning Electron Microscopic Study

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    Junaid ASLAM

    2014-06-01

    Full Text Available Catharanthus roseus (L. G. Don is an important medicinal plant as it contains several anti-cancerous compounds, like vinblastine and vincristine. Plant tissue culture technology (organogenesis and embryogenesis has currently been used in fast mass propagating raw materials for secondary metabolite synthesis. In this present communication, scanning electron microscopic (SEM study of somatic embryos was conducted and discussed. The embryogenic callus was first induced from hypocotyls of in vitro germinated seeds on which somatic embryos, differentiated in numbers, particularly on 2,4-D (1.0 mg/L Murashige and Skoog (MS was medium. To understand more about the regeneration method and in vitro formed embryos SEM was performed. The SEM study revealed normal somatic embryo origin and development from globular to heart-, torpedo- and then into cotyledonary-stage of embryos. At early stage, the embryos were clustered together in a callus mass and could not easily be detached from the parental tissue. The embryos were often long cylindrical structure with or without typical notch at the tip. Secondary embryos were also formed on primary embryo structure. The advanced cotyledonary embryos showed prominent roots and shoot axis, which germinated into plantlets. The morphology, structure and other details of somatic embryos at various stages were presented.

  19. Novel synthetic Medea selfish genetic elements drive population replacement in Drosophila; a theoretical exploration of Medea-dependent population suppression.

    Science.gov (United States)

    Akbari, Omar S; Chen, Chun-Hong; Marshall, John M; Huang, Haixia; Antoshechkin, Igor; Hay, Bruce A

    2014-12-19

    Insects act as vectors for diseases of plants, animals, and humans. Replacement of wild insect populations with genetically modified individuals unable to transmit disease provides a potentially self-perpetuating method of disease prevention. Population replacement requires a gene drive mechanism in order to spread linked genes mediating disease refractoriness through wild populations. We previously reported the creation of synthetic Medea selfish genetic elements able to drive population replacement in Drosophila. These elements use microRNA-mediated silencing of myd88, a maternally expressed gene required for embryonic dorso-ventral pattern formation, coupled with early zygotic expression of a rescuing transgene, to bring about gene drive. Medea elements that work through additional mechanisms are needed in order to be able to carry out cycles of population replacement and/or remove existing transgenes from the population, using second-generation elements that spread while driving first-generation elements out of the population. Here we report the synthesis and population genetic behavior of two new synthetic Medea elements that drive population replacement through manipulation of signaling pathways involved in cellular blastoderm formation or Notch signaling, demonstrating that in Drosophila Medea elements can be generated through manipulation of diverse signaling pathways. We also describe the mRNA and small RNA changes in ovaries and early embryos associated from Medea-bearing females. Finally, we use modeling to illustrate how Medea elements carrying genes that result in diapause-dependent female lethality could be used to bring about population suppression.

  20. The Drosophila Microtubule-Associated Protein Mars Stabilizes Mitotic Spindles by Crosslinking Microtubules through Its N-Terminal Region

    Science.gov (United States)

    Zhang, Gang; Beati, Hamze; Nilsson, Jakob; Wodarz, Andreas

    2013-01-01

    Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs) are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs) have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs. PMID:23593258

  1. The Drosophila microtubule-associated protein mars stabilizes mitotic spindles by crosslinking microtubules through its N-terminal region.

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    Full Text Available Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs.

  2. The Drosophila microtubule-associated protein mars stabilizes mitotic spindles by crosslinking microtubules through its N-terminal region.

    Science.gov (United States)

    Zhang, Gang; Beati, Hamze; Nilsson, Jakob; Wodarz, Andreas

    2013-01-01

    Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs) are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs) have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs.

  3. Tre1, a G protein-coupled receptor, directs transepithelial migration of Drosophila germ cells.

    Directory of Open Access Journals (Sweden)

    Prabhat S Kunwar

    2003-12-01

    Full Text Available In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR, Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

  4. Embryonic origins of a motor system: motor dendrites form a myotopic map in Drosophila.

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    Matthias Landgraf

    2003-11-01

    Full Text Available The organisational principles of locomotor networks are less well understood than those of many sensory systems, where in-growing axon terminals form a central map of peripheral characteristics. Using the neuromuscular system of the Drosophila embryo as a model and retrograde tracing and genetic methods, we have uncovered principles underlying the organisation of the motor system. We find that dendritic arbors of motor neurons, rather than their cell bodies, are partitioned into domains to form a myotopic map, which represents centrally the distribution of body wall muscles peripherally. While muscles are segmental, the myotopic map is parasegmental in organisation. It forms by an active process of dendritic growth independent of the presence of target muscles, proper differentiation of glial cells, or (in its initial partitioning competitive interactions between adjacent dendritic domains. The arrangement of motor neuron dendrites into a myotopic map represents a first layer of organisation in the motor system. This is likely to be mirrored, at least in part, by endings of higher-order neurons from central pattern-generating circuits, which converge onto the motor neuron dendrites. These findings will greatly simplify the task of understanding how a locomotor system is assembled. Our results suggest that the cues that organise the myotopic map may be laid down early in development as the embryo subdivides into parasegmental units.

  5. Mitochondrial DNA content in embryo culture medium is significantly associated with human embryo fragmentation.

    Science.gov (United States)

    Stigliani, S; Anserini, P; Venturini, P L; Scaruffi, P

    2013-10-01

    approach we are proposing may provide a novel, non-invasive, objective tool for embryo quality grading. The correlation between a high mtDNA concentration and the fragmentation rate of embryos is suggestive that fragments are mainly anuclear cytoplasmatic debris arising during cleavage. Therefore, blastomere shaping as an early event during in vitro development may play a homeostatic role and be related to embryo competence. This project was funded by Merck Serono (Grant for Fertility Innovation 2011). The sponsor had no role in study design, data collection, data analysis, data interpretation and writing of the paper. Authors declare no conflicts of interest. ClinicalTrials.gov Identifier: NCT01397136.

  6. Cell cycle-related fluctuations in transcellular ionic currents and plasma membrane Ca2+/Mg2+ ATPase activity during early cleavages of Lymnaea stagnalis embryos.

    Science.gov (United States)

    Zivkovic, Danica; Créton, Robbert; Dohmen, René

    1991-08-01

    During the first four mitotic division cycles of Lymnaea stagnalis embryos, we have detected cell cycle-dependent changes in the pattern of transcellular ionic currents and membrane-bound Ca 2+ -stimulated ATPase activity. Ionic currents ranging from 0.05 to 2.50 μA/cm 2 have been measured using the vibrating probe technique. Enzyme activity was detected using Ando's cytochemical method (Ando et al. 1981) which reveals Ca 2+ /Mg 2+ ATPase localization at the ultrastructural level, and under high-stringency conditions with respect to calcium availability, it reveals Ca 2+ -stimulated ATPase. The ionic currents and Ca 2+ -stimulated ATPase localization have in common that important changes occur during the M-phase of the cell cycles. Minimal outward current at the vegetal pole coincides with metaphase/anaphase. Maximal inward current at the animal pole coincides with the onset of cytokinesis at that pole. Ca 2+ -stimulated ATPase is absent from one half of the embryo at metaphase/anaphase of the two- and four-cell stage, whereas it is present in all cells during the remaining part of the cell cycle. Since fluctuations of cytosolic free calcium concentrations appear to correlate with both karyokinesis and cytokinesis, we speculate that part of the cyclic pattern of Ca 2+ -stimulated ATPase localization and of the transcellular ionic currents reflects the elevation of cytosolic free calcium concentration during the M-phase.

  7. In vitro fertilization in Japan — Early days of in vitro fertilization and embryo transfer and future prospects for assisted reproductive technology —

    Science.gov (United States)

    SUZUKI, Masakuni

    2014-01-01

    Assisted reproductive technology (ART) such as in vitro fertilization (IVF) and embryo transfer (ET) has been essential in the treatment of infertility. The world’s first IVF-ET baby was born in 1978 based on the technique developed by Dr. Robert Edwards and Dr. Patrick Steptoe.1) In Japan, the first IVF-ET birth was reported in 1983 by Prof. Masakuni Suzuki at Tohoku University School of Medicine.2,3) IVF-ET is a procedure used to achieve pregnancy that consists of extracting oocytes from an infertile woman, fertilizing them in vitro, and transferring fertilized eggs into the patient’s uterine cavity (Fig. 1). Since the first report of successful IVF-ET, numerous techniques related to ART, such as cryopreservation of oocytes and embryos, gamete intrafallopian transfer (GIFT), and microinsemination, have been developed and refined (Table 1). Herein we describe the history of basic research in IVF-ET that led to human applications, how the birth of the first IVF-ET baby was achieved in Japan, the current status of ART in Japan, issues related to ART, and future prospects for ART. PMID:24814992

  8. A highly conserved Poc1 protein characterized in embryos of the hydrozoan Clytia hemisphaerica: localization and functional studies.

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    Cécile Fourrage

    Full Text Available Poc1 (Protein of Centriole 1 proteins are highly conserved WD40 domain-containing centriole components, well characterized in the alga Chlamydomonas, the ciliated protazoan Tetrahymena, the insect Drosophila and in vertebrate cells including Xenopus and zebrafish embryos. Functions and localizations related to the centriole and ciliary axoneme have been demonstrated for Poc1 in a range of species. The vertebrate Poc1 protein has also been reported to show an additional association with mitochondria, including enrichment in the specialized "germ plasm" region of Xenopus oocytes. We have identified and characterized a highly conserved Poc1 protein in the cnidarian Clytia hemisphaerica. Clytia Poc1 mRNA was found to be strongly expressed in eggs and early embryos, showing a punctate perinuclear localization in young oocytes. Fluorescence-tagged Poc1 proteins expressed in developing embryos showed strong localization to centrioles, including basal bodies. Anti-human Poc1 antibodies decorated mitochondria in Clytia, as reported in human cells, but failed to recognise endogenous or fluorescent-tagged Clytia Poc1. Injection of specific morpholino oligonucleotides into Clytia eggs prior to fertilization to repress Poc1 mRNA translation interfered with cell division from the blastula stage, likely corresponding to when neosynthesis normally takes over from maternally supplied protein. Cell cycle lengthening and arrest were observed, phenotypes consistent with an impaired centriolar biogenesis or function. The specificity of the defects could be demonstrated by injection of synthetic Poc1 mRNA, which restored normal development. We conclude that in Clytia embryos, Poc1 has an essentially centriolar localization and function.

  9. Closure of the vertebral canal in human embryos and fetuses

    NARCIS (Netherlands)

    Mekonen, Hayelom K.; Hikspoors, Jill P. J. M.; Mommen, Greet; Kruepunga, Nutmethee; Köhler, S. Eleonore; Lamers, Wouter H.

    2017-01-01

    The vertebral column is the paradigm of the metameric architecture of the vertebrate body. Because the number of somites is a convenient parameter to stage early human embryos, we explored whether the closure of the vertebral canal could be used similarly for staging embryos between 7 and 10weeks of

  10. Mutant human torsinA, responsible for early-onset dystonia, dominantly suppresses GTPCH expression, dopamine levels and locomotion in Drosophila melanogaster

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    Noriko Wakabayashi-Ito

    2015-07-01

    Full Text Available Dystonia represents the third most common movement disorder in humans with over 20 genetic loci identified. TOR1A (DYT1, the gene responsible for the most common primary hereditary dystonia, encodes torsinA, an AAA ATPase family protein. Most cases of DYT1 dystonia are caused by a 3 bp (ΔGAG deletion that results in the loss of a glutamic acid residue (ΔE302/303 in the carboxyl terminal region of torsinA. This torsinAΔE mutant protein has been speculated to act in a dominant-negative manner to decrease activity of wild type torsinA. Drosophila melanogaster has a single torsin-related gene, dtorsin. Null mutants of dtorsin exhibited locomotion defects in third instar larvae. Levels of dopamine and GTP cyclohydrolase (GTPCH proteins were severely reduced in dtorsin-null brains. Further, the locomotion defect was rescued by the expression of human torsinA or feeding with dopamine. Here, we demonstrate that human torsinAΔE dominantly inhibited locomotion in larvae and adults when expressed in neurons using a pan-neuronal promoter Elav. Dopamine and tetrahydrobiopterin (BH4 levels were significantly reduced in larval brains and the expression level of GTPCH protein was severely impaired in adult and larval brains. When human torsinA and torsinAΔE were co-expressed in neurons in dtorsin-null larvae and adults, the locomotion rates and the expression levels of GTPCH protein were severely reduced. These results support the hypothesis that torsinAΔE inhibits wild type torsinA activity. Similarly, neuronal expression of a Drosophila DtorsinΔE equivalent mutation dominantly inhibited larval locomotion and GTPCH protein expression. These results indicate that both torsinAΔE and DtorsinΔE act in a dominant-negative manner. We also demonstrate that Dtorsin regulates GTPCH expression at the post-transcriptional level. This Drosophila model of DYT1 dystonia provides an important tool for studying the differences in the molecular function between the

  11. Effects of transgenic sterilization constructs and their repressor compounds on hatch, developmental rate and early survival of electroporated channel catfish embryos and fry.

    Science.gov (United States)

    Su, Baofeng; Shang, Mei; Li, Chao; Perera, Dayan A; Pinkert, Carl A; Irwin, Michael H; Peatman, Eric; Grewe, Peter; Patil, Jawahar G; Dunham, Rex A

    2015-04-01

    Channel catfish (Ictalurus punctatus) embryos were electroporated with sterilization constructs targeting primordial germ cell proteins or with buffer. Some embryos then were treated with repressor compounds, cadmium chloride, copper sulfate, sodium chloride or doxycycline, to prevent expression of the transgene constructs. Promoters included channel catfish nanos and vasa, salmon transferrin (TF), modified yeast Saccharomyces cerevisiae copper transport protein (MCTR) and zebrafish racemase (RM). Knock-down systems were the Tet-off (nanos and vasa constructs), MCTR, RM and TF systems. Knock-down genes included shRNAi targeting 5' nanos (N1), 3' nanos (N2) or dead end (DND), or double-stranded nanos RNA (dsRNA) for overexpression of nanos mRNA. These constructs previously were demonstrated to knock down nanos, vasa and dead end, with the repressors having variable success. Exogenous DNA affected percentage hatch (% hatch), as all 14 constructs, except for the TF dsRNA, TF N1 (T), RM DND (C), vasa DND (C), vasa N1 (C) and vasa N2 (C), had lower % hatch than the control electroporated with buffer. The MCTR and RM DND (T) constructs resulted in delayed hatch, and the vasa and nanos constructs had minimal effects on time of hatch (P nanos constructs, doxycycline greatly delayed hatch (P < 0.05). Adverse effects of the transgenes and repressors continued for several treatments for the first 6 days after hatch, but only in a few treatments during the next 10 days. Repressors and gene expression impacted the yield of putative transgenic channel catfish fry, and need to be considered and accounted for in the hatchery phase of producing transgenically sterilized catfish fry and their fertile counterparts. This fry output should be considered to ensure that sufficient numbers of transgenic fish are produced for future applications and for defining repressor systems that are the most successful.

  12. [Assisted reproductive technologies and the embryo status].

    Science.gov (United States)

    Englert, Y

    The status of the human embryo has always be a subject of philosophical and theological thoughts with major social consequences, but, until the 19th century, it has been mainly an abstraction. The arrival of the human embryo in vitro, materialized by Louise Brown's birth in 1978 and above all by the supernumerary embryos produced by the Australian team of Trounson and Wood following the introduction of ovarian stimulation, will turn theoretical thoughts into a reality. Nobody may ignore the hidden intentions behind the debate, as to recognise a status to a few days old embryo will immediately have a major impact on the status of a few weeks old foetus and therefore on the abortion rights. We will see that the embryo status, essentially based as well on a vision on the good and evil as on social order, cannot be based on a scientific analysis of the reproduction process but comes from a society's choice, by essence " arbitrary " and always disputable. This does not preclude the collectivity right and legitimacy to give a precise status and it is remarkable to observe the law is careful not to specify which status to give to the human embryo. It is more thru handling procedures and functioning rules that the law designed the embryo position, neither with a status of a person, nor of a thing. It nevertheless remains true that there is a constant risk that the legislation gives the embryo a status that would call into question it's unique characteristic of early reproductive stage, jeopardizing at once the hard-won reproductive freedom (reproductive choice) as well as freedom of research on embryonic stem cells, one of the most promising field of medical research.

  13. Metabolomic Studies in Drosophila.

    Science.gov (United States)

    Cox, James E; Thummel, Carl S; Tennessen, Jason M

    2017-07-01

    Metabolomic analysis provides a powerful new tool for studies of Drosophila physiology. This approach allows investigators to detect thousands of chemical compounds in a single sample, representing the combined contributions of gene expression, enzyme activity, and environmental context. Metabolomics has been used for a wide range of studies in Drosophila , often providing new insights into gene function and metabolic state that could not be obtained using any other approach. In this review, we survey the uses of metabolomic analysis since its entry into the field. We also cover the major methods used for metabolomic studies in Drosophila and highlight new directions for future research. Copyright © 2017 by the Genetics Society of America.

  14. Arabidopsis mitochondrial protein slow embryo development1 is essential for embryo development

    International Nuclear Information System (INIS)

    Ju, Yan; Liu, Chunying; Lu, Wenwen; Zhang, Quan; Sodmergen

    2016-01-01

    The plant seeds formation are crucial parts in reproductive process in seed plants as well as food source for humans. Proper embryo development ensure viable seed formation. Here, we showed an Arabidopsis T-DNA insertion mutant slow embryo development1 (sed1) which exhibited retarded embryogenesis, led to aborted seeds. Embryo without SED1 developed slower compared to normal one and could be recognized at early globular stage by its white appearance. In later development stage, storage accumulated poorly with less protein and lipid body production. In vitro culture did not rescue albino embryo. SED1 encoded a protein targeted to mitochondria. Transmission electron microscopic analysis revealed that mitochondria developed abnormally, and more strikingly plastid failed to construct grana in time in sed1/sed1 embryo. These data indicated that SED1 is indispensable for embryogenesis in Arabidopsis, and the mitochondria may be involved in the regulation of many aspects of seed development. -- Highlights: •Arabidopsis SED1 is essential for embryo development. •The sed1 embryo accumulates less storage and has abnormal ultrastructure. •SED1 localizes to the mitochondrion.

  15. Survival of embryo irradiated with gamma rays by embryo culture in Brassica pekinensis Rupr

    International Nuclear Information System (INIS)

    Moue, T.

    1984-01-01

    The effect of irradiation on the survival rates and embryonic development of Brassica pekinensis RUPR. (Varieties; Kashin, Kohai 65 nichi and kairyochitose) was investigated. The purpose of this study was to seek ways of increasing the survival rates of embryos such as B.oleracea obtained through embryo culture techniques after irradiation doses affecting seed fertility and germination, for the purpose of increasing mutation rates. Embryos at different developmental stages ranging from the globular to the early heart stages were irradiated with 20 KR of gamma rays at the daily rate 0L 20 KR or 10 KR (Fig.1 and Table 1). The embryos were excised from ovules 4 to 10 days after irradiation and cultured on White's medium. The shooting and rooting rates on the 34th day of culture were higher at the dose of 10 KR/day than 20 KR/day and were lower when the materials were irradiated at the young embryonic stage (Table 3). Varietal differences in the shooting and rooting rates were also observed. The irradiated embryos survived mainly in the state of callus. It was concluded that the embryo culture technique was successful when applied to irradiated embryos excised at the young embryonic stage and that the technique affected B.pekinensis less than B.oleracea

  16. Arabidopsis mitochondrial protein slow embryo development1 is essential for embryo development

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yan; Liu, Chunying; Lu, Wenwen; Zhang, Quan; Sodmergen, E-mail: sodmergn@pku.edu.cn

    2016-05-27

    The plant seeds formation are crucial parts in reproductive process in seed plants as well as food source for humans. Proper embryo development ensure viable seed formation. Here, we showed an Arabidopsis T-DNA insertion mutant slow embryo development1 (sed1) which exhibited retarded embryogenesis, led to aborted seeds. Embryo without SED1 developed slower compared to normal one and could be recognized at early globular stage by its white appearance. In later development stage, storage accumulated poorly with less protein and lipid body production. In vitro culture did not rescue albino embryo. SED1 encoded a protein targeted to mitochondria. Transmission electron microscopic analysis revealed that mitochondria developed abnormally, and more strikingly plastid failed to construct grana in time in sed1/sed1 embryo. These data indicated that SED1 is indispensable for embryogenesis in Arabidopsis, and the mitochondria may be involved in the regulation of many aspects of seed development. -- Highlights: •Arabidopsis SED1 is essential for embryo development. •The sed1 embryo accumulates less storage and has abnormal ultrastructure. •SED1 localizes to the mitochondrion.

  17. Preimplantation development of embryos in women of advanced maternal age

    Directory of Open Access Journals (Sweden)

    O. V. Chaplia

    2014-04-01

    Full Text Available In order to reveal the influence of genetic component on the early embryo development, the retrospective study of morphokinetic characteristics of 717 embryos subjected to preimplantation genetic testing was conducted. Blastomere biopsy for FISH-based preimplantation genetic screening of 7 chromosomes was performed on the third day of culture, while embryo developmental potential and morphological features at the cleavage and blastulation stage were studied regarding maternal age particularly in the group of younger women and patients older than 36. Results of genetic testing revealed that euploid embryos rate gradually decreased with maternal age comprising 39.9% in young women group and 25.3% of specimen belonging to elder patients. At the cleavage stage, morphological characteristics of aneuploid and euploid embryos didn’t differ significantly regardless of the age of patients that could be accounted for the transcriptional silence of embryo genome till the third day of its development. However, in case of prolonged culture chromosomally balanced embryos rarely faced developmental arrest (in 7.9% and formed blastocysts half more frequently compared to aberrant embryos (respectively 75.6 versus 49.8%. Nevertheless, no substantial difference was found between blastocyst formation rate among embryos with similar genetic component regardless of the maternal age. Taking into consideration high rate of chromosomally unbalanced embryos specific to patients of advanced maternal age, the relative proportion of aneuplouid blastocysts was significantly higher in this group of embryos. Thus, without genetic screening there is a possibility of inaccurate selection of embryos for women of advanced reproductive age for transfer procedure even in case of prolonged culture. Consequently, increase of aneuploid embryos frequency associated with permanent preimplantation natural selection effectiveness along with the postimplantation natural selection failure

  18. Characterization of migratory primordial germ cells in the aorta-gonad-mesonephros of a 4.5 week-old human embryo: a toolbox to evaluate in-vitro early gametogenesis.

    Science.gov (United States)

    Gomes Fernandes, Maria; Bialecka, Monika; Salvatori, Daniela C F; Chuva de Sousa Lopes, Susana M

    2018-03-08

    Which set of antibodies can be used to identify migratory and early post-migratory human primordial germ cells (hPGCs)? We validated the specificity of 33 antibodies for 31 markers, including POU5F1, NANOG, PRDM1 and TFAP2C as specific markers of hPGCs at 4.5 weeks of development of Carnegie stage (CS12-13), whereas KIT and SOX17 also marked the intra-aortic hematopoietic stem cell cluster in the aorta-gonad-mesonephros (AGM). The dynamics of gene expression during germ cell development in mice is well characterized and this knowledge has proved crucial to allow the development of protocols for the in-vitro derivation of functional gametes. Although there is a great interest in generating human gametes in vitro, it is still unclear which markers are expressed during the early stages of hPGC development and many studies use markers described in mouse to benchmark differentiation of human PGC-like cells (hPGCLCs). Early post-implantation development differs significantly between mice and humans, and so some germ cells markers, including SOX2, SOX17, IFITM3 and ITGA6 may not identify mPGCs and hPGCs equally well. This immunofluorescence study investigated the expression of putative hPGC markers in the caudal part of a single human embryo at 4.5 weeks of development. We have investigated by immunofluorescence the expression of a set of 33 antibodies for 31 markers, including pluripotency, germ cell, adhesion, migration, surface, mesenchymal and epigenetic markers on paraffin sections of the caudal part, including the AGM region, of a single human embryo (CS 12-13). The human material used was anonymously donated with informed consent from elective abortions without medical indication. We observed germ cell specific expression of NANOG, TFAP2C and PRDM1 in POU5F1+ hPGCs in the AGM. The epigenetic markers H3K27me3 and 5mC were sufficient to distinguish hPGCs from the surrounding somatic cells. Some mPGC-markers were not detected in hPGCs, but marked other tissues

  19. Severe Fertility Effects of sheepish Sperm Caused by Failure To Enter Female Sperm Storage Organs in Drosophila melanogaster

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    Masatoshi Tomaru

    2018-01-01

    Full Text Available In Drosophila, mature sperm are transferred from males to females during copulation, stored in the sperm storage organs of females, and then utilized for fertilization. Here, we report a gene named sheepish (shps of Drosophila melanogaster that is essential for sperm storage in females. shps mutant males, although producing morphologically normal and motile sperm that are effectively transferred to females, produce very few offspring. Direct counts of sperm indicated that the primary defect was correlated to failure of shps sperm to migrate into the female sperm storage organs. Increased sperm motion parameters were seen in the control after transfer to females, whereas sperm from shps males have characteristics of the motion parameters different from the control. The few sperm that occasionally entered the female sperm storage organs showed no obvious defects in fertilization and early embryo development. The female postmating responses after copulation with shps males appeared normal, at least with respect to conformational changes of uterus, mating plug formation, and female remating rates. The shps gene encodes a protein with homology to amine oxidases, including as observed in mammals, with a transmembrane region at the C-terminal end. The shps mutation was characterized by a nonsense replacement in the third exon of CG13611, and shps was rescued by transformants of the wild-type copy of CG13611. Thus, shps may define a new class of gene responsible for sperm storage.

  20. Concentrações de 6-benzilaminopurina no desenvolvimento in vitro de embriões de pêssegos e nectarinas precoces In vitro effects of 6-benzylaminopurine (BAP on early peach and nectarine embryos development

    Directory of Open Access Journals (Sweden)

    Wilson Barbosa

    1990-01-01

    Full Text Available Objetivando melhorar o desenvolvimento in vitro de embriões de pêssegos e nectarinas, de maturação precoce, adicionou-se, em meio básico de cultura, o regulador de crescimento 6-benzilaminopurina (BAP nas concentrações de 0,5,10,15 e 20µM. Esse meio consistiu na solução salina de Murashige & Skoog acrescido de tiamina, 1mg/l; ácido nicotínico, 0,5mg/l; inositol, 100mg/1, glicina, 250mg/l; glutamina, 500mg/l; asparagina, 250mg/l, ácido giberélico, 0,1mg/l; sacarose, 30g/l, e ágar, 6g/l. A melhor taxa de desenvolvimento dos embriões, após 30dias de cultura, ocorreu nas concentrações de 5 e 10µM de BAP, com uma emissão média de 4,5 brotos por embrião. Nas concentrações de 15 e 20mM de BAP, o número de brotações foi maior, porém com menor aproveitamento, devido à presença dos sintomas indesejáveis de vitrificação. O BAP não eliminou, totalmente, a roseta e o ananismo fisiológico dos embriões.Embryos of early peach and nectarine were cultured on Murashige and Skoog medium containing 3%sacarose,0.6%agar and(in mg/liter 1 thiamin, 0.5 nicotinic acid, 100 inositol, 250 glycin, 500 glutamin, 250 asparagin, 0.1 giberelic acid, and BAP at concentrations of 0, 5, 10, 15 and 20µM. The frequency of growth was as high as 100% when BAP was included in the medium. The best development of the embryos occurred with BAP rates of 5 and 10µM. At these concentrations of BAP, the mean number of adventitious shoots was 4.5 per embryo. The vitrification ratio was higher at concentrations of 15 and 20µM. The inclusion of BAP, consistently reduced but not fully eliminated lhe rosette and dwarf appearances in vitroplantules.

  1. Stem cell research on other worlds, or why embryos do not have a right to life.

    Science.gov (United States)

    Blackford, R

    2006-03-01

    Anxieties about the creation and destruction of human embryos for the purpose of scientific research on embryonic stem cells have given a new urgency to the question of whether embryos have moral rights. This article uses a thought experiment involving two possible worlds, somewhat removed from our own in the space of possibilities, to shed light on whether early embryos have such rights as a right not to be destroyed or discarded (a "right to life"). It is argued that early embryos do not have meaningful interests or any moral rights. Accordingly, claims about the moral rights of embryos do not justify restrictions on stem cell research.

  2. Deep sequencing analysis of the transcriptomes of peanut aerial and subterranean young pods identifies candidate genes related to early embryo abortion.

    Science.gov (United States)

    Chen, Xiaoping; Zhu, Wei; Azam, Sarwar; Li, Heying; Zhu, Fanghe; Li, Haifen; Hong, Yanbin; Liu, Haiyan; Zhang, Erhua; Wu, Hong; Yu, Shanlin; Zhou, Guiyuan; Li, Shaoxiong; Zhong, Ni; Wen, Shijie; Li, Xingyu; Knapp, Steve J; Ozias-Akins, Peggy; Varshney, Rajeev K; Liang, Xuanqiang

    2013-01-01

    The failure of peg penetration into the soil leads to seed abortion in peanut. Knowledge of genes involved in these processes is comparatively deficient. Here, we used RNA-seq to gain insights into transcriptomes of aerial and subterranean pods. More than 2 million transcript reads with an average length of 396 bp were generated from one aerial (AP) and two subterranean (SP1 and SP2) pod libraries using pyrosequencing technology. After assembly, sets of 49 632, 49 952 and 50 494 from a total of 74 974 transcript assembly contigs (TACs) were identified in AP, SP1 and SP2, respectively. A clear linear relationship in the gene expression level was observed between these data sets. In brief, 2194 differentially expressed TACs with a 99.0% true-positive rate were identified, among which 859 and 1068 TACs were up-regulated in aerial and subterranean pods, respectively. Functional analysis showed that putative function based on similarity with proteins catalogued in UniProt and gene ontology term classification could be determined for 59 342 (79.2%) and 42 955 (57.3%) TACs, respectively. A total of 2968 TACs were mapped to 174 KEGG pathways, of which 168 were shared by aerial and subterranean transcriptomes. TACs involved in photosynthesis were significantly up-regulated and enriched in the aerial pod. In addition, two senescence-associated genes were identified as significantly up-regulated in the aerial pod, which potentially contribute to embryo abortion in aerial pods, and in turn, to cessation of swelling. The data set generated in this study provides evidence for some functional genes as robust candidates underlying aerial and subterranean pod development and contributes to an elucidation of the evolutionary implications resulting from fruit development under light and dark conditions. © 2012 The Authors Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  3. Can Chlamydia abortus be transmitted by embryo transfer in goats?

    Science.gov (United States)

    Oseikria, M; Pellerin, J L; Rodolakis, A; Vorimore, F; Laroucau, K; Bruyas, J F; Roux, C; Michaud, S; Larrat, M; Fieni, F

    2016-10-01

    The objectives of this study were to determine (i) whether Chlamydia abortus would adhere to or penetrate the intact zona pellucida (ZP-intact) of early in vivo-derived caprine embryos, after in vitro infection; and (ii) the efficacy of the International Embryo Transfer Society (IETS) washing protocol for bovine embryos. Fifty-two ZP-intact embryos (8-16 cells), obtained from 14 donors were used in this experiment. The embryos were randomly divided into 12 batches. Nine batches (ZP-intact) of five embryos were incubated in a medium containing 4 × 10(7)Chlamydia/mL of AB7 strain. After incubation for 18 hours at 37 °C in an atmosphere of 5% CO2, the embryos were washed in batches in 10 successive baths of a phosphate buffer saline and 5% fetal calf serum solution in accordance with IETS guidelines. In parallel, three batches of ZP-intact embryos were used as controls by being subjected to similar procedures but without exposure to C. abortus. The 10 wash baths were collected separately and centrifuged for 1 hour at 13,000 × g. The washed embryos and the pellets of the 10 centrifuged wash baths were frozen at -20 °C before examination for evidence of C. abortus using polymerase chain reaction. C. abortus DNA was found in all of the infected batches of ZP-intact embryos (9/9) after 10 successive washes. It was also detected in the 10th wash fluid for seven batches of embryos, whereas for the two other batches, the last positive wash bath was the eighth and the ninth, respectively. In contrast, none of the embryos or their washing fluids in the control batches were DNA positive. These results report that C. abortus adheres to and/or penetrates the ZP of in vivo caprine embryos after in vitro infection, and that the standard washing protocol recommended by the IETS for bovine embryos, failed to remove it. The persistence of these bacteria after washing makes the embryo a potential means of transmission of the bacterium during embryo transfer from

  4. Time to take human embryo culture seriously.

    Science.gov (United States)

    Sunde, Arne; Brison, Daniel; Dumoulin, John; Harper, Joyce; Lundin, Kersti; Magli, M Cristina; Van den Abbeel, Etienne; Veiga, Anna

    2016-10-01

    Is it important that end-users know the composition of human embryo culture media? We argue that there is as strong case for full transparency concerning the composition of embryo culture media intended for human use. Published data suggest that the composition of embryo culture media may influence the phenotype of the offspring. A review of the literature was carried out. Data concerning the potential effects on embryo development of culture media were assessed and recommendations for users made. The safety of ART procedures, especially with respect to the health of the offspring, is of major importance. There are reports from the literature indicating a possible effect of culture conditions, including culture media, on embryo and fetal development. Since the introduction of commercially available culture media, there has been a rapid development of different formulations, often not fully documented, disclosed or justified. There is now evidence that the environment the early embryo is exposed to can cause reprogramming of embryonic growth leading to alterations in fetal growth trajectory, birthweight, childhood growth and long-term disease including Type II diabetes and cardiovascular problems. The mechanism for this is likely to be epigenetic changes during the preimplantation period of development. In the present paper the ESHRE working group on culture media summarizes the present knowledge of potential effects on embryo development related to culture media, and makes recommendations. There is still a need for large prospective randomized trials to further elucidate the link between the composition of embryo culture media used and the phenotype of the offspring. We do not presently know if the phenotypic changes induced by in vitro embryo culture represent a problem for long-term health of the offspring. Published data indicate that there is a strong case for demanding full transparency concerning the compositions of and the scientific rationale behind the

  5. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    Science.gov (United States)

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2015-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced. PMID:26858565

  6. Novel Synthetic Medea selfish genetic elements drive population replacement in Drosophila, and a theoretical exploration of Medea-dependent population suppression

    Science.gov (United States)

    Akbari, Omar S.; Chen, Chun-Hong; Marshall, John M.; Huang, Haixia; Antoshechkin, Igor; Hay, Bruce A.

    2013-01-01

    Insects act as vectors for diseases of plants, animals and humans. Replacement of wild insect populations with genetically modified individuals unable to transmit disease provides a potentially self-perpetuating method of disease prevention. Population replacement requires a gene drive mechanism in order to spread linked genes mediating disease refractoriness through wild populations. We previously reported the creation of synthetic Medea selfish genetic elements able to drive population replacement in Drosophila. These elements use microRNA-mediated silencing of myd88, a maternally expressed gene required for embryonic dorso-ventral pattern formation, coupled with early zygotic expression of a rescuing transgene, to bring about gene drive. Medea elements that work through additional mechanisms are needed in order to be able to carry out cycles of population replacement and/or remove existing transgenes from the population, using second-generation elements that spread while driving first-generation elements out of the population. Here we report the synthesis and population genetic behavior of two new synthetic Medea elements that drive population replacement through manipulation of signaling pathways involved in cellular blastoderm formation or Notch signaling, demonstrating that in Drosophila Medea elements can be generated through manipulation of diverse signaling pathways. We also describe the mRNA and small RNA changes in ovaries and early embryos associated from Medea-bearing females. Finally, we use modeling to illustrate how Medea elements carrying genes that result in diapause-dependent female lethality could be used to bring about population suppression. PMID:23654248

  7. Studies on Drosophila radiosensitivity strains

    International Nuclear Information System (INIS)

    Varentsova, E.R.; Sharygin, V.I.; Khromykh, Yu.U.

    1985-01-01

    Fertility of radiosensitive mutant drosophila female strain rad (2) 201 61 after irradiation and frequency of dominant lethal mutations (DLM), induced by γ-radiation for 0-5 h and 5-7 days, are investigated. It is shown, that oocytes of the mutant strain are more radiosensitive as compared with cells of mongrel flies as to criterion of DLM appearance over the period of maturing. Early oocytes of stages 2-7 are the most sensitive, i.e. at the stages, corresponding to the manifestation of previously established recombination-defective properties of mutations rad (2) 201 61 . It is also sown, that doses of γ-rays, exceeding 10 Gy produce a strong sterilizing effect on mutant females due to destruction and resorption of egg chambers, irradiated at the stages of previtellogenetic growth of oocytes. In females, carrying mutation of radiosensitivity there is no direct correlation betwen sensitivity of oocytes proper to DLM induction and sensitivity of egg folleicles to resorbing effect of γ-rays. The ways of possible involvement of mutant locus studied into genetic processes in various specialized cells of drosophila

  8. JAK/Stat signaling regulates heart precursor diversification in Drosophila

    Science.gov (United States)

    Johnson, Aaron N.; Mokalled, Mayssa H.; Haden, Tom N.; Olson, Eric N.

    2011-01-01

    Intercellular signal transduction pathways regulate the NK-2 family of transcription factors in a conserved gene regulatory network that directs cardiogenesis in both flies and mammals. The Drosophila NK-2 protein Tinman (Tin) was recently shown to regulate Stat92E, the Janus kinase (JAK) and Signal transducer and activator of transcription (Stat) pathway effector, in the developing mesoderm. To understand whether the JAK/Stat pathway also regulates cardiogenesis, we performed a systematic characterization of JAK/Stat signaling during mesoderm development. Drosophila embryos with mutations in the JAK/Stat ligand upd or in Stat92E have non-functional hearts with luminal defects and inappropriate cell aggregations. Using strong Stat92E loss-of-function alleles, we show that the JAK/Stat pathway regulates tin expression prior to heart precursor cell diversification. tin expression can be subdivided into four phases and, in Stat92E mutant embryos, the broad phase 2 expression pattern in the dorsal mesoderm does not restrict to the constrained phase 3 pattern. These embryos also have an expanded pericardial cell domain. We show the E(spl)-C gene HLHm5 is expressed in a pattern complementary to tin during phase 3 and that this expression is JAK/Stat dependent. In addition, E(spl)-C mutant embryos phenocopy the cardiac defects of Stat92E embryos. Mechanistically, JAK/Stat signals activate E(spl)-C genes to restrict Tin expression and the subsequent expression of the T-box transcription factor H15 to direct heart precursor diversification. This study is the first to characterize a role for the JAK/Stat pathway during cardiogenesis and identifies an autoregulatory circuit in which tin limits its own expression domain. PMID:21965617

  9. Mapping organism expression levels at cellular resolution in developing Drosophila

    Science.gov (United States)

    Knowles, David W.; Keranen, Soile; Biggin, Mark D.; Sudar, Damir

    2002-05-01

    The development of an animal embryo is orchestrated by a network of genetically determined, temporal and spatial gene expression patterns that determine the animals final form. To understand such networks, we are developing novel quantitative optical imaging techniques to map gene expression levels at cellular and sub-cellular resolution within pregastrula Drosophila. Embryos at different stages of development are labeled for total DNA and specific gene products using different fluorophors and imaged in 3D with confocal microscopy. Innovative steps have been made which allow the DNA-image to be automatically segmented to produce a morphological mask of the individual nuclear boundaries. For each stage of development an average morphology is chosen to which images from different embryo are compared. The morphological mask is then used to quantify gene-product on a per nuclei basis. What results is an atlas of the relative amount of the specific gene product expressed within the nucleus of every cell in the embryo at the various stages of development. We are creating a quantitative database of transcription factor and target gene expression patterns in wild-type and factor mutant embryos with single cell resolution. Our goal is to uncover the rules determining how patterns of gene expression are generated.

  10. Children born after cryopreservation of embryos or oocytes: a systematic review of outcome data

    DEFF Research Database (Denmark)

    Wennerholm, U-B; Söderström-Anttila, V; Bergh, C

    2009-01-01

    embryos, blastocysts and oocytes. METHODS: A systematic review was performed. We searched the PubMed, Cochrane and Embase databases from 1984 to September 2008. Inclusion criteria for slow freezing of early cleavage stage embryos were controlled studies reporting perinatal or child outcomes. For slow...... freezing and vitrification of blastocysts and oocytes, and vitrification of early cleavage stage embryos, case reports on perinatal or child outcomes were also included. Three reviewers independently read and evaluated all selected studies. RESULTS: For early cleavage embryos, data from controlled studies...... of blastocysts and for vitrification of early cleavage stage embryos, blastocysts and oocytes, limited neonatal data was reported. We found no long-term child follow-up data for any cryopreservation technique. CONCLUSION: Data concerning infant outcome after slow freezing of embryos was reassuring. Properly...

  11. Sex determination of duck embryos: observations on syrinx development

    Science.gov (United States)

    Wilson, Robert E.; Sonsthagen, Sarah A.; Franson, J. Christian

    2013-01-01

    Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx (bulla syringealis) is discernable at about 10 days of age in male Pekin duck (Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders (Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.

  12. Fluorescent visualization of macromolecules in Drosophila whole mounts.

    Science.gov (United States)

    Ramos, Ricardo Guelerman Pinheiro; Machado, Luciana Claudia Herculano; Moda, Livia Maria Rosatto

    2010-01-01

    The ability to determine the expression dynamics of individual genes "in situ" by visualizing the precise spatial and temporal distribution of their products in whole mounts by histochemical and immunocytochemical reactions has revolutionized our understanding of cellular processes. Drosophila developmental genetics was one of the fields that benefited most from these technologies, and a variety of fluorescent methods were specifically designed for investigating the localization of developmentally important proteins and cell markers during embryonic and post embryonic stages of this model organism. In this chapter we present detailed protocols for fluorescence immunocytochemistry of whole mount embryos, imaginal discs, pupal retinas, and salivary glands of Drosophila melanogaster, as well as methods for fluorescent visualization of specific subcellular structures in these tissues.

  13. Drosophila increase exploration after visually detecting predators.

    Directory of Open Access Journals (Sweden)

    Miguel de la Flor

    Full Text Available Novel stimuli elicit behaviors that are collectively known as specific exploration. These behaviors allow the animal to become more familiar with the novel objects within its environment. Specific exploration is frequently suppressed by defensive reactions to predator cues. Herein, we examine if this suppression occurs in Drosophila melanogaster by measuring the response of these flies to wild harvested predators. The flies used in our experiments have been cultured and had not lived under predator threat for multiple decades. In a circular arena with centrally-caged predators, wild type Drosophila actively avoided the pantropical jumping spider, Plexippus paykulli, and the Texas unicorn mantis, Phyllovates chlorophaena, indicating an innate defensive reaction to these predators. Interestingly, wild type Drosophila males also avoided a centrally-caged mock spider, and the avoidance of the mock spider became exaggerated when it was made to move within the cage. Visually impaired Drosophila failed to detect and avoid the Plexippus paykulli and the moving mock spider, while the broadly anosmic orco2 mutants were fully capable of detecting and avoiding Plexippus paykulli, indicating that these flies principally relied upon vison to perceive the predator stimuli. During early exploration of the arena, exploratory activity increased in the presence of Plexippus paykulli and the moving mock spider. The elevated activity induced by Plexippus paykulli disappeared after the fly had finished exploring, suggesting the flies were capable of habituating the predator cues. Taken together, these results indicate that despite being isolated from predators for decades Drosophila will visually detect these predators, retain innate defensive behaviors, respond by increasing exploratory activity in the arena rather than suppressing activity, and may habituate to normal predator cues.

  14. Hearing regulates Drosophila aggression.

    Science.gov (United States)

    Versteven, Marijke; Vanden Broeck, Lies; Geurten, Bart; Zwarts, Liesbeth; Decraecker, Lisse; Beelen, Melissa; Göpfert, Martin C; Heinrich, Ralf; Callaerts, Patrick

    2017-02-21

    Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly's auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.

  15. Negative regulation of P element excision by the somatic product and terminal sequences of P in drosophila melanogaster

    Science.gov (United States)

    A transient in vivo P element excision assay was used to test the regulatory properties of putative repressor-encoding plasmids in Drosophila melanogaster embryos. The somatic expression of an unmodified transposase transcription unit under the control of a heat shock gene promoter (phsn) effectivel...

  16. Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development

    Directory of Open Access Journals (Sweden)

    Hans-Werner Denker

    2016-10-01

    Full Text Available “Organoids”, i.e., complex structures that can develop when pluripotent or multipotent stem cells are maintained in three-dimensional cultures, have become a new area of interest in stem cell research. Hopes have grown that when focussing experimentally on the mechanisms behind this type of in vitro morphogenesis, research aiming at tissue and organ replacements can be boosted. Processes leading to the formation of organoids in vitro are now often addressed as self-organization, a term referring to the formation of complex tissue architecture in groups of cells without depending on specific instruction provided by other cells or tissues. The present article focuses on recent reports using the term self-organization in the context of studies on embryogenesis, specifically addressing pattern formation processes in human blastocysts attaching in vitro, or in colonies of pluripotent stem cells (“gastruloids”. These morphogenetic processes are of particular interest because, during development in vivo, they lead to basic body plan formation and individuation. Since improved methodologies like those employed by the cited authors became available, early embryonic pattern formation/self-organization appears to evolve now as a research topic of its own. This review discusses concepts concerning the involved mechanisms, focussing on autonomy of basic body plan development vs. dependence on external signals, as possibly provided by implantation in the uterus, and it addresses biological differences between an early mammalian embryo, e.g., a morula, and a cluster of pluripotent stem cells. It is concluded that, apart from being of considerable biological interest, the described type of research needs to be contemplated carefully with regard to ethical implications when performed with human cells.

  17. Brachyury expression in tailless Molgulid ascidian embryos.

    Science.gov (United States)

    Takada, Norio; York, Jonathan; Davis, J Muse; Schumpert, Brenda; Yasuo, Hitoyoshi; Satoh, Nori; Swalla, Billie J

    2002-01-01

    The T-box transcription factor gene Brachyury is important for the differentiation of notochord in all chordates, including the ascidians Halocynthia roretzi and Ciona intestinalis. We isolated Brachyury from molgulid ascidians, which have evolved tailless larvae multiple times independently, and found the genes appear functional by cDNA sequence analyses. We then compared the expression of Mocu-Bra in tailed Molgula oculata embryos to two tailless species, Molgula occulta (Mocc-Bra) and Molgula tectiformis (Mt-Bra). Here we show that both tailless species express Brachyury in the notochord lineage during embryogenesis. Initial expression of Mocu-Bra is normal in tailed M. oculata embryos; 10 precursor notochord cells divide twice to result in 40 notochord cells that converge and extend to make a notochord down the center of the tail. In contrast, in tailless Molgula occulta, Mocc-Bra expression disappears prematurely, and there is only one round of division, resulting in 20 cells in the final notochord lineage that never converge or extend. In M. occulta x M. oculata hybrid embryos, expression of Mocu-Bra is prolonged, and the embryos form a tail with 20 notochord cells that converge and extend normally. However, in Molgula tectiformis, a different tailless ascidian, Mt-Bra was expressed only in the 10 notochord precursor cells, which never divide, converge, or extend. In summary, neither Brachyury function nor the early establishment of the notochord lineage appears to be impaired in tailless embryos. In light of these results, we are continuing to investigate how and why notochord development is lost in tailless molgulid ascidian embryos.

  18. Analysis of a new morphogenetic mutation in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mglinets, V.A.

    1987-01-01

    Somatic mosaicism for mutations monster and yellow was induced by gamma-irradiation of Drosophila melanogaster y/y; Dp(1; 2)sc 19 M(2)z/mn d embryos and larvae. Frequencies of mosaicism increased with the age of treated larvae, especially in the end of the 2nd larval instar. Autonomous expression of mn was observed throughout the whole range of larval age studied, though neither for all y/y spots nor for all parts of the spots. Dissimilarities in dynamics of mosaic spots and duplication induction suggest that the latter are not due to mn expression in somatic clones

  19. Ovarian stimulation and embryo quality

    NARCIS (Netherlands)

    Baart, Esther; Macklon, Nick S.; Fauser, Bart J. C. M.

    To Study the effects of different ovarian stimulation approaches on oocyte and embryo quality, it is imperative to assess embryo quality with a reliable and objective method. Embryos rated as high quality by standardized morphological assessment are associated with higher implantation and pregnancy

  20. Expression of Aquaporins in Human Embryos and Potential Role of AQP3 and AQP7 in Preimplantation Mouse Embryo Development

    Directory of Open Access Journals (Sweden)

    Yun Xiong

    2013-05-01

    Full Text Available Background/Aims: Water channels, also named aquaporins (AQPs, play crucial roles in cellular water homeostasis. Methods: RT-PCR indicated the mRNA expression of AQPs 1-5, 7, 9, and 11-12, but not AQPs 0, 6, 8, and 10 in the 2∼8-cell stage human embryos. AQP3 and AQP7 were further analyzed for their mRNA expression and protein expression in the oocyte, zygote, 2-cell embryo, 4-cell embryo, 8-cell embryo, morula, and blastocyst from both human and mouse using RT-PCR and immunofluorescence, respectively. Results: AQP3 and AQP7 were detected in all these stages. Knockdown of either AQP3 or AQP7 by targeted siRNA injection into 2-cell mouse embryos significantly inhibited preimplantation embryo development. However, knockdown of AQP3 in JAr spheroid did not affect its attachment to Ishikawa cells. Conclusion: These data demonstrate that multiple aquaporins are expressed in the early stage human embryos and that AQP3 and AQP7 may play a role in preimplantation mouse embryo development.

  1. Dose estimation in embryo or fetus in external fields

    International Nuclear Information System (INIS)

    Gregori, Beatriz N.

    2001-01-01

    The embryo or the fetus can be irradiated as result of radiological procedures of diagnosis of therapy in where the beam effects directly on the same one or in tissues or peripherical organs. Some authors have suggested that in the first stages of the pregnancy the dose in ovaries can be the good estimated of the dose in embryo or fetus. In advanced conditions of the development, probably also in the early stage, is more appropriated to specify the dose in the embryo or fetus equal of the uterus. The dose in the uterus is a good estimated so much for external irradiation as for radionuclides incorporation

  2. The effects of X-rays on chicken embryos

    International Nuclear Information System (INIS)

    Wendt, E.

    1981-01-01

    The radiosensitivity of the chickens embryo changes in the course of its 21 days of development. A period of relatively high resistance in the early stages of development (1. to 3. day of incubation), is followed by an increase of sensitivity from the 4. day onwards. In 1- to 3-day-old embryos, X-rays cause nonspecific malformations in those organs which are in a phenocritical period at the moment of irradiation. In mature embryos (4. to 20. day of incubation) characteristic biochemical changes in the metabolism of proteins and amino-acids as well as the nitrogen excretion can be observed as the predominant radiation effects. (orig.)

  3. impact on embryo quality

    Directory of Open Access Journals (Sweden)

    Marijan Tandara

    2013-05-01

    Conclusions: In men with poorer semen quality, evaluated by standard semen parameters, a higher proportion of sperm with damaged DNA can also be expected. Higher sperm DNA damage, established by Halosperm test, also had an impact on embryo quality in this group of patients.

  4. BMAA neurotoxicity in Drosophila.

    Science.gov (United States)

    Zhou, Xianchong; Escala, Wilfredo; Papapetropoulos, Spyridon; Bradley, Walter G; Zhai, R Grace

    2009-01-01

    We report the establishment of an in vivo model using the fruit fly Drosophila melanogaster to investigate the toxic effects of L-BMAA. We found that dietary intake of BMAA reduced the lifespan as well as the neurological functions of flies. Furthermore, we have developed an HPLC method to reliably detect both free and protein-bound BMAA in fly tissue extracts.

  5. Cancer in Drosophila

    DEFF Research Database (Denmark)

    Herranz, Héctor; Eichenlaub, Teresa; Cohen, Stephen M

    2016-01-01

    Cancer genomics has greatly increased our understanding of the complexity of the genetic and epigenetic changes found in human tumors. Understanding the functional relationships among these elements calls for the use of flexible genetic models. We discuss the use of Drosophila models to study...

  6. Embryo Aggregation in Pig Improves Cloning Efficiency and Embryo Quality.

    Science.gov (United States)

    Buemo, Carla Paola; Gambini, Andrés; Moro, Lucia Natalia; Hiriart, María Inés; Fernández-Martín, Rafael; Collas, Philippe; Salamone, Daniel Felipe

    2016-01-01

    In this study, we analyzed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst diameter and cell number, DNA fragmentation levels and the expression of genes associated with pluripotency, apoptosis, trophoblast and DNA methylation in the porcine. Zona-free reconstructed cloned embryos were cultured in the well of the well system, placing one (1x non aggregated group) or three (3x group) embryos per microwell. Our results showed that aggregation of three embryos increased blastocyst formation rate and blastocyst diameter of cloned pig embryos. DNA fragmentation levels in 3x aggregated cloned blastocysts were significantly decreased compared to 1x blastocysts. Levels of Oct4, Klf4, Igf2, Bax and Dnmt 1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially non-detectable. Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

  7. Effects of hypo-O-GlcNAcylation on Drosophila development.

    Science.gov (United States)

    Mariappa, Daniel; Ferenbach, Andrew T; van Aalten, Daan M F

    2018-05-11

    Post-translational modification of serine/threonine residues in nucleocytoplasmic proteins with GlcNAc ( O -GlcNAcylation) is an essential regulatory mechanism in many cellular processes. In Drosophila , null mutants of the Polycomb gene O -GlcNAc transferase ( OGT ; also known as super sex combs ( sxc )) display homeotic phenotypes. To dissect the requirement for O -GlcNAc signaling in Drosophila development, we used CRISPR/Cas9 gene editing to generate rationally designed sxc catalytically hypomorphic or null point mutants. Of the fertile males derived from embryos injected with the CRISPR/Cas9 reagents, 25% produced progeny carrying precise point mutations with no detectable off-target effects. One of these mutants, the catalytically inactive sxc K872M , was recessive lethal, whereas a second mutant, the hypomorphic sxc H537A , was homozygous viable. We observed that reduced total protein O -GlcNAcylation in the sxc H537A mutant is associated with a wing vein phenotype and temperature-dependent lethality. Genetic interaction between sxc H537A and a null allele of Drosophila host cell factor ( dHcf ), encoding an extensively O -GlcNAcylated transcriptional coactivator, resulted in abnormal scutellar bristle numbers. A similar phenotype was also observed in sxc H537A flies lacking a copy of skuld ( skd ), a Mediator complex gene known to affect scutellar bristle formation. Interestingly, this phenotype was independent of OGT Polycomb function or dHcf downstream targets. In conclusion, the generation of the endogenous OGT hypomorphic mutant sxc H537A enabled us to identify pleiotropic effects of globally reduced protein O -GlcNAc during Drosophila development. The mutants generated and phenotypes observed in this study provide a platform for discovery of OGT substrates that are critical for Drosophila development. © 2018 Mariappa et al.

  8. Gap-Junctional communication between developing Drosophila muscles is essential for their normal development.

    Science.gov (United States)

    Todman, M G; Baines, R A; Stebbings, L A; Davies, J A; Bacon, J P

    1999-01-01

    Recent experiments have demonstrated that a family of proteins, known as the innexins, are structural components of invertebrate gap junctions. The shaking-B (shak-B) locus of Drosophila encodes two members of this emerging family, Shak-B(lethal) and Shak-B(neural). This study focuses on the role of Shak-B gap junctions in the development of embryonic and larval muscle. During embryogenesis, shak-B transcripts are expressed in a subset of the somatic muscles; expression is strong in ventral oblique muscles (VO4-6) but only weak in ventral longitudinals (VL3 and 4). Carboxyfluorescein injected into VO4 of wild-type early stage 16 embryos spreads, via gap junctions, to label adjacent muscles, including VL3 and 4. In shak-B2 embryos (in which the shak-B(neural) function is disrupted), dye injected into VO4 fails to spread into other muscles. In the first instar larva, when dye coupling between muscles is no longer present, another effect of the shak-B2 mutation is revealed by whole-cell voltage clamp. In a calcium-free saline, only two voltage-activated potassium currents are present in wild-type muscles; a fast IA and a slow IK current. In shak-B2 larvae, these two currents are significantly reduced in magnitude in VO4 and 5, but remain normal in VL3. Expression of shak-B(neural) in a shak-B2 background fully rescues both dye coupling in embryonic muscle and whole-cell currents in first instar VO4 and 5. Our observations show that Shak-B(neural) is one of a set of embryonic gap-junction proteins, and that it is required for the normal temporal development of potassium currents in some larval muscles.

  9. Pollen source effects on growth of kernel structures and embryo chemical compounds in maize.

    Science.gov (United States)

    Tanaka, W; Mantese, A I; Maddonni, G A

    2009-08-01

    Previous studies have reported effects of pollen source on the oil concentration of maize (Zea mays) kernels through modifications to both the embryo/kernel ratio and embryo oil concentration. The present study expands upon previous analyses by addressing pollen source effects on the growth of kernel structures (i.e. pericarp, endosperm and embryo), allocation of embryo chemical constituents (i.e. oil, protein, starch and soluble sugars), and the anatomy and histology of the embryos. Maize kernels with different oil concentration were obtained from pollinations with two parental genotypes of contrasting oil concentration. The dynamics of the growth of kernel structures and allocation of embryo chemical constituents were analysed during the post-flowering period. Mature kernels were dissected to study the anatomy (embryonic axis and scutellum) and histology [cell number and cell size of the scutellums, presence of sub-cellular structures in scutellum tissue (starch granules, oil and protein bodies)] of the embryos. Plants of all crosses exhibited a similar kernel number and kernel weight. Pollen source modified neither the growth period of kernel structures, nor pericarp growth rate. By contrast, pollen source determined a trade-off between embryo and endosperm growth rates, which impacted on the embryo/kernel ratio of mature kernels. Modifications to the embryo size were mediated by scutellum cell number. Pollen source also affected (P embryo chemical compounds. Negative correlations among embryo oil concentration and those of starch (r = 0.98, P embryos with low oil concentration had an increased (P embryo/kernel ratio and allocation of embryo chemicals seems to be related to the early established sink strength (i.e. sink size and sink activity) of the embryos.

  10. Modeling Human Cancers in Drosophila.

    Science.gov (United States)

    Sonoshita, M; Cagan, R L

    2017-01-01

    Cancer is a complex disease that affects multiple organs. Whole-body animal models provide important insights into oncology that can lead to clinical impact. Here, we review novel concepts that Drosophila studies have established for cancer biology, drug discovery, and patient therapy. Genetic studies using Drosophila have explored the roles of oncogenes and tumor-suppressor genes that when dysregulated promote cancer formation, making Drosophila a useful model to study multiple aspects of transformation. Not limited to mechanism analyses, Drosophila has recently been showing its value in facilitating drug development. Flies offer rapid, efficient platforms by which novel classes of drugs can be identified as candidate anticancer leads. Further, we discuss the use of Drosophila as a platform to develop therapies for individual patients by modeling the tumor's genetic complexity. Drosophila provides both a classical and a novel tool to identify new therapeutics, complementing other more traditional cancer tools. © 2017 Elsevier Inc. All rights reserved.

  11. Differential expression of parental alleles of BRCA1 in human preimplantation embryos

    Science.gov (United States)

    Tulay, Pinar; Doshi, Alpesh; Serhal, Paul; SenGupta, Sioban B

    2017-01-01

    Gene expression from both parental genomes is required for completion of embryogenesis. Differential methylation of each parental genome has been observed in mouse and human preimplantation embryos. It is possible that these differences in methylation affect the level of gene transcripts from each parental genome in early developing embryos. The aim of this study was to investigate if there is a parent-specific pattern of BRCA1 expression in human embryos and to examine if this affects embryo development when the embryo carries a BRCA1 or BRCA2 pathogenic mutation. Differential parental expression of ACTB, SNRPN, H19 and BRCA1 was semi-quantitatively analysed by minisequencing in 95 human preimplantation embryos obtained from 15 couples undergoing preimplantation genetic diagnosis. BRCA1 was shown to be differentially expressed favouring the paternal transcript in early developing embryos. Methylation-specific PCR showed a variable methylation profile of BRCA1 promoter region at different stages of embryonic development. Embryos carrying paternally inherited BRCA1 or 2 pathogenic variants were shown to develop more slowly compared with the embryos with maternally inherited BRCA1 or 2 pathogenic mutations. This study suggests that differential demethylation of the parental genomes can influence the early development of preimplantation embryos. Expression of maternal and paternal genes is required for the completion of embryogenesis. PMID:27677417

  12. Effect of women's age on embryo morphology, cleavage rate and competence-A multicenter cohort study

    DEFF Research Database (Denmark)

    Grøndahl, Marie Louise; Christiansen, Sofie Lindgren; Kesmodel, Ulrik Schiøler

    2017-01-01

    This multicenter cohort study on embryo assessment and outcome data from 11,744 IVF/ICSI cycles with 104,830 oocytes and 42,074 embryos, presents the effect of women's age on oocyte, zygote, embryo morphology and cleavage parameters, as well as cycle outcome measures corrected for confounding.......0001) with increasing age. Maternal age had no effect on cleavage parameters or on the morphology of the embryo day 2 post insemination. Interestingly, initial hCG value after single embryo transfer followed by ongoing pregnancy was increased with age in both IVF (p = 0.007) and ICSI (p = 0.001) cycles. For the first...... time, we show that a woman's age does impose a significant footprint on early embryo morphological development (3PN). In addition, the developmentally competent embryos were associated with increased initial hCG values as the age of the women increased. Further studies are needed to elucidate...

  13. Low doze γ-irradiation influence on drosophila life span in different genetics background

    International Nuclear Information System (INIS)

    Moskalev, A.

    2007-01-01

    Complete text of publication follows. The main goal of this work was to study in Drosophila melanogaster the contribution of DNA damage sensing and repair, apoptosis and heat shock defence into life span and physical activity alteration after gamma-irradiation at low doze rate. In our experiments, the strains were exposed to chronic gamma-irradiation from a 226Ra source (50 R/h) at doze rate 0.17 cGy/h at pre-imago development stages only. The absorbed radiation dose per generation (from embryo to imago, 12 days) was 60 cGy. Life span estimation was prepared in adult males and females separately. We compared the life span of apoptotic (p53, DIAP-1, dApaf-1, Dcp-1, reaper, grim and hid), heat shock defence (HSP70, HSP23, HSF), DNA damage sensing (ATR) and repair (XPF, XPC, PCNA, DSB repair helicase homologs) mutants after chronic irradiation with the control. On the basis of our investigation we have concluded: 1) Low doze irradiation alter the life span depending on genetic background (mutant alleles, heterozygosity level and sex); 2) Age dynamics of physical activity positively correlates with the life span; 3) Longevity potential forms at early development stages; 4) DNA damage sensing, DNA repair, heat shock defence and apoptosis as aging preventing mechanisms play crucial role in radiation-induced life span hormesis.

  14. Parameter estimation and determinability analysis applied to Drosophila gap gene circuits

    Directory of Open Access Journals (Sweden)

    Jaeger Johannes

    2008-09-01

    Full Text Available Abstract Background Mathematical modeling of real-life processes often requires the estimation of unknown parameters. Once the parameters are found by means of optimization, it is important to assess the quality of the parameter estimates, especially if parameter values are used to draw biological conclusions from the model. Results In this paper we describe how the quality of parameter estimates can be analyzed. We apply our methodology to assess parameter determinability for gene circuit models of the gap gene network in early Drosophila embryos. Conclusion Our analysis shows that none of the parameters of the considered model can be determined individually with reasonable accuracy due to correlations between parameters. Therefore, the model cannot be used as a tool to infer quantitative regulatory weights. On the other hand, our results show that it is still possible to draw reliable qualitative conclusions on the regulatory topology of the gene network. Moreover, it improves previous analyses of the same model by allowing us to identify those interactions for which qualitative conclusions are reliable, and those for which they are ambiguous.

  15. SWATH-MS data of Drosophila melanogaster proteome dynamics during embryogenesis

    Directory of Open Access Journals (Sweden)

    Bertrand Fabre

    2016-12-01

    Full Text Available Embryogenesis is one of the most important processes in the life of an animal. During this dynamic process, progressive cell division and cellular differentiation are accompanied by significant changes in protein expression at the level of the proteome. However, very few studies to date have described the dynamics of the proteome during the early development of an embryo in any organism. In this dataset, we monitor changes in protein expression across a timecourse of more than 20 h of Drosophila melanogaster embryonic development. Mass-spectrometry data were produced using a SWATH acquisition mode on a Sciex Triple-TOF 6600. A spectral library built in-house was used to analyse these data and more than 1950 proteins were quantified at each embryonic timepoint. The files presented here are a permanent digital map and can be reanalysed to test against new hypotheses. The data have been deposited with the ProteomeXchange Consortium with the dataset identifier PRIDE: PXD0031078.

  16. Immunoelectron microscopy in embryos.

    Science.gov (United States)

    Sierralta, W D

    2001-05-01

    Immunogold labeling of proteins in sections of embryos embedded in acrylate media provides an important analytical tool when the resolving power of the electron microscope is required to define sites of protein function. The protocol presented here was established to analyze the role and dynamics of the activated protein kinase C/Rack1 regulatory system in the patterning and outgrowth of limb bud mesenchyme. With minor changes, especially in the composition of the fixative solution, the protocol should be easily adaptable for the postembedding immunogold labeling of any other antigen in tissues of embryos of diverse species. Quantification of the labeling can be achieved by using electron microscope systems capable of supporting digital image analysis. Copyright 2001 Academic Press.

  17. DIRECT SELECTION ON LIFE-SPAN IN DROSOPHILA-MELANOGASTER

    NARCIS (Netherlands)

    ZWAAN, B; BIJLSMA, R; HOEKSTRA, RE

    An important issue in the study of the evolution of aging in Drosophila melanogaster is whether decreased early fecundity is inextricably coupled with increased life span in selection experiments on age at reproduction. Here, this problem has been tackled using an experimental design in which

  18. Role of microRNAs in embryo implantation

    Directory of Open Access Journals (Sweden)

    Jingjie Liang

    2017-11-01

    Full Text Available Abstract Failure of embryo implantation is a major limiting factor in early pregnancy and assisted reproduction. Determinants of implantation include the embryo viability, the endometrial receptivity, and embryo-maternal interactions. Multiple molecules are involved in the regulation of implantation, but their specific regulatory mechanisms remain unclear. MicroRNA (miRNA, functioning as the transcriptional regulator of gene expression, has been widely reported to be involved in embryo implantation. Recent studies reveal that miRNAs not only act inside the cells, but also can be released by cells into the extracellular environment through multiple packaging forms, facilitating intercellular communication and providing indicative information associated with physiological and pathological conditions. The discovery of extracellular miRNAs shed new light on implantation studies. MiRNAs provide new mechanisms for embryo-maternal communication. Moreover, they may serve as non-invasive biomarkers for embryo selection and assessment of endometrial receptivity in assisted reproduction, which improves the accuracy of evaluation while reducing the mechanical damage to the tissue. In this review, we discuss the involvement of miRNAs in embryo implantation from several aspects, focusing on the role of extracellular miRNAs and their potential applications in assisted reproductive technologies (ART to promote fertility efficiency.

  19. Nucleolar re-activation is delayed in mouse embryos cloned from two different cell lines

    DEFF Research Database (Denmark)

    Svarcova, Olga; Dinnyes, A.; Polgar, Z.

    2009-01-01

    displayed early NPBs transformation. In conclusion, despite normal onset of EGA in cloned embryos, activation of functional nucleoli was one cell cycle delayed in NT embryos. NT-MEF embryos displayed normal targeting but delayed activation of nucleolar proteins. Contrary, in NT-HM1 embryos, both......Aim of this study was to evaluate and compare embryonic genome activation (EGA) in mouse embryos of different origin using nucleolus as a marker. Early and late 2-cell and late 4-cell stage embryos, prepared by in vitro fertilization (IVF), parthenogenetic activation (PG), and nuclear transfer...... ofmouse embryonic fibroblast (MEF) and mouse HM1 emryonic stem cells (HM1), were processed for autoradiography following 3H-uridine incubation (transcriptional activity), transmission electron microscopy (ultrastructure) and immunofluorescence (nucleolar proteins; upstream binding factor, UBF...

  20. Influence of recipient cytoplasm cell stage on transcription in bovine nucleus transfer embryos

    DEFF Research Database (Denmark)

    Smith, Steven D.; Soloy, Eva; Kanka, Jiri

    1996-01-01

    Nucleus transfer for the production of multiple embryos derived from a donor embryo relies upon the reprogramming of the donor nucleus so that it behaves similar to a zygotic nucleus. One indication of nucleus reprogramming is the RNA synthetic activity. In normal bovine embryogenesis, the embryo....... NTE were produced using either a MII phase (nonactivated) cytoplasts at 32 hr of maturation or S-phase (activated) cytoplasts activated with calcium ionophore A23187 and cycloheximide treatment approximately 8 hr prior to fusion with a blastomere from an in-vitro-produced morula stage embryo at 32 hr...... of maturation. Control in-vitro-produced embryos were 3H-uridine-labelled and fixed at the 2-, 4-, early 8-, and late 8-cell stages. NTE were similarly prepared at 1, 3, and 20 hr postfusion and at the 2-, 4-, and 8-cell stages. In the control embryos, RNA synthesis was absent in the 2-, 4-, and early 8-cell...

  1. Tolerance in Drosophila

    OpenAIRE

    Atkinson, Nigel S.

    2009-01-01

    The set of genes that underlie ethanol tolerance (inducible resistance) are likely to overlap with the set of genes responsible for ethanol addiction. Whereas addiction is difficult to recognize in simple model systems, behavioral tolerance is readily identifiable and can be induced in large populations of animals. Thus, tolerance lends itself to analysis in model systems with powerful genetics. Drosophila melanogaster has been used by a variety of laboratories for the identification of genes...

  2. The dopaminergic system in the aging brain of Drosophila

    Directory of Open Access Journals (Sweden)

    Katherine E White

    2010-12-01

    Full Text Available Drosophila models of Parkinson’s disease are characterised by two principal phenotypes: the specific loss of dopaminergic neurons in the aging brain and defects in motor behavior. However, an age-related analysis of these baseline parameters in wildtype Drosophila is lacking. Here we analysed the dopaminergic system and motor behavior in aging Drosophila. Dopaminergic neurons in the adult brain can be grouped into bilateral symmetric clusters, each comprising a stereotypical number of cells. Analysis of TH>mCD8::GFP and cell type-specific MARCM clones revealed that dopaminergic neurons show cluster-specific, stereotypical projection patterns with terminal arborization in target regions that represent distinct functional areas of the adult brain. Target areas include the mushroom bodies, involved in memory formation and motivation, and the central complex, involved in the control of motor behavior, indicating that similar to the mammalian brain, dopaminergic neurons in the fly brain are involved in the regulation of specific behaviors. Behavioral analysis revealed that Drosophila show an age-related decline in startle-induced locomotion and negative geotaxis. Motion tracking however, revealed that walking activity and exploration behavior, but not centrophobism increase at late stages of life. Analysis of TH>Dcr2, mCD8::GFP revealed a specific effect of Dcr2 expression on walking activity but not on exploratory or centrophobic behavior, indicating that the siRNA pathway may modulate distinct dopaminergic behaviors in Drosophila. Moreover, dopaminergic neurons were maintained between early- and late life, as quantified by TH>mCD8::GFP and anti-TH labelling, indicating that adult onset, age-related degeneration of dopaminergic neurons does not occur in the aging brain of Drosophila. Taken together, our data establish baseline parameters in Drosophila for the study of Parkinson’s disease as well as other disorders affecting dopaminergic neurons

  3. Genome-wide analysis of promoter architecture in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Hoskins, Roger A.; Landolin, Jane M.; Brown, James B.; Sandler, Jeremy E.; Takahashi, Hazuki; Lassmann, Timo; Yu, Charles; Booth, Benjamin W.; Zhang, Dayu; Wan, Kenneth H.; Yang, Li; Boley, Nathan; Andrews, Justen; Kaufman, Thomas C.; Graveley, Brenton R.; Bickel, Peter J.; Carninci, Piero; Carlson, Joseph W.; Celniker, Susan E.

    2010-10-20

    Core promoters are critical regions for gene regulation in higher eukaryotes. However, the boundaries of promoter regions, the relative rates of initiation at the transcription start sites (TSSs) distributed within them, and the functional significance of promoter architecture remain poorly understood. We produced a high-resolution map of promoters active in the Drosophila melanogaster embryo by integrating data from three independent and complementary methods: 21 million cap analysis of gene expression (CAGE) tags, 1.2 million RNA ligase mediated rapid amplification of cDNA ends (RLMRACE) reads, and 50,000 cap-trapped expressed sequence tags (ESTs). We defined 12,454 promoters of 8037 genes. Our analysis indicates that, due to non-promoter-associated RNA background signal, previous studies have likely overestimated the number of promoter-associated CAGE clusters by fivefold. We show that TSS distributions form a complex continuum of shapes, and that promoters active in the embryo and adult have highly similar shapes in 95% of cases. This suggests that these distributions are generally determined by static elements such as local DNA sequence and are not modulated by dynamic signals such as histone modifications. Transcription factor binding motifs are differentially enriched as a function of promoter shape, and peaked promoter shape is correlated with both temporal and spatial regulation of gene expression. Our results contribute to the emerging view that core promoters are functionally diverse and control patterning of gene expression in Drosophila and mammals.

  4. Somatic Embryos in Catharanthus roseus: A Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Junaid ASLAM

    2014-06-01

    Full Text Available Catharanthus roseus (L. G. Don is an important medicinal plant as it contains several anti-cancerous compounds, like vinblastine and vincristine. Plant tissue culture technology (organogenesis and embryogenesis has currently been used in fast mass propagating raw materials for secondary metabolite synthesis. In this present communication, scanning electron microscopic (SEM study of somatic embryos was conducted and discussed. The embryogenic callus was first induced from hypocotyls of in vitro germinated seeds on which somatic embryos, differentiated in numbers, particularly on 2,4-D (1.0 mg/L Murashige and Skoog (MS was medium. To understand more about the regeneration method and in vitro formed embryos SEM was performed. The SEM study revealed normal somatic embryo origin and development from globular to heart-, torpedo- and then into cotyledonary-stage of embryos. At early stage, the embryos were clustered together in a callus mass and could not easily be detached from the parental tissue. The embryos were often long cylindrical structure with or without typical notch at the tip. Secondary embryos were also formed on primary embryo structure. The advanced cotyledonary embryos showed prominent roots and shoot axis, which germinated into plantlets. The morphology, structure and other details of somatic embryos at various stages were presented.

  5. Algorithms for automatic segmentation of bovine embryos produced in vitro

    International Nuclear Information System (INIS)

    Melo, D H; Oliveira, D L; Nascimento, M Z; Neves, L A; Annes, K

    2014-01-01

    In vitro production has been employed in bovine embryos and quantification of lipids is fundamental to understand the metabolism of these embryos. This paper presents a unsupervised segmentation method for histological images of bovine embryos. In this method, the anisotropic filter was used in the differents RGB components. After pre-processing step, the thresholding technique based on maximum entropy was applied to separate lipid droplets in the histological slides in different stages: early cleavage, morula and blastocyst. In the postprocessing step, false positives are removed using the connected components technique that identify regions with excess of dye near pellucid zone. The proposed segmentation method was applied in 30 histological images of bovine embryos. Experiments were performed with the images and statistical measures of sensitivity, specificity and accuracy were calculated based on reference images (gold standard). The value of accuracy of the proposed method was 96% with standard deviation of 3%

  6. Behavioral Teratogenesis in Drosophila melanogaster.

    Science.gov (United States)

    Mishra, Monalisa; Barik, Bedanta Kumar

    2018-01-01

    Developmental biology is a fascinating branch of science which helps us to understand the mechanism of development, thus the findings are used in various therapeutic approach. Drosophila melanogaster served as a model to find the key molecules that initiate and regulate the mechanism of development. Various genes, transcription factors, and signaling pathways helping in development are identified in Drosophila. Many toxic compounds, which can affect the development, are also recognized using Drosophila model. These compounds, which can affect the development, are named as a teratogen. Many teratogens identified using Drosophila may also act as a teratogen for a human being since 75% of conservation exist between the disease genes present in Drosophila and human. There are certain teratogens, which do not cause developmental defect if exposed during pregnancy, however; behavioral defect appears in later part of development. Such compounds are named as a behavioral teratogen. Thus, it is worthy to identify the potential behavioral teratogen using Drosophila model. Drosophila behavior is well studied in various developmental stages. This chapter describes various methods which can be employed to test behavioral teratogenesis in Drosophila.

  7. Insulin and the early bovine embryo

    OpenAIRE

    Laskowski, Denise

    2017-01-01

    Metabolic imbalance is a problem in the dairy industry because the metabolic demands of increased milk production can lead to decreased fertility, and more knowledge about improving the management and physical conditions of the cow (the links between fertility, nutrition, milking, and dry period) is needed. Insulin is an important hormone regulating the energy balance in the body, and insulin concentrations change in situations of energy deficiency or excess, both of which a...

  8. The Drosophila melanogaster host model

    Science.gov (United States)

    Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

  9. The Drosophila melanogaster host model

    Directory of Open Access Journals (Sweden)

    Christina O. Igboin

    2012-02-01

    Full Text Available The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

  10. The Drosophila melanogaster host model.

    Science.gov (United States)

    Igboin, Christina O; Griffen, Ann L; Leys, Eugene J

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen-host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial-host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis-host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

  11. Compartmentalizing the embryo

    Science.gov (United States)

    Ile, Kristina E.; Renault, Andrew D.

    2013-01-01

    Lipid phosphate phosphatases (LPPs) are a class of enzymes that can dephosphorylate a number of lysophopholipids in vitro. Analysis of knockouts of LPP family members has demonstrated striking but diverse developmental roles for these enzymes. LPP3 is required for mouse vascular development while the Drosophila LPPs Wunen (Wun) and Wunen2 (Wun2) are required during embryogenesis for germ cell migration and survival. In a recent publication we examined if these fly LPPs have further developmental roles and found that Wun is required for proper tracheal formation. In particular we highlight a role for Wun in septate junction mediated barrier function in the tracheal system. In this paper we discuss further the possible mechanisms by which LPPs may influence barrier activity. PMID:23221483

  12. Who abandons embryos after IVF?

    LENUS (Irish Health Repository)

    Walsh, A P H

    2010-04-01

    This investigation describes features of in vitro fertilisation (IVF) patients who never returned to claim their embryos following cryopreservation. Frozen embryo data were reviewed to establish communication patterns between patient and clinic; embryos were considered abandoned when 1) an IVF patient with frozen embryo\\/s stored at our facility failed to make contact with our clinic for > 2 yrs and 2) the patient could not be located after a multi-modal outreach effort was undertaken. For these patients, telephone numbers had been disconnected and no forwarding address was available. Patient, spouse and emergency family contact\\/s all escaped detection efforts despite an exhaustive public database search including death records and Internet directory portals. From 3244 IVF cycles completed from 2000 to 2008, > or = 1 embryo was frozen in 1159 cases (35.7%). Those without correspondence for > 2 yrs accounted for 292 (25.2%) patients with frozen embryos; 281 were contacted by methods including registered (signature involving abandoned embryos did not differ substantially from other patients. The goal of having a baby was achieved by 10\\/11 patients either by spontaneous conception, adoption or IVF. One patient moved away with conception status unconfirmed. The overall rate of embryo abandonment was 11\\/1159 (< 1%) in this IVF population. Pre-IVF counselling minimises, but does not totally eliminate, the problem of abandoned embryos. As the number of abandoned embryos from IVF accumulates, their fate urgently requires clarification. We propose that clinicians develop a policy consistent with relevant Irish Constitutional provisions to address this medical dilemma.

  13. Transgenerational propagation and quantitative maintenance of paternal centromeres depends on Cid/Cenp-A presence in Drosophila sperm.

    Directory of Open Access Journals (Sweden)

    Nitika Raychaudhuri

    Full Text Available In Drosophila melanogaster, as in many animal and plant species, centromere identity is specified epigenetically. In proliferating cells, a centromere-specific histone H3 variant (CenH3, named Cid in Drosophila and Cenp-A in humans, is a crucial component of the epigenetic centromere mark. Hence, maintenance of the amount and chromosomal location of CenH3 during mitotic proliferation is important. Interestingly, CenH3 may have different roles during meiosis and the onset of embryogenesis. In gametes of Caenorhabditis elegans, and possibly in plants, centromere marking is independent of CenH3. Moreover, male gamete differentiation in animals often includes global nucleosome for protamine exchange that potentially could remove CenH3 nucleosomes. Here we demonstrate that the control of Cid loading during male meiosis is distinct from the regulation observed during the mitotic cycles of early embryogenesis. But Cid is present in mature sperm. After strong Cid depletion in sperm, paternal centromeres fail to integrate into the gonomeric spindle of the first mitosis, resulting in gynogenetic haploid embryos. Furthermore, after moderate depletion, paternal centromeres are unable to re-acquire normal Cid levels in the next generation. We conclude that Cid in sperm is an essential component of the epigenetic centromere mark on paternal chromosomes and it exerts quantitative control over centromeric Cid levels throughout development. Hence, the amount of Cid that is loaded during each cell cycle appears to be determined primarily by the preexisting centromeric Cid, with little flexibility for compensation of accidental losses.

  14. Dose-response analysis of phthalate effects on gene expression in rat whole embryo culture

    NARCIS (Netherlands)

    Robinson, J.F.; Verhoef, A.; van Beelen, V.A.; Pennings, J.L.A.; Piersma, A.H.|info:eu-repo/dai/nl/071276947

    2012-01-01

    The rat postimplantation whole embryo culture (WEC) model serves as a potential screening tool for developmental toxicity. In this model, cultured rat embryos are exposed during early embryogenesis and evaluated for morphological effects. The integration of molecular-based markers may lead to

  15. Embryos, genes, and birth defects

    National Research Council Canada - National Science Library

    Ferretti, Patrizia

    2006-01-01

    ... Structural anomalies The genesis of chromosome abnormalities Embryo survival The cause of high levels of chromosome abnormality in human embryos Relative parental risks - age, translocations, inversions, gonadal and germinal mosaics 33 33 34 35 36 44 44 45 4 Identification and Analysis of Genes Involved in Congenital Malformation Syndromes Peter J. Scambler Ge...

  16. Aspects of energetic substrate metabolism of in vitro and in vivo bovine embryos

    International Nuclear Information System (INIS)

    Souza, D.K. de; Salles, L.P.; Rosa e Silva, A.A.M.

    2015-01-01

    Although the metabolism of early bovine embryos has not been fully elucidated, several publications have addressed this important issue to improve culture conditions for cattle reproductive biotechnologies, with the ultimate goal of producing in vitro embryos similar in quality to those developing in vivo. Here, we review general aspects of bovine embryo metabolism in vitro and in vivo, and discuss the use of metabolic analysis of embryos produced in vitro to assess viability and predict a viable pregnancy after transference to the female tract

  17. Aspects of energetic substrate metabolism of in vitro and in vivo bovine embryos

    Energy Technology Data Exchange (ETDEWEB)

    Souza, D.K. de [Laboratório de Biotecnologia da Saúde, Faculdade de Medicina, Universidade de Brasília, Brasília, DF (Brazil); Faculdade da Ceilândia, Universidade de Brasília, Brasília, DF (Brazil); Salles, L.P. [Laboratório de Biotecnologia da Saúde, Faculdade de Medicina, Universidade de Brasília, Brasília, DF (Brazil); Departamento de Biologia Molecular, Instituto de Biologia, Universidade de Brasília, Brasília, DF (Brazil); Rosa e Silva, A.A.M. [Laboratório de Biotecnologia da Saúde, Faculdade de Medicina, Universidade de Brasília, Brasília, DF (Brazil)

    2015-01-23

    Although the metabolism of early bovine embryos has not been fully elucidated, several publications have addressed this important issue to improve culture conditions for cattle reproductive biotechnologies, with the ultimate goal of producing in vitro embryos similar in quality to those developing in vivo. Here, we review general aspects of bovine embryo metabolism in vitro and in vivo, and discuss the use of metabolic analysis of embryos produced in vitro to assess viability and predict a viable pregnancy after transference to the female tract.

  18. Aspects of energetic substrate metabolism of in vitro and in vivo bovine embryos

    Directory of Open Access Journals (Sweden)

    D.K. de Souza

    2015-03-01

    Full Text Available Although the metabolism of early bovine embryos has not been fully elucidated, several publications have addressed this important issue to improve culture conditions for cattle reproductive biotechnologies, with the ultimate goal of producing in vitro embryos similar in quality to those developing in vivo. Here, we review general aspects of bovine embryo metabolism in vitro and in vivo, and discuss the use of metabolic analysis of embryos produced in vitro to assess viability and predict a viable pregnancy after transference to the female tract.

  19. Distinct developmental defense activations in barley embryos identified by transcriptome profiling

    DEFF Research Database (Denmark)

    Nielsen, ME; Lok, F; Nielsen, Henrik Bjørn

    2006-01-01

    analyses of > 22,000 genes, which together with measurements of jasmonic acid and salicylic acid during embryo development provide new information on the initiation in the developing barley embryo of at least two distinct types of developmental defense activation (DDA). Early DDA is characterized by the up......-regulation of several PR genes is notable. Throughout barley embryo development, there are no indications of an increased biosynthesis of either jasmonic acid or salicylic acid. Collectively, the results help explain how the proposed DDA enables protection of the developing barley embryo and grain for purposes...

  20. Laboratory techniques for human embryos.

    Science.gov (United States)

    Geber, Selmo; Sales, Liana; Sampaio, Marcos A C

    2002-01-01

    This review is concerned with laboratory techniques needed for assisted conception, particularly the handling of gametes and embryos. Such methods are being increasingly refined. Successive stages of fertilization and embryogenesis require especial care, and often involve the use of micromanipulative methods for intracytoplasmic sperm injection (ICSI) or preimplantation genetic diagnosis. Embryologists must take responsibility for gamete collection and preparation, and for deciding on the means of insemination or ICSI. Embryos must be assessed in culture, during the 1-cell, cleaving and morula/blastocyst stages, and classified according to quality. Co-culture methods may be necessary. The best embryos for transfer must be selected and loaded into the transfer catheter. Embryos not transferred must be cryopreserved, which demands the correct application of current methods of media preparation, seeding and the correct speed for cooling and warming. Before too long, methods of detecting abnormal embryos and avoiding their transfer may become widespread.

  1. Olfactory memory traces in Drosophila.

    Science.gov (United States)

    Berry, Jacob; Krause, William C; Davis, Ronald L

    2008-01-01

    In Drosophila, the fruit fly, coincident exposure to an odor and an aversive electric shock can produce robust behavioral memory. This behavioral memory is thought to be regulated by cellular memory traces within the central nervous system of the fly. These molecular, physiological, or structural changes in neurons, induced by pairing odor and shock, regulate behavior by altering the neurons' response to the learned environment. Recently, novel in vivo functional imaging techniques have allowed researchers to observe cellular memory traces in intact animals. These investigations have revealed interesting temporal and spatial dynamics of cellular memory traces. First, a short-term cellular memory trace was discovered that exists in the antennal lobe, an early site of olfactory processing. This trace represents the recruitment of new synaptic activity into the odor representation and forms for only a short period of time just after training. Second, an intermediate-term cellular memory trace was found in the dorsal paired medial neuron, a neuron thought to play a role in stabilizing olfactory memories. Finally, a long-term protein synthesis-dependent cellular memory trace was discovered in the mushroom bodies, a structure long implicated in olfactory learning and memory. Therefore, it appears that aversive olfactory associations are encoded by multiple cellular memory traces that occur in different regions of the brain with different temporal domains.

  2. Characterization and expression analysis of Galnts in developing Strongylocentrotus purpuratus embryos.

    Directory of Open Access Journals (Sweden)

    Amber L Famiglietti

    Full Text Available Mucin-type O-glycosylation is a ubiquitous posttranslational modification in which N-Acetylgalactosamine (GalNAc is added to the hydroxyl group of select serine or threonine residues of a protein by the family of UDP-GalNAc:Polypeptide N-Acetylgalactosaminyltransferases (GalNAc-Ts; EC 2.4.1.41. Previous studies demonstrate that O-glycosylation plays essential roles in protein function, cell-cell interactions, cell polarity and differentiation in developing mouse and Drosophila embryos. Although this type of protein modification is highly conserved among higher eukaryotes, little is known about this family of enzymes in echinoderms, basal deuterostome relatives of the chordates. To investigate the potential role of GalNAc-Ts in echinoderms, we have begun the characterization of this enzyme family in the purple sea urchin, S. purpuratus. We have fully or partially cloned a total of 13 genes (SpGalnts encoding putative sea urchin SpGalNAc-Ts, and have confirmed enzymatic activity of five recombinant proteins. Amino acid alignments revealed high sequence similarity among sea urchin and mammalian glycosyltransferases, suggesting the presence of putative orthologues. Structural models underscored these similarities and helped reconcile some of the substrate preferences observed. Temporal and spatial expression of SpGalnt transcripts, was studied by whole-mount in situ hybridization. We found that many of these genes are transcribed early in developing embryos, often with restricted expression to the endomesodermal region. Multicolor fluorescent in situ hybridization (FISH demonstrated that transcripts encoding SpGalnt7-2 co-localized with both Endo16 (a gene expressed in the endoderm, and Gcm (a gene expressed in secondary mesenchyme cells at the early blastula stage, 20 hours post fertilization (hpf. At late blastula stage (28 hpf, SpGalnt7-2 message co-expresses with Gcm, suggesting that it may play a role in secondary mesenchyme development. We

  3. Identification of a novel Drosophila gene, beltless, using injectable embryonic and adult RNA interference (RNAi

    Directory of Open Access Journals (Sweden)

    Manev Hari

    2003-08-01

    Full Text Available Abstract Background RNA interference (RNAi is a process triggered by a double-stranded RNA that leads to targeted down-regulation/silencing of gene expression and can be used for functional genomics; i.e. loss-of-function studies. Here we report on the use of RNAi in the identification of a developmentally important novel Drosophila (fruit fly gene (corresponding to a putative gene CG5652/GM06434, that we named beltless based on an embryonic loss-of-function phenotype. Results Beltless mRNA is expressed in all developmental stages except in 0–6 h embryos. In situ RT-PCR localized beltless mRNA in the ventral cord and brain of late stage embryos and in the nervous system, ovaries, and the accessory glands of adult flies. RNAi was induced by injection of short (22 bp beltless double-stranded RNAs into embryos or into adult flies. Embryonic RNAi altered cuticular phenotypes ranging from partially-formed to missing denticle belts (thus beltless of the abdominal segments A2–A4. Embryonic beltless RNAi was lethal. Adult RNAi resulted in the shrinkage of the ovaries by half and reduced the number of eggs laid. We also examined Df(1RK4 flies in which deletion removes 16 genes, including beltless. In some embryos, we observed cuticular abnormalities similar to our findings with beltless RNAi. After differentiating Df(1RK4 embryos into those with visible denticle belts and those missing denticle belts, we assayed the presence of beltless mRNA; no beltless mRNA was detectable in embryos with missing denticle belts. Conclusions We have identified a developmentally important novel Drosophila gene, beltless, which has been characterized in loss-of-function studies using RNA interference. The putative beltless protein shares homologies with the C. elegans nose resistant to fluoxetine (NRF NRF-6 gene, as well as with several uncharacterized C. elegans and Drosophila melanogaster genes, some with prominent acyltransferase domains. Future studies should

  4. Viability of bovine demi embryo after splitting of fresh and frozen thawed embryo derived from in vitro embryo production

    Directory of Open Access Journals (Sweden)

    M Imron

    2007-06-01

    Full Text Available In vivo embryo production was limited by number of donor, wide variability respond due to superovulation program and also immunoactifity of superovulation hormone (FSH. Splitting technology could be an alternative to increase the number of transferrable embryos into recipien cows. Splitting is done with cutting embryo becoming two equal pieces (called demi embrio base on ICM orientation. The objective of this research was to determine the viability of demi embryo obtained from embryo splitting of fresh and frozen thawed embryo. The results showed that demi embryos which performed blastocoel reexpansion 3 hours after embryo splitting using fresh and frozen thawed embryos were 76.9 and 76.2% respectively. Base on existention of inner cell mass (ICM, the number of demi embryos developed with ICM from fresh and frozen thawed embryos were not significantly different (90.6 and 85.7% respectively. The cell number of demi embryo from fresh embryos splitting was not different compared with those from frozen thawed embryos (36.1 and 35.9 respectively. These finding indicated that embryo splitting can be applied to frozen thawed embryos with certain condition as well as fresh embryos.

  5. Role of melatonin in embryo fetal development.

    Science.gov (United States)

    Voiculescu, S E; Zygouropoulos, N; Zahiu, C D; Zagrean, A M

    2014-01-01

    Melatonin is an indoleamine produced by the pineal gland and secreted in a circadian manner. In the past few decades, research over this topic has been enhanced. Melatonin has many important roles in the human physiology: regulator of the circadian rhythms, sleep inducer, antioxidant, anticarcinogenic. This paper reviews the involvement of melatonin in embryo fetal development. The pineal gland develops completely postpartum, so both the embryo and the fetus are dependent on the maternal melatonin provided transplacentally. Melatonin appears to be involved in the normal outcome of pregnancy beginning with the oocyte quality and finishing with the parturition. Its pregnancy night-time concentrations increase after 24 weeks of gestation, with significantly high levels after 32 weeks. Melatonin receptors are widespread in the embryo and fetus since early stages. There is solid evidence that melatonin is neuroprotective and has a positive effect on the outcome of the compromised pregnancies. In addition, chronodisruption leads to a reproductive dysfunction. Thus, the influence of melatonin on the developing human fetus may not be limited to the entertaining of circadian rhythmicity, but further studies are needed.

  6. Pre implanted mouse embryos as model for uranium toxicology studies

    International Nuclear Information System (INIS)

    Kundt, Miriam S.

    2001-01-01

    Full text: The search of 'in vitro' toxicology model that can predict toxicology effects 'in vivo' is a permanent challenge. A toxicology experimental model must to fill to certain requirements: to have a predictive character, an appropriate control to facilitate the interpretation of the data among the experimental groups, and to be able to control the independent variables that can interfere or modify the results that we are analyzing. The preimplantation embryos posses many advantages in this respect: they are a simple model that begins with the development of only one cell. The 'in vitro' model reproduces successfully the 'in vivo' situation. Due to the similarity that exists among the embryos of mammals during this period the model is practically valid for other species. The embryo is itself a stem cell, the toxicology effects are early observed in his clonal development and the physical-chemical parameters are easily controllable. The purpose of the exhibition is to explain the properties of the pre implanted embryo model for toxicology studies of uranium and to show our experimental results. The cultivation 'in vitro' of mouse embryos with uranylo nitrate demonstrated that the uranium causes from the 13 μgU/ml delay of development, decrease the number of cells per embryo and hipoploidy in the embryonic blastomere. (author)

  7. Impact of motorboats on fish embryos depends on engine type.

    Science.gov (United States)

    Jain-Schlaepfer, Sofia; Fakan, Eric; Rummer, Jodie L; Simpson, Stephen D; McCormick, Mark I

    2018-01-01

    Human generated noise is changing the natural underwater soundscapes worldwide. The most pervasive sources of underwater anthropogenic noise are motorboats, which have been found to negatively affect several aspects of fish biology. However, few studies have examined the effects of noise on early life stages, especially the embryonic stage, despite embryo health being critical to larval survival and recruitment. Here, we used a novel setup to monitor heart rates of embryos from the staghorn damselfish ( Amblyglyphidodon curacao ) in shallow reef conditions, allowing us to examine the effects of in situ boat noise in context with real-world exposure. We found that the heart rate of embryos increased in the presence of boat noise, which can be associated with the stress response. Additionally, we found 2-stroke outboard-powered boats had more than twice the effect on embryo heart rates than did 4-stroke powered boats, showing an increase in mean individual heart rate of 1.9% and 4.6%, respectively. To our knowledge this is the first evidence suggesting boat noise elicits a stress response in fish embryo and highlights the need to explore the ecological ramifications of boat noise stress during the embryo stage. Also, knowing the response of marine organisms caused by the sound emissions of particular engine types provides an important tool for reef managers to mitigate noise pollution.

  8. CELLULAR LOCALIZATION AND EXPRESSION OF pygo DURING DROSOPHILA DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    LINXin-da; LINXin-hua; CHENGJia-an

    2003-01-01

    Wg/Wnt signaling is a key signaling pathway in Drosophila. Many genes involved in Wingless(wg) signal transduction pathway downstream of Wg, or it'' s vertebrate Wg homologue Wnt, have been identified.Transduction of the Wg signal downstream of Wg is mediated by nuclear TCF/LEF-1, through association with Ar-madillo (Arm)/β-catenin. Pygopus (pygo) is a new identified component in this pathway . Cellular localization experiment showed that pygo was expressed specifically in the nucleus. The expression profile of pygo in embryos was examined using in situ hybridization. Although pygo expressed ubiquitously in the embryos, it expressed at relatively high level in pre-blastoderm embryos which indicate a high degree of maternally provided message, fol-lowed by a low level of ubiquitous zygotic expression. This continues into larval tissues (including wing disc, eye disc and leg disc), where pygo appears to be expressed at low level. Comparison of pygo expression levels, in the wing disc, eye disc and leg disc, showed pygo expression level in the wing disc pouch and leg disc were rela-tive higher.

  9. Developmental toxicity of cartap on zebrafish embryos.

    Science.gov (United States)

    Zhou, Shengli; Dong, Qiaoxiang; Li, Shaonan; Guo, Jiangfeng; Wang, Xingxing; Zhu, Guonian

    2009-12-13

    Cartap is a widely used insecticide which belongs to a member of nereistoxin derivatives and acts on nicotinic acetylcholine receptor site. Its effects on aquatic species are of grave concern. To explore the potential developmental toxicity of cartap, zebrafish embryos were continually exposed, from 0.5 to 144h post-fertilization, to a range of concentrations of 25-1000microg/l. Results of the experiment indicated that cartap concentrations of 100microg/l and above negatively affected embryo survival and hatching success. Morphological analysis uncovered a large suite of abnormalities such as less melanin pigmentation, wavy notochord, crooked trunk, fuzzy somites, neurogenesis defects and vasculature defects. The most sensitive organ was proved to be the notochord which displayed defects at concentrations as low as 25microg/l. Both sensitivity towards exposure and localization of the defect were stage specific. To elucidate mechanisms concerning notochord, pigmentation, and hatching defects, enzyme assay, RT Q-PCR, and different exposure strategies were performed. For embryos with hatching failure, chorion was verified not to be digested, while removing cartap from exposure at early pre-hatching stage could significantly increase the hatching success. However, cartap was proved, via vitro assay, to have no effect on proteolytic activity of hatching enzyme. These findings implied that the secretion of hatching enzyme might be blocked. We also revealed that cartap inhibited the activity of melanogenic enzyme tyrosinase and matrix enzyme lysyl oxidase and induced expression of their genes. These suggested that cartap could impaired melanin pigmentation of zebrafish embryos through inhibiting tyrosinase activity, while inhibition of lysyl oxidase activity was responsible for notochord undulation, which subsequently caused somite defect, and at least partially responsible for defects in vasculature and neurogenesis.

  10. SUMOylation in Drosophila Development

    Directory of Open Access Journals (Sweden)

    Albert J. Courey

    2012-07-01

    Full Text Available Small ubiquitin-related modifier (SUMO, an ~90 amino acid ubiquitin-like protein, is highly conserved throughout the eukaryotic domain. Like ubiquitin, SUMO is covalently attached to lysine side chains in a large number of target proteins. In contrast to ubiquitin, SUMO does not have a direct role in targeting proteins for proteasomal degradation. However, like ubiquitin, SUMO does modulate protein function in a variety of other ways. This includes effects on protein conformation, subcellular localization, and protein–protein interactions. Significant insight into the in vivo role of SUMOylation has been provided by studies in Drosophila that combine genetic manipulation, proteomic, and biochemical analysis. Such studies have revealed that the SUMO conjugation pathway regulates a wide variety of critical cellular and developmental processes, including chromatin/chromosome function, eggshell patterning, embryonic pattern formation, metamorphosis, larval and pupal development, neurogenesis, development of the innate immune system, and apoptosis. This review discusses our current understanding of the diverse roles for SUMO in Drosophila development.

  11. Effects of Spaceflight on Drosophila Neural Development

    Science.gov (United States)

    Keshishian, Haig S.

    1997-01-01

    The major goal from the animal side, however, has been achieved, namely to develop Drosophila lines where we can assay individual neuromuscular endings directly without dissection. This was achieved by means of using the GAL4-UAS system, where we have succeeded in establishing stocks of flies where the key neuromuscular connections can be assayed directly in undissected larvae by means of the expression of endogenously fluorescent reporters in the specific motor endings. The green fluorescent protein (GFP) as a reporter allows scoring of neural anatomy en-masse in whole mount using fluorescent microscopy without the need for either dissection or specific labeling. Two stocks have been developed. The first, which we developed first, uses the S65T mutant form, which has a dramatically brighter expression than the native protein. This animal will use GAL4 drivers with expression under the control of the elav gene, and which will ensure expression in all neurons of the embryo and larva. The second transgenic animal we have developed is of a novel kind, and makes use of dicistronic design, so that two copies of the protein will be expressed per insert. We have also developed a tricistronic form, but this has not yet been transformed into flies, and we do not imagine that this third line will be ready in time for the flight.

  12. Is there a link between blastomere contact surfaces of day 3 embryos and live birth rate?

    Directory of Open Access Journals (Sweden)

    Paternot Goedele

    2012-09-01

    Full Text Available Abstract Background Cell-cell communication and adhesion are essential for the compaction process of early stage embryos. The aim of this study was to develop a non-invasive objective calculation system of embryo compaction in order to test the hypothesis that embryos with a larger mean contact surface result in a higher live birth rate compared to embryos with a lower mean contact surface. Methods Multilevel images of 474 embryos transferred on day 3 were evaluated by the Cellify software. This software calculates the contact surfaces between the blastomeres. The primary outcome of this study was live birth. An ideal range of contact surface was determined and the positive and negative predictive value, the sensitivity, the specificity and the area under the curve for this new characteristic were calculated. Results In total, 115 (24% transferred embryos resulted in a live birth. Selection of an embryo for transfer on its mean contact surface could predict live birth with a high sensitivity (80% and high negative predicting value (83% but with a low positive predictive value (27%, a low specificity (31% and low area under the ROC curve (0.56. The mean contact surface of embryos cultured in a single medium was significantly higher compared to the mean contact surface of embryos cultured in a sequential medium (p = 0.0003. Conclusions Neither the mean contact surface nor the number of contact surfaces of a day 3 embryo had an additional value in the prediction of live birth. The type of culture medium, however, had an impact on the contact surface of an embryo. Embryos cultured in a single medium had a significant larger contact surface compared to embryos cultured in the sequential medium.

  13. Evolutionary genetics: the Drosophila model

    Indian Academy of Sciences (India)

    Unknown

    Evolutionary genetics straddles the two fundamental processes of life, ... of the genus Drosophila have been used extensively as model systems in experimental ... issue will prove interesting, informative and thought-provoking for both estab-.

  14. Radiation effects on cultured mouse embryos in relation to cell division cycle

    International Nuclear Information System (INIS)

    Domon, M.

    1982-01-01

    The authors have worked with mouse embryos in vitro asking first, what are the suitable parameters to define the radiation sensitivity of embryos, and second what is a major factor determining it. The LD 50 was adopted as a parameter of the radiation sensitivity of a population in a mouse embryo system in culture. The fertilized ova were collected into Whitten's medium at various times during the pronuclear and 2-cell stages of development. They were irradiated in chambers with X-rays at doses of 0 to 800 rads. After the embryos were cultured, a set of the lethal fractions for various X-ray doses were obtained. Regarding the radiation sensitivity variation of the embryos, the LD 50 varied from 100 to 200 rads during the pronuclear stage and from 100 to 600 rads during the 2-cell stage. The embryos during the pronuclear stage were most radioresistant at early G 2 phase, followed by an increase in the sensitivity. The embryos during the 2-cell stage were also most radioresistant at early G 2 phase and were more sensitive when they got close to either the first or the second cleavage division. Furthermore, it seems that the factor 6 of the large variation was due to the extremely long G 2 period, 14 hrs for the 2-cell embryos. That is, the pooled 2-cell embryos were in a relative sense well synchronized with G 2 phase. In contrast, the synchrony was poor during the pronuclear stage, which led to less variation of the LD 50 for the pronuclear embryos. It is concluded that during the early cleavage stages of mice, radiosensitivity is mainly governed by the content of cells of various cell cycle ages in the embryo. (Namekawa, K.)

  15. Identification of early zygotic genes in the yellow fever mosquito Aedes aegypti and discovery of a motif involved in early zygotic genome activation.

    Science.gov (United States)

    Biedler, James K; Hu, Wanqi; Tae, Hongseok; Tu, Zhijian

    2012-01-01

    During early embryogenesis the zygotic genome is transcriptionally silent and all mRNAs present are of maternal origin. The maternal-zygotic transition marks the time over which embryogenesis changes its dependence from maternal RNAs to zygotically transcribed RNAs. Here we present the first systematic investigation of early zygotic genes (EZGs) in a mosquito species and focus on genes involved in the onset of transcription during 2-4 hr. We used transcriptome sequencing to identify the "pure" (without maternal expression) EZGs by analyzing transcripts from four embryonic time ranges of 0-2, 2-4, 4-8, and 8-12 hr, which includes the time of cellular blastoderm formation and up to the start of gastrulation. Blast of 16,789 annotated transcripts vs. the transcriptome reads revealed evidence for 63 (P<0.001) and 143 (P<0.05) nonmaternally derived transcripts having a significant increase in expression at 2-4 hr. One third of the 63 EZG transcripts do not have predicted introns compared to 10% of all Ae. aegypti genes. We have confirmed by RT-PCR that zygotic transcription starts as early as 2-3 hours. A degenerate motif VBRGGTA was found to be overrepresented in the upstream sequences of the identified EZGs using a motif identification software called SCOPE. We find evidence for homology between this motif and the TAGteam motif found in Drosophila that has been implicated in EZG activation. A 38 bp sequence in the proximal upstream sequence of a kinesin light chain EZG (KLC2.1) contains two copies of the mosquito motif. This sequence was shown to support EZG transcription by luciferase reporter assays performed on injected early embryos, and confers early zygotic activity to a heterologous promoter from a divergent mosquito species. The results of these studies are consistent with the model of early zygotic genome activation via transcriptional activators, similar to what has been found recently in Drosophila.

  16. Identification of early zygotic genes in the yellow fever mosquito Aedes aegypti and discovery of a motif involved in early zygotic genome activation.

    Directory of Open Access Journals (Sweden)

    James K Biedler

    Full Text Available During early embryogenesis the zygotic genome is transcriptionally silent and all mRNAs present are of maternal origin. The maternal-zygotic transition marks the time over which embryogenesis changes its dependence from maternal RNAs to zygotically transcribed RNAs. Here we present the first systematic investigation of early zygotic genes (EZGs in a mosquito species and focus on genes involved in the onset of transcription during 2-4 hr. We used transcriptome sequencing to identify the "pure" (without maternal expression EZGs by analyzing transcripts from four embryonic time ranges of 0-2, 2-4, 4-8, and 8-12 hr, which includes the time of cellular blastoderm formation and up to the start of gastrulation. Blast of 16,789 annotated transcripts vs. the transcriptome reads revealed evidence for 63 (P<0.001 and 143 (P<0.05 nonmaternally derived transcripts having a significant increase in expression at 2-4 hr. One third of the 63 EZG transcripts do not have predicted introns compared to 10% of all Ae. aegypti genes. We have confirmed by RT-PCR that zygotic transcription starts as early as 2-3 hours. A degenerate motif VBRGGTA was found to be overrepresented in the upstream sequences of the identified EZGs using a motif identification software called SCOPE. We find evidence for homology between this motif and the TAGteam motif found in Drosophila that has been implicated in EZG activation. A 38 bp sequence in the proximal upstream sequence of a kinesin light chain EZG (KLC2.1 contains two copies of the mosquito motif. This sequence was shown to support EZG transcription by luciferase reporter assays performed on injected early embryos, and confers early zygotic activity to a heterologous promoter from a divergent mosquito species. The results of these studies are consistent with the model of early zygotic genome activation via transcriptional activators, similar to what has been found recently in Drosophila.

  17. Altered cleavage patterns in human tripronuclear embryos and their association to fertilization method

    DEFF Research Database (Denmark)

    Joergensen, Mette Warming; Agerholm, Inge; Hindkjaer, Johnny

    2014-01-01

    PURPOSE: To analyze the cleavage patterns in dipronuclear (2PN) and tripronuclear (3PN) embryos in relation to fertilization method. METHOD: Time-lapse analysis. RESULTS: Compared to 2PN, more 3PN IVF embryos displayed early cleavage into 3 cells (p ... stage (p embryos, the 2nd and 3rd cleavage cycles were completed within the expected time frame. However, timing of the cell divisions within the cleavage cycles differed between the two groups. In contrast......, the completion of the 1st, 2nd, and 3rd cleavage cycle was delayed, but with a similar division pattern for 3PN ICSI compared with the 2PN ICSI embryos. 3PN, more often than 2PN ICSI embryos, displayed early cleavage into 3 cells (p = 0.03) and arrested development from the compaction stage and onwards (p = 0...

  18. Expressional and functional analyses of transcription factors activated by BMP-4s signaling in early xenopus embryo; BMP-4 shigunaru dentatsu kiko to sono hyoteki kakunai tensha inshi ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Maeno, Mitsugu [Niigata University, Niigata (Japan). Faculty of Science

    1998-12-16

    The expression and physiological function of two transcription factors, GATA-2 and Xmsx-1, in amphibian embryos has been analyzed. The expression of these mRNAs in embryonic cells were firmly regulated by the BMP-4 signaling, that plays a central role in the formation of ventral tissues. The microinjection studies of GATA-2 RNA into embryonic cells suggested that this factor functions in two adjacent germ layers, mesoderm and ectoderm, to participate in blood cell formation in ventral area of embryo. Embryos injected with Xmsx-1 RNA, but not with GATA-2, in dorsal blastomeres exhibited a ventralized phenotype, with microcephaly and swollen abdomen. Thus, Xmsx-1 is a ventralizing agent. However, on the basis of molecular marker analyses, Xmsx-1 did not promote erythropoietic differentiation, but promoted muscle tissue formation. It has been concluded that Xmsx-1 si a target transcription factor of the BMP-4 signaling, but possesses a distinct activity on dorso-ventral patterning of mesodermal tissues. (author)

  19. Surgical manipulation of mammalian embryos in vitro.

    Science.gov (United States)

    Naruse, I; Keino, H; Taniguchi, M

    1997-04-01

    Whole-embryo culture systems are useful in the fields of not only embryology but also teratology, toxicology, pharmacology, and physiology. Of the many advantages of whole-embryo culture, we focus here on the surgical manipulation of mammalian embryos. Whole-embryo culture allows us to manipulate mammalian embryos, similarly to fish, amphibian and avian embryos. Many surgical experiments have been performed in mammalian embryos in vitro. Such surgical manipulation alters the destiny of morphogenesis of the embryos and can answer many questions concerning developmental issues. As an example of surgical manipulation using whole-embryo culture systems, one of our experiments is described. Microsurgical electrocauterization of the deep preaxial mesodermal programmed cell death zone (fpp) in the footplate prevented the manifestation of polydactyly in genetic polydactyly mouse embryos (Pdn/Pdn), in which fpp was abolished.

  20. Oxygen diffusion in fish embryos

    NARCIS (Netherlands)

    Kranenbarg, S.

    2002-01-01

    All vertebrate embryos pass through a developmental period of remarkably low morphological variability. This period has been called phylotypic period. During the phylotypic period, organogenesis takes place, including blood vessel development. Before the phylotypic

  1. Humidity Sensing in Drosophila.

    Science.gov (United States)

    Enjin, Anders; Zaharieva, Emanuela E; Frank, Dominic D; Mansourian, Suzan; Suh, Greg S B; Gallio, Marco; Stensmyr, Marcus C

    2016-05-23

    Environmental humidity influences the fitness and geographic distribution of all animals [1]. Insects in particular use humidity cues to navigate the environment, and previous work suggests the existence of specific sensory mechanisms to detect favorable humidity ranges [2-5]. Yet, the molecular and cellular basis of humidity sensing (hygrosensation) remains poorly understood. Here we describe genes and neurons necessary for hygrosensation in the vinegar fly Drosophila melanogaster. We find that members of the Drosophila genus display species-specific humidity preferences related to conditions in their native habitats. Using a simple behavioral assay, we find that the ionotropic receptors IR40a, IR93a, and IR25a are all required for humidity preference in D. melanogaster. Yet, whereas IR40a is selectively required for hygrosensory responses, IR93a and IR25a mediate both humidity and temperature preference. Consistent with this, the expression of IR93a and IR25a includes thermosensory neurons of the arista. In contrast, IR40a is excluded from the arista but is expressed (and required) in specialized neurons innervating pore-less sensilla of the sacculus, a unique invagination of the third antennal segment. Indeed, calcium imaging showed that IR40a neurons directly respond to changes in humidity, and IR40a knockdown or IR93a mutation reduced their responses to stimuli. Taken together, our results suggest that the preference for a specific humidity range depends on specialized sacculus neurons, and that the processing of environmental humidity can happen largely in parallel to that of temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Telomere Length Reprogramming in Embryos and Stem Cells

    Directory of Open Access Journals (Sweden)

    Keri Kalmbach

    2014-01-01

    Full Text Available Telomeres protect and cap linear chromosome ends, yet these genomic buffers erode over an organism’s lifespan. Short telomeres have been associated with many age-related conditions in humans, and genetic mutations resulting in short telomeres in humans manifest as syndromes of precocious aging. In women, telomere length limits a fertilized egg’s capacity to develop into a healthy embryo. Thus, telomere length must be reset with each subsequent generation. Although telomerase is purportedly responsible for restoring telomere DNA, recent studies have elucidated the role of alternative telomeres lengthening mechanisms in the reprogramming of early embryos and stem cells, which we review here.

  3. Propylthiouracil is teratogenic in murine embryos.

    Directory of Open Access Journals (Sweden)

    Valeria C Benavides

    Full Text Available Hyperthyroidism during pregnancy is treated with the antithyroid drugs (ATD propylthiouracil (PTU and methimazole (MMI. PTU currently is recommended as the drug of choice during early pregnancy. Yet, despite widespread ATD use in pregnancy, formal studies of ATD teratogenic effects have not been performed.We examined the teratogenic effects of PTU and MMI during embryogenesis in mice. To span different periods of embryogenesis, dams were treated with compounds or vehicle daily from embryonic day (E 7.5 to 9.5 or from E3.5 to E7.5. Embryos were examined for gross malformations at E10.5 or E18.5 followed by histological and micro-CT analysis. Influences of PTU on gene expression levels were examined by RNA microarray analysis.When dams were treated from E7.5 to E9.5 with PTU, neural tube and cardiac abnormalities were observed at E10.5. Cranial neural tube defects were significantly more common among the PTU-exposed embryos than those exposed to MMI or vehicle. Blood in the pericardial sac, which is a feature indicative of abnormal cardiac function and/or abnormal vasculature, was observed more frequently in PTU-treated than MMI-treated or vehicle-treated embryos. Following PTU treatment, a total of 134 differentially expressed genes were identified. Disrupted genetic pathways were those associated with cytoskeleton remodeling and keratin filaments. At E 18.5, no gross malformations were evident in either ATD group, but the number of viable PTU embryos per dam at E18.5 was significantly lower from those at E10.5, indicating loss of malformed embryos. These data show that PTU exposure during embryogenesis is associated with delayed neural tube closure and cardiac abnormalities. In contrast, we did not observe structural or cardiac defects associated with MMI exposure except at the higher dose. We find that PTU exposure during embryogenesis is associated with fetal loss. These observations suggest that PTU has teratogenic potential.

  4. [The destiny of cryopreserved embryos].

    Science.gov (United States)

    Karpel, L; Achour-Frydman, N; Frydman, R; Flis-Trèves, M

    2007-12-01

    To know the psychological motivations of couples who keep their embryos so long (five years and more) and do not make a decision about them. We studied 84 couples refrained from making a decision on their cryopreserved embryos for at least five years. They were invited to fill out a questionnaire focusing on three points: the reasons of the indecision, their own representation of the cryopreserved embryos and their choice for the future: donation to another couple, to research, pregnancy or no solution for the moment. Mean (S.D.) women's and men's age were respectively, 38.8 (2.5)- and 41.3 (2.5)-years old. On average, three (1-9) embryos are preserved since 7.5 (5-12) years. Most of couples are parents. Four major reasons explain their attitudes: feeling of being too aged (25%), fear of a multiple pregnancy (45%), disagreement between members of couple (20%) and fear of failure (42.5%). Multiple choices were given to the future of the embryos: 25% wanted a pregnancy, 8% wanted to give them to infertile couples, 20% to research and 27.5% did not find any solution. Twenty percent were hesitating. The representation of those embryos is more symbolic than material. Most of the time, they see them like a potential child, a hope for the future or a brother or sister of their alive children. Those embryos are symbolized. They are a proof of fertility, a hope for another child. So, whatever the legal statement, couples will be in a dilemma because it is never easy for an infertile person to renounce to embryos, and the hope for children.

  5. The route of infection determines Wolbachia antibacterial protection in Drosophila.

    Science.gov (United States)

    Gupta, Vanika; Vasanthakrishnan, Radhakrishnan B; Siva-Jothy, Jonathon; Monteith, Katy M; Brown, Sam P; Vale, Pedro F

    2017-06-14

    Bacterial symbionts are widespread among metazoans and provide a range of beneficial functions. Wolbachia -mediated protection against viral infection has been extensively demonstrated in Drosophila. In mosquitoes that are artificially transinfected with Drosophila melanogaster Wolbachia (wMel), protection from both viral and bacterial infections has been demonstrated. However, no evidence for Wolbachia -mediated antibacterial protection has been demonstrated in Drosophila to date. Here, we show that the route of infection is key for Wolbachia -mediated antibacterial protection. Drosophila melanogaster carrying Wolbachia showed reduced mortality during enteric-but not systemic-infection with the opportunist pathogen Pseudomonas aeruginosa Wolbachia -mediated protection was more pronounced in male flies and is associated with increased early expression of the antimicrobial peptide Attacin A , and also increased expression of a reactive oxygen species detoxification gene ( Gst D8 ). These results highlight that the route of infection is important for symbiont-mediated protection from infection, that Wolbachia can protect hosts by eliciting a combination of resistance and disease tolerance mechanisms, and that these effects are sexually dimorphic. We discuss the importance of using ecologically relevant routes of infection to gain a better understanding of symbiont-mediated protection. © 2017 The Authors.

  6. Utilization of endogenous fatty acid stores for energy production in bovine preimplantation embryos.

    Science.gov (United States)

    Sutton-McDowall, Melanie L; Feil, Deanne; Robker, Rebecca L; Thompson, Jeremy G; Dunning, Kylie R

    2012-05-01

    Although current embryo culture media are based on carbohydrate metabolism of embryos, little is known about metabolism of endogenous lipids. L-carnitine is a β-oxidation cofactor absent in most culture media. The objective was to investigate the influence of L-carnitine supplementation on bovine embryo development. Abattoir-derived bovine cumulus oocyte complexes were cultured and fertilized. Post-fertilization, presumptive zygotes were transferred into a basic cleavage medium ± carbohydrates (glucose, lactate and pyruvate) ± 5 mm L-carnitine and cultured for 4 days in vitro. In the absence of carbohydrates during culture, embryos arrested at the 2- and 4-cell stages. Remarkably, +L-carnitine increased development to the morula stage compared to +carbohydrates alone (P levels were higher and ATP: ADP ratio were 1.9-fold lower (main effect, P < 0.05) compared to embryos cultured in -L-carnitine. Therefore, we inferred that +L-carnitine embryos were more metabolically active, with higher rates of ATP-ADP conversion. In conclusion, L-carnitine supplementation supported precompaction embryo development and there was an additive effect of +L-carnitine +carbohydrates on early embryo development, most likely through increased β-oxidation within embryos. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  7. Change in energy metabolism of in vitro produced embryos: an alternative to make them more cryoresistant?

    Directory of Open Access Journals (Sweden)

    Luzia Renata Oliveira Dias

    2017-08-01

    Full Text Available For the development of in vitro produced (IVP as well as in vivo produced bovine embryos, it is extremely important that their energy metabolism works properly because the embryo must be able to metabolize energy substrates that are necessary for producing energy. Lipids play an important role in early embryonic development, acting as source of energy for oocytes and embryos. However, it is known that oocytes and embryos, mainly IVP, accumulate large amounts of lipids in the cytoplasm. Although they are extremely important in embryonic development, lipids have been associated with the reduced survival of bovine embryos following cryopreservation. There is evidence that at least four different categories of lipids affect embryo survival after cryopreservation, including triglycerides (TAG, free fatty acids, cholesterol and phospholipids. Thus, many studies are being conducted to improve the resistance of IVP embryos to the cryopreservation process by reducing the concentration or removing the source of serum from the medium or by reducing oocyte/embryo lipids using mechanical or chemical means. Regarding the use of delipidating agents that reduce the uptake and synthesis of fatty acids (FA by cells, substances such as phenazine ethosulfate (PES, forskolin, L-carnitine and isomers of conjugated linoleic acid (CLA have been utilized. This review aims to address important issues related to embryonic energy metabolism, the importance of lipid metabolism and its relation to the cryopreservation of IVP bovine embryos by summarizing the latest research in this field.

  8. Hermann Muller and Mutations in Drosophila

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis Hermann Muller and Mutations in Drosophila Resources with University of Texas. In Austin his experiments on fruit flies (Drosophila) first showed that exposure to September to spend a year at the only Drosophila laboratory in Europe which was doing parallel work

  9. Use of Drosophila to study DNA repair

    International Nuclear Information System (INIS)

    Boyd, J.B.; Harris, P.V.; Sakaguchi, K.

    1988-01-01

    This paper discusses Drosophila, the premier metazoan organism for analyzing many fundamental features of eukaryotic gene regulation. The authors present adaptations of several approaches for studying DNA repair to an analysis of repair-defective mutants in Drosophila. A current understanding of Drosophila DNA repair is described

  10. Ethanol impedes embryo transport and impairs oviduct epithelium

    International Nuclear Information System (INIS)

    Xu, Tonghui; Yang, Qiuhong; Liu, Ruoxi; Wang, Wenfu; Wang, Shuanglian; Liu, Chuanyong; Li, Jingxin

    2016-01-01

    Most studies have demonstrated that alcohol consumption is associated with decreased fertility. The aim of this study was to investigate the effects of alcohol on pre-implantation embryo transport and/or early embryo development in the oviduct. We reported here that ethanol concentration-dependently suppressed the spontaneous motility of isolated human oviduct strips (EC50 50 ± 6 mM), which was largely attenuated in the present of L-NAME, a classical nitric oxide synthase(NOS) competitive inhibitor. Notably, either acute or chronic alcohol intake delayed egg transport and retarded early development of the embryo in the mouse oviduct, which was largely rescued by co-administration of L-NAME in a acute alcohol intake group but not in chronic alcohol intake group. It is worth mentioning that the oviductal epithelium destruction was verified by scanning electron microscope (SEM) observations in chronic alcohol intake group. In conclusion, alcohol intake delayed egg transport and retarded early development of the embryo in the oviduct by suppressing the spontaneous motility of oviduct and/or impairing oviductal epithelium. These findings suggested that alcohol abuse increases the incident of ectopic pregnancy.

  11. Ethanol impedes embryo transport and impairs oviduct epithelium.

    Science.gov (United States)

    Xu, Tonghui; Yang, Qiuhong; Liu, Ruoxi; Wang, Wenfu; Wang, Shuanglian; Liu, Chuanyong; Li, Jingxin

    2016-05-16

    Most studies have demonstrated that alcohol consumption is associated with decreased fertility. The aim of this study was to investigate the effects of alcohol on pre-implantation embryo transport and/or early embryo development in the oviduct. We reported here that ethanol concentration-dependently suppressed the spontaneous motility of isolated human oviduct strips (EC50 50±6mM), which was largely attenuated in the present of L-NAME, a classical nitric oxide synthase(NOS) competitive inhibitor. Notably, either acute or chronic alcohol intake delayed egg transport and retarded early development of the embryo in the mouse oviduct, which was largely rescued by co-administration of L-NAME in a acute alcohol intake group but not in chronic alcohol intake group. It is worth mentioning that the oviductal epithelium destruction was verified by scanning electron microscope (SEM) observations in chronic alcohol intake group. In conclusion, alcohol intake delayed egg transport and retarded early development of the embryo in the oviduct by suppressing the spontaneous motility of oviduct and/or impairing oviductal epithelium. These findings suggested that alcohol abuse increases the incident of ectopic pregnancy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Wolbachia-induced paternal defect in Drosophila is likely by interaction with the juvenile hormone pathway.

    Science.gov (United States)

    Liu, Chen; Wang, Jia-Lin; Zheng, Ya; Xiong, En-Juan; Li, Jing-Jing; Yuan, Lin-Ling; Yu, Xiao-Qiang; Wang, Yu-Feng

    2014-06-01

    resulted in nuclear division defects in the early embryos. Finally, we found that Wolbachia-infected males decreased the propensity of the mated females to remating, a phenotype also caused by both JhI-26 and CG10433 overexpressing males. Taken together, our results provide a working hypothesis whereby Wolbachia induce paternal defects in Drosophila probably by interaction with the JH pathway via JH response genes JhI-26 and CG10433. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

    Science.gov (United States)

    Wellner, Karen L.

    2014-01-01

    In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

  14. Automated microinjection of recombinant BCL-X into mouse zygotes enhances embryo development.

    Directory of Open Access Journals (Sweden)

    Xinyu Liu

    Full Text Available Progression of fertilized mammalian oocytes through cleavage, blastocyst formation and implantation depends on successful implementation of the developmental program, which becomes established during oogenesis. The identification of ooplasmic factors, which are responsible for successful embryo development, is thus crucial in designing possible molecular therapies for infertility intervention. However, systematic evaluation of molecular targets has been hampered by the lack of techniques for efficient delivery of molecules into embryos. We have developed an automated robotic microinjection system for delivering cell impermeable compounds into preimplantation embryos with a high post-injection survival rate. In this paper, we report the performance of the system on microinjection of mouse embryos. Furthermore, using this system we provide the first evidence that recombinant BCL-XL (recBCL-XL protein is effective in preventing early embryo arrest imposed by suboptimal culture environment. We demonstrate that microinjection of recBCL-XL protein into early-stage embryos repairs mitochondrial bioenergetics, prevents reactive oxygen species (ROS accumulation, and enhances preimplantation embryo development. This approach may lead to a possible treatment option for patients with repeated in vitro fertilization (IVF failure due to poor embryo quality.

  15. Regulation of somatic embryo development in Norway spruce (Picea abies). A molecular approach to the characterization of specific developmental stages

    Energy Technology Data Exchange (ETDEWEB)

    Sabala, I. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

    1998-12-31

    Embryo development is a complex process involving a set of strictly regulated events. The regulation of these events is poorly understood especially during the early stages of embryo development. Somatic embryos go through the same developmental stages as zygotic embryos making them an ideal model system for studying the regulation of embryo development. We have used embryogenic cultures of Picea abies to study some aspects of the regulation of embryo development in gymnosperms. The bottle neck during somatic embryogenesis is the switch from the proliferation stage to the maturation stage. This switch is initiated by giving somatic embryos a maturation treatment i.e. the embryos are treated with abscisic acid (ABA). Somatic embryos which respond to ABA by forming mature somatic embryos were stimulated to secret a 70 kDa protein, AF70. The af70 gene was isolated and characterised. The expression of the af70 gene was constitutive in embryos but was highly ABA-induced in seedlings. Moreover, expression of this gene was stimulated during cold acclimation of Picea abies seedlings. A full length Picea abies cDNA clone Pa18, encoding a protein with the characteristics of plant lipid transfer proteins (LTPs), was isolated and characterised. The Pa18 gene is constitutively expressed in embryogenic cultures of Picea abies representing different stages of development as well as in nonembryogenic callus and seedlings. In situ hybridization showed that Pa18 gene is expressed in all embryonic cells of proliferating somatic embryos but the expression of the gene in mature somatic and zygotic embryos is restricted to the outer cell layer. Southern blot analysis at different stringencies was consistent with a single gene. An alteration in expression of Pa18 causes disturbance in the formation of the proper outer cell layer in the maturing somatic embryos. In addition to its influence on embryo development the Pa18 gene product also inhibits growth of Agrobacterium tumefaciens 195

  16. Action of uranium on pre implanted mouse embryos

    International Nuclear Information System (INIS)

    Kundt, Miriam S.

    2001-01-01

    The cultured preimplantation embryos are normally employed to evaluate the effects of environmental pollutants specially metals. Embryos were obtained from hybrid females CBA x C57 Bl following induction of super ovulation. They were incubated from 1 cell stage during 120 hs. in M16 cultured medium. Three different experiments were carried out: A, B and C using uranyl nitrate UO 2 (NO 3 ) 2 6H 2 O as source of uranium. In experiment 'A' the embryos were cultivated in the same culture dish containing final U concentrations of 13, 26, 52, 104 and 208 μgU/ml. In experiment 'B' embryos in a one cell stage were placed in culture medium with uranyl nitrate with final U concentrations of 26, 52, 104 μgU/ml. After 24 hours those embryos which had reached the two-cell stage were transferred to another culture dish to which fresh solutions of uranyl nitrate were added, maintaining the same concentrations of the previous one. In experiment 'C' the embryos were cultivated containing final U concentrations of 26, 52 and 104 μgU/ml and they were transferred to another culture dish every day to which fresh solutions of uranyl nitrate were added. Different embryos parameters were analyzed: 1) Development grade; 2) Number of cell per embryo and metaphases index; and 3) Embryo ploidy. 1) Embryos were observed each 24 hs. to evaluate development grade: 2, 4 and 8 cell stage, morula, early -expanded- hatched blastocysts and atresic embryos. No significant differences were observed in the proportion of embryos arrested either in the one-cell or in the two cell stages in control culture medium regarding different concentrations of U, in a total of 4388 embryos analyzed. From 2 cell stage, moment that the embryo begins to synthesize its own ARNm, the delay in embryonic development increased dose dependent. On the other hand, the toxicological effects in the same concentration are increase from 'A' treatment to 'C' treatment. Embriotoxicology effects are evidenced by an increment in

  17. Disparate patterns of thermal adaptation between life stages in temperate vs. tropical Drosophila melanogaster.

    Science.gov (United States)

    Lockwood, B L; Gupta, T; Scavotto, R

    2018-02-01

    Many terrestrial ectothermic species exhibit limited variation in upper thermal tolerance across latitude. However, these trends may not signify limited adaptive capacity to increase thermal tolerance in the face of climate change. Instead, thermal tolerance may be similar among populations because behavioural thermoregulation by mobile organisms or life stages may buffer natural selection for thermal tolerance. We compared thermal tolerance of adults and embryos among natural populations of Drosophila melanogaster from a broad range of thermal habitats around the globe to assess natural variation of thermal tolerance in mobile vs. immobile life stages. We found no variation among populations in adult thermal tolerance, but embryonic thermal tolerance was higher in tropical strains than in temperate strains. We further report that embryos live closer to their upper thermal limits than adults - that is, thermal safety margins are smaller for embryos than adults. F1 hybrid embryos from crosses between temperate and tropical populations had thermal tolerance that matched that of tropical embryos, suggesting the dominance of heat-tolerant alleles. Together, our findings suggest that thermal selection has led to divergence in embryonic thermal tolerance but that selection for divergent thermal tolerance may be limited in adults. Further, our results suggest that thermal traits should be measured across life stages to better predict adaptive limits. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  18. Effect of Short-Term Hypergravity Treatment on Mouse 2-Cell Embryo Development

    Science.gov (United States)

    Ning, Li-Na; Lei, Xiao-Hua; Cao, Yu-Jing; Zhang, Yun-Fang; Cao, Zhong-Hong; Chen, Qi; Duan, En-Kui

    2015-11-01

    Though there are numerous biological experiments, which have been performed in a space environment, to study the physiological effect of space travel on living organisms, while the potential effect of weightlessness or short-term hypergravity on the reproductive system in most species, particularly in mammalian is still controversial and unclear. In our previous study, we investigated the effect of space microgravity on the development of mouse 4-cell embryos by using Chinese SJ-8. .Unexpectedly, we did not get any developed embryo during the space-flight. Considering that the process of space experiment is quite different from most experiments done on earth in several aspects such as, the vibration and short-term hypergravity during the rock launching and landing. Thus we want to know whether the short-term hypergravity produced by the launch process affect the early embryo development in mice, and howthe early embryos respond to the hypergravity. In present study, we are mimicking the short-term hypergravity during launch by using a centrifuge to investigate its influence on the development of early embryo (2-cell) in mice. We also examined the actin filament distribution in 2-cell embryos by immunostaining to test their potential capacity of development under short-term hypergravity exposure. Our results showed that most 2-cell embryos in the hypergravity exposure groups developed into blastocysts with normal morphology after 72h cultured in vitro, and there is no obvious difference in the development rate of blastocyst formation compared to the control. Moreover, there were no statistically significant differences in birth rates after oviduct transfer of 2-cell mouse embryos exposed on short-term hypergravity compared with 1 g condition. In addition, the well-organized actin distribution appeared in 2-cell embryos after exposed on hypergravity and also in the subsequent developmental blastocysts. Taken together, our data shows that short-term exposure in

  19. Perinatal outcomes among singletons after assisted reproductive technology with single-embryo or double-embryo transfer versus no assisted reproductive technology.

    Science.gov (United States)

    Martin, Angela S; Chang, Jeani; Zhang, Yujia; Kawwass, Jennifer F; Boulet, Sheree L; McKane, Patricia; Bernson, Dana; Kissin, Dmitry M; Jamieson, Denise J

    2017-04-01

    To examine outcomes of singleton pregnancies conceived without assisted reproductive technology (non-ART) compared with singletons conceived with ART by elective single-embryo transfer (eSET), nonelective single-embryo transfer (non-eSET), and double-embryo transfer with the establishment of 1 (DET -1) or ≥2 (DET ≥2) early fetal heartbeats. Retrospective cohort using linked ART surveillance data and vital records from Florida, Massachusetts, Michigan, and Connecticut. Not applicable. Singleton live-born infants. None. Preterm birth (PTB score score approach, we found that singletons conceived after eSET were less likely to have a 5-minute Apgar Reproductive Medicine. All rights reserved.

  20. Developmental imaging: the avian embryo hatches to the challenge.

    Science.gov (United States)

    Kulesa, Paul M; McKinney, Mary C; McLennan, Rebecca

    2013-06-01

    The avian embryo provides a multifaceted model to study developmental mechanisms because of its accessibility to microsurgery, fluorescence cell labeling, in vivo imaging, and molecular manipulation. Early two-dimensional planar growth of the avian embryo mimics human development and provides unique access to complex cell migration patterns using light microscopy. Later developmental events continue to permit access to both light and other imaging modalities, making the avian embryo an excellent model for developmental imaging. For example, significant insights into cell and tissue behaviors within the primitive streak, craniofacial region, and cardiovascular and peripheral nervous systems have come from avian embryo studies. In this review, we provide an update to recent advances in embryo and tissue slice culture and imaging, fluorescence cell labeling, and gene profiling. We focus on how technical advances in the chick and quail provide a clearer understanding of how embryonic cell dynamics are beautifully choreographed in space and time to sculpt cells into functioning structures. We summarize how these technical advances help us to better understand basic developmental mechanisms that may lead to clinical research into human birth defects and tissue repair. Copyright © 2013 Wiley Periodicals, Inc.

  1. The Maternal Maverick/GDF15-like TGF-β Ligand Panda Directs Dorsal-Ventral Axis Formation by Restricting Nodal Expression in the Sea Urchin Embryo

    Science.gov (United States)

    Haillot, Emmanuel; Molina, Maria Dolores; Lapraz, François; Lepage, Thierry

    2015-01-01

    Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1

  2. The Maternal Maverick/GDF15-like TGF-β Ligand Panda Directs Dorsal-Ventral Axis Formation by Restricting Nodal Expression in the Sea Urchin Embryo.

    Science.gov (United States)

    Haillot, Emmanuel; Molina, Maria Dolores; Lapraz, François; Lepage, Thierry

    2015-01-01

    Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1

  3. A damped oscillator imposes temporal order on posterior gap gene expression in Drosophila

    Science.gov (United States)

    Verd, Berta; Clark, Erik; Wotton, Karl R.; Janssens, Hilde; Jiménez-Guri, Eva; Crombach, Anton

    2018-01-01

    Insects determine their body segments in two different ways. Short-germband insects, such as the flour beetle Tribolium castaneum, use a molecular clock to establish segments sequentially. In contrast, long-germband insects, such as the vinegar fly Drosophila melanogaster, determine all segments simultaneously through a hierarchical cascade of gene regulation. Gap genes constitute the first layer of the Drosophila segmentation gene hierarchy, downstream of maternal gradients such as that of Caudal (Cad). We use data-driven mathematical modelling and phase space analysis to show that shifting gap domains in the posterior half of the Drosophila embryo are an emergent property of a robust damped oscillator mechanism, suggesting that the regulatory dynamics underlying long- and short-germband segmentation are much more similar than previously thought. In Tribolium, Cad has been proposed to modulate the frequency of the segmentation oscillator. Surprisingly, our simulations and experiments show that the shift rate of posterior gap domains is independent of maternal Cad levels in Drosophila. Our results suggest a novel evolutionary scenario for the short- to long-germband transition and help explain why this transition occurred convergently multiple times during the radiation of the holometabolan insects. PMID:29451884

  4. Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

    Science.gov (United States)

    Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

    2017-08-01

    Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

  5. The Centrioles, Centrosomes, Basal Bodies, and Cilia of Drosophila melanogaster.

    Science.gov (United States)

    Lattao, Ramona; Kovács, Levente; Glover, David M

    2017-05-01

    Centrioles play a key role in the development of the fly. They are needed for the correct formation of centrosomes, the organelles at the poles of the spindle that can persist as microtubule organizing centers (MTOCs) into interphase. The ability to nucleate cytoplasmic microtubules (MTs) is a property of the surrounding pericentriolar material (PCM). The centriole has a dual life, existing not only as the core of the centrosome but also as the basal body, the structure that templates the formation of cilia and flagellae. Thus the structure and functions of the centriole, the centrosome, and the basal body have an impact upon many aspects of development and physiology that can readily be modeled in Drosophila Centrosomes are essential to give organization to the rapidly increasing numbers of nuclei in the syncytial embryo and for the spatially precise execution of cell division in numerous tissues, particularly during male meiosis. Although mitotic cell cycles can take place in the absence of centrosomes, this is an error-prone process that opens up the fly to developmental defects and the potential of tumor formation. Here, we review the structure and functions of the centriole, the centrosome, and the basal body in different tissues and cultured cells of Drosophila melanogaster , highlighting their contributions to different aspects of development and cell division. Copyright © 2017 Lattao et al.

  6. Ovarian activity and embryo yield in relation to the postpartum period in superovulated dairy cows

    Directory of Open Access Journals (Sweden)

    Luděk Stádník

    2017-01-01

    Full Text Available The aim of this study was to evaluate superovulation response in cows at various postpartum periods (early postpartum period up to 3.5 months; middle postpartum period 3.7–7 months; later postpartum period above 7.5 months after calving. The data included observation of 55 Holstein cows superovulated at one farm in the Czech Republic during the years 2010 and 2013. Reproduction traits (dependent variable were represented as number of the corpora lutea, number of transferable embryos, morulae, blastocysts, total number of embryos and embryo recovery. For statistical evaluation we used the PROC GLM of SAS® with fixed effect - breeding value of milk production. The study results show significant differences (P < 0.05–0.01 in the three postpartum periods (early, middle, and later postpartum periods and the number of corpora lutea (4.6; 7.4; 10.8, number of total embryos (3.2; 2.9; 6.5 and transferable embryos (1.8; 1.7; 4.4. Effective timing of embryo transfer in the later postpartum period resulted in greater ovarian activity and embryo yield compared to early lactation periods.

  7. Mapping the pericentric heterochromatin by comparative genomic hybridization analysis and chromosome deletions in Drosophila melanogaster.

    Science.gov (United States)

    He, Bing; Caudy, Amy; Parsons, Lance; Rosebrock, Adam; Pane, Attilio; Raj, Sandeep; Wieschaus, Eric

    2012-12-01

    Heterochromatin represents a significant portion of eukaryotic genomes and has essential structural and regulatory functions. Its molecular organization is largely unknown due to difficulties in sequencing through and assembling repetitive sequences enriched in the heterochromatin. Here we developed a novel strategy using chromosomal rearrangements and embryonic phenotypes to position unmapped Drosophila melanogaster heterochromatic sequence to specific chromosomal regions. By excluding sequences that can be mapped to the assembled euchromatic arms, we identified sequences that are specific to heterochromatin and used them to design heterochromatin specific probes ("H-probes") for microarray. By comparative genomic hybridization (CGH) analyses of embryos deficient for each chromosome or chromosome arm, we were able to map most of our H-probes to specific chromosome arms. We also positioned sequences mapped to the second and X chromosomes to finer intervals by analyzing smaller deletions with breakpoints in heterochromatin. Using this approach, we were able to map >40% (13.9 Mb) of the previously unmapped heterochromatin sequences assembled by the whole-genome sequencing effort on arm U and arm Uextra to specific locations. We also identified and mapped 110 kb of novel heterochromatic sequences. Subsequent analyses revealed that sequences located within different heterochromatic regions have distinct properties, such as sequence composition, degree of repetitiveness, and level of underreplication in polytenized tissues. Surprisingly, although heterochromatin is generally considered to be transcriptionally silent, we detected region-specific temporal patterns of transcription in heterochromatin during oogenesis and early embryonic development. Our study provides a useful approach to elucidate the molecular organization and function of heterochromatin and reveals region-specific variation of heterochromatin.

  8. Temporal and spatial expression of Drosophila DLGS97 during neural development.

    Science.gov (United States)

    Albornoz, Valeria; Mendoza-Topaz, Carolina; Oliva, Carlos; Tello, Judith; Olguín, Patricio; Sierralta, Jimena

    2008-07-01

    The products of the Drosophila discs-large (dlg) gene are members of the MAGUK family of proteins, a group of proteins involved in localization, transport and recycling of receptors and channels in cell junctions, including the synapse. In vertebrates, four genes with multiple splice variants homologous to dlg are described. dlg originates two main proteins, DLGA, similar to the vertebrate neuronal protein PSD95, and DLGS97, similar to the vertebrate neuronal and epithelial protein SAP97. DLGA is expressed in epithelia, neural tissue and muscle. DLGS97 is expressed in neural tissue and muscle but not in epithelia. The distinctive difference between them is the presence in DLGS97 of an L27 domain. The differential expression between these variants makes the study of DLGS97 of key relevance to understand the in vivo role of synaptic MAGUKs in neurons. Here we present the temporal and spatial expression pattern of DLGS97 during embryonic and larval nervous system development, during eye development and in adult brain. Our results show that DLGS97 is expressed zygotically, in neurons in the embryo, larvae and adult, and is absent at all stages in glial cells. During eye development DLGS97 starts to be expressed in photoreceptor cells at early stages of differentiation and localizes basal to the basolateral junctions. In the brain, DLGS97 is expressed in the mushroom bodies and optic lobes at larval and adult stages; and in the antennal lobe in the adult stage. In addition we show that both, dlgS97 and dlgA transcripts, express during development multiple splice variants with differences in the use of exons in two sites.

  9. Dynamic Maternal Gradients Control Timing and Shift-Rates for Drosophila Gap Gene Expression

    Science.gov (United States)

    Verd, Berta; Crombach, Anton

    2017-01-01

    Pattern formation during development is a highly dynamic process. In spite of this, few experimental and modelling approaches take into account the explicit time-dependence of the rules governing regulatory systems. We address this problem by studying dynamic morphogen interpretation by the gap gene network in Drosophila melanogaster. Gap genes are involved in segment determination during early embryogenesis. They are activated by maternal morphogen gradients encoded by bicoid (bcd) and caudal (cad). These gradients decay at the same time-scale as the establishment of the antero-posterior gap gene pattern. We use a reverse-engineering approach, based on data-driven regulatory models called gene circuits, to isolate and characterise the explicitly time-dependent effects of changing morphogen concentrations on gap gene regulation. To achieve this, we simulate the system in the presence and absence of dynamic gradient decay. Comparison between these simulations reveals that maternal morphogen decay controls the timing and limits the rate of gap gene expression. In the anterior of the embyro, it affects peak expression and leads to the establishment of smooth spatial boundaries between gap domains. In the posterior of the embryo, it causes a progressive slow-down in the rate of gap domain shifts, which is necessary to correctly position domain boundaries and to stabilise the spatial gap gene expression pattern. We use a newly developed method for the analysis of transient dynamics in non-autonomous (time-variable) systems to understand the regulatory causes of these effects. By providing a rigorous mechanistic explanation for the role of maternal gradient decay in gap gene regulation, our study demonstrates that such analyses are feasible and reveal important aspects of dynamic gene regulation which would have been missed by a traditional steady-state approach. More generally, it highlights the importance of transient dynamics for understanding complex regulatory

  10. Mapping the pericentric heterochromatin by comparative genomic hybridization analysis and chromosome deletions in Drosophila melanogaster

    Science.gov (United States)

    He, Bing; Caudy, Amy; Parsons, Lance; Rosebrock, Adam; Pane, Attilio; Raj, Sandeep; Wieschaus, Eric

    2012-01-01

    Heterochromatin represents a significant portion of eukaryotic genomes and has essential structural and regulatory functions. Its molecular organization is largely unknown due to difficulties in sequencing through and assembling repetitive sequences enriched in the heterochromatin. Here we developed a novel strategy using chromosomal rearrangements and embryonic phenotypes to position unmapped Drosophila melanogaster heterochromatic sequence to specific chromosomal regions. By excluding sequences that can be mapped to the assembled euchromatic arms, we identified sequences that are specific to heterochromatin and used them to design heterochromatin specific probes (“H-probes”) for microarray. By comparative genomic hybridization (CGH) analyses of embryos deficient for each chromosome or chromosome arm, we were able to map most of our H-probes to specific chromosome arms. We also positioned sequences mapped to the second and X chromosomes to finer intervals by analyzing smaller deletions with breakpoints in heterochromatin. Using this approach, we were able to map >40% (13.9 Mb) of the previously unmapped heterochromatin sequences assembled by the whole-genome sequencing effort on arm U and arm Uextra to specific locations. We also identified and mapped 110 kb of novel heterochromatic sequences. Subsequent analyses revealed that sequences located within different heterochromatic regions have distinct properties, such as sequence composition, degree of repetitiveness, and level of underreplication in polytenized tissues. Surprisingly, although heterochromatin is generally considered to be transcriptionally silent, we detected region-specific temporal patterns of transcription in heterochromatin during oogenesis and early embryonic development. Our study provides a useful approach to elucidate the molecular organization and function of heterochromatin and reveals region-specific variation of heterochromatin. PMID:22745230

  11. The Origin of the Second Centriole in the Zygote of Drosophila melanogaster

    Science.gov (United States)

    Blachon, Stephanie; Khire, Atul; Avidor-Reiss, Tomer

    2014-01-01

    Centrosomes are composed of two centrioles surrounded by pericentriolar material (PCM). However, the sperm and the oocyte modify or lose their centrosomes. Consequently, how the zygote establishes its first centrosome, and in particular, the origin of the second zygotic centriole, is uncertain. Drosophila melanogaster spermatids contain a single centriole called the Giant Centriole (GC) and a Proximal centriole-like (PCL) structure whose function is unknown. We found that, like the centriole, the PCL loses its protein markers at the end of spermiogenesis. After fertilization, the first two centrioles are observed via the recruitment of the zygotic PCM proteins and are seen in asterless mutant embryos that cannot form centrioles. The zygote’s centriolar proteins label only the daughter centrioles of the first two centrioles. These observations demonstrate that the PCL is the origin for the second centriole in the Drosophila zygote and that a paternal centriole precursor, without centriolar proteins, is transmitted to the egg during fertilization. PMID:24532732

  12. Functional conservation of the Drosophila gooseberry gene and its evolutionary alleles.

    Directory of Open Access Journals (Sweden)

    Wei Liu

    Full Text Available The Drosophila Pax gene gooseberry (gsb is required for development of the larval cuticle and CNS, survival to adulthood, and male fertility. These functions can be rescued in gsb mutants by two gsb evolutionary alleles, gsb-Prd and gsb-Pax3, which express the Drosophila Paired and mouse Pax3 proteins under the control of gooseberry cis-regulatory region. Therefore, both Paired and Pax3 proteins have conserved all the Gsb functions that are required for survival of embryos to fertile adults, despite the divergent primary sequences in their C-terminal halves. As gsb-Prd and gsb-Pax3 uncover a gsb function involved in male fertility, construction of evolutionary alleles may provide a powerful strategy to dissect hitherto unknown gene functions. Our results provide further evidence for the essential role of cis-regulatory regions in the functional diversification of duplicated genes during evolution.

  13. Characterization of a Smad motif similar to Drosophila mad in the mouse Msx 1 promoter.

    Science.gov (United States)

    Alvarez Martinez, Cristina E; Binato, Renata; Gonzalez, Sayonara; Pereira, Monica; Robert, Benoit; Abdelhay, Eliana

    2002-03-01

    Mouse Msx 1 gene, orthologous of the Drosophila msh, is involved in several developmental processes. BMP family members are major proteins in the regulation of Msx 1 expression. BMP signaling activates Smad 1/5/8 proteins, which associate to Smad 4 before translocating to the nucleus. Analysis of Msx 1 promoter revealed the presence of three elements similar to the consensus established for Mad, the Smad 1 Drosophila counterpart. Notably, such an element was identified in an enhancer important for Msx 1 regulation. Gel shift analysis demonstrated that proteins from 13.5 dpc embryo associate to this enhancer. Remarkably, supershift assays showed that Smad proteins are present in the complex. Purified Smad 1 and 4 also bind to this fragment. We demonstrate that functional binding sites in this enhancer are confined to the Mad motif and flanking region. Our data suggest that this Mad motif may be functional in response to BMP signaling. ©2002 Elsevier Science (USA).

  14. Efficient gene knock-out and knock-in with transgenic Cas9 in Drosophila.

    Science.gov (United States)

    Xue, Zhaoyu; Ren, Mengda; Wu, Menghua; Dai, Junbiao; Rong, Yikang S; Gao, Guanjun

    2014-03-21

    Bacterial Cas9 nuclease induces site-specific DNA breaks using small gRNA as guides. Cas9 has been successfully introduced into Drosophila for genome editing. Here, we improve the versatility of this method by developing a transgenic system that expresses Cas9 in the Drosophila germline. Using this system, we induced inheritable knock-out mutations by injecting only the gRNA into embryos, achieved highly efficient mutagenesis by expressing gRNA from the promoter of a novel non-coding RNA gene, and recovered homologous recombination-based knock-in of a fluorescent marker at a rate of 4.5% by co-injecting gRNA with a circular DNA donor. Copyright © 2014 Xue et al.

  15. The influence of zygote pronuclear morphology on in vitro human embryo development

    Directory of Open Access Journals (Sweden)

    Lidija Križančić-Bombek

    2007-09-01

    Full Text Available Background: The selection of embryos with largest implantation potential is an important part in assisted reproduction. Besides the embryo or blastocyst morphology, selection criteria such as position and orientation of pronuclei (PN in relation to polar body positioning and the number, size and distribution of nucleolar precursor bodies (NPB have been proposed. In our study, a correlation between PN and NBP morphology with the development of early embryos (day 2 of cultivation and blastocysts (day 5 was investigated.Methods: 653 zygotes from 113 IVF (in vitro fertilization and ICSI (intracytoplasmic sperm injection patients, younger than 40 years, were assessed 18–20 hours post-insemination. Optimal zygotes (Z1 had thouching centrally located PN with equall numbers of alligned NPB. Other zygote types differred from Z1 in having scattered NPB in both PN (Z2 or alligned NPB in one PN (Z3 or in PN beeing distant from one another (Z4. For each zygote type a percentage of normal early embryos and blastocysts was calculated.Results: Among 653 assessed zygotes 21.8 % were Z1; 29.1 % Z2, 34.6 % Z3 and 14.5 % Z4. The percentage of normal early embryos decreased from Z1 to Z4 zygote type (70.4 % vs. 55.3 % vs. 59.7 % vs.45.3 %; p < 0.05 as well as the percentage of developed blastocysts (63.4 % vs. 55.3 % vs. 58.8 % vs. 43.2 %. However, the percentages of optimal blastocysts in the four groups did not differ (11.3 % vs. 11.1 % vs. 8.4 % vs. 6.3 %.Conclusions: Best grade zygotes result in batter early embryo and blastocyst development suggesting that zygote morphology can be used in combination with embryo and/or blastocyst evaluation as a method for embryo selection prior to embryo transfer.

  16. Phylogeny of the Genus Drosophila

    Science.gov (United States)

    O’Grady, Patrick M.; DeSalle, Rob

    2018-01-01

    Understanding phylogenetic relationships among taxa is key to designing and implementing comparative analyses. The genus Drosophila, which contains over 1600 species, is one of the most important model systems in the biological sciences. For over a century, one species in this group, Drosophila melanogaster, has been key to studies of animal development and genetics, genome organization and evolution, and human disease. As whole-genome sequencing becomes more cost-effective, there is increasing interest in other members of this morphologically, ecologically, and behaviorally diverse genus. Phylogenetic relationships within Drosophila are complicated, and the goal of this paper is to provide a review of the recent taxonomic changes and phylogenetic relationships in this genus to aid in further comparative studies. PMID:29716983

  17. Feminists on the inalienability of human embryos.

    Science.gov (United States)

    McLeod, Carolyn; Baylis, Francoise

    2006-01-01

    The feminist literature against the commodification of embryos in human embryo research includes an argument to the effect that embryos are "intimately connected" to persons, or morally inalienable from them. We explore why embryos might be inalienable to persons and why feminists might find this view appealing. But, ultimately, as feminists, we reject this view because it is inconsistent with full respect for women's reproductive autonomy and with a feminist conception of persons as relational, embodied beings. Overall, feminists should avoid claims about embryos' being inalienable to persons in arguments for or against the commodification of human embryos.

  18. Endometrial signals improve embryo outcome: functional role of vascular endothelial growth factor isoforms on embryo development and implantation in mice.

    Science.gov (United States)

    Binder, N K; Evans, J; Gardner, D K; Salamonsen, L A; Hannan, N J

    2014-10-10

    Does vascular endothelial growth factor (VEGF) have important roles during early embryo development and implantation? VEGF plays key roles during mouse preimplantation embryo development, with beneficial effects on time to cavitation, blastocyst cell number and outgrowth, as well as implantation rate and fetal limb development. Embryo implantation requires synchronized dialog between maternal cells and those of the conceptus. Following ovulation, secretions from endometrial glands increase and accumulate in the uterine lumen. These secretions contain important mediators that support the conceptus during the peri-implantation phase. Previously, we demonstrated a significant reduction of VEGFA in the uterine cavity of women with unexplained infertility. Functional studies demonstrated that VEGF significantly enhanced endometrial epithelial cell adhesive properties and embryo outgrowth. Human endometrial lavages (n = 6) were obtained from women of proven fertility. Four-week old Swiss mice were superovulated and mated with Swiss males to obtain embryos for treatment with VEGF in vitro. Preimplantation embryo development was assessed prior to embryo transfer (n = 19-30/treatment group/output). Recipient F1 female mice (8-12 weeks of age) were mated with vasectomized males to induce pseudopregnancy and embryos were transferred. On Day 14.5 of pregnancy, uterine horns were collected for analysis of implantation rates as well as placental and fetal development (n = 14-19/treatment). Lavage fluid was assessed by western immunoblot analysis to determine the VEGF isoforms present. Mouse embryos were treated with either recombinant human (rh)VEGF, or VEGF isoforms 121 and 165. Preimplantation embryo development was quantified using time-lapse microscopy. Blastocysts were (i) stained for cell number, (ii) transferred to wells coated with fibronectin to examine trophoblast outgrowth or (iii) transferred to pseudo pregnant recipients to analyze implantation rates, placental and

  19. Transcription Factors Bind Thousands of Active and InactiveRegions in the Drosophila Blastoderm

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiao-Yong; MacArthur, Stewart; Bourgon, Richard; Nix, David; Pollard, Daniel A.; Iyer, Venky N.; Hechmer, Aaron; Simirenko, Lisa; Stapleton, Mark; Luengo Hendriks, Cris L.; Chu, Hou Cheng; Ogawa, Nobuo; Inwood, William; Sementchenko, Victor; Beaton, Amy; Weiszmann, Richard; Celniker, Susan E.; Knowles, David W.; Gingeras, Tom; Speed, Terence P.; Eisen, Michael B.; Biggin, Mark D.

    2008-01-10

    Identifying the genomic regions bound by sequence-specific regulatory factors is central both to deciphering the complex DNA cis-regulatory code that controls transcription in metazoans and to determining the range of genes that shape animal morphogenesis. Here, we use whole-genome tiling arrays to map sequences bound in Drosophila melanogaster embryos by the six maternal and gap transcription factors that initiate anterior-posterior patterning. We find that these sequence-specific DNA binding proteins bind with quantitatively different specificities to highly overlapping sets of several thousand genomic regions in blastoderm embryos. Specific high- and moderate-affinity in vitro recognition sequences for each factor are enriched in bound regions. This enrichment, however, is not sufficient to explain the pattern of binding in vivo and varies in a context-dependent manner, demonstrating that higher-order rules must govern targeting of transcription factors. The more highly bound regions include all of the over forty well-characterized enhancers known to respond to these factors as well as several hundred putative new cis-regulatory modules clustered near developmental regulators and other genes with patterned expression at this stage of embryogenesis. The new targets include most of the microRNAs (miRNAs) transcribed in the blastoderm, as well as all major zygotically transcribed dorsal-ventral patterning genes, whose expression we show to be quantitatively modulated by anterior-posterior factors. In addition to these highly bound regions, there are several thousand regions that are reproducibly bound at lower levels. However, these poorly bound regions are, collectively, far more distant from genes transcribed in the blastoderm than highly bound regions; are preferentially found in protein-coding sequences; and are less conserved than highly bound regions. Together these observations suggest that many of these poorly-bound regions are not involved in early

  20. Multiple transcription factors directly regulate Hox gene lin-39 expression in ventral hypodermal cells of the C. elegans embryo and larva, including the hypodermal fate regulators LIN-26 and ELT-6.

    Science.gov (United States)

    Liu, Wan-Ju; Reece-Hoyes, John S; Walhout, Albertha J M; Eisenmann, David M

    2014-05-13

    Hox genes encode master regulators of regional fate specification during early metazoan development. Much is known about the initiation and regulation of Hox gene expression in Drosophila and vertebrates, but less is known in the non-arthropod invertebrate model system, C. elegans. The C. elegans Hox gene lin-39 is required for correct fate specification in the midbody region, including the Vulval Precursor Cells (VPCs). To better understand lin-39 regulation and function, we aimed to identify transcription factors necessary for lin-39 expression in the VPCs, and in particular sought factors that initiate lin-39 expression in the embryo. We used the yeast one-hybrid (Y1H) method to screen for factors that bound to 13 fragments from the lin-39 region: twelve fragments contained sequences conserved between C. elegans and two other nematode species, while one fragment was known to drive reporter gene expression in the early embryo in cells that generate the VPCs. Sixteen transcription factors that bind to eight lin-39 genomic fragments were identified in yeast, and we characterized several factors by verifying their physical interactions in vitro, and showing that reduction of their function leads to alterations in lin-39 levels and lin-39::GFP reporter expression in vivo. Three factors, the orphan nuclear hormone receptor NHR-43, the hypodermal fate regulator LIN-26, and the GATA factor ELT-6 positively regulate lin-39 expression in the embryonic precursors to the VPCs. In particular, ELT-6 interacts with an enhancer that drives GFP expression in the early embryo, and the ELT-6 site we identified is necessary for proper embryonic expression. These three factors, along with the factors ZTF-17, BED-3 and TBX-9, also positively regulate lin-39 expression in the larval VPCs. These results significantly expand the number of factors known to directly bind and regulate lin-39 expression, identify the first factors required for lin-39 expression in the embryo, and hint at a

  1. Localization and activation of the Drosophila protease easter require the ER-resident saposin-like protein seele.

    Science.gov (United States)

    Stein, David; Charatsi, Iphigenie; Cho, Yong Suk; Zhang, Zhenyu; Nguyen, Jesse; DeLotto, Robert; Luschnig, Stefan; Moussian, Bernard

    2010-11-09

    Drosophila embryonic dorsal-ventral polarity is generated by a series of serine protease processing events in the egg perivitelline space. Gastrulation Defective processes Snake, which then cleaves Easter, which then processes Spätzle into the activating ligand for the Toll receptor. seele was identified in a screen for mutations that, when homozygous in ovarian germline clones, lead to the formation of progeny embryos with altered embryonic patterning; maternal loss of seele function leads to the production of moderately dorsalized embryos. By combining constitutively active versions of Gastrulation Defective, Snake, Easter, and Spätzle with loss-of-function alleles of seele, we find that Seele activity is dispensable for Spätzle-mediated activation of Toll but is required for Easter, Snake, and Gastrulation Defective to exert their effects on dorsal-ventral patterning. Moreover, Seele function is required specifically for secretion of Easter from the developing embryo into the perivitelline space and for Easter processing. Seele protein resides in the endoplasmic reticulum of blastoderm embryos, suggesting a role in the trafficking of Easter to the perivitelline space, prerequisite to its processing and function. Easter transport to the perivitelline space represents a previously unappreciated control point in the signal transduction pathway that controls Drosophila embryonic dorsal-ventral polarity. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Modelling Cooperative Tumorigenesis in Drosophila

    Science.gov (United States)

    2018-01-01

    The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression. PMID:29693007

  3. Modelling Cooperative Tumorigenesis in Drosophila

    Directory of Open Access Journals (Sweden)

    Helena E. Richardson

    2018-01-01

    Full Text Available The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression.

  4. The first cell-fate decisions in the mouse embryo: destiny is a matter of both chance and choice.

    Science.gov (United States)

    Zernicka-Goetz, Magdalena

    2006-08-01

    Development of the early mouse embryo has always been classified as regulative, meaning that when parts or blastomeres of the embryo are isolated they change their developmental fate and can even reconstruct the whole. However, regulative development does not mean that, in situ, these parts or blastomeres are equivalent; it does not mean that the early mammalian embryo is a ball of identical cells without any bias. Regulative development simply means that whatever bias the regions of the embryo might have they still remain flexible and can respond to experimental interference by changes of fate. This realization -- that regulative development and patterning can co-exist -- has led to a renaissance of interest in the first days of development of the mouse embryo, and several laboratories have provided evidence for some early bias. Now the challenge is to gain some understanding of the molecular basis of this bias.

  5. Pentachlorophenol exposure causes Warburg-like effects in zebrafish embryos at gastrulation stage

    International Nuclear Information System (INIS)

    Xu, Ting; Zhao, Jing; Hu, Ping; Dong, Zhangji; Li, Jingyun; Zhang, Hongchang; Yin, Daqiang; Zhao, Qingshun

    2014-01-01

    Pentachlorophenol (PCP) is a prevalent pollutant in the environment and has been demonstrated to be a serious toxicant to humans and animals. However, little is known regarding the molecular mechanism underlying its toxic effects on vertebrate early development. To explore the impacts and underlying mechanisms of PCP on early development, zebrafish (Danio rerio) embryos were exposed to PCP at concentrations of 0, 20 and 50 μg/L, and microscopic observation and cDNA microarray analysis were subsequently conducted at gastrulation stage. The morphological observations revealed that PCP caused a developmental delay of zebrafish embryos in a concentration-dependent manner. Transcriptomic data showed that 50 μg/L PCP treatment resulted in significant changes in gene expression level, and the genes involved in energy metabolism and cell behavior were identified based on gene functional enrichment analysis. The energy production of embryos was influenced by PCP via the activation of glycolysis along with the inhibition of oxidative phosphorylation (OXPHOS). The results suggested that PCP acts as an inhibitor of OXPHOS at 8 hpf (hours postfertilization). Consistent with the activated glycolysis, the cell cycle activity of PCP-treated embryos was higher than the controls. These characteristics are similar to the Warburg effect, which occurs in human tumors. The microinjection of exogenous ATP confirmed that an additional energy supply could rescue PCP-treated embryos from the developmental delay due to the energy deficit. Taken together, our results demonstrated that PCP causes a Warburg-like effect on zebrafish embryos during gastrulation, and the affected embryos had the phenotype of developmental delay. - Highlights: • We treat zebrafish embryos with PCP at gastrula stage. • PCP acts as an oxidative phosphorylation inhibitor, not an uncoupler, in gastrulation. • Exogenous ATP injection will rescue the development of effected embryos. • The transcriptome of PCP

  6. Pentachlorophenol exposure causes Warburg-like effects in zebrafish embryos at gastrulation stage

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ting; Zhao, Jing [Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Technology, Tongji University, Shanghai 200092 (China); Hu, Ping [Key Laboratory of Model Animal for Disease Study, Ministry of Education, Model Animal Research Center, Nanjing University, Nanjing 210061 (China); State Key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University, Nanjing 210029 (China); Dong, Zhangji; Li, Jingyun [Key Laboratory of Model Animal for Disease Study, Ministry of Education, Model Animal Research Center, Nanjing University, Nanjing 210061 (China); Zhang, Hongchang [Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Technology, Tongji University, Shanghai 200092 (China); Yin, Daqiang, E-mail: yindq@tongji.edu.cn [Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Technology, Tongji University, Shanghai 200092 (China); Zhao, Qingshun, E-mail: qingshun@nju.edu.cn [Key Laboratory of Model Animal for Disease Study, Ministry of Education, Model Animal Research Center, Nanjing University, Nanjing 210061 (China)

    2014-06-01

    Pentachlorophenol (PCP) is a prevalent pollutant in the environment and has been demonstrated to be a serious toxicant to humans and animals. However, little is known regarding the molecular mechanism underlying its toxic effects on vertebrate early development. To explore the impacts and underlying mechanisms of PCP on early development, zebrafish (Danio rerio) embryos were exposed to PCP at concentrations of 0, 20 and 50 μg/L, and microscopic observation and cDNA microarray analysis were subsequently conducted at gastrulation stage. The morphological observations revealed that PCP caused a developmental delay of zebrafish embryos in a concentration-dependent manner. Transcriptomic data showed that 50 μg/L PCP treatment resulted in significant changes in gene expression level, and the genes involved in energy metabolism and cell behavior were identified based on gene functional enrichment analysis. The energy production of embryos was influenced by PCP via the activation of glycolysis along with the inhibition of oxidative phosphorylation (OXPHOS). The results suggested that PCP acts as an inhibitor of OXPHOS at 8 hpf (hours postfertilization). Consistent with the activated glycolysis, the cell cycle activity of PCP-treated embryos was higher than the controls. These characteristics are similar to the Warburg effect, which occurs in human tumors. The microinjection of exogenous ATP confirmed that an additional energy supply could rescue PCP-treated embryos from the developmental delay due to the energy deficit. Taken together, our results demonstrated that PCP causes a Warburg-like effect on zebrafish embryos during gastrulation, and the affected embryos had the phenotype of developmental delay. - Highlights: • We treat zebrafish embryos with PCP at gastrula stage. • PCP acts as an oxidative phosphorylation inhibitor, not an uncoupler, in gastrulation. • Exogenous ATP injection will rescue the development of effected embryos. • The transcriptome of PCP

  7. Lack of metformin effect on mouse embryo AMPK activity: implications for metformin treatment during pregnancy.

    Science.gov (United States)

    Lee, Hyung-Yul; Wei, Dan; Loeken, Mary R

    2014-01-01

    Adenosine monophosphate-activated protein kinase (AMPK) is stimulated in embryos during diabetic pregnancy by maternal hyperglycaemia-induced embryo oxidative stress. Stimulation of AMPK disrupts embryo gene expression and causes neural tube defects. Metformin, which may be taken during early pregnancy, has been reported to stimulate AMPK activity. Thus, the benefits of improved glycaemic control could be offset by stimulated embryo AMPK activity. Here, we investigated whether metformin can stimulate AMPK activity in mouse embryos and can adversely affect embryo gene expression and neural tube defects. Pregnant nondiabetic mice were administered metformin beginning on the first day of pregnancy. Activation of maternal and embryo AMPK [phospho-AMPK α (Thr172) relative to total AMPK], expression of Pax3, a gene required for neural tube closure, and neural tube defects were studied. Mouse embryonic stem cells were used as a cell culture model of embryonic neuroepithelium to study metformin effects on AMPK and Pax3 expression. Metformin had no effect on AMPK in embryos or maternal skeletal muscle but increased activated AMPK in maternal liver. Metformin did not inhibit Pax3 expression or increase neural tube defects. However, metformin increased activated AMPK and inhibited Pax3 expression by mouse embryonic stem cells. Mate1/Slc47a1 and Oct3/Slc22a, which encode metformin transporters, were expressed at barely detectable levels by embryos. Although metformin can have effects associated with diabetic embryopathy in vitro, the lack of effects on mouse embryos in vivo may be due to lack of metformin transporters and indicates that the benefits of metformin on glycaemic control are not counteracted by stimulation of embryo AMPK activity and consequent embryopathy. Copyright © 2013 John Wiley & Sons, Ltd.

  8. Deoxyribonuclease probing of sea urchin embryo chromatin

    International Nuclear Information System (INIS)

    Landsman, D.

    1983-01-01

    The role that the sea urchin, Parechinus angulosus, embryo and sperm histone variants plays in chromatin structure has been investigated. Chromatin structure has been determined at different levels of resolution in sperm and in developing embryos using micrococcal nuclease, pancreatic deoxyribonuclease (DNase I) and restriction endonucleases. Micrococcal nuclease and restriction endonuclease digestions of sea urchin gastrula chromatin have been analysed and it is shown that it is not possible to isolate large polynucleosomal chromatin complexes which are soluble in low ionic strength buffers. The repeat length for sperm is significantly larger than blastula and gastrula repeat lengths whereas blastula and gastrula repeat lengths are not significantly different. Nucleosomal core particles have been isolated from early blastula, gastrula and sperm of sea urchins. After DNase I digestion of 5'-labelled core particles the rate constants of cutting of the DNA at the susceptible sites on these core particles have been determined. The DNase I digestion kinetics of blastula and gastrula core particles are similar whereas sperm core particles are digested at a slower rate, mainly at the sites which are closest to the ends of the core particle DNA

  9. [Embryo-fetal diseases in multiple pregnancies].

    Science.gov (United States)

    Colla, F; Alba, E; Grio, R

    2001-04-01

    Embryo-fetal diseases are the consequence of prenatal (progenetic and metagenetic or environmental) and intranatal (of a traumatic, infective, toxic nature) pathological factors. In multiple pregnancies this complex etiopathogenesis also includes an altered didymous embriogenesis. This study aimed to evaluate the pathologies affecting the fetus in multiple pregnancy, a special biological situation leading to the potential onset of severe fetal and neonatal damage. The authors studied 205 patients with multiple pregnancies, including 199 bigeminal, 5 trigeminal and 1 quadrigeminal, admitted to the Department B of the Obstetrics and Gynecological Clinic of Turin University between 1989-1999. Possible embyro-fetal damage was examined using a chronological criterion: namely following the development of the multiple fetuses from the zygotic to the neonatal phase. Pregnancies were biamniotic bichorionic in 54% of cases, biamniotic monochorionic in 45% and monochorionic monoamniotic in 1%. There were a total of 154 (79.38%) premature births out of 194 and neonatal birth weight was always SGA (small for gestational age). 66.84% of newborns were LBW (<2500 g) and 7.14% were VLBW (<1500 g). Fetal mortality (2.29%) was higher than early neonatal mortality (1.53%). Perinatal mortality (3.82%) was three times higher than in all neonates from the same period (1.03%). The severe embryo-fetal and neonatal damage found in multiple pregnancies is a clinical reality that calls for adequate diagnostic and therapeutic measures, and above all specific medical and social prevention to limit maternal pathogenic risks.

  10. Germinação de embriões e crescimento inicial in vitro de macaúba Germination and early growth of embryos of macaúba seedlings

    Directory of Open Access Journals (Sweden)

    Joyce Dória Rodrigues Soares

    2011-05-01

    Full Text Available A macaúba é uma palmeira oleaginosa altamente produtiva e seu óleo pode ser usado na produção de biocombustíveis. O presente trabalho teve como objetivos avaliar a influência de concentrações dos sais do meio de cultura MS e de água de coco na germinação in vitro de embriões zigóticos de macaúba e no crescimento inicial de plântulas. Os embriões foram excisados e em seguida inoculados em tubos de ensaio contendo 15mL de meio de cultura MS nas concentrações de 50 e 100% de sais minerais, acrescidos de água de coco (0, 50, 100 e 150mL L-1. As culturas foram mantidas em sala de crescimento com irradiância em torno de 42W m-2, temperatura de 25±2°C e fotoperíodo de 16 horas. Maior porcentagem de germinação de embriões de macaúba foi obtida aos 60 dias, em meio MS, na concentração original dos sais. O crescimento e a conversão de plântulas viáveis ou normais, passíveis de serem aclimatizadas, requerem metade da concentração de sais do meio MS suplementado com 50mL L-1 de água de coco.The macaw is a palm oleaginous that it is highly productive and in which their oil can be used to produce biofuels.This study aimed to evaluate the influence of concentrations of minerals of the culture medium MS and coconut water germination in vitro of zygotic embryos of macaw and initial growth of seedlings. The embryos were inoculated in test tubes containing 15mL of culture medium MS in concentrations of 50 and 100% of minerals, plus coconut water (0, 50, 100 and 150mL L-1. The cultures were kept in room for growth with irradiance around 42W m-2, at 25±2°C and photoperiod of 16 hours. Higher percentage of germination of embryos of 'macaúba' was obtained at 60 days in MS medium in the original concentration of salts. The growth and conversion to viable seedlings or normal, which can be acclimatized, require half the concentration of salts of MS medium supplemented with 50mL L-1 coconut water.

  11. A comparison of anterior-posterior development in the porcine versus the chicken embryo, using goosecoid expression as a marker

    NARCIS (Netherlands)

    Pavert, van de S.A.; Schipper, H.; Wit, de A.A.C.; Soede, N.M.; Hurk, van den R.; Taverne, M.A.M.; Boerjan, M.L.; Stroband, H.W.J.

    2001-01-01

    During early embryonic development, pig and chicken embryos share striking morphological similarities. In the present study, the timing and location of expression of mRNA for goosecoid (gsc), a gene classically expressed in the nodal region of developing embryos, was examined and compared in

  12. Fish embryos on land: terrestrial embryo deposition lowers oxygen uptake without altering growth or survival in the amphibious fish Kryptolebias marmoratus.

    Science.gov (United States)

    Wells, Michael W; Turko, Andy J; Wright, Patricia A

    2015-10-01

    Few teleost fishes incubate embryos out of water, but the oxygen-rich terrestrial environment could provide advantages for early growth and development. We tested the hypothesis that embryonic oxygen uptake is limited in aquatic environments relative to air using the self-fertilizing amphibious mangrove rivulus, Kryptolebias marmoratus, which typically inhabits hypoxic, water-filled crab burrows. We found that adult mangrove rivulus released twice as many embryos in terrestrial versus aquatic environments and that air-reared embryos had accelerated developmental rates. Surprisingly, air-reared embryos consumed 44% less oxygen and possessed larger yolk reserves, but attained the same mass, length and chorion thickness. Water-reared embryos moved their opercula ∼2.5 more times per minute compared with air-reared embryos at 7 days post-release, which probably contributed to the higher rates of oxygen uptake and yolk utilization we observed. Genetically identical air- and water-reared embryos from the same parent were raised to maturity, but the embryonic environment did not affect growth, reproduction or emersion ability in adults. Therefore, although aspects of early development were plastic, these early differences were not sustained into adulthood. Kryptolebias marmoratus embryos hatched out of water when exposed to aerial hypoxia. We conclude that exposure to a terrestrial environment reduces the energetic costs of development partly by reducing the necessity of embryonic movements to dispel stagnant boundary layers. Terrestrial incubation of young would be especially beneficial to amphibious fishes that occupy aquatic habitats of poor water quality, assuming low terrestrial predation and desiccation risks. © 2015. Published by The Company of Biologists Ltd.

  13. Single-embryo transfer versus multiple-embryo transfer.

    Science.gov (United States)

    Gerris, Jan

    2009-01-01

    Despite the progress made in assisted reproductive technology, live birth rates remain disappointingly low. Multiple-embryo transfer has been an accepted practice with which to increase the success rate. This has led to a higher incidence of multiple-order births compared with natural conception, which not only increase the risk of mortality and morbidity to both mother and children but are also associated with social and economic consequences. Elective single-embryo transfer (eSET) was developed in an effort to increase singleton pregnancies in assisted reproduction. Studies comparing eSET with multiple-embryo transfer highlight the benefit of this approach and suggest that, with careful patient selection and the transfer of good-quality embryos, the risk of a multiple-order pregnancy can be reduced without significantly decreasing live birth rates. Although the use of eSET has gradually increased in clinical practice, its acceptance has been limited by factors such as availability of funding and awareness of the procedure. An open discussion of eSET is warranted in an effort to enable a broader understanding by physicians and patients of the merits of this approach. Ultimately, eSET may provide a more cost-effective, potentially safer approach to patients undergoing assisted reproduction technology.

  14. A pupal transcriptomic screen identifies Ral as a target of store-operated calcium entry in Drosophila neurons

    OpenAIRE

    Richhariya, Shlesha; Jayakumar, Siddharth; Abruzzi, Katharine; Rosbash, Michael; Hasan, Gaiti

    2017-01-01

    Transcriptional regulation by Store-operated Calcium Entry (SOCE) is well studied in non-excitable cells. However, the role of SOCE has been poorly documented in neuronal cells with more complicated calcium dynamics. Previous reports demonstrated a requirement for SOCE in neurons that regulate Drosophila flight bouts. We refine this requirement temporally to the early pupal stage and use RNA-sequencing to identify SOCE mediated gene expression changes in the developing Drosophila pupal nervou...

  15. Silver nanoparticles incite size- and dose-dependent developmental phenotypes and nanotoxicity in zebrafish embryos.

    Science.gov (United States)

    Browning, Lauren M; Lee, Kerry J; Nallathamby, Prakash D; Xu, Xiao-Hong Nancy

    2013-10-21

    Nanomaterials possess distinctive physicochemical properties and promise a wide range of applications, from advanced technology to leading-edge medicine. However, their effects on living organisms remain largely unknown. Here we report that the purified silver nanoparticles (Ag NPs) (97 ± 13 nm) incite specific developmental stage embryonic phenotypes and nanotoxicity in a dose-dependent manner, upon acute exposure of given stage embryos to the NPs (0-24 pM) for only 2 h. The critical concentrations of the NPs that cause 50% of embryos to develop normally for cleavage, early gastrula, early segmentation, late segmentation, and hatching stage zebrafish embryos are 3.5, 4, 6, 6, and 8 pM, respectively, showing that the earlier developmental stage embryos are much more sensitive to the effects of the NPs than the later stage embryos. Interestingly, distinctive phenotypes (head abnormality and no eyes) are observed only in cleavage and early gastrula stage embryos treated with the NPs, showing the stage-specific effects of the NPs. By comparing these Ag NPs with smaller Ag NPs (13.1 ± 2.5 nm), we found that the embryonic phenotypes strikingly depend upon the sizes of Ag NPs and embryonic developmental stages. These notable findings suggest that the Ag NPs are unlike any conventional chemicals or ions. They can potentially enable target-specific study and therapy for early embryonic development in size-, stage-, dose-, and exposure duration-dependent manners.

  16. Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory.

    Science.gov (United States)

    Shuai, Yichun; Hirokawa, Areekul; Ai, Yulian; Zhang, Min; Li, Wanhe; Zhong, Yi

    2015-12-01

    Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β'1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.

  17. Pro-apoptotic Effect of Pifithrin-α on Preimplantation Porcine Fertilized Embryo Development

    Directory of Open Access Journals (Sweden)

    Brendan Mulligan

    2012-12-01

    Full Text Available The aim of this study was to investigate the impact of a reported p53 inhibitor, pifithrin-α (PFT-α, on preimplantation porcine in vitro fertilized (IVF embryo development in culture. Treatment of PFT-α was administered at both early (0 to 48 hpi, and later stages (48 to 168 hpi of preimplantation development, and its impact upon the expression of five genes related to apoptosis (p53, bak, bcl-xL, p66Shc and caspase3, was assessed in resulting d 7 blastocysts, using real-time quantitative PCR. Total cell numbers, along with the number of apoptotic nuclei, as detected by the in situ cell death detection assay, were also calculated on d 7 in treated and non-treated control embryos. The results indicate that PFT-α, when administered at both early and later stages of porcine IVF embryo development, increases the incidence of apoptosis in resulting blastocysts. When administered at early cleavage stages, PFT-α treatment was shown to reduce the developmental competence of porcine IVF embryos, as well as reducing the quality of resulting blastocysts in terms of overall cell numbers. In contrast, at later stages, PFT-α administration resulted in marginally increased blastocyst development rates amongst treated embryos, but did not affect cell numbers. However, PFT-α treatment induced apoptosis and apoptotic related gene expression, in all treated embryos, irrespective of the timing of treatment. Our results indicate that PFT-α may severely compromise the developmental potential of porcine IVF embryos, and is a potent apoptotic agent when placed into porcine embryo culture media. Thus, caution should be exercised when using PFT-α as a specific inhibitor of p53 mediated apoptosis, in the context of porcine IVF embryo culture systems.

  18. The genetic basis of Haldane's rule and the nature of asymmetric hybrid male sterility among Drosophila simulans, Drosophila mauritiana and Drosophila sechellia.

    Science.gov (United States)

    Zeng, L W; Singh, R S

    1993-05-01

    Haldane's rule (i.e., the preferential hybrid sterility and inviability of heterogametic sex) has been known for 70 years, but its genetic basis, which is crucial to the understanding of the process of species formation, remains unclear. In the present study, we have investigated the genetic basis of hybrid male sterility using Drosophila simulans, Drosophila mauritiana and Drosophila sechellia. An introgression of D. sechellia Y chromosome into a fairly homogenous background of D. simulans did not show any effect of the introgressed Y on male sterility. The substitution of D. simulans Y chromosome into D. sechellia, and both reciprocal Y chromosome substitutions between D. simulans and D. mauritiana were unsuccessful. Introgressions of cytoplasm between D. simulans and D. mauritiana (or D. sechellia) also did not have any effect on hybrid male sterility. These results rule out the X-Y interaction hypothesis as a general explanation of Haldane's rule in this species group and indicate an involvement of an X-autosome interaction. Models of symmetrical and asymmetrical X-autosome interaction have been developed which explain the Y chromosome substitution results and suggest that evolution of interactions between different genetic elements in the early stages of speciation is more likely to be of an asymmetrical nature. The model of asymmetrical X-autosome interaction also predicts that different sets of interacting genes may be involved in different pairs of related species and can account for the observation that hybrid male sterility in many partially isolated species is often nonreciprocal or unidirectional.

  19. Soluble CD146, an innovative and non-invasive biomarker of embryo selection for in vitro fertilization.

    Directory of Open Access Journals (Sweden)

    Sylvie Bouvier

    Full Text Available Although progress was made in in vitro fertilization (IVF techniques, the majority of embryos transferred fail to implant. Morphology embryo scoring is the standard procedure for most of IVF centres for choosing the best embryo, but remains limited since even the embryos classified as "top quality" may not implant. As it has been shown that i CD146 is involved in embryo implantation and ii membrane form is shed to generate soluble CD146 (sCD146, we propose that sCD146 in embryo supernatants may constitute a new biomarker of embryo selection. Immunocytochemical staining showed expression of CD146 in early embryo stages and sCD146 was detected by ELISA and Western-blot in embryo supernatants from D2. We retrospectively studied 126 couples who underwent IVF attempt. The embryo culture medium from each transferred embryo (n = 222 was collected for measurement of sCD146 by ELISA. Significantly higher sCD146 concentrations were present in embryo supernatants that did not implant (n = 185 as compared to those that successfully implanted (n = 37 (1310 +/- 1152 pg.mL-1 vs. 845+/- 1173 pg.mL-1, p = 0.024. Sensitivity analysis performed on single embryo transfers (n = 71 confirmed this association (p = 0.0054. The computed ROC curve established that the optimal sCD146 concentration for embryo implantation is under 1164 pg.mL-1 (sensitivity: 76%, specificity: 48%, PPV: 25% and NPV: 92%. Over this sCD146 threshold, the implantation rate was significantly lower (9% with sCD146 levels >1164 pg.ml-1 vs. 22% with sCD146 levels ≤ 1164 pg.mL-1, p = 0.01. Among the embryos preselected by morphologic scoring, sCD146 determination could allow a better selection of the embryo(s, thus improving the success of elective single embryo transfer. This study establishes the proof of concept for the use of sCD146 as a biomarker for IVF by excluding the embryo with the highest sCD146 level. A multicentre prospective study will now be necessary to further establish its use in

  20. Differences in gene expression profiles between human preimplantation embryos cultured in two different IVF culture media.

    Science.gov (United States)

    Kleijkers, Sander H M; Eijssen, Lars M T; Coonen, Edith; Derhaag, Josien G; Mantikou, Eleni; Jonker, Martijs J; Mastenbroek, Sebastiaan; Repping, Sjoerd; Evers, Johannes L H; Dumoulin, John C M; van Montfoort, Aafke P A

    2015-10-01

    culture experiment until Day 6. This study shows that gene expression in human preimplantation embryos is altered by the culture medium used during IVF treatment and provides insight into the biological pathways that are affected. Whether these changes in gene expression have any long-term effects on children born after IVF remains unknown. However, it is possible that early adaptations of the preimplantation embryo to its environment persist during fetal and post-natal development. No funding and no competing interests declared. Not applicable. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Human cloning and embryo research: the 2003 John J. Conley Lecture on medical ethics.

    Science.gov (United States)

    George, Robert P

    2004-01-01

    The author, a member of the U.S. President's Council on Bioethics, discusses ethical issues raised by human cloning, whether for purposes of bringing babies to birth or for research purposes. He first argues that every cloned human embryo is a new, distinct, and enduring organism, belonging to the species Homo sapiens, and directing its own development toward maturity. He then distinguishes between two types of capacities belonging to individual organisms belonging to this species, an immediately exerciseable capacity and a basic natural capacity that develops over time. He argues that it is the second type of capacity that is the ground for full moral respect, and that this capacity (and its concomitant degree of respect) belongs to cloned human embryos no less than to adult human beings. He then considers and rejects counter-arguments to his position, including the suggestion that the capacity of embryos is equivalent to the capacity of somatic cells, that full human rights are afforded only to human organisms with functioning brains, that the possibility of twinning diminishes the moral status of embryos, that the fact that people do not typically mourn the loss of early embryos implies that they have a diminished moral status, that the fact that early spontaneous abortions occur frequently diminishes the moral status of embryos, and that his arguments depend upon a concept of ensoulment. He concludes that if the moral status of cloned human embryos is equivalent to that of adults, then public policy should be based upon this assumption.

  2. Improving embryo quality in assisted reproduction

    NARCIS (Netherlands)

    Mantikou, E.

    2013-01-01

    The goal of this thesis was to improve embryo quality in assisted reproductive technologies by gaining more insight into human preimplantation embryo development and by improving in vitro culture conditions. To do so, we investigated an intriguing feature of the human preimplantation embryo, i.e.

  3. Mechanistic dissection of plant embryo initiation

    NARCIS (Netherlands)

    Radoeva, T.M.

    2016-01-01

    Land plants can reproduce sexually by developing an embryo from a fertilized egg cell, the zygote. After fertilization, the zygote undergoes several rounds of controlled cell divisions to generate a mature embryo. However, embryo formation can also be induced in a variety of other cell types in

  4. Cryotop vitrification for in vitro produced bovine and buffalo (Bubalus bubalis embryos at different stages of development

    Directory of Open Access Journals (Sweden)

    B. Gasparrini

    2010-02-01

    Full Text Available The aim of this study was to evaluate the possibility to vitrify in vitro produced (IVP buffalo and bovine embryos at different stages of development by an advanced version of the “minimal volume approaches”: the Cryotop method. In both experiments, the embryos were vitrified at the tight morula (TM, early blastocyst (eBl, blastocyst (Bl, expanded blastocyst (xBl and, only for buffalo, at the hatched blastocyst (hBl stage. After warming, the embryos were cultured in vitro for 24 hours. Stage of development affected the freezability of IVP embryos of both species with the highest embryo survival rates at advanced stages (xBl=76% and hBl=75% for buffalos and xBl=75% for bovine. These results suggest that Cryotop vitrification is an efficient method for buffalo and bovine IVP embryo cryopreservation.

  5. Dose estimation in embryo or fetus in external fields; Estimacion de dosis en embrion o feto

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, Beatriz N [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    The embryo or the fetus can be irradiated as result of radiological procedures of diagnosis of therapy in where the beam effects directly on the same one or in tissues or peripherical organs. Some authors have suggested that in the first stages of the pregnancy the dose in ovaries can be the good estimated of the dose in embryo or fetus. In advanced conditions of the development, probably also in the early stage, is more appropriated to specify the dose in the embryo or fetus equal of the uterus. The dose in the uterus is a good estimated so much for external irradiation as for radionuclides incorporation.

  6. Untwisting the Caenorhabditis elegans embryo

    Science.gov (United States)

    Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

    2015-01-01

    The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis. DOI: http://dx.doi.org/10.7554/eLife.10070.001 PMID:26633880

  7. Untwisting the Caenorhabditis elegans embryo.

    Science.gov (United States)

    Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

    2015-12-03

    The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis.

  8. Functional evolution of cis-regulatory modules at a homeotic gene in Drosophila.

    Directory of Open Access Journals (Sweden)

    Margaret C W Ho

    2009-11-01

    Full Text Available It is a long-held belief in evolutionary biology that the rate of molecular evolution for a given DNA sequence is inversely related to the level of functional constraint. This belief holds true for the protein-coding homeotic (Hox genes originally discovered in Drosophila melanogaster. Expression of the Hox genes in Drosophila embryos is essential for body patterning and is controlled by an extensive array of cis-regulatory modules (CRMs. How the regulatory modules functionally evolve in different species is not clear. A comparison of the CRMs for the Abdominal-B gene from different Drosophila species reveals relatively low levels of overall sequence conservation. However, embryonic enhancer CRMs from other Drosophila species direct transgenic reporter gene expression in the same spatial and temporal patterns during development as their D. melanogaster orthologs. Bioinformatic analysis reveals the presence of short conserved sequences within defined CRMs, representing gap and pair-rule transcription factor binding sites. One predicted binding site for the gap transcription factor KRUPPEL in the IAB5 CRM was found to be altered in Superabdominal (Sab mutations. In Sab mutant flies, the third abdominal segment is transformed into a copy of the fifth abdominal segment. A model for KRUPPEL-mediated repression at this binding site is presented. These findings challenge our current understanding of the relationship between sequence evolution at the molecular level and functional activity of a CRM. While the overall sequence conservation at Drosophila CRMs is not distinctive from neighboring genomic regions, functionally critical transcription factor binding sites within embryonic enhancer CRMs are highly conserved. These results have implications for understanding mechanisms of gene expression during embryonic development, enhancer function, and the molecular evolution of eukaryotic regulatory modules.

  9. Morphometric analysis of human embryos to predict developmental competence

    DEFF Research Database (Denmark)

    Ziebe, Søren

    2013-01-01

    pregnancy test, no matter what we choose in the laboratory. Still, both with the increasing complexity of infertile patients treated today and the important focus on reducing multiple pregnancies, it becomes increasingly important to improve our ability to predict the developmental competence of each embryo....... This involves an improved understanding of the basic biology controlling early embryonic development and, over the years, many groups have tried to identify parameters reflecting embryonic competence....

  10. Developmental mechanisms of arsenite toxicity in zebrafish (Danio rerio) embryos

    International Nuclear Information System (INIS)

    Li Dan; Lu Cailing; Wang Ju; Hu Wei; Cao Zongfu; Sun Daguang; Xia Hongfei; Ma Xu

    2009-01-01

    Arsenic usually accumulates in soil, water and airborne particles, from which it is taken up by various organisms. Exposure to arsenic through food and drinking water is a major public health problem affecting some countries. At present there are limited laboratory data on the effects of arsenic exposure on early embryonic development and the mechanisms behind its toxicity. In this study, we used zebrafish as a model system to investigate the effects of arsenite on early development. Zebrafish embryos were exposed to a range of sodium arsenite concentrations (0-10.0 mM) between 4 and 120 h post-fertilization (hpf). Survival and early development of the embryos were not obviously influenced by arsenite concentrations below 0.5 mM. However, embryos exposed to higher concentrations (0.5-10.0 mM) displayed reduced survival and abnormal development including delayed hatching, retarded growth and changed morphology. Alterations in neural development included weak tactile responses to light (2.0-5.0 mM, 30 hpf), malformation of the spinal cord and disordered motor axon projections (2.0 mM, 48 hpf). Abnormal cardiac function was observed as bradycardia (0.5-2.0 mM, 60 hpf) and altered ventricular shape (2.0 mM, 48 hpf). Furthermore, altered cell proliferation (2.0 mM, 24 hpf) and apoptosis status (2.0 mM, 24 and 48 hpf), as well as abnormal genomic DNA methylation patterning (2.0 mM, 24 and 48 hpf) were detected in the arsenite-treated embryos. All of these indicate a possible relationship between arsenic exposure and developmental failure in early embryogenesis. Our studies suggest that the negative effects of arsenic on vertebrate embryogenesis are substantial

  11. Transcriptomic analysis highlights epigenetic and transcriptional regulation during zygotic embryo development of Pinus pinaster.

    Science.gov (United States)

    de Vega-Bartol, José J; Simões, Marta; Lorenz, W Walter; Rodrigues, Andreia S; Alba, Rob; Dean, Jeffrey F D; Miguel, Célia M

    2013-08-30

    It is during embryogenesis that the plant body plan is established and the meristems responsible for all post-embryonic growth are specified. The molecular mechanisms governing conifer embryogenesis are still largely unknown. Their elucidation may contribute valuable information to clarify if the distinct features of embryo development in angiosperms and gymnosperms result from differential gene regulation. To address this issue, we have performed the first transcriptomic analysis of zygotic embryo development in a conifer species (Pinus pinaster) focusing our study in particular on regulatory genes playing important roles during plant embryo development, namely epigenetic regulators and transcription factors. Microarray analysis of P. pinaster zygotic embryogenesis was performed at five periods of embryo development from early developing to mature embryos. Our results show that most changes in transcript levels occurred in the first and the last embryo stage-to-stage transitions, namely early to pre-cotyledonary embryo and cotyledonary to mature embryo. An analysis of functional categories for genes that were differentially expressed through embryogenesis highlighted several epigenetic regulation mechanisms. While putative orthologs of transcripts associated with mechanisms that target transposable elements and repetitive sequences were strongly expressed in early embryogenesis, PRC2-mediated repression of genes seemed more relevant during late embryogenesis. On the other hand, functions related to sRNA pathways appeared differentially regulated across all stages of embryo development with a prevalence of miRNA functions in mid to late embryogenesis. Identification of putative transcription factor genes differentially regulated between consecutive embryo stages was strongly suggestive of the relevance of auxin responses and regulation of auxin carriers during early embryogenesis. Such responses could be involved in establishing embryo patterning. Later in

  12. Factors involved in early polarization of the anterior-posterior axis in the milkweed bug Oncopeltus fasciatus.

    Science.gov (United States)

    Ginzburg, Neta; Cohen, Mira; Chipman, Ariel D

    2017-05-01

    The axes of insect embryos are defined early in the blastoderm stage. Genes involved in this polarization are well known in Drosophila, but less so in other insects, such as the milkweed bug Oncopeltus fasciatus. Using quantitative PCR, we looked at differential expression of several candidate genes for early anterior-posterior patterning and found that none of them are expressed asymmetrically in the early blastoderm. We then used an RNA-Seq approach to identify novel candidate genes that might be involved in early polarization in Oncopeltus. We focused on transcription factors (TFs) as these are likely to be central players in developmental processes. Using both homology and domain based identification approaches, we were unable to find any TF encoding transcripts that are expressed asymmetrically along the anterior-posterior axis at early stages. Using a GO-term analysis of all asymmetrically expressed mRNAs, we found an enrichment of genes relating to mitochondrial function in the posterior at the earliest studied time-point. We also found a gradual enrichment of transcription related activities, giving us a putative time frame for the maternal to zygotic transition. Our dataset provides us with a list of new candidate genes in early development, which can be followed up experimentally. © 2017 Wiley Periodicals, Inc.

  13. Cleavage events and sperm dynamics in chick intrauterine embryos.

    Directory of Open Access Journals (Sweden)

    Hyung Chul Lee

    Full Text Available This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White Leghorn intrauterine eggs were retrieved from 95 cyclic hens aged up to 54-56 weeks and morphogenetic observation was made under both bright field and fluorescent image in a time course manner. Differing from mammals, asymmetric cleavage to yield preblastodermal cells was observed throughout early embryogenesis. The first two divisions occurred synchronously and four polarized preblastodermal cells resulted after cruciform cleavage. Then, asynchronous cleavage continued in a radial manner and overall cell size in the initial cleavage region was smaller than that in the distal area. Numerous sperms were visible, regardless of zygotic nuclei formation. Condensed sperm heads were present mainly in the perivitelline space and cytoplasm, and rarely in the yolk region, while decondensed sperm heads were only visible in the yolk. In conclusion, apparent differences in sperm dynamics and early cleavage events compared with mammalian embryos were detected in chick embryo development, which demonstrated polarized cleavage with penetrating supernumerary sperm into multiple regions.

  14. Phospholipid transfer activities in toad oocytes and developing embryos

    International Nuclear Information System (INIS)

    Rusinol, A.; Salomon, R.A.; Bloj, B.

    1987-01-01

    The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing 14 C-labeled phospholipids and 3 H-labeled triolein, as donor particles and cross-linked erythrocyte ghosts as acceptor particles were used to measure phospholipid transfer activities in unfertilized oocytes and in developing embryos of the toad Bufo arenarum. Phosphatidylcholine transfer activity in pH 5.1 supernatant of unfertilized oocytes was 8-fold higher than the activity found in female toad liver supernatant, but dropped steadily after fertilization. After 20 hr of development, at the stage of late blastula, the phosphatidylcholine transfer activity had dropped 4-fold. Unfertilized oocyte supernatant exhibited phosphatidylinositol and phosphatidylethanolamine transfer activity also, but at the late blastula stage the former had dropped 18-fold and the latter was no longer detectable under our assay conditions. Our results show that fertilization does not trigger a phospholipid transport process catalyzed by lipid transfer proteins. Moreover, they imply that 75% of the phosphatidylcholine transfer activity and more than 95% of the phosphatidylinositol and phosphatidylethanolamine transfer activities present in pH 5.1 supernatants of unfertilized oocytes may not be essential for toad embryo development. Our findings do not rule out, however, that a phosphatidylcholine-specific lipid transfer protein could be required for embryo early growth

  15. Influence of carbon nanotube length on toxicity to zebrafish embryos

    Directory of Open Access Journals (Sweden)

    Cheng J

    2012-07-01

    Full Text Available Jinping Cheng,1,2 Shuk Han Cheng11Department of Biology and Chemistry, City University of Hong Kong, Hong Kong; 2State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, ChinaAbstract: There is currently a large difference of opinion in nanotoxicology studies of nanomaterials. There is concern about why some studies have indicated that there is strong toxicity, while others have not. In this study, the length of carbon nanotubes greatly affected their toxicity in zebrafish embryos. Multiwalled carbon nanotubes (MWCNTs were sonicated in a nitric acid solution for 24 hours and 48 hours. The modified MWCNTs were tested in early developing zebrafish embryo. MWCNTs prepared with the longer sonication time resulted in severe developmental toxicity; however, the shorter sonication time did not induce any obvious toxicity in the tested developing zebrafish embryos. The cellular and molecular changes of the affected zebrafish embryos were studied and the observed phenotypes scored. This study suggests that length plays an important role in the in vivo toxicity of functionalized CNTs. This study will help in furthering the understanding on current differences in toxicity studies of nanomaterials.Keywords: length, carbon nanotubes, sonication, developmental toxicity, zebrafish

  16. PLANETARY EMBRYO BOW SHOCKS AS A MECHANISM FOR CHONDRULE FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Christopher R.; Boley, Aaron C. [Department of Physics and Astronomy University of British Columbia Vancouver, BC V6T 1Z1 (Canada); Morris, Melissa A. [Physics Department State University of New York at Cortland Cortland, NY 13045 (United States)

    2016-02-20

    We use radiation hydrodynamics with direct particle integration to explore the feasibility of chondrule formation in planetary embryo bow shocks. The calculations presented here are used to explore the consequences of a Mars-size planetary embryo traveling on a moderately excited orbit through the dusty, early environment of the solar system. The embryo’s eccentric orbit produces a range of supersonic relative velocities between the embryo and the circularly orbiting gas and dust, prompting the formation of bow shocks. Temporary atmospheres around these embryos, which can be created via volatile outgassing and gas capture from the surrounding nebula, can non-trivially affect thermal profiles of solids entering the shock. We explore the thermal environment of solids that traverse the bow shock at different impact radii, the effects that planetoid atmospheres have on shock morphologies, and the stripping efficiency of planetoidal atmospheres in the presence of high relative winds. Simulations are run using adiabatic and radiative conditions, with multiple treatments for the local opacities. Shock speeds of 5, 6, and 7 km s{sup −1} are explored. We find that a high-mass atmosphere and inefficient radiative conditions can produce peak temperatures and cooling rates that are consistent with the constraints set by chondrule furnace studies. For most conditions, the derived cooling rates are potentially too high to be consistent with chondrule formation.

  17. Semi-automated quantitative Drosophila wings measurements.

    Science.gov (United States)

    Loh, Sheng Yang Michael; Ogawa, Yoshitaka; Kawana, Sara; Tamura, Koichiro; Lee, Hwee Kuan

    2017-06-28

    Drosophila melanogaster is an important organism used in many fields of biological research such as genetics and developmental biology. Drosophila wings have been widely used to study the genetics of development, morphometrics and evolution. Therefore there is much interest in quantifying wing structures of Drosophila. Advancement in technology has increased the ease in which images of Drosophila can be acquired. However such studies have been limited by the slow and tedious process of acquiring phenotypic data. We have developed a system that automatically detects and measures key points and vein segments on a Drosophila wing. Key points are detected by performing image transformations and template matching on Drosophila wing images while vein segments are detected using an Active Contour algorithm. The accuracy of our key point detection was compared against key point annotations of users. We also performed key point detection using different training data sets of Drosophila wing images. We compared our software with an existing automated image analysis system for Drosophila wings and showed that our system performs better than the state of the art. Vein segments were manually measured and compared against the measurements obtained from our system. Our system was able to detect specific key points and vein segments from Drosophila wing images with high accuracy.

  18. Effect of arachidonic acid supplementation and cyclooxygenase/lipoxygenase inhibition on the development of early bovine embryos Influência do ácido araquidónico e da inibição da ciclo-oxigenase ou lipo-oxigenase no desenvolvimento inicial de embriões bovinos

    Directory of Open Access Journals (Sweden)

    Rosa Maria Pereira

    2006-04-01

    Full Text Available The effect of arachidonic acid (AA cascade on bovine embryo development in a granulosa cell co-culture system was studied. Arachidonic acid (100 µM was supplemented from 1-cell to 8-16 cell block stage (first three days of co-culture and from 1-cell to hatching. Specific cyclooxygenase (indomethacin, 28 µM and lipoxygenase (nordihydroguaiaretic acid - NDGA, 28 µM inhibitors were used from 1-cell to 8-16 cell block stage with AA. Embryo development was assessed by cleavage, day 7-day 8 and hatched embryo rates and by measuring growth rates through development stages found in days 7-10 of culture (day 0 = insemination day. Embryo quality was scored at day 8. A 6.5-10.4% increase on cleavage rate after AA supplementation was found. This AA supplementation from 1-cell to hatching delayed embryo growth rate beyond day 7 and a reduction on hatching rate was detected. When AA supplementation was restricted to the first three days of co-culture those negative effects were overcome. Also, indomethacin and NDGA prevented the positive effect of AA and induced a significant reduction on cleavage, respectively. NDGA further decreased day 7 embryo rate and quality. Results suggest that AA has a two-phase action on bovine embryos, promoting early development and impairing embryo growth from day 7 onwards and hatching rates. Both cyclooxygenase and lipoxygenase were found to be important pathways to promote cleavage.Estudou-se a influência da cascata do ácido araquidónico (AA no desenvolvimento de embriões bovinos produzidos in vitro em co-cultura com células da granulosa. Os embriões foram suplementados com AA (100 µM desde o estádio de 1 célula até 8-16 células (primeiros três dias de co-cultura ou até a eclosão. Introduziram-se inibidores específicos da ciclo-oxigenase (indometacina, 28 µM e da lipo-oxigenase (ácido nordihidroguaiarético - NDGA, 28 µM, juntamente com o ácido araquidónico, desde o estádio de 1 célula até 8-16 c

  19. ME31B globally represses maternal mRNAs by two distinct mechanisms during the Drosophila maternal-to-zygotic transition.

    Science.gov (United States)

    Wang, Miranda; Ly, Michael; Lugowski, Andrew; Laver, John D; Lipshitz, Howard D; Smibert, Craig A; Rissland, Olivia S

    2017-09-06

    In animal embryos, control of development is passed from exclusively maternal gene products to those encoded by the embryonic genome in a process referred to as the maternal-to-zygotic transition (MZT). We show that the RNA-binding protein, ME31B, binds to and represses the expression of thousands of maternal mRNAs during the Drosophila MZT. However, ME31B carries out repression in different ways during different phases of the MZT. Early, it represses translation while, later, its binding leads to mRNA destruction, most likely as a consequence of translational repression in the context of robust mRNA decay. In a process dependent on the PNG kinase, levels of ME31B and its partners, Cup and Trailer Hitch (TRAL), decrease by over 10-fold during the MZT, leading to a change in the composition of mRNA-protein complexes. We propose that ME31B is a global repressor whose regulatory impact changes based on its biological context.

  20. Non-invasive long-term fluorescence live imaging of Tribolium castaneum embryos.

    Science.gov (United States)

    Strobl, Frederic; Stelzer, Ernst H K

    2014-06-01

    Insect development has contributed significantly to our understanding of metazoan development. However, most information has been obtained by analyzing a single species, the fruit fly Drosophila melanogaster. Embryonic development of the red flour beetle Tribolium castaneum differs fundamentally from that of Drosophila in aspects such as short-germ development, embryonic leg development, extensive extra-embryonic membrane formation and non-involuted head development. Although Tribolium has become the second most important insect model organism, previous live imaging attempts have addressed only specific questions and no long-term live imaging data of Tribolium embryogenesis have been available. By combining light sheet-based fluorescence microscopy with a novel mounting method, we achieved complete, continuous and non-invasive fluorescence live imaging of Tribolium embryogenesis at high spatiotemporal resolution. The embryos survived the 2-day or longer imaging process, developed into adults and produced fertile progeny. Our data document all morphogenetic processes from the rearrangement of the uniform blastoderm to the onset of regular muscular movement in the same embryo and in four orientations, contributing significantly to the understanding of Tribolium development. Furthermore, we created a comprehensive chronological table of Tribolium embryogenesis, integrating most previous work and providing a reference for future studies. Based on our observations, we provide evidence that serosa window closure and serosa opening, although deferred by more than 1 day, are linked. All our long-term imaging datasets are available as a resource for the community. Tribolium is only the second insect species, after Drosophila, for which non-invasive long-term fluorescence live imaging has been achieved. © 2014. Published by The Company of Biologists Ltd.

  1. Drosophila homologues of adenomatous polyposis coli (APC) and the formin diaphanous collaborate by a conserved mechanism to stimulate actin filament assembly.

    Science.gov (United States)

    Jaiswal, Richa; Stepanik, Vince; Rankova, Aneliya; Molinar, Olivia; Goode, Bruce L; McCartney, Brooke M

    2013-05-10

    Vertebrate APC collaborates with Dia through its Basic domain to assemble actin filaments. Despite limited sequence homology between the vertebrate and Drosophila APC Basic domains, Drosophila APC1 collaborates with Dia to stimulate actin assembly in vitro. The mechanism of actin assembly is highly conserved over evolution. APC-Dia collaborations may be crucial in a wide range of animal cells. Adenomatous polyposis coli (APC) is a large multidomain protein that regulates the cytoskeleton. Recently, it was shown that vertebrate APC through its Basic domain directly collaborates with the formin mDia1 to stimulate actin filament assembly in the presence of nucleation barriers. However, it has been unclear whether these activities extend to homologues of APC and Dia in other organisms. Drosophila APC and Dia are each required to promote actin furrow formation in the syncytial embryo, suggesting a potential collaboration in actin assembly, but low sequence homology between the Basic domains of Drosophila and vertebrate APC has left their functional and mechanistic parallels uncertain. To address this question, we purified Drosophila APC1 and Dia and determined their individual and combined effects on actin assembly using both bulk fluorescence assays and total internal reflection fluorescence microscopy. Our data show that APC1, similar to its vertebrate homologue, bound to actin monomers and nucleated and bundled filaments. Further, Drosophila Dia nucleated actin assembly and protected growing filament barbed ends from capping protein. Drosophila APC1 and Dia directly interacted and collaborated to promote actin assembly in the combined presence of profilin and capping protein. Thus, despite limited sequence homology, Drosophila and vertebrate APCs exhibit highly related activities and mechanisms and directly collaborate with formins. These results suggest that APC-Dia interactions in actin assembly are conserved and may underlie important in vivo functions in a broad

  2. Excess Imidacloprid Exposure Causes the Heart Tube Malformation of Chick Embryos.

    Science.gov (United States)

    Gao, Lin-Rui; Li, Shuai; Zhang, Jing; Liang, Chang; Chen, En-Ni; Zhang, Shi-Yao; Chuai, Manli; Bao, Yong-Ping; Wang, Guang; Yang, Xuesong

    2016-11-30

    As a neonicotinoid pesticide, imidacloprid is widely used to control sucking insects on agricultural planting and fleas on domestic animals. However, the extent to which imidacloprid exposure has an influence on cardiogensis in early embryogenesis is still poorly understood. In vertebrates, the heart is the first organ to be formed. In this study, to address whether imidacloprid exposure affects early heart development, the early chick embryo has been used as an experimental model because of its accessibility at its early developmental stage. The results demonstrate that exposure of the early chick embryo to imidacloprid caused malformation of heart tube. Furthermore, the data reveal that down-regulation of GATA4, NKX2.5, and BMP4 and up-regulation of Wnt3a led to aberrant cardiomyocyte differentiation. In addition, imidacloprid exposure interfered with basement membrane breakdown, E-cadherin/laminin expression, and mesoderm formation during the epithelial-mesenchymal transition (EMT) in gastrula chick embryos. Finally, the DiI-labeled cell migration trajectory indicated that imidacloprid restricted the cell migration of cardiac progenitors to primary heart field in gastrula chick embryos. A similar observation was also obtained from the cell migration assay of scratch wounds in vitro. Additionally, imidacloprid exposure negatively affected the cytoskeleton structure and expression of corresponding adhesion molecules. Taken together, these results reveal that the improper EMT, cardiac progenitor migration, and differentiation are responsible for imidacloprid exposure-induced malformation of heart tube during chick embryo development.

  3. Noninvasive embryo assessment technique based on buoyancy and its association with embryo survival after cryopreservation.

    Science.gov (United States)

    Wessels, Cara; Penrose, Lindsay; Ahmad, Khaliq; Prien, Samuel

    2017-11-01

    Embryo cryopreservation offers many benefits by allowing genetic preservation, genetic screening, cost reduction, global embryo transport and single embryo transfer. However, freezing of embryos decreases embryo viability, as intracellular ice crystal formation often damages embryos. Success rates of frozen embryo transfer are expected to be 15-20% less than fresh embryo transfer. We have developed a noninvasive embryo assessment technique (NEAT) which enables us to predict embryo viability based on buoyancy. The purpose of this research was twofold. First was to determine if a NEAT, through a specific gravity device can detect embryo survival of cryopreservation. Second, it was to relate embryo buoyancy to embryo viability for establishing pregnancies in sheep. Blastocysts descent times were measured on one-hundred sixty-nine mice blastocysts before cryopreservation, according to standard protocol and post-thawing blastocysts descent times were measured again. There was a significant difference in blastocyst post-thaw descent times with NEAT in those blastocysts which demonstrated viability from those that did not (P embryos. Further studies on a larger scale commercial setting will evaluate the efficacy of NEAT. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Manipulation of gene expression by infrared laser heat shock and its application to the study of tracheal development in Drosophila.

    Science.gov (United States)

    Miao, Guangxia; Hayashi, Shigeo

    2015-03-01

    Induction of gene expression in a specific cell and a defined time window is desirable to investigate gene function at the cellular level during morphogenesis. To achieve this, we attempted to introduce the infrared laser-evoked gene operator system (IR-LEGO, Kamei et al., 2009) in the Drosophila embryo. In this technique, infrared laser light illumination induces genes to be expressed under the control of heat shock promoters at the single cell level. We applied IR-LEGO to a transgenic fly stock, HS-eGFP, in which the enhanced green fluorescent protein (eGFP) gene is placed under the control of heat shock protein 70 promoter, and showed that eGFP expression can be induced in single cells within 1-2 hr after IR illumination. Furthermore, induction of HS-Branchless transgene encoding the Drosophila fibroblast growth factor (FGF) effectively altered the migration and branching patterns of the tracheal system. Our results indicated that IR-LEGO is a promising choice for the timely control of gene expression in a small group of cells in the Drosophila embryo. By using IR-LEGO, we further demonstrated that the tracheal terminal branching program is sensitive to localized expression of exogenous FGF. © 2014 Wiley Periodicals, Inc.

  5. Transcriptomic Response of Drosophila Melanogaster Pupae Developed in Hypergravity

    Science.gov (United States)

    Hosamani, Ravikumar; Hateley, Shannon; Bhardwaj, Shilpa R.; Pachter, Lior; Bhattacharya, Sharmila

    2016-01-01

    The metamorphosis of Drosophila is evolutionarily adapted to Earth's gravity, and is a tightly regulated process. Deviation from 1g to microgravity or hypergravity can influence metamorphosis, and alter associated gene expression. Understanding the relationship between an altered gravity environment and developmental processes is important for NASA's space travel goals. In the present study, 20 female and 20 male synchronized (Canton S, 2 to 3day old) flies were allowed to lay eggs while being maintained in a hypergravity environment (3g). Centrifugation was briefly stopped to discard the parent flies after 24hrs of egg laying, and then immediately continued until the eggs developed into P6-staged pupae (25 - 43 hours after pupation initiation). Post hypergravity exposure, P6-staged pupae were collected, total RNA was extracted using Qiagen RNeasy mini kits. We used RNA-Seq and qRT-PCR techniques to profile global transcriptomic changes in early pupae exposed to chronic hypergravity. During the pupal stage, Drosophila relies upon gravitational cues for proper development. Assessing gene expression changes in the pupa under altered gravity conditions helps highlight gravity dependent genetic pathways. A robust transcriptional response was observed in hypergravity-exposed pupae compared to controls, with 1,513 genes showing a significant (q Drosophila pupae in response to hypergravity.

  6. Developmental expression of Drosophila Wiskott-Aldrich Syndrome family proteins

    Science.gov (United States)

    Rodriguez-Mesa, Evelyn; Abreu-Blanco, Maria Teresa; Rosales-Nieves, Alicia E.; Parkhurst, Susan M.

    2012-01-01

    Background Wiskott-Aldrich Syndrome (WASP) family proteins participate in many cellular processes involving rearrangements of the actin cytoskeleton. To the date, four WASP subfamily members have been described in Drosophila: Wash, WASp, SCAR, and Whamy. Wash, WASp, and SCAR are essential during early Drosophila development where they function in orchestrating cytoplasmic events including membrane-cytoskeleton interactions. A mutant for Whamy has not yet been reported. Results We generated monoclonal antibodies that are specific to Drosophila Wash, WASp, SCAR, and Whamy, and use these to describe their spatial and temporal localization patterns. Consistent with the importance of WASP family proteins in flies, we find that Wash, WASp, SCAR, and Whamy are dynamically expressed throughout oogenesis and embryogenesis. For example, we find that Wash accumulates at the oocyte cortex. WASp is highly expressed in the PNS, while SCAR is the most abundantly expressed in the CNS. Whamy exhibits an asymmetric subcellular localization that overlaps with mitochondria and is highly expressed in muscle. Conclusion All four WASP family members show specific expression patterns, some of which reflect their previously known roles and others revealing new potential functions. The monoclonal antibodies developed offer valuable new tools to investigate how WASP family proteins regulate actin cytoskeleton dynamics. PMID:22275148

  7. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  8. Limited taste discrimination in Drosophila.

    Science.gov (United States)

    Masek, Pavel; Scott, Kristin

    2010-08-17

    In the gustatory systems of mammals and flies, different populations of sensory cells recognize different taste modalities, such that there are cells that respond selectively to sugars and others to bitter compounds. This organization readily allows animals to distinguish compounds of different modalities but may limit the ability to distinguish compounds within one taste modality. Here, we developed a behavioral paradigm in Drosophila melanogaster to evaluate directly the tastes that a fly distinguishes. These studies reveal that flies do not discriminate among different sugars, or among different bitter compounds, based on chemical identity. Instead, flies show a limited ability to distinguish compounds within a modality based on intensity or palatability. Taste associative learning, similar to olfactory learning, requires the mushroom bodies, suggesting fundamental similarities in brain mechanisms underlying behavioral plasticity. Overall, these studies provide insight into the discriminative capacity of the Drosophila gustatory system and the modulation of taste behavior.

  9. Nucleoli from two-cell embryos support the development of enucleolated germinal vesicle oocytes in the pig.

    Science.gov (United States)

    Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi

    2012-11-01

    Recent research has shown that nucleoli of oocytes at the germinal vesicle (GV) stage (GV nucleoli) are not necessary for oocyte maturation but are essential for early embryonic development. Nucleoli of 2-cell embryos (2-cell nucleoli) have morphology similar to that of nucleoli in oocytes at the GV stage. In this study, we examined the ability of 2-cell nucleoli to substitute for GV nucleoli in terms of supporting early embryonic development by nucleolus aspiration (enucleolation) and transfer into metaphase II (MII) oocytes or 2-cell embryos that were derived from enucleolated oocytes at the GV stage in the pig. When 2-cell embryos were centrifuged to move the lipid droplets to one side of the blastomere, multiple nucleoli in the nucleus fused into a single nucleolus. The nucleoli were then aspirated from the 2-cell embryos by micromanipulation. The injection of 2-cell nucleoli to GV enucleolated oocytes at the MII stage rescued the embryos from the early embryonic arrest, and the resulting oocytes developed to blastocysts. However, the injection of 2-cell and GV nucleoli to 2-cell embryos derived from GV enucleolated oocytes rarely restored the development to blastocysts. These results indicate that 2-cell nucleoli support early embryonic development as GV nucleoli and that the presence of nucleoli is essential for pig embryos before the 2-cell stage.

  10. Distinct types of glial cells populate the Drosophila antenna

    Directory of Open Access Journals (Sweden)

    Jhaveri Dhanisha

    2005-11-01

    Full Text Available Abstract Background The development of nervous systems involves reciprocal interactions between neurons and glia. In the Drosophila olfactory system, peripheral glial cells arise from sensory lineages specified by the basic helix-loop-helix transcription factor, Atonal. These glia wrap around the developing olfactory axons early during development and pattern the three distinct fascicles as they exit the antenna. In the moth Manduca sexta, an additional set of central glia migrate to the base of the antennal nerve where axons sort to their glomerular targets. In this work, we have investigated whether similar types of cells exist in the Drosophila antenna. Results We have used different P(Gal4 lines to drive Green Fluorescent Protein (GFP in distinct populations of cells within the Drosophila antenna. Mz317::GFP, a marker for cell body and perineural glia, labels the majority of peripheral glia. An additional ~30 glial cells detected by GH146::GFP do not derive from any of the sensory lineages and appear to migrate into the antenna from the brain. Their appearance in the third antennal segment is regulated by normal function of the Epidermal Growth Factor receptor and small GTPases. We denote these distinct populations of cells as Mz317-glia and GH146-glia respectively. In the adult, processes of GH146-glial cells ensheath the olfactory receptor neurons directly, while those of the Mz317-glia form a peripheral layer. Ablation of GH146-glia does not result in any significant effects on the patterning of the olfactory receptor axons. Conclusion We have demonstrated the presence of at least two distinct populations of glial cells within the Drosophila antenna. GH146-glial cells originate in the brain and migrate to the antenna along the newly formed olfactory axons. The number of cells populating the third segment of the antenna is regulated by signaling through the Epidermal Growth Factor receptor. These glia share several features of the sorting

  11. Studies on Drosophila radiosensitive strains

    International Nuclear Information System (INIS)

    Varentsova, E.P.; Zakharov, I.A.

    1976-01-01

    45 of radiosensitive strains of Drosophila melanogaster were isolated by Curly/Lobe technique after EMS treatment of Livadia population males. The lethality of non-Curly late larvae after gamma-irradiation (4000r) characterized radiosensitivity strains. Most of them exhibited higher frequency of the spontaneous dominant lethals (up to 69%). The males of 6 strains were semi-sterile. 5 of these strains exhibited higher frequency of X-chromosome non-disjunction

  12. Olfactory memory traces in Drosophila

    OpenAIRE

    Berry, Jacob; Krause, William C.; Davis, Ronald L.

    2008-01-01

    In Drosophila the fruit fly, coincident exposure to an odor and an aversive electric shock can produce robust behavioral memory. This behavioral memory is thought to be regulated by cellular memory traces within the central nervous system of the fly. These molecular, physiological or structural changes in neurons, induced by pairing odor and shock, regulate behavior by altering the neurons’ response to the learned environment. Recently, novel in vivo functional imaging techniques have allowed...

  13. Cultures of preimplantation mouse embryos

    International Nuclear Information System (INIS)

    Streffer, C.; Molls, M.

    1987-01-01

    In the preimplantation mouse embryos the chromosomal damage develops through several postradiation cell cycles and mitoses. New chromosome aberrations are seen during the second and third postradiation mitoses. Also, more micronuclei appear during later postradiation interphases. This is in agreement with the assumption that unrepaired chromosomal radiation damage develops during the cell generation cycle to such a form (i.e. double-strand breaks in DNA) that chromosomal breaks occur. This proposition is strengthened by the observation that radiation-induced damage is more rapidly expressed after neutron exposure (first or second postradiation mitosis) than after exposure to X rays at the one- or two-cell stage. The preimplantation mouse embryo culture is an inviting system for additional studies at the molecular level, especially now that within the last few years more sensitive methods have been developed for study of DNA and protein structure, regulation, and synthesis. The results from these studies of cultures of preimplantation mouse embryos present a favorable case for the study of complex biological systems under very defined conditions in vitro for extrapolation to effects in vivo

  14. Human embryo culture media comparisons.

    Science.gov (United States)

    Pool, Thomas B; Schoolfield, John; Han, David

    2012-01-01

    Every program of assisted reproduction strives to maximize pregnancy outcomes from in vitro fertilization and selecting an embryo culture medium, or medium pair, consistent with high success rates is key to this process. The common approach is to replace an existing medium with a new one of interest in the overall culture system and then perform enough cycles of IVF to see if a difference is noted both in laboratory measures of embryo quality and in pregnancy. This approach may allow a laboratory to select one medium over another but the outcomes are only relevant to that program, given that there are well over 200 other variables that may influence the results in an IVF cycle. A study design that will allow for a more global application of IVF results, ones due to culture medium composition as the single variable, is suggested. To perform a study of this design, the center must have a patient caseload appropriate to meet study entrance criteria, success rates high enough to reveal a difference if one exists and a strong program of quality assurance and control in both the laboratory and clinic. Sibling oocytes are randomized to two study arms and embryos are evaluated on day 3 for quality grades. Inter and intra-observer variability are evaluated by kappa statistics and statistical power and study size estimates are performed to bring discriminatory capability to the study. Finally, the complications associated with extending such a study to include blastocyst production on day 5 or 6 are enumerated.

  15. [INFLUENCE OF NANODIAMONDS AND CARBON NANOWIRES ON SURVIVAL AND CELLS STRUCTURE IN CHICKEN EMBRYO].

    Science.gov (United States)

    Lavrinenko, V; Zinabadinova, S; Chaikovsky, Yu; Sokurenko, L; Shobat, L

    2016-06-01

    Aim - to determine the effect of nanodiamonds and carbon nanowires on the survival and ultrastructure of chicken embryo cells. The experiment was carried out on chicken embryos, incubated from eggs of Hy-Line breed. Control and two experimental groups were formed (total number of embryos - 100). Diamond nanoparticles and carbon nanowires were administered on day 3 of incubation as a suspension of a biocompatible dextran. Ultrastructural analysis and general study of embryos state were carried out. The most expressed pathological effects were observed in the group with the introduction of the CNW, which caused visual impairment of embryogenesis that started from the early incubation periods. As for ND we can claim their prolonged impact on the development of embryos, manifested in the gradual deterioration of the embryos condition with the manifestations of the pathology in the provisory organs and the body of embryos. The results of our study demonstrate that both types of nanostructures can cause sublethal and irreversible morphologic changes. Detection of morphological evidence of the impact of nanomaterials at significant distances from the site of administration of nanoparticles shows highly penetrating ability of nanomaterials. The presence of damages specific for each type of nanoparticles shows affinity to various tissues and cellular structures. It is demonstrated that similar, at first glance, impact of nanomaterials, such as the induction of oxidative stress might be caused by specific structural transformations. So, ND cause vacuolization of mitochondria, and the CNW - deformation of their shape and appearance of dark inclusions in them.

  16. Chromosome fragility at FRAXA in human cleavage stage embryos at risk for fragile X syndrome.

    Science.gov (United States)

    Verdyck, Pieter; Berckmoes, Veerle; De Vos, Anick; Verpoest, Willem; Liebaers, Inge; Bonduelle, Maryse; De Rycke, Martine

    2015-10-01

    Fragile X syndrome (FXS), the most common inherited intellectual disability syndrome, is caused by expansion and hypermethylation of the CGG repeat in the 5' UTR of the FMR1 gene. This expanded repeat, also known as the rare fragile site FRAXA, causes X chromosome fragility in cultured cells from patients but only when induced by perturbing pyrimidine synthesis. We performed preimplantation genetic diagnosis (PGD) on 595 blastomeres biopsied from 442 cleavage stage embryos at risk for FXS using short tandem repeat (STR) markers. In six blastomeres, from five embryos an incomplete haplotype was observed with loss of all alleles telomeric to the CGG repeat. In all five embryos, the incomplete haplotype corresponded to the haplotype carrying the CGG repeat expansion. Subsequent analysis of additional blastomeres from three embryos by array comparative genomic hybridization (aCGH) confirmed the presence of a terminal deletion with a breakpoint close to the CGG repeat in two blastomeres from one embryo. A blastomere from another embryo showed the complementary duplication. We conclude that a CGG repeat expansion at FRAXA causes X chromosome fragility in early human IVF embryos at risk for FXS. © 2015 Wiley Periodicals, Inc.

  17. Drosophila: Retrotransposons Making up Telomeres.

    Science.gov (United States)

    Casacuberta, Elena

    2017-07-19

    Drosophila and extant species are the best-studied telomerase exception. In this organism, telomere elongation is coupled with targeted retrotransposition of Healing Transposon (HeT-A) and Telomere Associated Retrotransposon (TART) with sporadic additions of Telomere Associated and HeT-A Related (TAHRE), all three specialized non-Long Terminal Repeat (non-LTR) retrotransposons. These three very special retroelements transpose in head to tail arrays, always in the same orientation at the end of the chromosomes but never in interior locations. Apparently, retrotransposon and telomerase telomeres might seem very different, but a detailed view of their mechanisms reveals similarities explaining how the loss of telomerase in a Drosophila ancestor could successfully have been replaced by the telomere retrotransposons. In this review, we will discover that although HeT-A, TART, and TAHRE are still the only examples to date where their targeted transposition is perfectly tamed into the telomere biology of Drosophila, there are other examples of retrotransposons that manage to successfully integrate inside and at the end of telomeres. Because the aim of this special issue is viral integration at telomeres, understanding the base of the telomerase exceptions will help to obtain clues on similar strategies that mobile elements and viruses could have acquired in order to ensure their survival in the host genome.

  18. Optogenetic pacing in Drosophila melanogaster

    Science.gov (United States)

    Alex, Aneesh; Li, Airong; Tanzi, Rudolph E.; Zhou, Chao

    2015-01-01

    Electrical stimulation is currently the gold standard for cardiac pacing. However, it is invasive and nonspecific for cardiac tissues. We recently developed a noninvasive cardiac pacing technique using optogenetic tools, which are widely used in neuroscience. Optogenetic pacing of the heart provides high spatial and temporal precisions, is specific for cardiac tissues, avoids artifacts associated with electrical stimulation, and therefore promises to be a powerful tool in basic cardiac research. We demonstrated optogenetic control of heart rhythm in a well-established model organism, Drosophila melanogaster. We developed transgenic flies expressing a light-gated cation channel, channelrhodopsin-2 (ChR2), specifically in their hearts and demonstrated successful optogenetic pacing of ChR2-expressing Drosophila at different developmental stages, including the larva, pupa, and adult stages. A high-speed and ultrahigh-resolution optical coherence microscopy imaging system that is capable of providing images at a rate of 130 frames/s with axial and transverse resolutions of 1.5 and 3.9 μm, respectively, was used to noninvasively monitor Drosophila cardiac function and its response to pacing stimulation. The development of a noninvasive integrated optical pacing and imaging system provides a novel platform for performing research studies in developmental cardiology. PMID:26601299

  19. 'Peer pressure' in larval Drosophila?

    Science.gov (United States)

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-06-06

    Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. © 2014. Published by The Company of Biologists Ltd.

  20. Quantification of Drosophila Grooming Behavior.

    Science.gov (United States)

    Barradale, Francesca; Sinha, Kairav; Lebestky, Tim

    2017-07-19

    Drosophila grooming behavior is a complex multi-step locomotor program that requires coordinated movement of both forelegs and hindlegs. Here we present a grooming assay protocol and novel chamber design that is cost-efficient and scalable for either small or large-scale studies of Drosophila grooming. Flies are dusted all over their body with Brilliant Yellow dye and given time to remove the dye from their bodies within the chamber. Flies are then deposited in a set volume of ethanol to solubilize the dye. The relative spectral absorbance of dye-ethanol samples for groomed versus ungroomed animals are measured and recorded. The protocol yields quantitative data of dye accumulation for individual flies, which can be easily averaged and compared across samples. This allows experimental designs to easily evaluate grooming ability for mutant animal studies or circuit manipulations. This efficient procedure is both versatile and scalable. We show work-flow of the protocol and comparative data between WT animals and mutant animals for the Drosophila type I Dopamine Receptor (DopR).

  1. Laser fusion of mouse embryonic cells and intra-embryonic fusion of blastomeres without affecting the embryo integrity.

    Science.gov (United States)

    Krivokharchenko, Alexander; Karmenyan, Artashes; Sarkisov, Oleg; Bader, Michael; Chiou, Arthur; Shakhbazyan, Avetik

    2012-01-01

    Manipulation with early mammalian embryos is the one of the most important approach to study preimplantation development. Artificial cell fusion is a research tool for various biotechnological experiments. However, the existing methods have various disadvantages, first of them impossibility to fuse selected cells within multicellular structures like mammalian preimplantation embryos. In our experiments we have successfully used high repetition rate picosecond near infrared laser beam for fusion of pairs of oocytes and oocytes with blastomeres. Fused cells looked morphologically normal and keep their ability for further divisions in vitro. We also fused two or three blastomeres inside four-cell mouse embryos. The presence of one, two or three nuclei in different blastomeres of the same early preimplantation mouse embryo was confirmed under UV-light after staining of DNA with the vital dye Hoechst-33342. The most of established embryos demonstrated high viability and developed in vitro to the blastocyst stage. We demonstrated for the first time the use of laser beam for the fusion of various embryonic cells of different size and of two or three blastomeres inside of four-cell mouse embryos without affecting the embryo's integrity and viability. These embryos with blastomeres of various ploidy maybe unique model for numerous purposes. Thus, we propose laser optical manipulation as a new tool for investigation of fundamental mechanisms of mammalian development.

  2. The current status and future of commercial embryo transfer in cattle.

    Science.gov (United States)

    Hasler, John F

    2003-12-15

    A commercially viable cattle embryo transfer (ET) industry was established in North America during the early 1970s, approximately 80 years after the first successful embryo transfer was reported in a mammal. Initially, techniques for recovering and transferring cattle embryos were exclusively surgical. However, by the late 1970s, most embryos were recovered and transferred nonsurgically. Successful cryopreservation of embryos was widespread by the early 1980s, followed by the introduction of embryo splitting, in vitro procedures, direct transfer of frozen embryos and sexing of embryos. The wide spread adoption of ethylene glycol as a cryoprotectant has simplified the thaw-transfer procedures for frozen embryos. The number of embryos recovered annually has not grown appreciably over the last 10 years in North America and Europe; however, there has been significant growth of commercial ET in South America. Within North America, ET activity has been relatively constant in Holstein cattle, whereas there has been a large ET increase in the Angus breed and a concomitant ET decrease in some other beef breeds. Although a number of new technologies have been adopted within the ET industry in the last decade, the basic procedure of superovulation of donor cattle has undergone little improvement over the last 20 years. The export-import of frozen cattle embryos has become a well-established industry, governed by specific health regulations. The international movement of embryos is subject to sudden and dramatic disturbances, as exemplified by the 2001 outbreak of foot and mouth disease in Great Britain. It is probable that there will be an increased influence of animal rights issues on the ET industry in the future. Several companies in North America are currently commercially producing cloned cattle. The sexing of bovine semen with the use of flow cytometry is extremely accurate and moderate pregnancy rates in heifers have been achieved in field trials, but sexed semen

  3. Germline progenitors escape the widespread phenomenon of homolog pairing during Drosophila development.

    Directory of Open Access Journals (Sweden)

    Eric F Joyce

    Full Text Available Homolog pairing, which plays a critical role in meiosis, poses a potential risk if it occurs in inappropriate tissues or between nonallelic sites, as it can lead to changes in gene expression, chromosome entanglements, and loss-of-heterozygosity due to mitotic recombination. This is particularly true in Drosophila, which supports organismal-wide pairing throughout development. Discovered over a century ago, such extensive pairing has led to the perception that germline pairing in the adult gonad is an extension of the pairing established during embryogenesis and, therefore, differs from the mechanism utilized in most species to initiate pairing specifically in the germline. Here, we show that, contrary to long-standing assumptions, Drosophila meiotic pairing in the gonad is not an extension of pairing established during embryogenesis. Instead, we find that homologous chromosomes are unpaired in primordial germ cells from the moment the germline can be distinguished from the soma in the embryo and remain unpaired even in the germline stem cells of the adult gonad. We further establish that pairing originates immediately after the stem cell stage. This pairing occurs well before the initiation of meiosis and, strikingly, continues through the several mitotic divisions preceding meiosis. These discoveries indicate that the spatial organization of the Drosophila genome differs between the germline and the soma from the earliest moments of development and thus argue that homolog pairing in the germline is an active process as versus a passive continuation of pairing established during embryogenesis.

  4. The Drosophila melanogaster methuselah gene: a novel gene with ancient functions.

    Directory of Open Access Journals (Sweden)

    Ana Rita Araújo

    Full Text Available The Drosophila melanogaster G protein-coupled receptor gene, methuselah (mth, has been described as a novel gene that is less than 10 million years old. Nevertheless, it shows a highly specific expression pattern in embryos, larvae, and adults, and has been implicated in larval development, stress resistance, and in the setting of adult lifespan, among others. Although mth belongs to a gene subfamily with 16 members in D. melanogaster, there is no evidence for functional redundancy in this subfamily. Therefore, it is surprising that a novel gene influences so many traits. Here, we explore the alternative hypothesis that mth is an old gene. Under this hypothesis, in species distantly related to D. melanogaster, there should be a gene with features similar to those of mth. By performing detailed phylogenetic, synteny, protein structure, and gene expression analyses we show that the D. virilis GJ12490 gene is the orthologous of mth in species distantly related to D. melanogaster. We also show that, in D. americana (a species of the virilis group of Drosophila, a common amino acid polymorphism at the GJ12490 orthologous gene is significantly associated with developmental time, size, and lifespan differences. Our results imply that GJ12490 orthologous genes are candidates for developmental time and lifespan differences in Drosophila in general.

  5. Neurl4 contributes to germ cell formation and integrity in Drosophila

    Directory of Open Access Journals (Sweden)

    Jennifer Jones

    2015-08-01

    Full Text Available Primordial germ cells (PGCs form at the posterior pole of the Drosophila embryo, and then migrate to their final destination in the gonad where they will produce eggs or sperm. Studies of the different stages in this process, including assembly of germ plasm in the oocyte during oogenesis, specification of a subset of syncytial embryonic nuclei as PGCs, and migration, have been informed by genetic analyses. Mutants have defined steps in the process, and the identities of the affected genes have suggested biochemical mechanisms. Here we describe a novel PGC phenotype. When Neurl4 activity is reduced, newly formed PGCs frequently adopt irregular shapes and appear to bud off vesicles. PGC number is also reduced, an effect exacerbated by a separate role for Neurl4 in germ plasm formation during oogenesis. Like its mammalian homolog, Drosophila Neurl4 protein is concentrated in centrosomes and downregulates centrosomal protein CP110. Reducing CP110 activity suppresses the abnormal PGC morphology of Neurl4 mutants. These results extend prior analyses of Neurl4 in cultured cells, revealing a heightened requirement for Neurl4 in germ-line cells in Drosophila.

  6. Radioresistance and radiosensitivity in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Reguly, M.L.

    1983-01-01

    Studying the mechanisms controlling radioresistant in Drosophila the sensibility of four strains of Drosophila melanogaster to sex-linked recessive lethal mutations induced by 5kR Cobalt-60 gamma radiation and 0,006 M EMS or 0,25% of caffeine was determined. (M.A.C.) [pt

  7. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Keywords. circadian rhythm; neuronal network; ion channel; behaviour; neurotransmitter; electrophysiology; Drosophila. Abstract. As an experimental model system, the fruit fly Drosophila melanogaster has been seminal in shaping our understanding of the circadian clockwork. The wealth of genetic tools ...

  8. PXD101 significantly improves nuclear reprogramming and the in vitro developmental competence of porcine SCNT embryos

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jun-Xue; Kang, Jin-Dan; Li, Suo; Jin, Long; Zhu, Hai-Ying; Guo, Qing; Gao, Qing-Shan; Yan, Chang-Guo; Yin, Xi-Jun, E-mail: yinxj33@msn.com

    2015-01-02

    Highlights: • First explored that the effects of PXD101 on the development of SCNT embryos in vitro. • 0.5 μM PXD101 treated for 24 h improved the development of porcine SCNT embryos. • Level of AcH3K9 was significantly higher than control group at early stages. - Abstract: In this study, we investigated the effects of the histone deacetylase inhibitor PXD101 (belinostat) on the preimplantation development of porcine somatic cell nuclear transfer (SCNT) embryos and their expression of the epigenetic markers histone H3 acetylated at lysine 9 (AcH3K9). We compared the in vitro developmental competence of SCNT embryos treated with various concentrations of PXD101 for 24 h. Treatment with 0.5 μM PXD101 significantly increased the proportion of SCNT embryos that reached the blastocyst stage, in comparison to the control group (23.3% vs. 11.5%, P < 0.05). We tested the in vitro developmental competence of SCNT embryos treated with 0.5 μM PXD101 for various amounts of times following activation. Treatment for 24 h significantly improved the development of porcine SCNT embryos, with a significantly higher proportion of embryos reaching the blastocyst stage in comparison to the control group (25.7% vs. 10.6%, P < 0.05). PXD101-treated SCNT embryos were transferred into two surrogate sows, one of whom became pregnant and four fetuses developed. PXD101 treatment significantly increased the fluorescence intensity of immunostaining for AcH3K9 in embryos at the pseudo-pronuclear and 2-cell stages. At these stages, the fluorescence intensities of immunostaining for AcH3K9 were significantly higher in PXD101-treated embryos than in control untreated embryos. In conclusion, this study demonstrates that PXD101 can significantly improve the in vitro and in vivo developmental competence of porcine SCNT embryos and can enhance their nuclear reprogramming.

  9. Silver Nanoparticles Incite Size and Dose-Dependent Developmental Phenotypes and Nanotoxicity in Zebrafish Embryos

    Science.gov (United States)

    Browning, Lauren M.; Lee, Kerry J.; Nallathamby, Prakash D.; Xu, Xiao-Hong Nancy

    2013-01-01

    Nanomaterials possess distinctive physicochemical properties and promise a wide range of applications, from advanced technology to leading-edge medicine. However, their effects on living organisms remain largely unknown. Here we report that the purified silver nanoparticles (Ag NPs, 97 ± 13 nm) incite specific developmental stage embryonic phenotypes and nanotoxicity in a dose-dependent manner, upon acute exposure of given-stage embryos to the NPs (0–24 pM) for only 2 h. The critical concentrations of the NPs that cause 50% of embryos develop normally for cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stage zebrafish embryos are 3.5, 4, 6, 6, and 8 pM, respectively, showing that the earlier developmental stage embryos are much more sensitive to the effects of the NPs than the later stage. Interestingly, distinctive phenotypes (head abnormality and no eyes) are observed only in cleavage and early-gastrula stage embryos treated with the NPs, showing the stage-specific effects of the NPs. By comparing with our study of the smaller Ag NPs (13.1 ± 2.5 nm), we found that the embryonic phenotypes strikingly depend upon the sizes of Ag NPs and embryonic developmental stages. These notable findings suggest that the Ag NPs are unlike any conventional chemicals or ions. They can potentially enable target specific study and therapy for early embryonic development in size, stage, dose, and exposure-duration dependent manners. PMID:24024906

  10. Entire mesodermal mantle behaves as Spemann's organizer in dorsoanterior enhanced Xenopus laevis embryos

    International Nuclear Information System (INIS)

    Kao, K.R.; Elinson, R.P.

    1988-01-01

    The body plan of Xenopus laevis can be respecified by briefly exposing early cleavage stage embryos to lithium. Such embryos develop exaggerated dorsoanterior structures such as a radial eye and cement gland. In this paper, we demonstrate that the enhanced dorsoanterior phenotype results from an overcommitment of mesoderm to dorsoanterior mesoderm. Histological and immunohistochemical observations reveal that the embryos have a greatly enlarged notochord with very little muscle tissue. In addition, they develop a radial, beating heart, suggesting that lithium also specifies anterior mesoderm and pharyngeal endoderm. Randomly oriented diametrically opposed marginal zone grafts from lithium-treated embryos, when transplanted into ultraviolet (uv)-irradiated axis-deficient hosts, rescue dorsal axial structures. These transplantation experiments demonstrate that the entire marginal zone of the early gastrula consists of presumptive dorsal mesoderm. Vital dye marking experiments also indicate that the entire marginal zone maps to the prominent proboscis that is composed of chordamesoderm and represents the long axis of the embryo. These results suggest that lithium respecifies the mesoderm of Xenopus laevis embryos so that it differentiates into the Spemann organizer. We suggest that the origin of the dorsoanterior enhanced phenotypes generated by lithium and the dorsoanterior deficient phenotypes generated by uv irradiation are due to relative quantities of organizer. Our evidence demonstrates the existence of a continuum of body plan phenotypes based on this premise

  11. Drosophila Protein Kinase CK2: Genetics, Regulatory Complexity and Emerging Roles during Development

    Directory of Open Access Journals (Sweden)

    Mohna Bandyopadhyay

    2016-12-01

    Full Text Available CK2 is a Ser/Thr protein kinase that is highly conserved amongst all eukaryotes. It is a well-known oncogenic kinase that regulates vital cell autonomous functions and animal development. Genetic studies in the fruit fly Drosophila are providing unique insights into the roles of CK2 in cell signaling, embryogenesis, organogenesis, neurogenesis, and the circadian clock, and are revealing hitherto unknown complexities in CK2 functions and regulation. Here, we review Drosophila CK2 with respect to its structure, subunit diversity, potential mechanisms of regulation, developmental abnormalities linked to mutations in the gene encoding CK2 subunits, and emerging roles in multiple aspects of eye development. We examine the Drosophila CK2 “interaction map” and the eye-specific “transcriptome” databases, which raise the prospect that this protein kinase has many additional targets in the developing eye. We discuss the possibility that CK2 functions during early retinal neurogenesis in Drosophila and mammals bear greater similarity than has been recognized, and that this conservation may extend to other developmental programs. Together, these studies underscore the immense power of the Drosophila model organism to provide new insights and avenues to further investigate developmentally relevant targets of this protein kinase.

  12. Radionuclide transfer from mother to embryo

    International Nuclear Information System (INIS)

    Toader, M.; Vasilache, R.A.; Scridon, R.; Toader, M.L.

    1998-01-01

    The transfer of radionuclides from mother to embryo is still a matter of high interest. Therefore, the relation was investigated between the amount of radionuclides in the embryo and the dietary intake of the mother, this for two scenarios: a recurrent intake of variable amounts of radionuclides, and a long-term intake of a relatively constant amount of radionuclides, the radionuclide being 137 Cs. In the first case, the amount of radionuclides present in the embryo increases with the age of the embryo and with the intake of the mother. In the second case, no correlation could be found between the age of the embryo and its radioactive content; only the correlation between the intake of the mother and the radionuclide content of the embryo remained. (A.K.)

  13. Effect of progesterone supplementation in the first week post conception on embryo survival in beef heifers.

    Science.gov (United States)

    Beltman, M E; Lonergan, P; Diskin, M G; Roche, J F; Crowe, M A

    2009-04-15

    Progesterone is essential for establishment and maintenance of pregnancy in mammals. The objective of this study was to examine the effect of elevating progesterone during the different physiological stages of early embryo development on embryo survival. Estrus was synchronized in cross-bred beef heifers (n=197, approximately 2-years old) and they were inseminated 12-18h after estrus onset (=Day 0). Inseminated heifers were randomly assigned to 1 of 3 treatments: (1) Control, n=69; (2) progesterone supplementation using a Controlled Internal Drug Release Device (CIDR) from Day 3 to 6.5, n=64; or (3) progesterone supplementation using a CIDR from Day 4.5 to 8, n=64. Body condition (BCS) and locomotion scores (scale of 1-5) were recorded for all animals. Animals with a locomotion score >/=4 (very lame) were excluded. Embryo survival rate was determined at slaughter on Day 25. Conceptus length and weight were recorded and the corpus luteum (CL) of all pregnant animals was dissected and weighed. Supplementation with exogenous progesterone increased (Prate compared with controls. Mean CL weight, conceptus length and conceptus weight were not different between treatments. There was a positive relationship (Prate in treated heifers and a similar trend existed between the increase from Days 4.5 to 8 (Prate in treated heifers. A direct correlation was seen between locomotion score and embryo survival rate, with higher (Prates in heifers with a lower locomotion score. In conclusion, supplementation with progesterone at different stages of early embryo development increased peripheral progesterone concentration and resulted in a positive association between changes in progesterone concentration during the early luteal phase and embryo survival rate. Supplementation with progesterone had no effect on either CL weight or conceptus size in pregnant animals. Lameness had a significant negative effect on early embryo survival.

  14. The fate of paternal mitochondria in marmoset pre-implantation embryos.

    Science.gov (United States)

    Luetjens, C M; Wesselmann, R

    2008-06-01

    Sperm-derived mitochondria are integrated into the oocyte at fertilization but seem to vanish during the early cleavage phase. The developmental potential of pre-implantation embryos seems to be closely related to their ability to induce degeneration of these mitochondria, but the mechanisms underlying their loss of function are not yet understood. This study focuses on the fate of paternal mitochondria in pre-implantation embryos. Stimulation, collection and in vitro culture of oocytes from Callithrix jacchus, allows the study of the destiny of paternal mitochondria by utilizing immunostaining of pre-implantation embryos, fluorescence and laserscanning microscopy. Live pre-implantation embryos were stained with a fluorescence indicator reflecting mitochondrial membrane potential. Evidence indicating the loss of mitochondrial function was not found nor that apoptosis pathways were involved in the disappearance of paternally derived mitochondria. These findings may have implications for mitochondrially inherited diseases and could lead to new strategies for improving assisted reproduction.

  15. Insights from imaging the implanting embryo and the uterine environment in three dimensions

    Science.gov (United States)

    Arora, Ripla; Fries, Adam; Oelerich, Karina; Marchuk, Kyle; Sabeur, Khalida; Giudice, Linda C.

    2016-01-01

    Although much is known about the embryo during implantation, the architecture of the uterine environment in which the early embryo develops is not well understood. We employed confocal imaging in combination with 3D analysis to identify and quantify dynamic changes to the luminal structure of murine uterus in preparation for implantation. When applied to mouse mutants with known implantation defects, this method detected striking peri-implantation abnormalities in uterine morphology that cannot be visualized by histology. We revealed 3D organization of uterine glands and found that they undergo a stereotypical reorientation concurrent with implantation. Furthermore, we extended this technique to generate a 3D rendering of the cycling human endometrium. Analyzing the uterine and embryo structure in 3D for different genetic mutants and pathological conditions will help uncover novel molecular pathways and global structural changes that contribute to successful implantation of an embryo. PMID:27836961

  16. Ultrastructural observations of lethal yellow (A/sup y//A/sup y/) mouse embryos

    Energy Technology Data Exchange (ETDEWEB)

    Calarco, P G; Pedersen, R A

    1976-01-01

    A/sup y//A/sup y/ embryos were identified by the presence of large excluded blastomeres (Pedersen, 1974) and examined cytologically and ultrastructurally. Cell organelles, inclusions and junctions in the excluded blastomeres were compared with those of non-excluded cells of A/sup y//A/sup y/ embryos and control embryos. Excluded blastomeres always had the fine structural characteristics of earlier developmental stages and may have arrested at the 4- to 8-cell stage or slightly later. Interior cells (inner cell mass) were observed in all mutant blastocysts. Nonexcluded cells of A/sup y//A/sup y/ embryos were normal until degenerative changes appear in the late blastocyst stage. The mode of action of the +/sup A/sup y/ gene was not determined, but evidence from this study and others indicates that the effects of +/sup A/sup y/ gene action occur over a wide range of time in early cleavage and implantation.

  17. Drosophila olfactory memory: single genes to complex neural circuits.

    Science.gov (United States)

    Keene, Alex C; Waddell, Scott

    2007-05-01

    A central goal of neuroscience is to understand how neural circuits encode memory and guide behaviour. Studying simple, genetically tractable organisms, such as Drosophila melanogaster, can illuminate principles of neural circuit organization and function. Early genetic dissection of D. melanogaster olfactory memory focused on individual genes and molecules. These molecular tags subsequently revealed key neural circuits for memory. Recent advances in genetic technology have allowed us to manipulate and observe activity in these circuits, and even individual neurons, in live animals. The studies have transformed D. melanogaster from a useful organism for gene discovery to an ideal model to understand neural circuit function in memory.

  18. Large-scale discovery of promoter motifs in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Thomas A Down

    2007-01-01

    Full Text Available A key step in understanding gene regulation is to identify the repertoire of transcription factor binding motifs (TFBMs that form the building blocks of promoters and other regulatory elements. Identifying these experimentally is very laborious, and the number of TFBMs discovered remains relatively small, especially when compared with the hundreds of transcription factor genes predicted in metazoan genomes. We have used a recently developed statistical motif discovery approach, NestedMICA, to detect candidate TFBMs from a large set of Drosophila melanogaster promoter regions. Of the 120 motifs inferred in our initial analysis, 25 were statistically significant matches to previously reported motifs, while 87 appeared to be novel. Analysis of sequence conservation and motif positioning suggested that the great majority of these discovered motifs are predictive of functional elements in the genome. Many motifs showed associations with specific patterns of gene expression in the D. melanogaster embryo, and we were able to obtain confident annotation of expression patterns for 25 of our motifs, including eight of the novel motifs. The motifs are available through Tiffin, a new database of DNA sequence motifs. We have discovered many new motifs that are overrepresented in D. melanogaster promoter regions, and offer several independent lines of evidence that these are novel TFBMs. Our motif dictionary provides a solid foundation for further investigation of regulatory elements in Drosophila, and demonstrates techniques that should be applicable in other species. We suggest that further improvements in computational motif discovery should narrow the gap between the set of known motifs and the total number of transcription factors in metazoan genomes.

  19. Methanol as a cryoprotectant for equine embryos.

    Science.gov (United States)

    Bass, L D; Denniston, D J; Maclellan, L J; McCue, P M; Seidel, G E; Squires, E L

    2004-09-15

    Equine embryos (n=43) were recovered nonsurgically 7-8 days after ovulation and randomly assigned to be cryopreserved in one of two cryoprotectants: 48% (15M) methanol (n=22) or 10% (136 M) glycerol (n=21). Embryos (300-1000 microm) were measured at five intervals after exposure to glycerol (0, 2, 5, 10 and 15 min) or methanol (0, 15, 35, 75 and 10 min) to determine changes (%) in diameter over time (+/-S.D.). Embryos were loaded into 0.25-ml plastic straws, sealed, placed in a programmable cell freezer and cooled from room temperature (22 degrees C) to -6 degrees C. Straws were then seeded, held at -6 degrees C for 10 min and then cooled to -33 degrees C before being plunged into liquid nitrogen. Two or three embryos within a treatment group were thawed and assigned to be either cultured for 12 h prior to transfer or immediately nonsurgically transferred to a single mare. Embryo diameter decreased in all embryos upon initial exposure to cryoprotectant. Embryos in methanol shrank and recovered slightly to 76+/-8 % of their original diameter; however, embryos in glycerol continued to shrink, reaching 57+/-6 % of their original diameter prior to cryopreservation. Survival rates of embryos through Day 16 of pregnancy were 38 and 23%, respectively (P>0.05) for embryos cryopreserved in the presence of glycerol or methanol. There was no difference in pregnancy rates of mares receiving embryos that were cultured prior to transfer or not cultured (P>0.05). Preliminary experiments indicated that 48% methanol was not toxic to fresh equine embryos but methanol provided no advantage over glycerol as a cryoprotectant for equine blastocysts.

  20. Functional analysis of lysosomes during mouse preimplantation embryo development.

    Science.gov (United States)

    Tsukamoto, Satoshi; Hara, Taichi; Yamamoto, Atsushi; Ohta, Yuki; Wada, Ayako; Ishida, Yuka; Kito, Seiji; Nishikawa, Tetsu; Minami, Naojiro; Sato, Ken; Kokubo, Toshiaki

    2013-01-01

    Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers decreased slightly in blastocysts. Consistently, the protein expression level of mature cathepsins B and D was high from the one-cell to morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes also caused developmental retardation, resulting in accumulation of lipofuscin. Our findings highlight the functional changes in lysosomes in mouse preimplantation embryos.

  1. Impact of GnRH analogues on oocyte/embryo quality and embryo development in in vitro fertilization/intracytoplasmic sperm injection cycles: a case control study

    Directory of Open Access Journals (Sweden)

    Rigó János

    2009-09-01

    Full Text Available Abstract Background Despite the clinical outcomes of ovarian stimulation with either GnRH-agonist or GnRH-antagonist analogues for in vitro fertilization (IVF being well analysed, the effect of analogues on oocyte/embryo quality and embryo development is still not known in detail. The aim of this case-control study was to compare the efficacy of a multiple-dose GnRH antagonist protocol with that of the GnRH agonist long protocol with a view to oocyte and embryo quality, embryo development and IVF treatment outcome. Methods Between October 2001 and December 2008, 100 patients were stimulated with human menopausal gonadotrophin (HMG and GnRH antagonist in their first treatment cycle for IVF or intracytoplasmic sperm injection (ICSI. One hundred combined GnRH agonist + HMG (long protocol cycles were matched to the GnRH antagonist + HMG cycles by age, BMI, baseline FSH levels and by cause of infertility. We determined the number and quality of retrieved oocytes, the rate of early-cleavage embryos, the morphology and development of embryos, as well as clinical pregnancy rates. Statistical analysis was performed using Wilcoxon's matched pairs rank sum test and McNemar's chi-square test. P Results The rate of cytoplasmic abnormalities in retrieved oocytes was significantly higher with the use of GnRH antagonist than in GnRH agonist cycles (62.1% vs. 49.9%; P Conclusion Antagonist seemed to influence favourably some parameters of early embryo development dynamics, while other morphological parameters seemed not to be altered according to GnRH analogue used for ovarian stimulation in IVF cycles.

  2. Cardio-respiratory development in bird embryos: new insights from a venerable animal model

    Directory of Open Access Journals (Sweden)

    Warren W. Burggren

    Full Text Available ABSTRACT The avian embryo is a time-honored animal model for understanding vertebrate development. A key area of extensive study using bird embryos centers on developmental phenotypic plasticity of the cardio-respiratory system and how its normal development can be affected by abiotic factors such as temperature and oxygen availability. Through the investigation of the plasticity of development, we gain a better understanding of both the regulation of the developmental process and the embryo's capacity for self-repair. Additionally, experiments with abiotic and biotic stressors during development have helped delineate not just critical windows for avian cardio-respiratory development, but the general characteristics (e.g., timing and dose-dependence of critical windows in all developing vertebrates. Avian embryos are useful in exploring fetal programming, in which early developmental experiences have implications (usually negative later in life. The ability to experimentally manipulate the avian embryo without the interference of maternal behavior or physiology makes it particularly useful in future studies of fetal programming. The bird embryo is also a key participant in studies of transgenerational epigenetics, whether by egg provisioning or effects on the germline that are transmitted to the F1 generation (or beyond. Finally, the avian embryo is heavily exploited in toxicology, in which both toxicological testing of potential consumer products as well as the consequences of exposure to anthropogenic pollutants are routinely carried out in the avian embryo. The avian embryo thus proves useful on numerous experimental fronts as an animal model that is concurrently both of adequate complexity and sufficient simplicity for probing vertebrate cardio-respiratory development.

  3. Paternal breed effects on expression of IGF-II, BAK1 and BCL2-L1 in bovine preimplantation embryos

    DEFF Research Database (Denmark)

    Valleh, Mehdi Vafaye; Tahmoorespur, Mojtaba; Joupari, Morteza Daliri

    2015-01-01

    of this study was to investigate the effects of the paternal breed on the early embryonic development and relative expression of the maternally imprinted gene, IGF-II, and the apoptosis-related genes BAK1 and BCL2-L1 in in vitro produced (IVP) bovine embryos derived from two unrelated paternal breeds (Holstein......Summary The effects of the paternal breed on early embryo and later pre- and postnatal development are well documented. Several recent studies have suggested that such paternal effects may be mediated by the paternally induced epigenetic modifications during early embryogenesis. The objective...... and Brown Swiss). The degree of correlation of IGF-II expression pattern with embryo developmental competence and apoptosis-related genes was also investigated. The relative abundance of IGF-II, BCL2-L1 and BAK1 transcripts in day 8 embryos was measured by quantitative reverse-transcription polymerase chain...

  4. Post-implantation mortality of in vitro produced embryos is associated with DNA methyltransferase 1 dysfunction in sheep placenta.

    Science.gov (United States)

    Ptak, Grazyna Ewa; D'Agostino, Antonella; Toschi, Paola; Fidanza, Antonella; Zacchini, Federica; Czernik, Marta; Monaco, Federica; Loi, Pasqualino

    2013-02-01

    Is DNA methyltransferase 1 (DNMT1) dysfunction involved in epigenetic deregulation of placentae from embryos obtained by assisted reproduction technologies (ARTs)? DNMT1 expression in growing placentae of in vitro produced (IVP) embryos is compromised and associated with pregnancy loss. DNMT1 maintains the methylation profile of genes during cell division. The methylation status of genes involved in placenta development is altered in embryos obtained in vitro. Disturbances in the epigenetic regulation of gene expression during placentogenesis could be involved in the frequent developmental arrest and loss of IVP embryos. Forty sheep were naturally mated (Group 1, CTR). IVP blastocysts (2-4 per ewe) were surgically transferred to the remaining 46 recipient sheep 6 days after oestrus (Group 2). Twenty-one recipients from Group 1 and 27 recipients from Group 2 were allowed to deliver in order to compare embryo survival in both groups at term (150 days). From the remaining recipients (n = 38), fetuses and placentae of both groups were recovered by paramedian laparotomy at Days 20, 22, 24, 26 and 28 of gestation. Immediately after collection, early placental tissues (chorion-allantois) were snap frozen in liquid nitrogen and DNMT1 expression and activity was evaluated. mRNA levels (for DNMT1, HDAC2, PCNA, DMAP1, MEST, IGF2, CDKN1C, H19) and the methylation status of H19 were also analyzed. Furthermore, embryo size and survival rate were measured. Our study shows that DNMT1 expression was reduced in early placentae from sheep IVP embryos. This reduction was associated with growth arrest and subsequent death of the sheep embryos. Conversely, normal levels of DNMT1 and its cofactors were observed in placentae from IVP embryos that survived this developmental bottleneck. Although DNA methylation machinery was severely compromised in IVP placentae only up to Day 24, the low DNMT1 enzymatic activity that persisted after this stage in IVP placentae was not lethal for the

  5. Nano-nutrition of chicken embryos

    DEFF Research Database (Denmark)

    Sawosz, Filip; Pineda, Lane Manalili; Hotowy, Anna

    2013-01-01

    It has been suggested that the quantity and quality of nutrients stored in the egg might not be optimal for the fast rate of chicken embryo development in modern broilers, and embryos could be supplemented with nutrients by in ovo injection. Recent experiments showed that in ovo feeding reduces...... broiler eggs was randomly divided into a Control group without injection and injected groups with hydrocolloids of Nano-Ag, ATP or a complex of Nano-Ag and ATP (Nano-Ag/ATP). The embryos were evaluated on day 20 of incubation. The results indicate that the application of ATP to chicken embryos increases...

  6. Die Behandlung menschliches Embryos und Menschenwurde

    OpenAIRE

    Matsui, Fumio

    2002-01-01

    We are confronted with an old and new problem, which has come up with the progress of modern biotechnologies: what is a life or when does a life begin? The expectation of order-made medicine has build up since the discovery of Embryo Stem cell called "a dream master cell", while there is any condemnation against the destruction of human embryo in order to gain it. It is a question whether a human embryo is a human being in the world. Human dignity(=HD) is a principle that keeps human embryos ...

  7. Modulatory Action by the Serotonergic System: Behavior and Neurophysiology in Drosophila melanogaster

    OpenAIRE

    Majeed, Zana R.; Abdeljaber, Esraa; Soveland, Robin; Cornwell, Kristin; Bankemper, Aubrey; Koch, Felicitas; Cooper, Robin L.

    2016-01-01

    Serotonin modulates various physiological processes and behaviors. This study investigates the role of 5-HT in locomotion and feeding behaviors as well as in modulation of sensory-motor circuits. The 5-HT biosynthesis was dysregulated by feeding Drosophila larvae 5-HT, a 5-HT precursor, or an inhibitor of tryptophan hydroxylase during early stages of development. The effects of feeding fluoxetine, a selective serotonin reuptake inhibitor, during early second instars were also examined. 5-HT r...

  8. Identification and characterization of pyrokinin and CAPA peptides, and corresponding GPCRs from spotted wing drosophila, Drosophila suzukii.

    Science.gov (United States)

    Choi, Man-Yeon; Ahn, Seung-Joon; Kim, A Young; Koh, Youngho

    2017-05-15

    The family of FXPRLamide peptides serves as a major insect hormone. It is characterized by a core active amino acid sequence conserved at the C-terminal ends, and provides various physiological roles across the Insecta. In this study we identified and characterized pyrokinin (PK) and CAPA cDNAs encoding two FXPRLamide peptides, pyrokinin and CAPA-DH (diapause hormone), and two corresponding G protein-coupled receptors (GPCRs) from spotted wing drosophila (SWD), Drosophila suzukii. Expressions of PK and CAPA mRNAs were differentially observed during all life stages except the embryo, and the detection of CAPA transcription was relatively strong compared with the PK gene in SWD. Both D. suzukii pyrokinin receptor (DrosuPKr) and CAPA-DH receptor (DrosuCAPA-DHr) were functionally expressed and confirmed through binding to PK and DH peptides. Differential expression of two GPCRs occurred during all life stages; a strong transcription of DrosuPKr was observed in the 3rd instar. DrosuCAPA-DHr was clearly expressed from the embryo to the larva, but not detected in the adult. Gene regulation during the life stages was not synchronized between ligand and receptor. For example, SWD CAPA mRNA has been up-regulated in the adult while CAPA-DHr was down-regulated. The difference could be from the CAPA mRNA translating multiple peptides including CAPA-DH and two CAPA-PVK (periviscerokinin) peptides to act on different receptors. Comparing the genes of SWD PK, CAPA, PKr and CAPA-DHr to four corresponding genes of D. melanogaster, SWD CAPA and the receptor are more similar to D. melanogaster than PK and the receptor. These data suggest that the CAPA gene could be evolutionally more conserved to have a common biological role in insects. In addition, the effect of Kozak sequences was investigated by the expression of the GPCRs with or without Kozak sequences in Sf9 insect cells. The Kozak sequenced PK receptor was significantly less active than the original (= no Kozak sequenced

  9. [Relationship between mitochondrial DNA copy number, membrane potential of human embryo and embryo morphology].

    Science.gov (United States)

    Zhao, H; Teng, X M; Li, Y F

    2017-11-25

    Objective: To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number, the membrane potential. Methods: Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected. According to evaluation of international standard in embryos, all cleavage stage embryos were divided into class Ⅰ frozen embryo group ( n= 64), class Ⅱ frozen embryo group ( n= 42) and class Ⅲ fresh embryonic group (not transplanted embryos; n= 117). Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo. The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared. Results: The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7±1.0)×10(5) copy/μl, 1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×10(5) copy/μl, 2.66±0.21] and class Ⅱ frozen embryo group [(2.6±1.2)×10(5) copy/μl, 1.80±0.32; all Pembryo group were significantly higher than those in classⅡ frozen embryo group (both Pembryos of the better quality embryo are higher.

  10. Functional neuroanatomy of Drosophila olfactory memory formation.

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L

    2014-10-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying Drosophila learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry extending from the site(s) of acquisition to