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APC functions at the centrosome to stimulate microtubule growth.

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Lui, Christina; Ashton, Cahora; Sharma, Manisha; Brocardo, Mariana G; Henderson, Beric R

2016-01-01

The adenomatous polyposis coli (APC) tumor suppressor is multi-functional. APC is known to localize at the centrosome, and in mitotic cells contributes to formation of the mitotic spindle. To test whether APC contributes to nascent microtubule (MT) growth at interphase centrosomes, we employed MT regrowth assays in U2OS cells to measure MT assembly before and after nocodazole treatment and release. We showed that siRNA knockdown of full-length APC delayed both initial MT aster formation and MT elongation/regrowth. In contrast, APC-mutant SW480 cancer cells displayed a defect in MT regrowth that was unaffected by APC knockdown, but which was rescued by reconstitution of full-length APC. Our findings identify APC as a positive regulator of centrosome MT initial assembly and suggest that this process is disrupted by cancer mutations. We confirmed that full-length APC associates with the MT-nucleation factor γ-tubulin, and found that the APC cancer-truncated form (1-1309) also bound to γ-tubulin through APC amino acids 1-453. While binding to γ-tubulin may help target APC to the site of MT nucleation complexes, additional C-terminal sequences of APC are required to stimulate and stabilize MT growth. Copyright © 2015 Elsevier Ltd. All rights reserved.
A centrosome-autonomous signal that involves centriole disengagement permits centrosome duplication in G2 phase after DNA damage.

LENUS (Irish Health Repository)

2010-11-15

DNA damage can induce centrosome overduplication in a manner that requires G2-to-M checkpoint function, suggesting that genotoxic stress can decouple the centrosome and chromosome cycles. How this happens is unclear. Using live-cell imaging of cells that express fluorescently tagged NEDD1\\/GCP-WD and proliferating cell nuclear antigen, we found that ionizing radiation (IR)-induced centrosome amplification can occur outside S phase. Analysis of synchronized populations showed that significantly more centrosome amplification occurred after irradiation of G2-enriched populations compared with G1-enriched or asynchronous cells, consistent with G2 phase centrosome amplification. Irradiated and control populations of G2 cells were then fused to test whether centrosome overduplication is allowed through a diffusible stimulatory signal, or the loss of a duplication-inhibiting signal. Irradiated G2\\/irradiated G2 cell fusions showed significantly higher centrosome amplification levels than irradiated G2\\/unirradiated G2 fusions. Chicken-human cell fusions demonstrated that centrosome amplification was limited to the irradiated partner. Our finding that only the irradiated centrosome can duplicate supports a model where a centrosome-autonomous inhibitory signal is lost upon irradiation of G2 cells. We observed centriole disengagement after irradiation. Although overexpression of dominant-negative securin did not affect IR-induced centrosome amplification, Plk1 inhibition reduced radiation-induced amplification. Together, our data support centriole disengagement as a licensing signal for DNA damage-induced centrosome amplification.
LRRC45 Is a Centrosome Linker Component Required for Centrosome Cohesion

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Runsheng He

2013-09-01

Full Text Available During interphase, centrosomes are connected by a proteinaceous linker between the proximal ends of the centrioles, which is important for the centrosomes to function as a single microtubule-organizing center. However, the composition and regulation of centrosomal linker remain largely unknown. Here, we show that LRRC45 is a centrosome linker that localizes at the proximal ends of the centrioles and forms fiber-like structures between them. Depletion of LRRC45 results in centrosome splitting during interphase. Moreover, LRRC45 interacts with both C-Nap1 and rootletin and is phosphorylated by Nek2A at S661 during mitosis. After phosphorylation, both LRRC45 centrosomal localization and fiber-like structures are significantly reduced, which subsequently leads to centrosome separation. Thus, LRRC45 is a critical component of the proteinaceous linker between two centrioles and is required for centrosome cohesion.
Centrosome Amplification Increases Single-Cell Branching in Post-mitotic Cells.

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Ricolo, Delia; Deligiannaki, Myrto; Casanova, Jordi; Araújo, Sofia J

2016-10-24

Centrosome amplification is a hallmark of cancer, although we are still far from understanding how this process affects tumorigenesis [1, 2]. Besides the contribution of supernumerary centrosomes to mitotic defects, their biological effects in the post-mitotic cell are not well known. Here, we exploit the effects of centrosome amplification in post-mitotic cells during single-cell branching. We show that Drosophila tracheal cells with extra centrosomes branch more than wild-type cells. We found that mutations in Rca1 and CycA affect subcellular branching, causing tracheal tip cells to form more than one subcellular lumen. We show that Rca1 and CycA post-mitotic cells have supernumerary centrosomes and that other mutant conditions that increase centrosome number also show excess of subcellular lumen branching. Furthermore, we show that de novo lumen formation is impaired in mutant embryos with fewer centrioles. The data presented here define a requirement for the centrosome as a microtubule-organizing center (MTOC) for the initiation of subcellular lumen formation. We propose that centrosomes are necessary to drive subcellular lumen formation. In addition, centrosome amplification increases single-cell branching, a process parallel to capillary sprouting in blood vessels [3]. These results shed new light on how centrosomes can contribute to pathology independently of mitotic defects. Copyright © 2016 Elsevier Ltd. All rights reserved.
GF-15, a Novel Inhibitor of Centrosomal Clustering, Suppresses Tumor Cell Growth In Vitro and In Vivo

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Raab, Marc S.; Breitkreutz, Iris; Anderhub, Simon

2012-01-01

In contrast to normal cells, malignant cells are frequently aneuploid and contain multiple centrosomes. To allow for bipolar mitotic division, supernumerary centrosomes are clustered into two functional spindle poles in many cancer cells. Recently, we have shown that griseofulvin forces tumor cells......) for proliferation and survival were in the range of 1 to 5 μmol/L and were associated with apoptotic cell death. Importantly, treatment of mouse xenograft models of human colon cancer and multiple myeloma resulted in tumor growth inhibition and significantly prolonged survival. These results show the in vitro...
Centrosome Clustering in the Development of Bovine Binucleate Trophoblast Giant Cells.

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Klisch, Karl; Schraner, Elisabeth M; Boos, Alois

2017-01-01

Binucleate trophoblast giant cells (BNC) are the characteristic feature of the ruminant placenta. During their development, BNC pass through 2 acytokinetic mitoses and become binucleate with 2 tetraploid nuclei. In this study, we investigate the number and location of centrosomes in bovine BNC. Centrosomes typically consist of 2 centrioles surrounded by electron-dense pericentriolar material. Duplication of centrosomes is tightly linked to the cell cycle, which ensures that the number of centrosomes remains constant in proliferating diploid cells. Alterations of the cell cycle, which affect the number of chromosome sets, also affect the number of centrosomes. In this study, we use placentomal tissue from pregnant cows (gestational days 80-230) for immunohistochemical staining of γ-tubulin (n = 3) and transmission electron microscopy (n = 3). We show that mature BNC have 4 centrosomes with 8 centrioles, clustered in the angle between the 2 cell nuclei. During the second acytokinetic mitosis, the centrosomes must be clustered to form the poles of a bipolar spindle. In rare cases, centrosome clustering fails and tripolar mitosis leads to the formation of trinucleate "BNC". Generally, centrosome clustering occurs in polyploid tumor cells, which have an increased number of centrioles, but it is absent in proliferating diploid cells. Thus, inhibition of centrosome clustering in tumor cells is a novel promising strategy for cancer treatment. BNC are a cell population in which centrosome clustering occurs as part of the normal life history. Thus, they might be a good model for the study of the molecular mechanisms of centrosome clustering. © 2016 S. Karger AG, Basel.
Centrosomes are autocatalytic droplets of pericentriolar material organized by centrioles

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Zwicker, David; Decker, Markus; Jaensch, Steffen; Hyman, Anthony A.; Jülicher, Frank

2014-03-01

We propose a physical description of the centrosome, a membrane-less organelle involved in cell division. In our model, centrosome material occurs in a soluble form in the cytosol and a form that tends to undergo phase separation from the cytosol. We find that an autocatalytic chemical transition between these forms accounts for the temporal evolution observed in experiments. Interestingly, the nucleation of centrosomes can be controlled by an enzymatic activity of the centrioles, which are present at the core of all centrosomes. This non-equilibrium feature also allows for multiple stable centrosomes, a situation which is unstable in equilibrium phase separation. Our theory explains the growth dynamics of centrosomes for all cell sizes down to the eight-cell stage of the C. elegans embryo. It also accounts for data acquired in experiments with aberrant numbers of centrosomes and altered cell volumes. Furthermore, our model can describe unequal centrosome sizes observed in cells with disturbed centrioles. Our example suggests a general picture of the organization of membrane-less organelles.
Cep192 controls the balance of centrosome and non-centrosomal microtubules during interphase.

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Brian P O'Rourke

Full Text Available Cep192 is a centrosomal protein that contributes to the formation and function of the mitotic spindle in mammalian cells. Cep192's mitotic activities stem largely from its role in the recruitment to the centrosome of numerous additional proteins such as gamma-tubulin and Pericentrin. Here, we examine Cep192's function in interphase cells. Our data indicate that, as in mitosis, Cep192 stimulates the nucleation of centrosomal microtubules thereby regulating the morphology of interphase microtubule arrays. Interestingly, however, cells lacking Cep192 remain capable of generating normal levels of MTs as the loss of centrosomal microtubules is augmented by MT nucleation from other sites, most notably the Golgi apparatus. The depletion of Cep192 results in a significant decrease in the level of centrosome-associated gamma-tubulin, likely explaining its impact on centrosome microtubule nucleation. However, in stark contrast to mitosis, Cep192 appears to maintain an antagonistic relationship with Pericentrin at interphase centrosomes. Interphase cells depleted of Cep192 display significantly higher levels of centrosome-associated Pericentrin while overexpression of Cep192 reduces the levels of centrosomal Pericentrin. Conversely, depletion of Pericentrin results in elevated levels of centrosomal Cep192 and enhances microtubule nucleation at centrosomes, at least during interphase. Finally, we show that depletion of Cep192 negatively impacts cell motility and alters normal cell polarization. Our current working hypothesis is that the microtubule nucleating capacity of the interphase centrosome is determined by an antagonistic balance of Cep192, which promotes nucleation, and Pericentrin, which inhibits nucleation. This in turn determines the relative abundance of centrosomal and non-centrosomal microtubules that tune cell movement and shape.
Discovery of centrosomal RNA and centrosomal hypothesis of cellular ageing and differentiation.

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Chichinadze, Konstantin; Tkemaladze, Jaba; Lazarashvili, Ann

2012-01-01

In 2006, a group of scientists studying centrosomes of Spisula solidissima mollusc oocytes under the leadership of Alliegro (Alliegro, M.C.; Alliegro, M.A.; Palazzo, R.E. Centrosome-associated RNA in surf clam oocytes. Proc. Natl. Acad. Sci. USA 2006, 103(24), 9034-9038) reliably demonstrated the existence of specific RNA in centrosome, called centrosomal RNA (cnRNA). In their first article, five different RNAs (cnRNAs 11, 102, 113, 170, and 184) were described. During the process of full sequencing of the first transcript (cnRNA 11), it was discovered that the transcript contained a conserved structure-a reverse transcriptase domain located together with the most important centrosomal protein, γ-tubulin. In an article published in 2005, we made assumptions about several possible mechanisms for determining the most important functions of centrosomal structures and referred to one of them as a "RNA-dependent mechanism." This idea about participation of hypothetic centrosomal small interference RNA and/or microRNA in the process was made one year prior to the discovery of cnRNA by Alliegro's group. The discovery of specific RNA in a centrosome is indirect evidence of a centrosomal hypothesis of cellular ageing and differentiation. The presence of a reverse transcriptase domain in this type of RNA, together with its uniqueness and specificity, makes the centrosome a place of information storage and reproduction.
The centrosomal linker and microtubules provide dual levels of spatial coordination of centrosomes.

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Marko Panic

2015-05-01

Full Text Available The centrosome is the principal microtubule organizing center in most animal cells. It consists of a pair of centrioles surrounded by pericentriolar material. The centrosome, like DNA, duplicates exactly once per cell cycle. During interphase duplicated centrosomes remain closely linked by a proteinaceous linker. This centrosomal linker is composed of rootletin filaments that are anchored to the centrioles via the protein C-Nap1. At the onset of mitosis the linker is dissolved by Nek2A kinase to support the formation of the bipolar mitotic spindle. The importance of the centrosomal linker for cell function during interphase awaits characterization. Here we assessed the phenotype of human RPE1 C-Nap1 knockout (KO cells. The absence of the linker led to a modest increase in the average centrosome separation from 1 to 2.5 μm. This small impact on the degree of separation is indicative of a second level of spatial organization of centrosomes. Microtubule depolymerisation or stabilization in C-Nap1 KO cells dramatically increased the inter-centrosomal separation (> 8 μm. Thus, microtubules position centrosomes relatively close to one another in the absence of linker function. C-Nap1 KO cells had a Golgi organization defect with a two-fold expansion of the area occupied by the Golgi. When the centrosomes of C-Nap1 KO cells showed considerable separation, two spatially distinct Golgi stacks could be observed. Furthermore, migration of C-Nap1 KO cells was slower than their wild type RPE1 counterparts. These data show that the spatial organization of centrosomes is modulated by a combination of centrosomal cohesion and microtubule forces. Furthermore a modest increase in centrosome separation has major impact on Golgi organization and cell migration.
Sequential activities of Dynein, Mud and Asp in centrosome-spindle coupling maintain centrosome number upon mitosis.

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Bosveld, Floris; Ainslie, Anna; Bellaïche, Yohanns

2017-10-15

Centrosomes nucleate microtubules and are tightly coupled to the bipolar spindle to ensure genome integrity, cell division orientation and centrosome segregation. While the mechanisms of centrosome-dependent microtubule nucleation and bipolar spindle assembly have been the focus of numerous works, less is known about the mechanisms ensuring the centrosome-spindle coupling. The conserved NuMA protein (Mud in Drosophila ) is best known for its role in spindle orientation. Here, we analyzed the role of Mud and two of its interactors, Asp and Dynein, in the regulation of centrosome numbers in Drosophila epithelial cells. We found that Dynein and Mud mainly initiate centrosome-spindle coupling prior to nuclear envelope breakdown (NEB) by promoting correct centrosome positioning or separation, while Asp acts largely independently of Dynein and Mud to maintain centrosome-spindle coupling. Failure in the centrosome-spindle coupling leads to mis-segregation of the two centrosomes into one daughter cell, resulting in cells with supernumerary centrosomes during subsequent divisions. Altogether, we propose that Dynein, Mud and Asp operate sequentially during the cell cycle to ensure efficient centrosome-spindle coupling in mitosis, thereby preventing centrosome mis-segregation to maintain centrosome number. © 2017. Published by The Company of Biologists Ltd.
Centrosome Dysfunction Contributes To Chromosome Instability, Chromoanagenesis And Genome Reprograming In Cancer.

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German A Pihan

2013-11-01

Full Text Available The unique ability of centrosomes to nucleate and organize microtubules makes them unrivaled conductors of important interphase processes, such as intracellular payload traffic, cell polarity, cell locomotion, and organization of the immunologic synapse. But it is in mitosis that centrosomes loom large, for they orchestrate, with clockmaker’s precision, the assembly and functioning of the mitotic spindle, ensuring the equal partitioning of the replicated genome into daughter cells. Centrosome dysfunction is inextricably linked to aneuploidy and chromosome instability, both hallmarks of cancer cells. Several aspects of centrosome function in normal and cancer cells have been molecularly characterized during the last two decades, greatly enhancing our mechanistic understanding of this tiny organelle. Whether centrosome defects alone can cause cancer, remains unanswered. Until recently, the aggregate of the evidence had suggested that centrosome dysfunction, by deregulating the fidelity of chromosome segregation, promotes and accelerates the characteristic Darwinian evolution of the cancer genome enabled by increased mutational load and/or decreased DNA repair. Very recent experimental work has shown that missegreated chromosomes resulting from centrosome dysfunction may experience extensive DNA damage, suggesting additional dimensions to the role of centrosomes in cancer. Centrosome dysfunction is particularly prevalent in tumors in which the genome has undergone extensive structural rearrangements and chromosome domain reshuffling. Ongoing gene reshuffling reprograms the genome for continuous growth, survival, and evasion of the immune system. Manipulation of molecular networks controlling centrosome function may soon become a viable target for specific therapeutic intervention in cancer, particularly since normal cells, which lack centrosome alterations, may be spared the toxicity of such therapies.
Ouabain affects cell migration via Na,K-ATPase-p130cas and via nucleus-centrosome association.

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Young Ou

Full Text Available Na,K-ATPase is a membrane protein that catalyzes ATP to maintain transmembrane sodium and potassium gradients. In addition, Na,K-ATPase also acts as a signal-transducing receptor for cardiotonic steroids such as ouabain and activates a number of signalling pathways. Several studies report that ouabain affects cell migration. Here we used ouabain at concentrations far below those required to block Na,K-ATPase pump activity and show that it significantly reduced RPE cell migration through two mechanisms. It causes dephosphorylation of a 130 kD protein, which we identify as p130cas. Src is involved, because Src inhibitors, but not inhibitors of other kinases tested, caused a similar reduction in p130cas phosphorylation and ouabain increased the association of Na,K-ATPase and Src. Knockdown of p130cas by siRNA reduced cell migration. Unexpectedly, ouabain induced separation of nucleus and centrosome, also leading to a block in cell migration. Inhibitor and siRNA experiments show that this effect is mediated by ERK1,2. This is the first report showing that ouabain can regulate cell migration by affecting nucleus-centrosome association.
p53 Dependent Centrosome Clustering Prevents Multipolar Mitosis in Tetraploid Cells

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Yi, Qiyi; Zhao, Xiaoyu; Huang, Yun; Ma, Tieliang; Zhang, Yingyin; Hou, Heli; Cooke, Howard J.; Yang, Da-Qing; Wu, Mian; Shi, Qinghua

2011-01-01

Background p53 abnormality and aneuploidy often coexist in human tumors, and tetraploidy is considered as an intermediate between normal diploidy and aneuploidy. The purpose of this study was to investigate whether and how p53 influences the transformation from tetraploidy to aneuploidy. Principal Findings Live cell imaging was performed to determine the fates and mitotic behaviors of several human and mouse tetraploid cells with different p53 status, and centrosome and spindle immunostaining was used to investigate centrosome behaviors. We found that p53 dominant-negative mutation, point mutation, or knockout led to a 2∼ 33-fold increase of multipolar mitosis in N/TERT1, 3T3 and mouse embryonic fibroblasts (MEFs), while mitotic entry and cell death were not significantly affected. In p53-/- tetraploid MEFs, the ability of centrosome clustering was compromised, while centrosome inactivation was not affected. Suppression of RhoA/ROCK activity by specific inhibitors in p53-/- tetraploid MEFs enhanced centrosome clustering, decreased multipolar mitosis from 38% to 20% and 16% for RhoA and ROCK, respectively, while expression of constitutively active RhoA in p53+/+ tetraploid 3T3 cells increased the frequency of multipolar mitosis from 15% to 35%. Conclusions p53 could not prevent tetraploid cells entering mitosis or induce tetraploid cell death. However, p53 abnormality impaired centrosome clustering and lead to multipolar mitosis in tetraploid cells by modulating the RhoA/ROCK signaling pathway. PMID:22076149
ATX-2, the C. elegans Ortholog of Human Ataxin-2, Regulates Centrosome Size and Microtubule Dynamics.

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Michael D Stubenvoll

2016-09-01

Full Text Available Centrosomes are critical sites for orchestrating microtubule dynamics, and exhibit dynamic changes in size during the cell cycle. As cells progress to mitosis, centrosomes recruit more microtubules (MT to form mitotic bipolar spindles that ensure proper chromosome segregation. We report a new role for ATX-2, a C. elegans ortholog of Human Ataxin-2, in regulating centrosome size and MT dynamics. ATX-2, an RNA-binding protein, forms a complex with SZY-20 in an RNA-independent fashion. Depleting ATX-2 results in embryonic lethality and cytokinesis failure, and restores centrosome duplication to zyg-1 mutants. In this pathway, SZY-20 promotes ATX-2 abundance, which inversely correlates with centrosome size. Centrosomes depleted of ATX-2 exhibit elevated levels of centrosome factors (ZYG-1, SPD-5, γ-Tubulin, increasing MT nucleating activity but impeding MT growth. We show that ATX-2 influences MT behavior through γ-Tubulin at the centrosome. Our data suggest that RNA-binding proteins play an active role in controlling MT dynamics and provide insight into the control of proper centrosome size and MT dynamics.
Emerging connection between centrosome and DNA repair machinery

International Nuclear Information System (INIS)

Shimada, Mikio; Komatsu, Kenshi

2009-01-01

Centrosomes function in proper cell division in animal cells. The centrosome consists of a pair of centrioles and the surrounding pericentriolar matrix (PCM). After cytokinesis, daughter cells each acquire one centrosome, which subsequently duplicates at the G1/S phase in a manner that is dependent upon CDK2/cyclin-E activity. Defects in the regulation of centrosome duplication lead to tumorigenesis through abnormal cell division and resulting inappropriate chromosome segregation. Therefore, maintenance of accurate centrosome number is important for cell fate. Excess number of centrosomes can be induced by several factors including ionizing radiation (IR). Recent studies have shown that several DNA repair proteins localize to the centrosome and are involved in the regulation of centrosome number possibly through cell cycle checkpoints or direct modification of centrosome proteins. Furthermore, it has been reported that the development of microcephaly is likely caused by defective expression of centrosome proteins, such as ASPM, which are also involved in the response to IR. The present review highlights centrosome duplication in association with genotoxic stresses and the regulatory mechanism mediated by DNA repair proteins. (author)
A fraction of Crm1 locates at centrosomes by its CRIME domain and regulates the centrosomal localization of pericentrin

International Nuclear Information System (INIS)

Liu, Qinying; Jiang, Qing; Zhang, Chuanmao

2009-01-01

Crm1 plays a role in exporting proteins containing nuclear export signals (NESs) from the nucleus to the cytoplasm. Some proteins that are capable of interacting with Ran/Crm1 were reported to be localized at centrosomes and to function as centrosome checkpoints. But it remains unclear how Crm1 locates at centrosomes. In this study, we found that a fraction of Crm1 is located at centrosomes through its N-terminal CRM1, importin β etc. (CRIME) domain, which is responsible for interacting with RanGTP, suggesting that Crm1 might target to centrosomes through binding centrosomal RanGTP. Moreover, overexpression of the CRIME domain, which is free of NES binding domain, resulted in the dissociation of pericentrin and γ-tubulin complex from centrosomes and the disruption of microtubule nucleation. Deficiency of Crm1 provoked by RNAi also decreased the spindle poles localization of pericentrin and γ-tubulin complex, coupled with mitotic defects. Since pericentrin was sensitive to Crm1 specific inhibitor leptomycin B, we propose that the centrosomal Crm1 might interact with pericentrin and regulate the localization and function of pericentrin at centrosomes.
Centrosome – a promising anti-cancer target

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Rivera-Rivera Y

2016-12-01

Full Text Available Yainyrette Rivera-Rivera, Harold I Saavedra Department of Pharmacology, Ponce Health Sciences University-School of Medicine, Ponce Research Institute, Ponce, Puerto Rico Abstract: The centrosome, an organelle discovered >100 years ago, is the main microtubule-organizing center in mammalian organisms. The centrosome is composed of a pair of centrioles surrounded by the pericentriolar material (PMC and plays a major role in the regulation of cell cycle transitions (G1-S, G2-M, and metaphase-anaphase, ensuring the normality of cell division. Hundreds of proteins found in the centrosome exert a variety of roles, including microtubule dynamics, nucleation, and kinetochore–microtubule attachments that allow correct chromosome alignment and segregation. Errors in these processes lead to structural (shape, size, number, position, and composition, functional (abnormal microtubule nucleation and disorganized spindles, and numerical (centrosome amplification [CA] centrosome aberrations causing aneuploidy and genomic instability. Compelling data demonstrate that centrosomes are implicated in cancer, because there are important oncogenic and tumor suppressor proteins that are localized in this organelle and drive centrosome aberrations. Centrosome defects have been found in pre-neoplasias and tumors from breast, ovaries, prostate, head and neck, lung, liver, and bladder among many others. Several drugs/compounds against centrosomal proteins have shown promising results. Other drugs have higher toxicity with modest or no benefits, and there are more recently developed agents being tested in clinical trials. All of this emerging evidence suggests that targeting centrosome aberrations may be a future avenue for therapeutic intervention in cancer research. Keywords: centrosomes, cell cycle, mitosis, CA, CIN, cancer therapy
High LET Radiation Amplifies Centrosome Overduplication Through a Pathway of γ-Tubulin Monoubiquitination

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Shimada, Mikio [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto (Japan); Hirayama, Ryoichi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Komatsu, Kenshi, E-mail: komatsu@house.rbc.kyoto-u.ac.jp [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto (Japan)

2013-06-01

Purpose: Radiation induces centrosome overduplication, leading to mitotic catastrophe and tumorigenesis. Because mitotic catastrophe is one of the major tumor cell killing factors in high linear energy transfer (LET) radiation therapy and long-term survivors from such treatment have a potential risk of secondary tumors, we investigated LET dependence of radiation-induced centrosome overduplication and the underlying mechanism. Methods and Materials: Carbon and iron ion beams (13-200 keV/μm) and γ-rays (0.5 keV/μm) were used as radiation sources. To count centrosomes after IR exposure, human U2OS and mouse NIH3T3 cells were immunostained with antibodies of γ-tubulin and centrin 2. Similarly, Nbs1-, Brca1-, Ku70-, and DNA-PKcs-deficient mouse cells and their counterpart wild-type cells were used for measurement of centrosome overduplication. Results: The number of excess centrosome-containing cells at interphase and the resulting multipolar spindle at mitosis were amplified with increased LET, reaching a maximum level of 100 keV/μm, followed by sharp decrease in frequency. Interestingly, Ku70 and DNA-PKcs deficiencies marginally affected the induction of centrosome overduplication, whereas the cell killings were significantly enhanced. This was in contrast to observation that high LET radiation significantly enhanced frequencies of centrosome overduplication in Nbs1- and Brca1-deficient cells. Because NBS1/BRCA1 is implicated in monoubiquitination of γ-tubulin, we subsequently tested whether it is affected by high LET radiation. As a result, monoubiquitination of γ-tubulin was abolished in 48 to 72 hours after exposure to high LET radiation, although γ-ray exposure slightly decreased it 48 hours postirradiation and was restored to a normal level at 72 hours. Conclusions: High LET radiation significantly reduces NBS1/BRCA1-mediated monoubiquitination of γ-tubulin and amplifies centrosome overduplication with a peak at 100 keV/μm. In contrast, Ku70 and DNA
Activation of maternal centrosomes in unfertilized sea urchin eggs

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Schatten, H.; Walter, M.; Biessmann, H.; Schatten, G.

1992-01-01

Centrosomes are undetectable in unfertilized sea urchin eggs, and normally the sperm introduces the cell's microtubule-organizing center (MTOC) at fertilization. However, artificial activation or parthenogenesis triggers microtubule assembly in the unfertilized egg, and this study explores the reappearance and behavior of the maternal centrosome. During activation with A23187 or ammonia, microtubules appear first at the cortex; centrosomal antigen is detected diffusely throughout the entire cytoplasm. Later, the centrosome becomes more distinct and organizes a radial microtubule shell, and eventually a compact centrosome at the egg center organizes a monaster. In these activated eggs, centrosomes undergo cycles of compaction and decompaction in synchrony with the chromatin, which also undergoes cycles of condensation and decondensation. Parthenogenetic activation with heavy water (50% D2O) or the microtubule-stabilizing drug taxol (10 microM) induces numerous centrosomal foci in the unfertilized sea urchin egg. Within 15 min after incubation in D2O, numerous fine centrosomal foci are detected, and they organize a connected network of numerous asters which fill the entire egg. Taxol induces over 100 centrosomal foci by 15 min after treatment, which organize a corresponding number of asters. The centrosomal material in either D2O- or taxol-treated eggs aggregates with time to form fewer but denser foci, resulting in fewer and larger asters. Fertilization of eggs pretreated with either D2O or taxol shows that the paternal centrosome is dominant over the maternal centrosome. The centrosomal material gradually becomes associated with the enlarged sperm aster. These experiments demonstrate that maternal centrosomal material is present in the unfertilized egg, likely as dispersed undetectable material, which can be activated without paternal contributions. At fertilization, paternal centrosomes become dominant over the maternal centrosomal material.

Fanconi anemia complementation group A (FANCA) localizes to centrosomes and functions in the maintenance of centrosome integrity.

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Kim, Sunshin; Hwang, Soo Kyung; Lee, Mihee; Kwak, Heejin; Son, Kook; Yang, Jiha; Kim, Sung Hak; Lee, Chang-Hun

2013-09-01

Fanconi anemia (FA) proteins are known to play roles in the cellular response to DNA interstrand cross-linking lesions; however, several reports have suggested that FA proteins play additional roles. To elucidate novel functions of FA proteins, we used yeast two-hybrid screening to identify binding partners of the Fanconi anemia complementation group A (FANCA) protein. The candidate proteins included never-in-mitosis-gene A (NIMA)-related kinase 2 (Nek2), which functions in the maintenance of centrosome integrity. The interaction of FANCA and Nek2 was confirmed in human embryonic kidney (HEK) 293T cells. Furthermore, FANCA interacted with γ-tubulin and localized to centrosomes, most notably during the mitotic phase, confirming that FANCA is a centrosomal protein. Knockdown of FANCA increased the frequency of centrosomal abnormalities and enhanced the sensitivity of U2OS osteosarcoma cells to nocodazole, a microtubule-interfering agent. In vitro kinase assays indicated that Nek2 can phosphorylate FANCA at threonine-351 (T351), and analysis with a phospho-specific antibody confirmed that this phosphorylation occurred in response to nocodazole treatment. Furthermore, U2OS cells overexpressing the phosphorylation-defective T351A FANCA mutant showed numerical centrosomal abnormalities, aberrant mitotic arrest, and enhanced nocodazole sensitivity, implying that the Nek2-mediated T351 phosphorylation of FANCA is important for the maintenance of centrosomal integrity. Taken together, this study revealed that FANCA localizes to centrosomes and is required for the maintenance of centrosome integrity, possibly through its phosphorylation at T351 by Nek2. Copyright © 2013 Elsevier Ltd. All rights reserved.
Same but different: pleiotropy in centrosome-related microcephaly.

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O'Neill, Ryan S; Schoborg, Todd A; Rusan, Nasser M

2018-02-01

An intimate link between centrosome function and neurogenesis is revealed by the identification of many genes with centrosome-associated functions that are mutated in microcephaly disorders. Consistent with the major role of the centrosome in mitosis, mutations in these centrosome-related microcephaly (CRM) genes are thought to affect neurogenesis by depleting the pool of neural progenitor cells, primarily through apoptosis as a consequence of mitotic failure or premature differentiation as a consequence of cell cycle delay and randomization of spindle orientation. However, as suggested by the wide range of microcephaly phenotypes and the multifunctional nature of many CRM proteins, this picture of CRM gene function is incomplete. Here, we explore several examples of CRM genes pointing to additional functions that contribute to microcephaly, including regulation of cell cycle signaling, actin cytoskeleton, and Hippo pathway proteins, as well as functions in postmitotic neurons and glia. As these examples are likely just the tip of the iceberg, further exploration of the roles of microcephaly-related genes are certain to reveal additional unforeseen functions important for neurodevelopment. © 2018 O‘Neill 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).
Phosphorylation of the centrosomal protein, Cep169, by Cdk1 promotes its dissociation from centrosomes in mitosis.

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Mori, Yusuke; Inoue, Yoko; Taniyama, Yuki; Tanaka, Sayori; Terada, Yasuhiko

2015-12-25

Cep169 is a centrosomal protein conserved among vertebrates. In our previous reports, we showed that mammalian Cep169 interacts and collaborates with CDK5RAP2 to regulate microtubule (MT) dynamics and stabilization. Although Cep169 is required for MT regulation, its precise cellular function remains largely elusive. Here we show that Cep169 associates with centrosomes during interphase, but dissociates from these structures from the onset of mitosis, although CDK5RAP2 (Cep215) is continuously located at the centrosomes throughout cell cycle. Interestingly, treatment with purvalanol A, a Cdk1 inhibitor, nearly completely blocked the dissociation of Cep169 from centrosomes during mitosis. In addition, mass spectrometry analyses identified 7 phosphorylated residues of Cep169 corresponding to consensus phosphorylation sequence for Cdk1. These data suggest that the dissociation of Cep169 from centrosomes is controlled by Cdk1/Cyclin B during mitosis, and that Cep169 might regulate MT dynamics of mitotic spindle. Copyright © 2015 Elsevier Inc. All rights reserved.
HSPB1 facilitates the formation of non-centrosomal microtubules.

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Leonardo Almeida-Souza

Full Text Available The remodeling capacity of microtubules (MT is essential for their proper function. In mammals, MTs are predominantly formed at the centrosome, but can also originate from non-centrosomal sites, a process that is still poorly understood. We here show that the small heat shock protein HSPB1 plays a role in the control of non-centrosomal MT formation. The HSPB1 expression level regulates the balance between centrosomal and non-centrosomal MTs. The HSPB1 protein can be detected specifically at sites of de novo forming non-centrosomal MTs, while it is absent from the centrosomes. In addition, we show that HSPB1 binds preferentially to the lattice of newly formed MTs in vitro, suggesting that its function occurs by stabilizing MT seeds. Our findings open new avenues for the understanding of the role of HSPB1 in the development, maintenance and protection of cells with specialized non-centrosomal MT arrays.
Communication, the centrosome and the immunological synapse.

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Stinchcombe, Jane C; Griffiths, Gillian M

2014-09-05

Recent findings on the behaviour of the centrosome at the immunological synapse suggest a critical role for centrosome polarization in controlling the communication between immune cells required to generate an effective immune response. The features observed at the immunological synapse show parallels to centrosome (basal body) polarization seen in cilia and flagella, and the cellular communication that is now known to occur at all of these sites.
Structure and non-structure of centrosomal proteins.

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Dos Santos, Helena G; Abia, David; Janowski, Robert; Mortuza, Gulnahar; Bertero, Michela G; Boutin, Maïlys; Guarín, Nayibe; Méndez-Giraldez, Raúl; Nuñez, Alfonso; Pedrero, Juan G; Redondo, Pilar; Sanz, María; Speroni, Silvia; Teichert, Florian; Bruix, Marta; Carazo, José M; Gonzalez, Cayetano; Reina, José; Valpuesta, José M; Vernos, Isabelle; Zabala, Juan C; Montoya, Guillermo; Coll, Miquel; Bastolla, Ugo; Serrano, Luis

2013-01-01

Here we perform a large-scale study of the structural properties and the expression of proteins that constitute the human Centrosome. Centrosomal proteins tend to be larger than generic human proteins (control set), since their genes contain in average more exons (20.3 versus 14.6). They are rich in predicted disordered regions, which cover 57% of their length, compared to 39% in the general human proteome. They also contain several regions that are dually predicted to be disordered and coiled-coil at the same time: 55 proteins (15%) contain disordered and coiled-coil fragments that cover more than 20% of their length. Helices prevail over strands in regions homologous to known structures (47% predicted helical residues against 17% predicted as strands), and even more in the whole centrosomal proteome (52% against 7%), while for control human proteins 34.5% of the residues are predicted as helical and 12.8% are predicted as strands. This difference is mainly due to residues predicted as disordered and helical (30% in centrosomal and 9.4% in control proteins), which may correspond to alpha-helix forming molecular recognition features (α-MoRFs). We performed expression assays for 120 full-length centrosomal proteins and 72 domain constructs that we have predicted to be globular. These full-length proteins are often insoluble: Only 39 out of 120 expressed proteins (32%) and 19 out of 72 domains (26%) were soluble. We built or retrieved structural models for 277 out of 361 human proteins whose centrosomal localization has been experimentally verified. We could not find any suitable structural template with more than 20% sequence identity for 84 centrosomal proteins (23%), for which around 74% of the residues are predicted to be disordered or coiled-coils. The three-dimensional models that we built are available at http://ub.cbm.uam.es/centrosome/models/index.php.
Breaking the ties that bind: new advances in centrosome biology.

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Mardin, Balca R; Schiebel, Elmar

2012-04-02

The centrosome, which consists of two centrioles and the surrounding pericentriolar material, is the primary microtubule-organizing center (MTOC) in animal cells. Like chromosomes, centrosomes duplicate once per cell cycle and defects that lead to abnormalities in the number of centrosomes result in genomic instability, a hallmark of most cancer cells. Increasing evidence suggests that the separation of the two centrioles (disengagement) is required for centrosome duplication. After centriole disengagement, a proteinaceous linker is established that still connects the two centrioles. In G2, this linker is resolved (centrosome separation), thereby allowing the centrosomes to separate and form the poles of the bipolar spindle. Recent work has identified new players that regulate these two processes and revealed unexpected mechanisms controlling the centrosome cycle.
Association of TCTP with Centrosome and Microtubules

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Mariusz K. Jaglarz

2012-01-01

Full Text Available Translationally Controlled Tumour Protein (TCTP associates with microtubules (MT, however, the details of this association are unknown. Here we analyze the relationship of TCTP with MTs and centrosomes in Xenopus laevis and mammalian cells using immunofluorescence, tagged TCTP expression and immunoelectron microscopy. We show that TCTP associates both with MTs and centrosomes at spindle poles when detected by species-specific antibodies and by Myc-XlTCTP expression in Xenopus and mammalian cells. However, when the antibodies against XlTCTP were used in mammalian cells, TCTP was detected exclusively in the centrosomes. These results suggest that a distinct pool of TCTP may be specific for, and associate with, the centrosomes. Double labelling for TCTP and γ-tubulin with immuno-gold electron microscopy in Xenopus laevis oogonia shows localization of TCTP at the periphery of the γ-tubulin-containing pericentriolar material (PCM enveloping the centriole. TCTP localizes in the close vicinity of, but not directly on the MTs in Xenopus ovary suggesting that this association requires unidentified linker proteins. Thus, we show for the first time: (1 the association of TCTP with centrosomes, (2 peripheral localization of TCTP in relation to the centriole and the γ-tubulin-containing PCM within the centrosome, and (3 the indirect association of TCTP with MTs.
Centrosome structure and function is altered by chloral hydrate and diazepam during the first reproductive cell cycles in sea urchin eggs

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Schatten, H.; Chakrabarti, A.

1998-01-01

This paper explores the mode of action of the tranquillizers chloral hydrate and diazepam during fertilization and mitosis of the first reproductive cell cycles in sea urchin eggs. Most striking effects of these drugs are the alteration of centrosomal material and the abnormal microtubule configurations during exposure and after recovery from the drugs. This finding is utilized to study the mechanisms of centrosome compaction and decompaction and the dynamic configurational changes of centrosomal material and its interactions with microtubules. When 0.1% chloral hydrate or 350-750 microM diazepam is applied at specific phases during the first cell cycle of sea urchin eggs, expanded centrosomal material compacts at distinct regions and super-compacts into dense spheres while microtubules disassemble. When eggs are treated before pronuclear fusion, centrosomal material aggregates around each of the two pronuclei while microtubules disappear. Upon recovery, atypical asters oftentimes with multiple foci are formed from centrosomal material surrounding the pronuclei which indicates that the drugs have affected centrosomal material and prevent it from functioning normally. Electron microscopy and immunofluorescence studies with antibodies that routinely stain centrosomes in sea urchin eggs (4D2; and Ah-6) depict centrosomal material that is altered when compared to control cells. This centrosomal material is not able to reform normal microtubule patterns upon recovery but will form multiple asters around the two pronuclei. When cells are treated with 0.1% chloral hydrate or 350-750 microM diazepam during mitosis, the bipolar centrosomal material becomes compacted and aggregates into multiple dense spheres while spindle and polar microtubules disassemble. With increased incubation time, the smaller dense centrosome particles aggregate into bigger and fewer spheres. Upon recovery, unusual irregular microtubule configurations are formed from centrosomes that have lost their
The Centrosome and Its Duplication Cycle

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Fu, Jingyan; Hagan, Iain M.; Glover, David M.

2015-01-01

The centrosome was discovered in the late 19th century when mitosis was first described. Long recognized as a key organelle of the spindle pole, its core component, the centriole, was realized more than 50 or so years later also to comprise the basal body of the cilium. Here, we chart the more recent acquisition of a molecular understanding of centrosome structure and function. The strategies for gaining such knowledge were quickly developed in the yeasts to decipher the structure and function of their distinctive spindle pole bodies. Only within the past decade have studies with model eukaryotes and cultured cells brought a similar degree of sophistication to our understanding of the centrosome duplication cycle and the multiple roles of this organelle and its component parts in cell division and signaling. Now as we begin to understand these functions in the context of development, the way is being opened up for studies of the roles of centrosomes in human disease. PMID:25646378
Increased centrosome amplification in aged stem cells of the Drosophila midgut

International Nuclear Information System (INIS)

Park, Joung-Sun; Pyo, Jung-Hoon; Na, Hyun-Jin; Jeon, Ho-Jun; Kim, Young-Shin; Arking, Robert; Yoo, Mi-Ae

2014-01-01

Highlights: • Increased centrosome amplification in ISCs of aged Drosophila midguts. • Increased centrosome amplification in ISCs of oxidative stressed Drosophila midguts. • Increased centrosome amplification in ISCs by overexpression of PVR, EGFR, and AKT. • Supernumerary centrosomes can be responsible for abnormal ISC polyploid cells. • Supernumerary centrosomes can be a useful marker for aging stem cells. - Abstract: Age-related changes in long-lived tissue-resident stem cells may be tightly linked to aging and age-related diseases such as cancer. Centrosomes play key roles in cell proliferation, differentiation and migration. Supernumerary centrosomes are known to be an early event in tumorigenesis and senescence. However, the age-related changes of centrosome duplication in tissue-resident stem cells in vivo remain unknown. Here, using anti-γ-tubulin and anti-PH3, we analyzed mitotic intestinal stem cells with supernumerary centrosomes in the adult Drosophila midgut, which may be a versatile model system for stem cell biology. The results showed increased centrosome amplification in intestinal stem cells of aged and oxidatively stressed Drosophila midguts. Increased centrosome amplification was detected by overexpression of PVR, EGFR, and AKT in intestinal stem cells/enteroblasts, known to mimic age-related changes including hyperproliferation of intestinal stem cells and hyperplasia in the midgut. Our data show the first direct evidence for the age-related increase of centrosome amplification in intestinal stem cells and suggest that the Drosophila midgut is an excellent model for studying molecular mechanisms underlying centrosome amplification in aging adult stem cells in vivo
Increased centrosome amplification in aged stem cells of the Drosophila midgut

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Park, Joung-Sun; Pyo, Jung-Hoon; Na, Hyun-Jin; Jeon, Ho-Jun; Kim, Young-Shin [Department of Molecular Biology, Pusan National University, Busan 609-735 (Korea, Republic of); Arking, Robert, E-mail: aa2210@wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, MI 48202 (United States); Yoo, Mi-Ae, E-mail: mayoo@pusan.ac.kr [Department of Molecular Biology, Pusan National University, Busan 609-735 (Korea, Republic of)

2014-07-25

Highlights: • Increased centrosome amplification in ISCs of aged Drosophila midguts. • Increased centrosome amplification in ISCs of oxidative stressed Drosophila midguts. • Increased centrosome amplification in ISCs by overexpression of PVR, EGFR, and AKT. • Supernumerary centrosomes can be responsible for abnormal ISC polyploid cells. • Supernumerary centrosomes can be a useful marker for aging stem cells. - Abstract: Age-related changes in long-lived tissue-resident stem cells may be tightly linked to aging and age-related diseases such as cancer. Centrosomes play key roles in cell proliferation, differentiation and migration. Supernumerary centrosomes are known to be an early event in tumorigenesis and senescence. However, the age-related changes of centrosome duplication in tissue-resident stem cells in vivo remain unknown. Here, using anti-γ-tubulin and anti-PH3, we analyzed mitotic intestinal stem cells with supernumerary centrosomes in the adult Drosophila midgut, which may be a versatile model system for stem cell biology. The results showed increased centrosome amplification in intestinal stem cells of aged and oxidatively stressed Drosophila midguts. Increased centrosome amplification was detected by overexpression of PVR, EGFR, and AKT in intestinal stem cells/enteroblasts, known to mimic age-related changes including hyperproliferation of intestinal stem cells and hyperplasia in the midgut. Our data show the first direct evidence for the age-related increase of centrosome amplification in intestinal stem cells and suggest that the Drosophila midgut is an excellent model for studying molecular mechanisms underlying centrosome amplification in aging adult stem cells in vivo.
Identification of a novel centrosomal protein CrpF46 involved in cell cycle progression and mitosis

International Nuclear Information System (INIS)

Wei Yi; Shen Enzhi; Zhao Na; Liu Qian; Fan Jinling; Marc, Jan; Wang Yongchao; Sun Le; Liang Qianjin

2008-01-01

A novel centrosome-related protein Crp F46 was detected using a serum F46 from a patient suffering from progressive systemic sclerosis. We identified the protein by immunoprecipitation and Western blotting followed by tandem mass spectrometry sequencing. The protein Crp F46 has an apparent molecular mass of ∼ 60 kDa, is highly homologous to a 527 amino acid sequence of the C-terminal portion of the protein Golgin-245, and appears to be a splice variant of Golgin-245. Immunofluorescence microscopy of synchronized HeLa cells labeled with an anti-Crp F46 monoclonal antibody revealed that Crp F46 localized exclusively to the centrosome during interphase, although it dispersed throughout the cytoplasm at the onset of mitosis. Domain analysis using Crp F46 fragments in GFP-expression vectors transformed into HeLa cells revealed that centrosomal targeting is conferred by a C-terminal coiled-coil domain. Antisense Crp F46 knockdown inhibited cell growth and proliferation and the cell cycle typically stalled at S phase. The knockdown also resulted in the formation of poly-centrosomal and multinucleate cells, which finally became apoptotic. These results suggest that Crp F46 is a novel centrosome-related protein that associates with the centrosome in a cell cycle-dependent manner and is involved in the progression of the cell cycle and M phase mechanism
Purinergic A2b Receptor Activation by Extracellular Cues Affects Positioning of the Centrosome and Nucleus and Causes Reduced Cell Migration*

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Ou, Young; Chan, Gordon; Zuo, Jeremy; Rattner, Jerome B.; van der Hoorn, Frans A.

2016-01-01

The tight, relative positioning of the nucleus and centrosome in mammalian cells is important for the regulation of cell migration. Under pathophysiological conditions, the purinergic A2b receptor can regulate cell motility, but the underlying mechanism remains unknown. Expression of A2b, normally low, is increased in tissues experiencing adverse physiological conditions, including hypoxia and inflammation. ATP is released from such cells. We investigated whether extracellular cues can regulate centrosome-nucleus positioning and cell migration. We discovered that hypoxia as well as extracellular ATP cause a reversible increase in the distance between the centrosome and nucleus and reduced cell motility. We uncovered the underlying pathway: both treatments act through the A2b receptor and specifically activate the Epac1/RapGef3 pathway. We show that cells lacking A2b do not respond in this manner to hypoxia or ATP but transfection of A2b restores this response, that Epac1 is critically involved, and that Rap1B is important for the relative positioning of the centrosome and nucleus. Our results represent, to our knowledge, the first report demonstrating that pathophysiological conditions can impact the distance between the centrosome and nucleus. Furthermore, we identify the A2b receptor as a central player in this process. PMID:27226580
Myeloproliferative disorder FOP-FGFR1 fusion kinase recruits phosphoinositide-3 kinase and phospholipase Cγ at the centrosome

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Tassin Anne-Marie

2008-04-01

Full Text Available Abstract Background The t(6;8 translocation found in rare and agressive myeloproliferative disorders results in a chimeric gene encoding the FOP-FGFR1 fusion protein. This protein comprises the N-terminal region of the centrosomal protein FOP and the tyrosine kinase of the FGFR1 receptor. FOP-FGFR1 is localized at the centrosome where it exerts a constitutive kinase activity. Results We show that FOP-FGFR1 interacts with the large centrosomal protein CAP350 and that CAP350 is necessary for FOP-FGFR1 localisation at centrosome. FOP-FGFR1 activates the phosphoinositide-3 kinase (PI3K pathway. We show that p85 interacts with tyrosine 475 of FOP-FGFR1, which is located in a YXXM consensus binding sequence for an SH2 domain of p85. This interaction is in part responsible for PI3K activation. Ba/F3 cells that express FOP-FGFR1 mutated at tyrosine 475 have reduced proliferative ability. Treatment with PI3K pathway inhibitors induces death of FOP-FGFR1 expressing cells. FOP-FGFR1 also recruits phospholipase Cγ1 (PLCγ1 at the centrosome. We show that this enzyme is recruited by FOP-FGFR1 at the centrosome during interphase. Conclusion These results delineate a particular type of oncogenic mechanism by which an ectopic kinase recruits its substrates at the centrosome whence unappropriate signaling induces continuous cell growth and MPD.
β-catenin at the centrosome: discrete pools of β-catenin communicate during mitosis and may co-ordinate centrosome functions and cell cycle progression.

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Mbom, Bertrade C; Nelson, W James; Barth, Angela

2013-09-01

Beta-catenin is a multifunctional protein with critical roles in cell-cell adhesion, Wnt-signaling and the centrosome cycle. Whereas the roles of β-catenin in cell-cell adhesion and Wnt-signaling have been studied extensively, the mechanism(s) involving β-catenin in centrosome functions are poorly understood. β-Catenin localizes to centrosomes and promotes mitotic progression. NIMA-related protein kinase 2 (Nek2), which stimulates centrosome separation, binds to and phosphorylates β-catenin. β-Catenin interacting proteins involved in Wnt signaling such as adenomatous polyposis coli, Axin, and GSK3β, are also localized at centrosomes and play roles in promoting mitotic progression. Additionally, proteins associated with cell-cell adhesion sites, such as dynein, regulate mitotic spindle positioning. These roles of proteins at the cell cortex and Wnt signaling that involve β-catenin indicate a cross-talk between different sub-cellular sites in the cell at mitosis, and that different pools of β-catenin may co-ordinate centrosome functions and cell cycle progression. © 2013 WILEY Periodicals, Inc.
Centrosome polarization in T cells: a task for formins

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Laura eAndrés-Delgado

2013-07-01

Full Text Available T-cell antigen receptor (TCR engagement triggers the rapid reorientation of the centrosome, which is associated with the secretory machinery, towards the immunological synapse (IS for polarized protein trafficking. Recent evidence indicates that upon TCR triggering the INF2 formin, together with the formins DIA1 and FMNL1, promotes the formation of a specialized array of stable detyrosinated MTs that breaks the symmetrical organization of the T-cell microtubule (MT cytoskeleton. The detyrosinated MT array and TCR-induced tyrosine phosphorylation should coincide for centrosome polarization. We propose that the pushing forces produced by the detyrosinated MT array, which modify the position of the centrosome, in concert with Src kinase dependent TCR signaling, which provide the reference frame with respect to which the centrosome reorients, result in the repositioning of the centrosome to the IS.
Centrosome Amplification Is Sufficient to Promote Spontaneous Tumorigenesis in Mammals

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Levine, Michelle S.; Bakker, Bjorn; Boeckx, Bram; Moyett, Julia; Lu, James; Vitre, Benjamin; Spierings, Diana C.; Lansdorp, Peter M.; Cleveland, Don W.; Lambrechts, Diether; Foijer, Floris; Holland, Andrew J.

2017-01-01

Centrosome amplification is a common feature of human tumors, but whether this is a cause or a consequence of cancer remains unclear. Here, we test the consequence of centrosome amplification by creating mice in which centrosome number can be chronically increased in the absence of additional
Germ Cell-less Promotes Centrosome Segregation to Induce Germ Cell Formation

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Dorothy A. Lerit

2017-01-01

Full Text Available The primordial germ cells (PGCs specified during embryogenesis serve as progenitors to the adult germline stem cells. In Drosophila, the proper specification and formation of PGCs require both centrosomes and germ plasm, which contains the germline determinants. Centrosomes are microtubule (MT-organizing centers that ensure the faithful segregation of germ plasm into PGCs. To date, mechanisms that modulate centrosome behavior to engineer PGC development have remained elusive. Only one germ plasm component, Germ cell-less (Gcl, is known to play a role in PGC formation. Here, we show that Gcl engineers PGC formation by regulating centrosome dynamics. Loss of gcl leads to aberrant centrosome separation and elaboration of the astral MT network, resulting in inefficient germ plasm segregation and aborted PGC cellularization. Importantly, compromising centrosome separation alone is sufficient to mimic the gcl loss-of-function phenotypes. We conclude Gcl functions as a key regulator of centrosome separation required for proper PGC development.
Centrosome-Based Mechanisms, Prognostics and Therapeutics in Prostate Cancer

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2006-12-01

Roberts, J. M. CDK inhibitors: positive and negative regulators of G1- phase progression. Genes Dev. 13, 1501–1512 (1999). 20. La Terra , S. et al. The...centrosome matura - tion because disruption of the tubulin–pericentrin inter- action disrupts spindle pole assembly and possibly centrosome maturation...monitoring. We favor a model in which the check- point senses spindle pole assembly/centrosome matura - tion because disruption of the tubulin

Centrioles, centrosomes, and cilia in health and disease.

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Nigg, Erich A; Raff, Jordan W

2009-11-13

Centrioles are barrel-shaped structures that are essential for the formation of centrosomes, cilia, and flagella. Here we review recent advances in our understanding of the function and biogenesis of these organelles, and we emphasize their connection to human disease. Deregulation of centrosome numbers has long been proposed to contribute to genome instability and tumor formation, whereas mutations in centrosomal proteins have recently been genetically linked to microcephaly and dwarfism. Finally, structural or functional centriole aberrations contribute to ciliopathies, a variety of complex diseases that stem from the absence or dysfunction of cilia.
Actin and Arp2/3 localize at the centrosome of interphase cells

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Hubert, Thomas; Vandekerckhove, Joel; Gettemans, Jan, E-mail: jan.gettemans@vib-ugent.be

2011-01-07

Research highlights: {yields} Actin was detected at the centrosome with the anti-actin antibody 1C7 that recognizes antiparallel ('lower dimer') actin dimers. {yields} Centrosomal actin was found in interphase but not mitotic MDA-MB-231 cells. {yields} Neither the anti-actin antibody C4 that binds to globular, monomer actin, nor the anti-actin antibody 2G2 that recognizes the nuclear conformation of actin detect actin at the centrosome. {yields} The Arp2/3 complex transiently localizes at the pericentriolar matrix but not at the centrioles of interphase HEK 293T cells. -- Abstract: Although many actin binding proteins such as cortactin and the Arp2/3 activator WASH localize at the centrosome, the presence and conformation of actin at the centrosome has remained elusive. Here, we report the localization of actin at the centrosome in interphase but not in mitotic MDA-MB-231 cells. Centrosomal actin was detected with the anti-actin antibody 1C7 that recognizes antiparallel ('lower dimer') actin dimers. In addition, we report the transient presence of the Arp2/3 complex at the pericentriolar matrix but not at the centrioles of interphase HEK 293T cells. Overexpression of an Arp2/3 component resulted in expansion of the pericentriolar matrix and selective accumulation of the Arp2/3 component in the pericentriolar matrix. Altogether, we hypothesize that the centrosome transiently recruits Arp2/3 to perform processes such as centrosome separation prior to mitotic entry, whereas the observed constitutive centrosomal actin staining in interphase cells reinforces the current model of actin-based centrosome reorientation toward the leading edge in migrating cells.
Actin and Arp2/3 localize at the centrosome of interphase cells

International Nuclear Information System (INIS)

Hubert, Thomas; Vandekerckhove, Joel; Gettemans, Jan

2011-01-01

Research highlights: → Actin was detected at the centrosome with the anti-actin antibody 1C7 that recognizes antiparallel ('lower dimer') actin dimers. → Centrosomal actin was found in interphase but not mitotic MDA-MB-231 cells. → Neither the anti-actin antibody C4 that binds to globular, monomer actin, nor the anti-actin antibody 2G2 that recognizes the nuclear conformation of actin detect actin at the centrosome. → The Arp2/3 complex transiently localizes at the pericentriolar matrix but not at the centrioles of interphase HEK 293T cells. -- Abstract: Although many actin binding proteins such as cortactin and the Arp2/3 activator WASH localize at the centrosome, the presence and conformation of actin at the centrosome has remained elusive. Here, we report the localization of actin at the centrosome in interphase but not in mitotic MDA-MB-231 cells. Centrosomal actin was detected with the anti-actin antibody 1C7 that recognizes antiparallel ('lower dimer') actin dimers. In addition, we report the transient presence of the Arp2/3 complex at the pericentriolar matrix but not at the centrioles of interphase HEK 293T cells. Overexpression of an Arp2/3 component resulted in expansion of the pericentriolar matrix and selective accumulation of the Arp2/3 component in the pericentriolar matrix. Altogether, we hypothesize that the centrosome transiently recruits Arp2/3 to perform processes such as centrosome separation prior to mitotic entry, whereas the observed constitutive centrosomal actin staining in interphase cells reinforces the current model of actin-based centrosome reorientation toward the leading edge in migrating cells.
Localization of MLH3 at the Centrosomes

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Lennart M. Roesner

2014-08-01

Full Text Available Mutations in human DNA mismatch repair (MMR genes are commonly associated with hereditary nonpolyposis colorectal cancer (HNPCC. MLH1 protein heterodimerizes with PMS2, PMS1, and MLH3 to form MutLα, MutLβ, and MutLγ, respectively. We reported recently stable expression of GFP-linked MLH3 in human cell lines. Monitoring these cell lines during the cell cycle using live cell imaging combined with confocal microscopy, we detected accumulation of MLH3 at the centrosomes. Fluorescence recovery after photobleaching (FRAP revealed high mobility and fast exchange rates at the centrosomes as it has been reported for other DNA repair proteins. MLH3 may have a role in combination with other repair proteins in the control of centrosome numbers.
Coiled-Coil Proteins Facilitated the Functional Expansion of the Centrosome

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Kuhn, Michael; Hyman, Anthony A.; Beyer, Andreas

2014-01-01

Repurposing existing proteins for new cellular functions is recognized as a main mechanism of evolutionary innovation, but its role in organelle evolution is unclear. Here, we explore the mechanisms that led to the evolution of the centrosome, an ancestral eukaryotic organelle that expanded its functional repertoire through the course of evolution. We developed a refined sequence alignment technique that is more sensitive to coiled coil proteins, which are abundant in the centrosome. For proteins with high coiled-coil content, our algorithm identified 17% more reciprocal best hits than BLAST. Analyzing 108 eukaryotic genomes, we traced the evolutionary history of centrosome proteins. In order to assess how these proteins formed the centrosome and adopted new functions, we computationally emulated evolution by iteratively removing the most recently evolved proteins from the centrosomal protein interaction network. Coiled-coil proteins that first appeared in the animal–fungi ancestor act as scaffolds and recruit ancestral eukaryotic proteins such as kinases and phosphatases to the centrosome. This process created a signaling hub that is crucial for multicellular development. Our results demonstrate how ancient proteins can be co-opted to different cellular localizations, thereby becoming involved in novel functions. PMID:24901223
Dynein Transmits Polarized Actomyosin Cortical Flows to Promote Centrosome Separation

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Alessandro De Simone

2016-03-01

Full Text Available The two centrosomes present at the onset of mitosis must separate in a timely and accurate fashion to ensure proper bipolar spindle assembly. The minus-end-directed motor dynein plays a pivotal role in centrosome separation, but the underlying mechanisms remain elusive, particularly regarding how dynein coordinates this process in space and time. We addressed these questions in the one-cell C. elegans embryo, using a combination of 3D time-lapse microscopy and computational modeling. Our analysis reveals that centrosome separation is powered by the joint action of dynein at the nuclear envelope and at the cell cortex. Strikingly, we demonstrate that dynein at the cell cortex acts as a force-transmitting device that harnesses polarized actomyosin cortical flows initiated by the centrosomes earlier in the cell cycle. This mechanism elegantly couples cell polarization with centrosome separation, thus ensuring faithful cell division.
Novel microcephalic primordial dwarfism disorder associated with variants in the centrosomal protein ninein.

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Dauber, Andrew; Lafranchi, Stephen H; Maliga, Zoltan; Lui, Julian C; Moon, Jennifer E; McDeed, Cailin; Henke, Katrin; Zonana, Jonathan; Kingman, Garrett A; Pers, Tune H; Baron, Jeffrey; Rosenfeld, Ron G; Hirschhorn, Joel N; Harris, Matthew P; Hwa, Vivian

2012-11-01

Microcephalic primordial dwarfism (MPD) is a rare, severe form of human growth failure in which growth restriction is evident in utero and continues into postnatal life. Single causative gene defects have been identified in a number of patients with MPD, and all involve genes fundamental to cellular processes including centrosome functions. The objective of the study was to find the genetic etiology of a novel presentation of MPD. The design of the study was whole-exome sequencing performed on two affected sisters in a single family. Molecular and functional studies of a candidate gene were performed using patient-derived primary fibroblasts and a zebrafish morpholino oligonucleotides knockdown model. Two sisters presented with a novel subtype of MPD, including severe intellectual disabilities. NIN, encoding Ninein, a centrosomal protein critically involved in asymmetric cell division, was identified as a candidate gene, and functional impacts in fibroblasts and zebrafish were studied. From 34,606 genomic variants, two very rare missense variants in NIN were identified. Both probands were compound heterozygotes. In the zebrafish, ninein knockdown led to specific and novel defects in the specification and morphogenesis of the anterior neuroectoderm, resulting in a deformity of the developing cranium with a small, squared skull highly reminiscent of the human phenotype. We identified a novel clinical subtype of MPD in two sisters who have rare variants in NIN. We show, for the first time, that reduction of ninein function in the developing zebrafish leads to specific deficiencies of brain and skull development, offering a developmental basis for the myriad phenotypes in our patients.
Conserved molecular interactions in centriole-to-centrosome conversion.

Science.gov (United States)

Fu, Jingyan; Lipinszki, Zoltan; Rangone, Hélène; Min, Mingwei; Mykura, Charlotte; Chao-Chu, Jennifer; Schneider, Sandra; Dzhindzhev, Nikola S; Gottardo, Marco; Riparbelli, Maria Giovanna; Callaini, Giuliano; Glover, David M

2016-01-01

Centrioles are required to assemble centrosomes for cell division and cilia for motility and signalling. New centrioles assemble perpendicularly to pre-existing ones in G1-S and elongate throughout S and G2. Fully elongated daughter centrioles are converted into centrosomes during mitosis to be able to duplicate and organize pericentriolar material in the next cell cycle. Here we show that centriole-to-centrosome conversion requires sequential loading of Cep135, Ana1 (Cep295) and Asterless (Cep152) onto daughter centrioles during mitotic progression in both Drosophila melanogaster and human. This generates a molecular network spanning from the inner- to outermost parts of the centriole. Ana1 forms a molecular strut within the network, and its essential role can be substituted by an engineered fragment providing an alternative linkage between Asterless and Cep135. This conserved architectural framework is essential for loading Asterless or Cep152, the partner of the master regulator of centriole duplication, Plk4. Our study thus uncovers the molecular basis for centriole-to-centrosome conversion that renders daughter centrioles competent for motherhood.
Centrosome isolation and analysis by mass spectrometry-based proteomics

DEFF Research Database (Denmark)

Jakobsen, Lis; Schrøder, Jacob Morville; Larsen, Katja M

2013-01-01

Centrioles are microtubule-based scaffolds that are essential for the formation of centrosomes, cilia, and flagella with important functions throughout the cell cycle, in physiology and during development. The ability to purify centriole-containing organelles on a large scale, combined with advan...... to isolate centrosomes from human cells and strategies to selectively identify and study the properties of the associated proteins using quantitative mass spectrometry-based proteomics.......Centrioles are microtubule-based scaffolds that are essential for the formation of centrosomes, cilia, and flagella with important functions throughout the cell cycle, in physiology and during development. The ability to purify centriole-containing organelles on a large scale, combined...... with advances in protein identification using mass spectrometry-based proteomics, have revealed multiple centriole-associated proteins that are conserved during evolution in eukaryotes. Despite these advances, the molecular basis for the plethora of processes coordinated by cilia and centrosomes is not fully...
Single-cell analysis of ploidy and centrosomes underscores the peculiarity of normal hepatocytes.

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Francesca Faggioli

Full Text Available Polyploidization is the most well recognized feature of the liver. Yet, a quantitative and behavioral analysis of centrosomes and DNA content in normal hepatocytes has been limited by the technical challenges of methods available. By using a novel approach employing FISH for chromosomes 18, X and Y we provide, for the first time, a detailed analysis of DNA copies during physiological development in the liver at single cell level. We demonstrate that aneuploidy and unbalanced DNA content in binucleated hepatocytes are common features in normal adult liver. Despite the common belief that hepatocytes contain 1, 2 or no more than 4 centrosomes, our double staining for centrosome associated proteins reveals extranumerary centrosomes in a high percentage of cells as early as 15 days of age. We show that in murine liver the period between 15 days and 1.5 months marks the transition from a prevalence of mononucleated cells to up to 75% of binucleated cells. Our data demonstrate that this timing correlates with a switch in centrosomes number. At 15 days the expected 1 or 2 centrosomes converge with several hepatocytes that contain 3 centrosomes; at 1.5 months the percentage of cells with 3 centrosomes decreases concomitantly with the increase of cells with more than 4 centrosomes. Our analysis shows that the extranumerary centrosomes emerge in concomitance with the process of binucleation and polyploidization and maintain α-tubulin nucleation activity. Finally, by integrating interphase FISH and immunofluorescent approaches, we detected an imbalance between centrosome number and DNA content in liver cells that deviates from the equilibrium expected in normal cells. We speculate that these unique features are relevant to the peculiar biological function of liver cells which are continuously challenged by stress, a condition that could predispose to genomic instability.
The Centrioles, Centrosomes, Basal Bodies, and Cilia of Drosophila melanogaster.

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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.
Centrosome proteins form an insoluble perinuclear matrix during muscle cell differentiation

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Srsen Vlastimil

2009-04-01

Full Text Available Abstract Background Muscle fibres are formed by elongation and fusion of myoblasts into myotubes. During this differentiation process, the cytoskeleton is reorganized, and proteins of the centrosome re-localize to the surface of the nucleus. The exact timing of this event, and the underlying molecular mechanisms are still poorly understood. Results We performed studies on mouse myoblast cell lines that were induced to differentiate in culture, to characterize the early events of centrosome protein re-localization. We demonstrate that this re-localization occurs already at the single cell stage, prior to fusion into myotubes. Centrosome proteins that accumulate at the nuclear surface form an insoluble matrix that can be reversibly disassembled if isolated nuclei are exposed to mitotic cytoplasm from Xenopus egg extract. Our microscopy data suggest that this perinuclear matrix of centrosome proteins consists of a system of interconnected fibrils. Conclusion Our data provide new insights into the reorganization of centrosome proteins during muscular differentiation, at the structural and biochemical level. Because we observe that centrosome protein re-localization occurs early during differentiation, we believe that it is of functional importance for the reorganization of the cytoskeleton in the differentiation process.
Microtubules are organized independently of the centrosome in Drosophila neurons

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Nguyen Michelle M

2011-12-01

Full Text Available Abstract Background The best-studied arrangement of microtubules is that organized by the centrosome, a cloud of microtubule nucleating and anchoring proteins is clustered around centrioles. However, noncentrosomal microtubule arrays are common in many differentiated cells, including neurons. Although microtubules are not anchored at neuronal centrosomes, it remains unclear whether the centrosome plays a role in organizing neuronal microtubules. We use Drosophila as a model system to determine whether centrosomal microtubule nucleation is important in mature neurons. Results In developing and mature neurons, centrioles were not surrounded by the core nucleation protein γ-tubulin. This suggests that the centrioles do not organize functional centrosomes in Drosophila neurons in vivo. Consistent with this idea, centriole position was not correlated with a specific region of the cell body in neurons, and growing microtubules did not cluster around the centriole, even after axon severing when the number of growing plus ends is dramatically increased. To determine whether the centrosome was required for microtubule organization in mature neurons, we used two approaches. First, we used DSas-4 centriole duplication mutants. In these mutants, centrioles were present in many larval sensory neurons, but they were not fully functional. Despite reduced centriole function, microtubule orientation was normal in axons and dendrites. Second, we used laser ablation to eliminate the centriole, and again found that microtubule polarity in axons and dendrites was normal, even 3 days after treatment. Conclusion We conclude that the centrosome is not a major site of microtubule nucleation in Drosophila neurons, and is not required for maintenance of neuronal microtubule organization in these cells.
Proteomic characterization of the human centrosome by protein correlation profiling

DEFF Research Database (Denmark)

Andersen, Jens S; Wilkinson, Christopher J; Mayor, Thibault

2003-01-01

chromosomes between dividing cells. Despite the importance of this organelle to cell biology and more than 100 years of study, many aspects of its function remain enigmatic and its structure and composition are still largely unknown. We performed a mass-spectrometry-based proteomic analysis of human...... centrosomes in the interphase of the cell cycle by quantitatively profiling hundreds of proteins across several centrifugation fractions. True centrosomal proteins were revealed by both correlation with already known centrosomal proteins and in vivo localization. We identified and validated 23 novel...... components and identified 41 likely candidates as well as the vast majority of the known centrosomal proteins in a large background of nonspecific proteins. Protein correlation profiling permits the analysis of any multiprotein complex that can be enriched by fractionation but not purified to homogeneity....
Behavior of centrosomes during fertilization and cell division in mouse oocytes and in sea urchin eggs

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Schatten, Heide; Schatten, Gerald; Balczon, Ron; Simerly, Calvin; Mazia, Daniel

1986-01-01

The behavior of centrosomes during the stages of fertilization and cell division in mouse oocytes and in sea urchin eggs was monitored in an immunofluorescence microscope, using autoimmune centrosomal antiserum derived from a patient with scleroderma to label the centrosomal material. These observations showed that centrosomes reproduce during the interphase and aggregate and separate during cell mitosis. Results supported the hypothesis of Mazia (1984), who proposed that centrosomes are 'flexible bodies'. It was also found that, while the sea urchin centrosomes are paternally inherited as was initially proposed by Bovery (1904), the mouse centrosomes are of maternal origin.
Drosophila Ana1 is required for centrosome assembly and centriole elongation.

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Saurya, Saroj; Roque, Hélio; Novak, Zsofia A; Wainman, Alan; Aydogan, Mustafa G; Volanakis, Adam; Sieber, Boris; Pinto, David Miguel Susano; Raff, Jordan W

2016-07-01

Centrioles organise centrosomes and cilia, and these organelles have an important role in many cell processes. In flies, the centriole protein Ana1 is required for the assembly of functional centrosomes and cilia. It has recently been shown that Cep135 (also known as Bld10) initially recruits Ana1 to newly formed centrioles, and that Ana1 then recruits Asl (known as Cep152 in mammals) to promote the conversion of these centrioles into centrosomes. Here, we show that ana1 mutants lack detectable centrosomes in vivo, that Ana1 is irreversibly incorporated into centrioles during their assembly and appears to play a more important role in maintaining Asl at centrioles than in initially recruiting Asl to centrioles. Unexpectedly, we also find that Ana1 promotes centriole elongation in a dose-dependent manner: centrioles are shorter when Ana1 dosage is reduced and are longer when Ana1 is overexpressed. This latter function of Ana1 appears to be distinct from its role in centrosome and cilium function, as a GFP-Ana1 fusion lacking the N-terminal 639 amino acids of the protein can support centrosome assembly and cilium function but cannot promote centriole over-elongation when overexpressed. © 2016. Published by The Company of Biologists Ltd.
Centrosome/Cell cycle uncoupling and elimination in the endoreduplicating intestinal cells of C. elegans.

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Yu Lu

Full Text Available The centrosome cycle is most often coordinated with mitotic cell division through the activity of various essential cell cycle regulators, consequently ensuring that the centriole is duplicated once, and only once, per cell cycle. However, this coupling can be altered in specific developmental contexts; for example, multi-ciliated cells generate hundreds of centrioles without any S-phase requirement for their biogenesis, while Drosophila follicle cells eliminate their centrosomes as they begin to endoreduplicate. In order to better understand how the centrosome cycle and the cell cycle are coordinated in a developmental context we use the endoreduplicating intestinal cell lineage of C. elegans to address how novel variations of the cell cycle impact this important process. In C. elegans, the larval intestinal cells undergo one nuclear division without subsequent cytokinesis, followed by four endocycles that are characterized by successive rounds of S-phase. We monitored the levels of centriolar/centrosomal markers and found that centrosomes lose their pericentriolar material following the nuclear division that occurs during the L1 stage and is thereafter never re-gained. The centrioles then become refractory to S phase regulators that would normally promote duplication during the first endocycle, after which they are eliminated during the L2 stage. Furthermore, we show that SPD-2 plays a central role in the numeral regulation of centrioles as a potential target of CDK activity. On the other hand, the phosphorylation on SPD-2 by Polo-like kinase, the transcriptional regulation of genes that affect centriole biogenesis, and the ubiquitin/proteasome degradation pathway, contribute collectively to the final elimination of the centrioles during the L2 stage.
A genome-wide RNAi screen to dissect centriole duplication and centrosome maturation in Drosophila.

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Jeroen Dobbelaere

2008-09-01

Full Text Available Centrosomes comprise a pair of centrioles surrounded by an amorphous pericentriolar material (PCM. Here, we have performed a microscopy-based genome-wide RNA interference (RNAi screen in Drosophila cells to identify proteins required for centriole duplication and mitotic PCM recruitment. We analysed 92% of the Drosophila genome (13,059 genes and identified 32 genes involved in centrosome function. An extensive series of secondary screens classified these genes into four categories: (1 nine are required for centriole duplication, (2 11 are required for centrosome maturation, (3 nine are required for both functions, and (4 three genes regulate centrosome separation. These 32 hits include several new centrosomal components, some of which have human homologs. In addition, we find that the individual depletion of only two proteins, Polo and Centrosomin (Cnn can completely block centrosome maturation. Cnn is phosphorylated during mitosis in a Polo-dependent manner, suggesting that the Polo-dependent phosphorylation of Cnn initiates centrosome maturation in flies.
Synthesis and Structure-Activity Relationship of Griseofulvin Analogues as Inhibitors of Centrosomal Clustering in Cancer Cells

DEFF Research Database (Denmark)

Rønnest, Mads Holger; Rebacz, Blanka; Markworth, Lene

2009-01-01

Griseofulvin was identified as an inhibitor of centrosomal clustering in a recently developed assay. Centrosomal clustering is an important cellular event that enables bipolar mitosis for cancer cell lines harboring supernumerary centrosomes. We report herein the synthesis and SAR of 34 griseoful......Griseofulvin was identified as an inhibitor of centrosomal clustering in a recently developed assay. Centrosomal clustering is an important cellular event that enables bipolar mitosis for cancer cell lines harboring supernumerary centrosomes. We report herein the synthesis and SAR of 34...
Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

International Nuclear Information System (INIS)

Arachchige Don, Aruni S.; Dallapiazza, Robert F.; Bennin, David A.; Brake, Tiffany; Cowan, Colleen E.; Horne, Mary C.

2006-01-01

Cyclin G2 is an atypical cyclin that associates with active protein phosphatase 2A. Cyclin G2 gene expression correlates with cell cycle inhibition; it is significantly upregulated in response to DNA damage and diverse growth inhibitory stimuli, but repressed by mitogenic signals. Ectopic expression of cyclin G2 promotes cell cycle arrest, cyclin dependent kinase 2 inhibition and the formation of aberrant nuclei [Bennin, D. A., Don, A. S., Brake, T., McKenzie, J. L., Rosenbaum, H., Ortiz, L., DePaoli-Roach, A. A., and Horne, M. C. (2002). Cyclin G2 associates with protein phosphatase 2A catalytic and regulatory B' subunits in active complexes and induces nuclear aberrations and a G 1 /S-phase cell cycle arrest. J Biol Chem 277, 27449-67]. Here we report that endogenous cyclin G2 copurifies with centrosomes and microtubules (MT) and that ectopic G2 expression alters microtubule stability. We find exogenous and endogenous cyclin G2 present at microtubule organizing centers (MTOCs) where it colocalizes with centrosomal markers in a variety of cell lines. We previously reported that cyclin G2 forms complexes with active protein phosphatase 2A (PP2A) and colocalizes with PP2A in a detergent-resistant compartment. We now show that cyclin G2 and PP2A colocalize at MTOCs in transfected cells and that the endogenous proteins copurify with isolated centrosomes. Displacement of the endogenous centrosomal scaffolding protein AKAP450 that anchors PP2A at the centrosome resulted in the depletion of centrosomal cyclin G2. We find that ectopic expression of cyclin G2 induces microtubule bundling and resistance to depolymerization, inhibition of polymer regrowth from MTOCs and a p53-dependent cell cycle arrest. Furthermore, we determined that a 100 amino acid carboxy-terminal region of cyclin G2 is sufficient to both direct GFP localization to centrosomes and induce cell cycle inhibition. Colocalization of endogenous cyclin G2 with only one of two GFP-centrin-tagged centrioles, the

GABARAP activates ULK1 and traffics from the centrosome dependent on Golgi partners WAC and GOLGA2/GM130

OpenAIRE

Joachim, Justin; Tooze, Sharon A.

2016-01-01

ABSTRACT WAC and GOLGA2/GM130 are 2 Golgi proteins that affect autophagy; however, their mechanism of action was unknown. We have shown that WAC binding to GOLGA2 at the Golgi displaces GABARAP from GOLGA2 to allow the maintenance of a nonlipidated centrosomal GABARAP pool. Centrosomal GABARAP can traffic to autophagic structures during starvation. In addition GABARAP specifically promotes ULK1 activation and this is independent of GABARAP lipidation but likely requires a LIR-mediated GABARAP...
GABARAP activates ULK1 and traffics from the centrosome dependent on Golgi partners WAC and GOLGA2/GM130.

Science.gov (United States)

Joachim, Justin; Tooze, Sharon A

2016-05-03

WAC and GOLGA2/GM130 are 2 Golgi proteins that affect autophagy; however, their mechanism of action was unknown. We have shown that WAC binding to GOLGA2 at the Golgi displaces GABARAP from GOLGA2 to allow the maintenance of a nonlipidated centrosomal GABARAP pool. Centrosomal GABARAP can traffic to autophagic structures during starvation. In addition GABARAP specifically promotes ULK1 activation and this is independent of GABARAP lipidation but likely requires a LIR-mediated GABARAP-ULK1 interaction.
Centrioles regulate centrosome size by controlling the rate of Cnn incorporation into the PCM.

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Conduit, Paul T; Brunk, Kathrin; Dobbelaere, Jeroen; Dix, Carly I; Lucas, Eliana P; Raff, Jordan W

2010-12-21

centrosomes are major microtubule organizing centers in animal cells, and they comprise a pair of centrioles surrounded by an amorphous pericentriolar material (PCM). Centrosome size is tightly regulated during the cell cycle, and it has recently been shown that the two centrosomes in certain stem cells are often asymmetric in size. There is compelling evidence that centrioles influence centrosome size, but how centrosome size is set remains mysterious. we show that the conserved Drosophila PCM protein Cnn exhibits an unusual dynamic behavior, because Cnn molecules only incorporate into the PCM closest to the centrioles and then spread outward through the rest of the PCM. Cnn incorporation into the PCM is driven by an interaction with the conserved centriolar proteins Asl (Cep152 in humans) and DSpd-2 (Cep192 in humans). The rate of Cnn incorporation into the PCM is tightly regulated during the cell cycle, and this rate influences the amount of Cnn in the PCM, which in turn is an important determinant of overall centrosome size. Intriguingly, daughter centrioles in syncytial embryos only start to incorporate Cnn as they disengage from their mothers; this generates a centrosome size asymmetry, with mother centrioles always initially organizing more Cnn than their daughters. centrioles can control the amount of PCM they organize by regulating the rate of Cnn incorporation into the PCM. This mechanism can explain how centrosome size is regulated during the cell cycle and also allows mother and daughter centrioles to set centrosome size independently of one another.
Metformin inhibits age-related centrosome amplification in Drosophila midgut stem cells through AKT/TOR pathway.

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Na, Hyun-Jin; Park, Joung-Sun; Pyo, Jung-Hoon; Jeon, Ho-Jun; Kim, Young-Shin; Arking, Robert; Yoo, Mi-Ae

2015-07-01

We delineated the mechanism regulating the inhibition of centrosome amplification by metformin in Drosophila intestinal stem cells (ISCs). Age-related changes in tissue-resident stem cells may be closely associated with tissue aging and age-related diseases, such as cancer. Centrosome amplification is a hallmark of cancers. Our recent work showed that Drosophila ISCs are an excellent model for stem cell studies evaluating age-related increase in centrosome amplification. Here, we showed that metformin, a recognized anti-cancer drug, inhibits age- and oxidative stress-induced centrosome amplification in ISCs. Furthermore, we revealed that this effect is mediated via down-regulation of AKT/target of rapamycin (TOR) activity, suggesting that metformin prevents centrosome amplification by inhibiting the TOR signaling pathway. Additionally, AKT/TOR signaling hyperactivation and metformin treatment indicated a strong correlation between DNA damage accumulation and centrosome amplification in ISCs, suggesting that DNA damage might mediate centrosome amplification. Our study reveals the beneficial and protective effects of metformin on centrosome amplification via AKT/TOR signaling modulation. We identified a new target for the inhibition of age- and oxidative stress-induced centrosome amplification. We propose that the Drosophila ISCs may be an excellent model system for in vivo studies evaluating the effects of anti-cancer drugs on tissue-resident stem cell aging. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
FancJ regulates interstrand crosslinker induced centrosome amplification through the activation of polo-like kinase 1

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Jianqiu Zou

2013-08-01

DNA damage response (DDR and the centrosome cycle are two of the most critical processes for maintaining a stable genome in animals. Sporadic evidence suggests a connection between these two processes. Here, we report our findings that six Fanconi Anemia (FA proteins, including FancI and FancJ, localize to the centrosome. Intriguingly, we found that the localization of FancJ to the mother centrosome is stimulated by a DNA interstrand crosslinker, Mitomycin C (MMC. We further show that, in addition to its role in interstrand crosslinking (ICL repair, FancJ also regulates the normal centrosome cycle as well as ICL induced centrosome amplification by activating the polo-like kinase 1 (PLK1. We have uncovered a novel function of FancJ in centrosome biogenesis and established centrosome amplification as an integral part of the ICL response.
Arsenic promotes centrosome abnormalities and cell colony formation in p53 compromised human lung cells

International Nuclear Information System (INIS)

Liao Weiting; Lin Pinpin; Cheng, T.-S.; Yu, H.-S.; Chang, Louis W.

2007-01-01

Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus, an interaction between arsenic and cigarette smoking in lung carcinogenesis was suspected. p53 dysfunction or mutation in lung epithelial cells was frequently observed in cigarette smokers. Our present study was to explore the differential effects by arsenic on H1355 cells (human lung adenocarcinoma cell line with mutation in p53), BEAS-2B (immortalized lung epithelial cell with functional p53) and pifithrin-α-treated BEAS-2B cells (p53-inhibited cells). These cells were treated with different doses of sodium arsenite (0, 0.1, 1, 5 and 10 μM) for 48 h. A greater reduction in cell viability was observed in the BEAS-2B cells vs. p53 compromised cells (H1355 or p53-inhibited BEAS-2B). Similar observation was also made on 7-day cell survival (growth) study. TUNEL analysis confirmed that there was indeed a significantly reduced arsenite-induced apoptosis found in p53-compromised cells. Centrosomal abnormality has been attributed to eventual chromosomal missegregation, aneuploidy and tumorigenesis. In our present study, reduced p21 and Gadd45a expressions and increased centrosomal abnormality (atopic and multiple centrosomes) were observed in both arsenite-treated H1355 and p53-inhibited BEAS-2B cells as compared with similarly treated BEAS-2B cells. Increased anchorage-independent growth (colony formation) of BEAS-2B cells co-treated with pifithrin-α and 5 μM sodium arsenite was also observed in soft agar. Our present investigation demonstrated that arsenic would act specifically on p53 compromised cells (either with p53 dysfunction or inhibited) to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenic, especially under the condition of p53 dysfunction
CENTROSOMES AND MICROTUBULES DURING MEIOSIS IN THE MUSHROOM BOLETUS RUBINELLUS

Science.gov (United States)

McLaughlin, David J.

1971-01-01

The double centrosome in the basidium of Boletus rubinellus has been observed in three planes with the electron microscope at interphase preceding nuclear fusion, at prophase I, and at interphase I. It is composed of two components connected by a band-shaped middle part. At anaphase I a single, enlarged centrosome is found at the spindle pole, which is attached to the cell membrane. Microtubules mainly oriented parallel to the longitudinal axis of the basidium are present at prefusion, prophase I and interphase I. Cytoplasmic microtubules are absent when the spindle is present. The relationship of the centrosome in B. rubinellus to that in other organisms and the role of the cytoplasmic microtubules are discussed. PMID:4329156
Centrosomes split in the presence of impaired DNA integrity during mitosis

NARCIS (Netherlands)

Hut, HMJ; Lemstra, W; Blaauw, EH; van Cappellen, GWA; Kampinga, HH; Sibon, OCM

A well-established function of centrosomes is their role in accomplishing a successful mitosis that gives rise to a pair of identical daughter cells. We recently showed that DNA replication defects and DNA damage in Drosophila embryos trigger centrosomal changes, but it remained unclear whether
Centrosome and microtubule instability in aging Drosophila cells

Science.gov (United States)

Schatten, H.; Chakrabarti, A.; Hedrick, J.

1999-01-01

Several cytoskeletal changes are associated with aging which includes alterations in muscle structure leading to muscular atrophy, and weakening of the microtubule network which affects cellular secretion and maintenance of cell shape. Weakening of the microtubule network during meiosis in aging oocytes can result in aneuploidy or trisomic zygotes with increasing maternal age. Imbalances of cytoskeletal organization can lead to disease such as Alzheimer's, muscular disorders, and cancer. Because many cytoskeletal diseases are related to age we investigated the effects of aging on microtubule organization in cell cultures of the Drosophila cell model system (Schneider S-1 and Kc23 cell lines). This cell model is increasingly being used as an alternative system to mammalian cell cultures. Drosophila cells are amenable to genetic manipulations and can be used to identify and manipulate genes which are involved in the aging processes. Immunofluorescence, scanning, and transmission electron microscopy were employed for the analysis of microtubule organizing centers (centrosomes) and microtubules at various times after subculturing cells in fresh medium. Our results reveal that centrosomes and the microtubule network becomes significantly affected in aging cells after 5 days of subculture. At 5-14 days of subculture, 1% abnormal out of 3% mitoses were noted which were clearly distinguishable from freshly subcultured control cells in which 3% of cells undergo normal mitosis with bipolar configurations. Microtubules are also affected in the midbody during cell division. The midbody in aging cells becomes up to 10 times longer when compared with midbodies in freshly subcultured cells. During interphase, microtubules are often disrupted and disorganized, which may indicate improper function related to transport of cell organelles along microtubules. These results are likely to help explain some cytoskeletal disorders and diseases related to aging.
Drosophila parthenogenesis: A tool to decipher centrosomal vs acentrosomal spindle assembly pathways

International Nuclear Information System (INIS)

Riparbelli, Maria Giovanna; Callaini, Giuliano

2008-01-01

Development of unfertilized eggs in the parthenogenetic strain K23-O-im of Drosophila mercatorum requires the stochastic interactions of self-assembled centrosomes with the female chromatin. In a portion of the unfertilized eggs that do not assemble centrosomes, microtubules organize a bipolar anastral mitotic spindle around the chromatin like the one formed during the first female meiosis, suggesting that similar pathways may be operative. In the cytoplasm of eggs in which centrosomes do form, monastral and biastral spindles are found. Analysis by laser scanning confocal microscopy suggests that these spindles are derived from the stochastic interaction of astral microtubules directly with kinetochore regions or indirectly with kinetochore microtubules. Our findings are consistent with the idea that mitotic spindle assembly requires both acentrosomal and centrosomal pathways, strengthening the hypothesis that astral microtubules can dictate the organization of the spindle by capturing kinetochore microtubules
Function of donor cell centrosome in intraspecies and interspecies nuclear transfer embryos

International Nuclear Information System (INIS)

Zhong Zhisheng; Zhang Gang; Meng Xiaoqian; Zhang Yanling; Chen Dayuan; Schatten, Heide; Sun Qingyuan

2005-01-01

Centrosomes, the main microtubule-organizing centers (MTOCs) in most animal cells, are important for many cellular activities such as assembly of the mitotic spindle, establishment of cell polarity, and cell movement. In nuclear transfer (NT), MTOCs that are located at the poles of the meiotic spindle are removed from the recipient oocyte, while the centrosome of the donor cell is introduced. We used mouse MII oocytes as recipients, mouse fibroblasts, rat fibroblasts, or pig granulosa cells as donor cells to construct intraspecies and interspecies nuclear transfer embryos in order to observe centrosome dynamics and functions. Three antibodies against centrin, γ-tubulin, and NuMA, respectively, were used to stain the centrosome. Centrin was not detected either at the poles of transient spindles or at the poles of first mitotic spindles. γ-tubulin translocated into the two poles of the transient spindles, while no accumulated γ-tubulin aggregates were detected in the area adjacent to the two pseudo-pronuclei. At first mitotic metaphase, γ-tubulin was translocated to the spindle poles. The distribution of γ-tubulin was similar in mouse intraspecies and rat-mouse interspecies embryos. The NuMA antibody that we used can recognize porcine but not murine NuMA protein, so it was used to trace the NuMA protein of donor cell in reconstructed embryos. In the pig-mouse interspecies reconstructed embryos, NuMA concentrated between the disarrayed chromosomes soon after activation and translocated to the transient spindle poles. NuMA then immigrated into pseudo-pronuclei. After pseudo-pronuclear envelope breakdown, NuMA was located between the chromosomes and then translocated to the spindle poles of first mitotic metaphase. γ-tubulin antibody microinjection resulted in spindle disorganization and retardation of the first cell division. NuMA antibody microinjection also resulted in spindle disorganization. Our findings indicate that (1) the donor cell centrosome, defined as
Centrosomal protein 55 activates NF-?B signalling and promotes pancreatic cancer cells aggressiveness

OpenAIRE

Peng, Tao; Zhou, Wei; Guo, Feng; Wu, He-shui; Wang, Chun-you; Wang, Li; Yang, Zhi-yong

2017-01-01

Centrosomal protein 55 (CEP55) is a microtubule-bundling protein that participants in cell mitosis. It is overexpressed in several solid tumours and promotes the growth and invasion of cancer cells. However, the role of CEP55 in pancreatic cancer (PANC) remains unclear. Herein, upregulated expression of CEP55 (associated with poor prognosis) was detected in PANC using quantitative real-time reverse transcription PCR, western blotting, and immunohistochemistry. Cell migration, colony formation...
Arsenite promotes centrosome abnormalities under a p53 compromised status induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

International Nuclear Information System (INIS)

Liao, W.-T.; Yu, H.-S.; Lin Pinpin; Chang, Louis W.

2010-01-01

Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus an interaction between arsenite and cigarette smoking in lung carcinogenesis was suspected. In the present study, we investigated the interactions of a tobacco-specific carcinogen 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone (nicotine-derived nitrosamine ketone, NNK) and arsenite on lung cell transformation. BEAS-2B, an immortalized human lung epithelial cell line, was selected to test the centrosomal abnormalities and colony formation by NNK and arsenite. We found that NNK, alone, could enhance BEAS-2B cell growth at 1-5 μM. Under NNK exposure, arsenite was able to increase centrosomal abnormality as compared with NNK or arsenite treatment alone. NNK treatment could also reduce arsenite-induced G2/M cell cycle arrest and apoptosis, these cellular effects were found to be correlated with p53 dysfunction. Increased anchorage-independent growth (colony formation) of BEAS-2B cells cotreated with NNK and arsenite was also observed in soft agar. Our present investigation demonstrated that NNK could provide a p53 compromised status. Arsenite would act specifically on this p53 compromised status to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenite under tobacco-specific carcinogen co-exposure.
Cleavage of the SUN-domain protein Mps3 at its N-terminus regulates centrosome disjunction in budding yeast meiosis.

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Ping Li

2017-06-01

Full Text Available Centrosomes organize microtubules and are essential for spindle formation and chromosome segregation during cell division. Duplicated centrosomes are physically linked, but how this linkage is dissolved remains unclear. Yeast centrosomes are tethered by a nuclear-envelope-attached structure called the half-bridge, whose components have mammalian homologues. We report here that cleavage of the half-bridge protein Mps3 promotes accurate centrosome disjunction in budding yeast. Mps3 is a single-pass SUN-domain protein anchored at the inner nuclear membrane and concentrated at the nuclear side of the half-bridge. Using the unique feature in yeast meiosis that centrosomes are linked for hours before their separation, we have revealed that Mps3 is cleaved at its nucleus-localized N-terminal domain, the process of which is regulated by its phosphorylation at serine 70. Cleavage of Mps3 takes place at the yeast centrosome and requires proteasome activity. We show that noncleavable Mps3 (Mps3-nc inhibits centrosome separation during yeast meiosis. In addition, overexpression of mps3-nc in vegetative yeast cells also inhibits centrosome separation and is lethal. Our findings provide a genetic mechanism for the regulation of SUN-domain protein-mediated activities, including centrosome separation, by irreversible protein cleavage at the nuclear periphery.
Cleavage of the SUN-domain protein Mps3 at its N-terminus regulates centrosome disjunction in budding yeast meiosis

Science.gov (United States)

Koch, Bailey A.; Han, Xuemei

2017-01-01

Centrosomes organize microtubules and are essential for spindle formation and chromosome segregation during cell division. Duplicated centrosomes are physically linked, but how this linkage is dissolved remains unclear. Yeast centrosomes are tethered by a nuclear-envelope-attached structure called the half-bridge, whose components have mammalian homologues. We report here that cleavage of the half-bridge protein Mps3 promotes accurate centrosome disjunction in budding yeast. Mps3 is a single-pass SUN-domain protein anchored at the inner nuclear membrane and concentrated at the nuclear side of the half-bridge. Using the unique feature in yeast meiosis that centrosomes are linked for hours before their separation, we have revealed that Mps3 is cleaved at its nucleus-localized N-terminal domain, the process of which is regulated by its phosphorylation at serine 70. Cleavage of Mps3 takes place at the yeast centrosome and requires proteasome activity. We show that noncleavable Mps3 (Mps3-nc) inhibits centrosome separation during yeast meiosis. In addition, overexpression of mps3-nc in vegetative yeast cells also inhibits centrosome separation and is lethal. Our findings provide a genetic mechanism for the regulation of SUN-domain protein-mediated activities, including centrosome separation, by irreversible protein cleavage at the nuclear periphery. PMID:28609436
Spectrum of centrosome autoantibodies in childhood varicella and post-varicella acute cerebellar ataxia

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Stinton Laura M

2003-09-01

Full Text Available Abstract Background Sera from children with post-varicella infections have autoantibodies that react with centrosomes in brain and tissue culture cells. We investigated the sera of children with infections and post-varicella ataxia and related conditions for reactivity to five recombinant centrosome proteins: γγ-enolase, pericentrin, ninein, PCM-1, and Mob1. Methods Sera from 12 patients with acute post-varicella ataxia, 1 with post-Epstein Barr virus (EBV ataxia, 5 with uncomplicated varicella infections, and other conditions were tested for reactivity to cryopreserved cerebellum tissue and recombinant centrosome proteins. The distribution of pericentrin in the cerebellum was studied by indirect immunofluorescence (IIF using rabbit antibodies to the recombinant protein. Antibodies to phospholipids (APL were detected by ELISA. Results Eleven of 12 children with post-varicella ataxia, 4/5 children with uncomplicated varicella infections, 1/1 with post-EBV ataxia, 2/2 with ADEM, 1/2 with neuroblastoma and ataxia, and 2/2 with cerebellitis had antibodies directed against 1 or more recombinant centrosome antigens. Antibodies to pericentrin were seen in 5/12 children with post-varicella ataxia but not in any of the other sera tested. IIF demonstrated that pericentrin is located in axons and centrosomes of cerebellar cells. APL were detected in 75% of the sera from children with post-varicella ataxia and 50% of children with varicella without ataxia and in none of the controls. Conclusion This is the first study to show the antigen specificity of anti-centrosome antibodies in children with varicella. Our data suggest that children with post-varicella ataxia have unique autoantibody reactivity to pericentrin.
Simultaneous Aurora-A/STK15 overexpression and centrosome amplification induce chromosomal instability in tumour cells with a MIN phenotype

International Nuclear Information System (INIS)

Lentini, Laura; Amato, Angela; Schillaci, Tiziana; Di Leonardo, Aldo

2007-01-01

Genetic instability is a hallmark of tumours and preneoplastic lesions. The predominant form of genome instability in human cancer is chromosome instability (CIN). CIN is characterized by chromosomal aberrations, gains or losses of whole chromosomes (aneuploidy), and it is often associated with centrosome amplification. Centrosomes control cell division by forming a bipolar mitotic spindle and play an essential role in the maintenance of chromosomal stability. However, whether centrosome amplification could directly cause aneuploidy is not fully established. Also, alterations in genes required for mitotic progression could be involved in CIN. A major candidate is represented by Aurora-A/STK15 that associates with centrosomes and is overexpressed in several types of human tumour. Centrosome amplification were induced by hydroxyurea treatment and visualized by immunofluorescence microscopy. Aurora-A/STK15 ectopic expression was achieved by retroviral infection and puromycin selection in HCT116 tumour cells. Effects of Aurora-A/STK15 depletion on centrosome status and ploidy were determined by Aurora-A/STK15 transcriptional silencing by RNA interference. Changes in the expression levels of some mitotic genes were determined by Real time RT-PCR. We investigated whether amplification of centrosomes and overexpression of Aurora-A/STK15 induce CIN using as a model system a colon carcinoma cell line (HCT116). We found that in HCT116 cells, chromosomally stable and near diploid cells harbouring a MIN phenotype, centrosome amplification induced by hydroxyurea treatment is neither maintained nor induces aneuploidy. On the contrary, ectopic overexpression of Aurora-A/STK15 induced supernumerary centrosomes and aneuploidy. Aurora-A/STK15 transcriptional silencing by RNA interference in cells ectopically overexpressing this kinase promptly decreased cell numbers with supernumerary centrosomes and aneuploidy. Our results show that centrosome amplification alone is not sufficient
Simultaneous Aurora-A/STK15 overexpression and centrosome amplification induce chromosomal instability in tumour cells with a MIN phenotype

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Schillaci Tiziana

2007-11-01

Full Text Available Abstract Background Genetic instability is a hallmark of tumours and preneoplastic lesions. The predominant form of genome instability in human cancer is chromosome instability (CIN. CIN is characterized by chromosomal aberrations, gains or losses of whole chromosomes (aneuploidy, and it is often associated with centrosome amplification. Centrosomes control cell division by forming a bipolar mitotic spindle and play an essential role in the maintenance of chromosomal stability. However, whether centrosome amplification could directly cause aneuploidy is not fully established. Also, alterations in genes required for mitotic progression could be involved in CIN. A major candidate is represented by Aurora-A/STK15 that associates with centrosomes and is overexpressed in several types of human tumour. Methods Centrosome amplification were induced by hydroxyurea treatment and visualized by immunofluorescence microscopy. Aurora-A/STK15 ectopic expression was achieved by retroviral infection and puromycin selection in HCT116 tumour cells. Effects of Aurora-A/STK15 depletion on centrosome status and ploidy were determined by Aurora-A/STK15 transcriptional silencing by RNA interference. Changes in the expression levels of some mitotic genes were determined by Real time RT-PCR. Results We investigated whether amplification of centrosomes and overexpression of Aurora-A/STK15 induce CIN using as a model system a colon carcinoma cell line (HCT116. We found that in HCT116 cells, chromosomally stable and near diploid cells harbouring a MIN phenotype, centrosome amplification induced by hydroxyurea treatment is neither maintained nor induces aneuploidy. On the contrary, ectopic overexpression of Aurora-A/STK15 induced supernumerary centrosomes and aneuploidy. Aurora-A/STK15 transcriptional silencing by RNA interference in cells ectopically overexpressing this kinase promptly decreased cell numbers with supernumerary centrosomes and aneuploidy. Conclusion Our
Phosphorylation of DEPDC1 at Ser110 is required to maintain centrosome organization during mitosis.

Science.gov (United States)

Chen, Dan; Ito, Satoko; Hyodo, Toshinori; Asano-Inami, Eri; Yuan, Hong; Senga, Takeshi

2017-09-15

DEPDC1 (DEP domain containing 1) is overexpressed in multiple cancers and is associated with cell cycle progression. In this report, we have investigated the expression, localization, phosphorylation and function of DEPDC1 during mitosis. DEPDC1 has two isoforms (isoform a and isoform b), and both of them are increased in mitosis and degraded once cells exit mitosis. DEPDC1a is localized to the centrosome in metaphase, whereas DEPDC1b is localized to the entire cell cortex during mitosis. DEPDC1a, but not DEPDC1b, was required for the integrity of centrosome and organization of the bipolar spindle. Mass spectrometry and biochemical analyses revealed phosphorylation of DEPDC1 at Ser110. The phosphorylation of Ser110 is essential for localization of DEPDC1a to the centrosome. Consistently, non-phosphorylation mutants of DEPDC1a did not rescue disruption of centrosome organization by depletion of endogenous DEPDC1. Our results show a novel role for DEPDC1 in maintaining centrosome integrity during mitosis for the accurate distribution of chromosomes. Copyright © 2017. Published by Elsevier Inc.
Laser irradiation of centrosomes in newt eosinophils: evidence of centriole role in motility

Energy Technology Data Exchange (ETDEWEB)

Koonce, M.P.; Cloney, R.A.; Berns, M.W.

1984-06-01

Newt eosinophils are motile granulated leukocytes that uniquely display a highly visible centrosomal area. Electron microscope and tubulin antibody fluorescence confirms the presence of centrioles, pericentriolar material, and radiating microtubules within this visible area. Actin antibodies intensely stain the advancing cell edges and tail but only weakly stain pseudopods being withdrawn into the cell. Randomly activated eosinophils follow a roughly consistent direction with an average rate of 22.5 ..mu..m/min. The position of the centrosome is always located between the trailing cell nucleus and advancing cell edge. If the cell extends more than one pseudopod, the one closest to or containing the centrosome is always the one in which motility continues. Laser irradiation of the visible centrosomal area resulted in rapid cell rounding. After several minutes following irradiation, most cells flattened and movement continued. However, postirradiation motility was uncoordinated and directionless, and the rate decreased to an average of 14.5 ..mu..m/min. Electron microscopy and tubulin immunofluorescence indicated that an initial disorganization of microtubules resulted from the laser microirradiations. After several minutes, organized microtubules reappeared, but the centrioles appeared increasingly damaged. The irregularities in motility due to irradiation are probably related to the damaged centrioles. The results presented in this paper suggest that the centrosome is an important structure in controlling the rate and direction of newt eosinophil motility.

RPL41, a Small Ribosomal Peptide Deregulated in Tumors, Is Essential for Mitosis and Centrosome Integrity

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Shan Wang

2010-03-01

Full Text Available Ribosomal large subunit protein RPL41 is a basic (positively charged peptide consisting of only 25 amino acids. An antisense-based functional screening revealed that the down-regulation of RPL41 led to an anchorage-independent growth of NIH3T3 cells in soft agar plates. RPL41 depletion with gene-specific small interfering RNA also resulted in malignant transformation of NIH3T3 cells including increased tumor growth in mice. RPL41 deletion was detected in 59% of tumor cell lines by fluorescence in situ hybridization analyses and RPL41 down-regulation in 75% of primary breast cancers by real-time quantitative reverse transcription-polymerase chain reaction. These studies suggest a tumor suppression role for RPL41. By mass spectrometry, RPL41 was associated with several cytoskeleton components including tubulin β, γ, and myosin IIA, which was confirmed by Western blot analysis on both cellular lysis and individually in vitro-expressed proteins. RPL41 also bound directly to polymerized tubulins. Cells overexpressing a GFP-RPL41 were resistant to nocodazole-induced microtubule depolymerization. A synthetic RPL41 induced cellular α-tubulin acetylation and G2/M cell cycle arrest. These results indicate a stabilizing role of RPL41 on microtubule. Microtubule spindles are essential for chromosome segregation during mitosis. Cells with RPL41 knock-down showed abnormal spindles, frequent failure of cytokinesis, and formation of polynuclear cells. In interphase cells, RPL41-depleted cells had premature splitting of centrosome. Our results provide evidence that RPL41 is a microtubule-associated protein essential for functional spindles and for the integrity of centrosome and that the abnormal mitosis and disrupted centrosome associated with the RPL41 down-regulation may be related to malignant transformation.
Excess free histone H3 localizes to centrosomes for proteasome-mediated degradation during mitosis in metazoans.

Science.gov (United States)

Wike, Candice L; Graves, Hillary K; Wason, Arpit; Hawkins, Reva; Gopalakrishnan, Jay; Schumacher, Jill; Tyler, Jessica K

2016-08-17

The cell tightly controls histone protein levels in order to achieve proper packaging of the genome into chromatin, while avoiding the deleterious consequences of excess free histones. Our accompanying study has shown that a histone modification that loosens the intrinsic structure of the nucleosome, phosphorylation of histone H3 on threonine 118 (H3 T118ph), exists on centromeres and chromosome arms during mitosis. Here, we show that H3 T118ph localizes to centrosomes in humans, flies, and worms during all stages of mitosis. H3 abundance at the centrosome increased upon proteasome inhibition, suggesting that excess free histone H3 localizes to centrosomes for degradation during mitosis. In agreement, we find ubiquitinated H3 specifically during mitosis and within purified centrosomes. These results suggest that targeting of histone H3 to the centrosome for proteasome-mediated degradation is a novel pathway for controlling histone supply, specifically during mitosis.
Mother Centriole Distal Appendages Mediate Centrosome Docking at the Immunological Synapse and Reveal Mechanistic Parallels with Ciliogenesis.

Science.gov (United States)

Stinchcombe, Jane C; Randzavola, Lyra O; Angus, Karen L; Mantell, Judith M; Verkade, Paul; Griffiths, Gillian M

2015-12-21

Cytotoxic T lymphocytes (CTLs) are highly effective serial killers capable of destroying virally infected and cancerous targets by polarized release from secretory lysosomes. Upon target contact, the CTL centrosome rapidly moves to the immunological synapse, focusing microtubule-directed release at this point [1-3]. Striking similarities have been noted between centrosome polarization at the synapse and basal body docking during ciliogenesis [1, 4-8], suggesting that CTL centrosomes might dock with the plasma membrane during killing, in a manner analogous to primary cilia formation [1, 4]. However, questions remain regarding the extent and function of centrosome polarization at the synapse, and recent reports have challenged its role [9, 10]. Here, we use high-resolution transmission electron microscopy (TEM) tomography analysis to show that, as in ciliogenesis, the distal appendages of the CTL mother centriole contact the plasma membrane directly during synapse formation. This is functionally important as small interfering RNA (siRNA) targeting of the distal appendage protein, Cep83, required for membrane contact during ciliogenesis [11], impairs CTL secretion. Furthermore, the regulatory proteins CP110 and Cep97, which must dissociate from the mother centriole to allow cilia formation [12], remain associated with the mother centriole in CTLs, and neither axoneme nor transition zone ciliary structures form. Moreover, complete centrosome docking can occur in proliferating CTLs with multiple centriole pairs. Thus, in CTLs, centrosomes dock transiently with the membrane, within the cell cycle and without progression into ciliogenesis. We propose that this transient centrosome docking without cilia formation is important for CTLs to deliver rapid, repeated polarized secretion directed by the centrosome. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Microtubules Growth Rate Alteration in Human Endothelial Cells

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Irina B. Alieva

2010-01-01

Full Text Available To understand how microtubules contribute to the dynamic reorganization of the endothelial cell (EC cytoskeleton, we established an EC model expressing EB3-GFP, a protein that marks microtubule plus-ends. Using this model, we were able to measure microtubule growth rate at the centrosome region and near the cell periphery of a single human EC and in the EC monolayer. We demonstrate that the majority of microtubules in EC are dynamic, the growth rate of their plus-ends is highest in the internal cytoplasm, in the region of the centrosome. Growth rate of microtubule plus-ends decreases from the cell center toward the periphery. Our data suggest the existing mechanism(s of local regulation of microtubule plus-ends growth in EC. Microtubule growth rate in the internal cytoplasm of EC in the monolayer is lower than that of single EC suggesting the regulatory effect of cell-cell contacts. Centrosomal microtubule growth rate distribution in single EC indicated the presence of two subpopulations of microtubules with “normal” (similar to those in monolayer EC and “fast” (three times as much growth rates. Our results indicate functional interactions between cell-cell contacts and microtubules.
A phenanthrene derived PARP inhibitor is an extra-centrosomes de-clustering agent exclusively eradicating human cancer cells

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Izraeli Shai

2011-09-01

Full Text Available Abstract Background Cells of most human cancers have supernumerary centrosomes. To enable an accurate chromosome segregation and cell division, these cells developed a yet unresolved molecular mechanism, clustering their extra centrosomes at two poles, thereby mimicking mitosis in normal cells. Failure of this bipolar centrosome clustering causes multipolar spindle structures and aberrant chromosomes segregation that prevent normal cell division and lead to 'mitotic catastrophe cell death'. Methods We used cell biology and biochemical methods, including flow cytometry, immunocytochemistry and live confocal imaging. Results We identified a phenanthrene derived PARP inhibitor, known for its activity in neuroprotection under stress conditions, which exclusively eradicated multi-centrosomal human cancer cells (mammary, colon, lung, pancreas, ovarian while acting as extra-centrosomes de-clustering agent in mitosis. Normal human proliferating cells (endothelial, epithelial and mesenchymal cells were not impaired. Despite acting as PARP inhibitor, the cytotoxic activity of this molecule in cancer cells was not attributed to PARP inhibition alone. Conclusion We identified a water soluble phenanthridine that exclusively targets the unique dependence of most human cancer cells on their supernumerary centrosomes bi-polar clustering for their survival. This paves the way for a new selective cancer-targeting therapy, efficient in a wide range of human cancers.
The PAM-1 aminopeptidase regulates centrosome positioning to ensure anterior-posterior axis specification in one-cell C. elegans embryos.

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Fortin, Samantha M; Marshall, Sara L; Jaeger, Eva C; Greene, Pauline E; Brady, Lauren K; Isaac, R Elwyn; Schrandt, Jennifer C; Brooks, Darren R; Lyczak, Rebecca

2010-08-15

In the one-cell Caenorhabditis elegans embryo, the anterior-posterior (A-P) axis is established when the sperm donated centrosome contacts the posterior cortex. While this contact appears to be essential for axis polarization, little is known about the mechanisms governing centrosome positioning during this process. pam-1 encodes a puromycin sensitive aminopeptidase that regulates centrosome positioning in the early embryo. Previously we showed that pam-1 mutants fail to polarize the A-P axis. Here we show that PAM-1 can be found in mature sperm and in cytoplasm throughout early embryogenesis where it concentrates around mitotic centrosomes and chromosomes. We provide further evidence that PAM-1 acts early in the polarization process by showing that PAR-1 and PAR-6 do not localize appropriately in pam-1 mutants. Additionally, we tested the hypothesis that PAM-1's role in polarity establishment is to ensure centrosome contact with the posterior cortex. We inactivated the microtubule motor dynein, DHC-1, in pam-1 mutants, in an attempt to prevent centrosome movement from the cortex and restore anterior-posterior polarity. When this was done, the aberrant centrosome movements of pam-1 mutants were not observed and anterior-posterior polarity was properly established, with proper localization of cortical and cytoplasmic determinants. We conclude that PAM-1's role in axis polarization is to prevent premature movement of the centrosome from the posterior cortex, ensuring proper axis establishment in the embryo. Copyright 2010 Elsevier Inc. All rights reserved.
Casein kinase II is required for proper cell division and acts as a negative regulator of centrosome duplication in Caenorhabditis elegans embryos

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Jeffrey C. Medley

2017-01-01

Full Text Available Centrosomes are the primary microtubule-organizing centers that orchestrate microtubule dynamics during the cell cycle. The correct number of centrosomes is pivotal for establishing bipolar mitotic spindles that ensure accurate segregation of chromosomes. Thus, centrioles must duplicate once per cell cycle, one daughter per mother centriole, the process of which requires highly coordinated actions among core factors and modulators. Protein phosphorylation is shown to regulate the stability, localization and activity of centrosome proteins. Here, we report the function of Casein kinase II (CK2 in early Caenorhabditis elegans embryos. The catalytic subunit (KIN-3/CK2α of CK2 localizes to nuclei, centrosomes and midbodies. Inactivating CK2 leads to cell division defects, including chromosome missegregation, cytokinesis failure and aberrant centrosome behavior. Furthermore, depletion or inhibiting kinase activity of CK2 results in elevated ZYG-1 levels at centrosomes, restoring centrosome duplication and embryonic viability to zyg-1 mutants. Our data suggest that CK2 functions in cell division and negatively regulates centrosome duplication in a kinase-dependent manner.
Downregulation of Protein 4.1R impairs centrosome function,bipolar spindle organization and anaphase

Energy Technology Data Exchange (ETDEWEB)

Spence, Jeffrey R.; Go, Minjoung M.; Bahmanyar, S.; Barth,A.I.M.; Krauss, Sharon Wald

2006-03-17

Centrosomes nucleate and organize interphase MTs and areinstrumental in the assembly of the mitotic bipolar spindle. Here wereport that two members of the multifunctional protein 4.1 family havedistinct distributions at centrosomes. Protein 4.1R localizes to maturecentrioles whereas 4.1G is a component of the pericentriolar matrixsurrounding centrioles. To selectively probe 4.1R function, we used RNAinterference-mediated depletion of 4.1R without decreasing 4.1Gexpression. 4.1R downregulation reduces MT anchoring and organization atinterphase and impairs centrosome separation during prometaphase.Metaphase chromosomes fail to properly condense/align and spindleorganization is aberrant. Notably 4.1R depletion causes mislocalizationof its binding partner NuMA (Nuclear Mitotic Apparatus Protein),essential for spindle pole focusing, and disrupts ninein. Duringanaphase/telophase, 4.1R-depleted cells have lagging chromosomes andaberrant MT bridges. Our data provide functional evidence that 4.1R makescrucial contributions to centrosome integrity and to mitotic spindlestructure enabling mitosis and anaphase to proceed with the coordinatedprecision required to avoid pathological events.
GAS2L1 Is a Centriole-Associated Protein Required for Centrosome Dynamics and Disjunction.

NARCIS (Netherlands)

Au, F.K.; Jia, Y.; Jiang, K.; Grigoriev, I.S.; Hau, B.K.; Shen, Y.; Du, S.; Akhmanova, A.S.; Qi, R.Z.

2017-01-01

Mitotic spindle formation and chromosome segregation require timely separation of the two duplicated centrosomes, and this process is initiated in late G2 by centrosome disjunction. Here we report that GAS2L1, a microtubule- and actin-binding protein, associates with the proximal end of mature
Stabilization of cartwheel-less centrioles for duplication requires CEP295-mediated centriole to centrosome conversion

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Izquierdo, Denisse; Wang, Won-Jing; Uryu, Kunihiro; Tsou, Meng-Fu Bryan

2014-01-01

SUMMARY Vertebrate centrioles lose their geometric scaffold, the cartwheel, during mitosis, concurrently with gaining the ability to recruit the pericentriolar material (PCM) and thereby function as the centrosome. Cartwheel removal has recently been implicated in centriole duplication, but whether “cartwheel-less” centrioles are intrinsically stable, or must be maintained through other modifications remains unclear. Here, we identify a newborn centriole-enriched protein, KIAA1731/CEP295, specifically mediating centriole-to-centrosome conversion but dispensable for cartwheel removal. In the absence of CEP295, centrioles form in S/G2 phase, and lose their associated cartwheel in mitosis, but cannot be converted to centrosomes, uncoupling the two events. Strikingly, centrioles devoid of both the PCM and cartwheel progressively lose centriolar components, whereas centrioles associating with either the cartwheel or PCM alone can exist stably. Thus, cartwheel removal can have grave repercussions to centriole stability, and centriole-to-centrosome conversion mediated by CEP295 must occur in parallel to maintain cartwheel-less centrioles for duplication. PMID:25131205
Novel asymmetrically localizing components of human centrosomes identified by complementary proteomics methods

DEFF Research Database (Denmark)

Jakobsen, Lis; Vanselow, Katja; Skogs, Marie

2011-01-01

by identifying a novel set of five proteins preferentially associated with mother or daughter centrioles, comprising genes implicated in cell polarity. Pulsed labelling demonstrates a remarkable variation in the stability of centrosomal protein complexes. These spatiotemporal proteomics data provide leads......Centrosomes in animal cells are dynamic organelles with a proteinaceous matrix of pericentriolar material assembled around a pair of centrioles. They organize the microtubule cytoskeleton and the mitotic spindle apparatus. Mature centrioles are essential for biogenesis of primary cilia that mediate...
Centrosome-Based Mechanisms, Prognostics and Therapeutics in Prostate Cancer

National Research Council Canada - National Science Library

Doxsey, Stephen J

2007-01-01

.... Our results show that the centrosome protein pericentrin is present at the midbody, a structure involved in the final stage of cell division called cytokinesis, where it anchors PKA, PKB/Akt and PKC...
Nonequivalence of maternal centrosomes/centrioles in starfish oocytes: selective casting-off of reproductive centrioles into polar bodies.

Science.gov (United States)

Uetake, Yumi; Kato, Koichi H; Washitani-Nemoto, Setsuko; Nemoto Si, Shin-ichi

2002-07-01

It is believed that in most animals only the paternal centrosome provides the division poles for mitosis in zygotes. This paternal inheritance of the centrosomes depends on the selective loss of the maternal centrosome. In order to understand the mechanism of centrosome inheritance, the behavior of all maternal centrosomes/centrioles was investigated throughout the meiotic and mitotic cycles by using starfish eggs that had polar body (PB) formation suppressed. In starfish oocytes, the centrioles do not duplicate during meiosis II. Hence, each centrosome of the meiosis II spindle has only one centriole, whereas in meiosis I, each has a pair of centrioles. When two pairs of meiosis I centrioles were retained in the cytoplasm of oocytes by complete suppression of PB extrusion, they separated into four single centrioles in meiosis II. However, after completion of the meiotic process, only two of the four single centrioles were found in addition to the pronucleus. When the two single centrioles of a meiosis II spindle were retained in the oocyte cytoplasm by suppressing the extrusion of the second PB, only one centriole was found with the pronucleus after the completion of the meiotic process. When these PB-suppressed eggs were artificially activated to drive the mitotic cycles, all the surviving single centrioles duplicated repeatedly to form pairs of centrioles, which could organize mitotic spindles. These results indicate that the maternal centrioles are not equivalent in their intrinsic stability and reproductive capacity. The centrosomes with the reproductive centrioles are selectively cast off into the PBs, resulting in the mature egg inheriting a nonreproductive centriole, which would degrade shortly after the completion of meiosis. (c) 2002 Elsevier Science (USA).
Epstein-Barr virus thymidine kinase is a centrosomal resident precisely localized to the periphery of centrioles.

Science.gov (United States)

Gill, Michael B; Kutok, Jeffery L; Fingeroth, Joyce D

2007-06-01

The thymidine kinase (TK) encoded by Epstein-Barr virus (EBV) differs not only from that of the alphaherpesviruses but also from that of the gamma-2 herpesvirus subfamily. Because cellular location is frequently a determinant of regulatory function, to gain insight into additional role(s) of EBV TK and to uncover how the lymphocryptovirus and rhadinovirus enzymes differ, the subcellular localizations of EBV TK and the related cercopithecine herpesvirus-15 TK were investigated. We show that in contrast to those of the other family members, the gamma-1 herpesvirus TKs localize to the centrosome and even more precisely to the periphery of the centriole, tightly encircling the tubulin-rich centrioles in a microtubule-independent fashion. Centrosomal localization is observed in diverse cell types and occurs whether the protein is expressed independently or in the context of lytic EBV infection. Surprisingly, analysis of mutants revealed that the unique N-terminal domain was not critical for targeting to the centrosome, but rather, peptide sequences located C terminal to this domain were key. This is the first herpesvirus protein documented to reside in the centrosome, or microtubule-organizing center, an amembranous organelle that regulates the structural biology of the cell cycle through control of chromosome separation and cytokinesis. More recently, proteasome-mediated degradation of cell cycle regulatory proteins, production and loading of antigenic peptides onto HLA molecules, and transient homing of diverse virion proteins required for entry and/or egress have been shown to be coordinated at the centrosome. Potential implications of centrosomal localization for EBV TK function are discussed.
Stabilization of cartwheel-less centrioles for duplication requires CEP295-mediated centriole-to-centrosome conversion.

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Izquierdo, Denisse; Wang, Won-Jing; Uryu, Kunihiro; Tsou, Meng-Fu Bryan

2014-08-21

Vertebrate centrioles lose their geometric scaffold, the cartwheel, during mitosis, concurrently with gaining the ability to recruit the pericentriolar material (PCM) and thereby function as the centrosome. Cartwheel removal has recently been implicated in centriole duplication, but whether "cartwheel-less" centrioles are intrinsically stable or must be maintained through other modifications remains unclear. Here, we identify a newborn centriole-enriched protein, KIAA1731/CEP295, specifically mediating centriole-to-centrosome conversion but dispensable for cartwheel removal. In the absence of CEP295, centrioles form in the S/G2 phase and lose their associated cartwheel in mitosis but cannot be converted to centrosomes, uncoupling the two events. Strikingly, centrioles devoid of both the PCM and the cartwheel progressively lose centriolar components, whereas centrioles associating with either the cartwheel or PCM alone can exist stably. Thus, cartwheel removal can have grave repercussions to centriole stability, and centriole-to-centrosome conversion mediated by CEP295 must occur in parallel to maintain cartwheel-less centrioles for duplication. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
Stabilization of Cartwheel-less Centrioles for Duplication Requires CEP295-Mediated Centriole-to-Centrosome Conversion

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Denisse Izquierdo

2014-08-01

Full Text Available Vertebrate centrioles lose their geometric scaffold, the cartwheel, during mitosis, concurrently with gaining the ability to recruit the pericentriolar material (PCM and thereby function as the centrosome. Cartwheel removal has recently been implicated in centriole duplication, but whether “cartwheel-less” centrioles are intrinsically stable or must be maintained through other modifications remains unclear. Here, we identify a newborn centriole-enriched protein, KIAA1731/CEP295, specifically mediating centriole-to-centrosome conversion but dispensable for cartwheel removal. In the absence of CEP295, centrioles form in the S/G2 phase and lose their associated cartwheel in mitosis but cannot be converted to centrosomes, uncoupling the two events. Strikingly, centrioles devoid of both the PCM and the cartwheel progressively lose centriolar components, whereas centrioles associating with either the cartwheel or PCM alone can exist stably. Thus, cartwheel removal can have grave repercussions to centriole stability, and centriole-to-centrosome conversion mediated by CEP295 must occur in parallel to maintain cartwheel-less centrioles for duplication.
RABL6A, a Novel RAB-Like Protein, Controls Centrosome Amplification and Chromosome Instability in Primary Fibroblasts

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Zhang, Xuefeng; Hagen, Jussara; Muniz, Viviane P.; Smith, Tarik; Coombs, Gary S.; Eischen, Christine M.; Mackie, Duncan I.; Roman, David L.; Van Rheeden, Richard; Darbro, Benjamin; Tompkins, Van S.; Quelle, Dawn E.

2013-01-01

RABL6A (RAB-like 6 isoform A) is a novel protein that was originally identified based on its association with the Alternative Reading Frame (ARF) tumor suppressor. ARF acts through multiple p53-dependent and p53-independent pathways to prevent cancer. How RABL6A functions, to what extent it depends on ARF and p53 activity, and its importance in normal cell biology are entirely unknown. We examined the biological consequences of RABL6A silencing in primary mouse embryo fibroblasts (MEFs) that express or lack ARF, p53 or both proteins. We found that RABL6A depletion caused centrosome amplification, aneuploidy and multinucleation in MEFs regardless of ARF and p53 status. The centrosome amplification in RABL6A depleted p53−/− MEFs resulted from centrosome reduplication via Cdk2-mediated hyperphosphorylation of nucleophosmin (NPM) at threonine-199. Thus, RABL6A prevents centrosome amplification through an ARF/p53-independent mechanism that restricts NPM-T199 phosphorylation. These findings demonstrate an essential role for RABL6A in centrosome regulation and maintenance of chromosome stability in non-transformed cells, key processes that ensure genomic integrity and prevent tumorigenesis. PMID:24282525
Increased separase activity and occurrence of centrosome aberrations concur with transformation of MDS.

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Ruppenthal, Sabrina; Kleiner, Helga; Nolte, Florian; Fabarius, Alice; Hofmann, Wolf-Karsten; Nowak, Daniel; Seifarth, Wolfgang

2018-01-01

ESPL1/separase, a cysteine endopeptidase, is a key player in centrosome duplication and mitotic sister chromatid separation. Aberrant expression and/or altered separase proteolytic activity are associated with centrosome amplification, aneuploidy, tumorigenesis and disease progression. Since centrosome alterations are a common and early detectable feature in patients with myelodysplastic syndrome (MDS) and cytogenetic aberrations play an important role in disease risk stratification, we examined separase activity on single cell level in 67 bone marrow samples obtained from patients with MDS, secondary acute myeloid leukemia (sAML), de novo acute myeloid leukemia (AML) and healthy controls by a flow cytometric separase activity assay. The separase activity distribution (SAD) value, a calculated measure for the occurrence of cells with prominent separase activity within the analyzed sample, was tested for correlation with the centrosome, karyotype and gene mutation status. We found higher SAD values in bone marrow cells of sAML patients than in corresponding cells of MDS patients. This concurred with an increased incidence of aberrant centrosome phenotypes in sAML vs. MDS samples. No correlation was found between SAD values and the karyotype/gene mutation status. During follow-up of four MDS patients we observed increasing SAD values after transformation to sAML, in two patients SAD values decreased during azacitidine therapy. Cell culture experiments employing MDS-L cells as an in vitro model of MDS revealed that treatment with rigosertib, a PLK1 inhibitor and therapeutic drug known to induce G2/M arrest, results in decreased SAD values. In conclusion, the appearance of cells with unusual high separase activity levels, as indicated by increased SAD values, concurs with the transformation of MDS to sAML and may reflect separase dysregulation potentially contributing to clonal evolution during MDS progression. Separase activity measurement may therefore be useful as a
Differential expression of centrosomal proteins at different stages of human glioma

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Loh, Joon-Khim; Lieu, Ann-Shung; Chou, Chia-Hua; Lin, Fang-Yi; Wu, Chia-Hung; Howng, Sheng-Long; Chio, Chung-Ching; Hong, Yi-Ren

2010-01-01

High-grade gliomas have poor prognosis, requiring aggressive treatment. The aim of this study is to explore mitotic and centrosomal dysregulation in gliomas, which may provide novel targets for treatment. A case-control study was performed using 34 resected gliomas, which were separated into low- and high-grade groups. Normal human brain tissue was used as a control. Using immunohistochemical analysis, immunofluorescent microscopy, and RT-PCR, detection of centrins 1 and 2, γ-tubulin, hNinein, Aurora A, and Aurora B, expression was performed. Analysis of the GBM8401 glioma cell line was also undertaken to complement the in vivo studies. In high-grade gliomas, the cells had greater than two very brightly staining centrioles within large, atypical nuclei, and moderate-to-strong Aurora A staining. Comparing with normal human brain tissue, most of the mRNAs expression in gliomas for centrosomal structural proteins, including centrin 3, γ-tubulin, and hNinein isoforms 1, 2, 5 and 6, Aurora A and Aurora B were elevated. The significant different expression was observed between high- and low-grade glioma in both γ-tubulin and Aurora A mRNA s. In the high-grade glioma group, 78.6% of the samples had higher than normal expression of γ-tubulin mRNA, which was significantly higher than in the low-grade glioma group (18.2%, p < 0.05). Markers for mitotic dysregulation, such as supernumerary centrosomes and altered expression of centrosome-related mRNA and proteins were more frequently detected in higher grade gliomas. Therefore, these results are clinically useful for glioma staging as well as the development of novel treatments strategies
Differential expression of centrosomal proteins at different stages of human glioma

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Lin Fang-Yi

2010-06-01

Full Text Available Abstract Background High-grade gliomas have poor prognosis, requiring aggressive treatment. The aim of this study is to explore mitotic and centrosomal dysregulation in gliomas, which may provide novel targets for treatment. Methods A case-control study was performed using 34 resected gliomas, which were separated into low- and high-grade groups. Normal human brain tissue was used as a control. Using immunohistochemical analysis, immunofluorescent microscopy, and RT-PCR, detection of centrins 1 and 2, γ-tubulin, hNinein, Aurora A, and Aurora B, expression was performed. Analysis of the GBM8401 glioma cell line was also undertaken to complement the in vivo studies. Results In high-grade gliomas, the cells had greater than two very brightly staining centrioles within large, atypical nuclei, and moderate-to-strong Aurora A staining. Comparing with normal human brain tissue, most of the mRNAs expression in gliomas for centrosomal structural proteins, including centrin 3, γ-tubulin, and hNinein isoforms 1, 2, 5 and 6, Aurora A and Aurora B were elevated. The significant different expression was observed between high- and low-grade glioma in both γ-tubulin and Aurora A mRNA s. In the high-grade glioma group, 78.6% of the samples had higher than normal expression of γ-tubulin mRNA, which was significantly higher than in the low-grade glioma group (18.2%, p Conclusions Markers for mitotic dysregulation, such as supernumerary centrosomes and altered expression of centrosome-related mRNA and proteins were more frequently detected in higher grade gliomas. Therefore, these results are clinically useful for glioma staging as well as the development of novel treatments strategies.

A Novel Role of Human Holliday Junction Resolvase GEN1 in the Maintenance of Centrosome Integrity

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Gao, M.; Danielsen, Jannie Michaela Rendtlew; Wei, L.-Z.

2012-01-01

but not catalytic activity of GEN1 is required for preventing centrosome hyper-amplification, formation of multiple mitotic spindles, and multi-nucleation. Our findings provide novel insight into the biological functions of GEN1 by uncovering an important role of GEN1 in the regulation of centrosome integrity....
Protein kinase C zeta suppresses low- or high-grade colorectal cancer (CRC) phenotypes by interphase centrosome anchoring.

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Deevi, Ravi Kiran; Javadi, Arman; McClements, Jane; Vohhodina, Jekaterina; Savage, Kienan; Loughrey, Maurice Bernard; Evergren, Emma; Campbell, Frederick Charles

2018-04-01

Histological grading provides prognostic stratification of colorectal cancer (CRC) by scoring heterogeneous phenotypes. Features of aggressiveness include aberrant mitotic spindle configurations, chromosomal breakage, and bizarre multicellular morphology, but pathobiology is poorly understood. Protein kinase C zeta (PKCz) controls mitotic spindle dynamics, chromosome segregation, and multicellular patterns, but its role in CRC phenotype evolution remains unclear. Here, we show that PKCz couples genome segregation to multicellular morphology through control of interphase centrosome anchoring. PKCz regulates interdependent processes that control centrosome positioning. Among these, interaction between the cytoskeletal linker protein ezrin and its binding partner NHERF1 promotes the formation of a localized cue for anchoring interphase centrosomes to the cell cortex. Perturbation of these phenomena induced different outcomes in cells with single or extra centrosomes. Defective anchoring of a single centrosome promoted bipolar spindle misorientation, multi-lumen formation, and aberrant epithelial stratification. Collectively, these disturbances induce cribriform multicellular morphology that is typical of some categories of low-grade CRC. By contrast, defective anchoring of extra centrosomes promoted multipolar spindle formation, chromosomal instability (CIN), disruption of glandular morphology, and cell outgrowth across the extracellular matrix interface characteristic of aggressive, high-grade CRC. Because PKCz enhances apical NHERF1 intensity in 3D epithelial cultures, we used an immunohistochemical (IHC) assay of apical NHERF1 intensity as an indirect readout of PKCz activity in translational studies. We show that apical NHERF1 IHC intensity is inversely associated with multipolar spindle frequency and high-grade morphology in formalin-fixed human CRC samples. To conclude, defective PKCz control of interphase centrosome anchoring may underlie distinct categories of
PKA and PDE4D3 anchoring to AKAP9 provides distinct regulation of cAMP signals at the centrosome

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Terrin, Anna; Monterisi, Stefania; Stangherlin, Alessandra; Zoccarato, Anna; Koschinski, Andreas; Surdo, Nicoletta C.; Mongillo, Marco; Sawa, Akira; Jordanides, Niove E.; Mountford, Joanne C.

2012-01-01

Previous work has shown that the protein kinase A (PKA)–regulated phosphodiesterase (PDE) 4D3 binds to A kinase–anchoring proteins (AKAPs). One such protein, AKAP9, localizes to the centrosome. In this paper, we investigate whether a PKA–PDE4D3–AKAP9 complex can generate spatial compartmentalization of cyclic adenosine monophosphate (cAMP) signaling at the centrosome. Real-time imaging of fluorescence resonance energy transfer reporters shows that centrosomal PDE4D3 modulated a dynamic microdomain within which cAMP concentration selectively changed over the cell cycle. AKAP9-anchored, centrosomal PKA showed a reduced activation threshold as a consequence of increased autophosphorylation of its regulatory subunit at S114. Finally, disruption of the centrosomal cAMP microdomain by local displacement of PDE4D3 impaired cell cycle progression as a result of accumulation of cells in prophase. Our findings describe a novel mechanism of PKA activity regulation that relies on binding to AKAPs and consequent modulation of the enzyme activation threshold rather than on overall changes in cAMP levels. Further, we provide for the first time direct evidence that control of cell cycle progression relies on unique regulation of centrosomal cAMP/PKA signals. PMID:22908311
The daughter centriole controls ciliogenesis by regulating Neurl-4 localization at the centrosome

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Loukil, Abdelhalim; Tormanen, Kati

2017-01-01

The two centrioles of the centrosome differ in age and function. Although the mother centriole mediates most centrosome-dependent processes, the role of the daughter remains poorly understood. A recent study has implicated the daughter centriole in centriole amplification in multiciliated cells, but its contribution to primary ciliogenesis is unclear. We found that manipulations that prevent daughter centriole formation or induce its separation from the mother abolish ciliogenesis. This defect was caused by stabilization of the negative ciliogenesis regulator CP110 and was corrected by CP110 depletion. CP110 dysregulation may be caused by effects on Neurl-4, a daughter centriole–associated ubiquitin ligase cofactor, which was required for ciliogenesis. Centrosome-targeted Neurl-4 was sufficient to restore ciliogenesis in cells with manipulated daughter centrioles. Interestingly, early during ciliogenesis, Neurl-4 transiently associated with the mother centriole in a process that required mother–daughter centriole proximity. Our data support a model in which the daughter centriole promotes ciliogenesis through Neurl-4–dependent regulation of CP110 levels at the mother centriole. PMID:28385950
Epstein–Barr virus particles induce centrosome amplification and chromosomal instability

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Shumilov, Anatoliy; Tsai, Ming-Han; Schlosser, Yvonne T.; Kratz, Anne-Sophie; Bernhardt, Katharina; Fink, Susanne; Mizani, Tuba; Lin, Xiaochen; Jauch, Anna; Mautner, Josef; Kopp-Schneider, Annette; Feederle, Regina; Hoffmann, Ingrid; Delecluse, Henri-Jacques

2017-01-01

Infections with Epstein–Barr virus (EBV) are associated with cancer development, and EBV lytic replication (the process that generates virus progeny) is a strong risk factor for some cancer types. Here we report that EBV infection of B-lymphocytes (in vitro and in a mouse model) leads to an increased rate of centrosome amplification, associated with chromosomal instability. This effect can be reproduced with virus-like particles devoid of EBV DNA, but not with defective virus-like particles that cannot infect host cells. Viral protein BNRF1 induces centrosome amplification, and BNRF1-deficient viruses largely lose this property. These findings identify a new mechanism by which EBV particles can induce chromosomal instability without establishing a chronic infection, thereby conferring a risk for development of tumours that do not necessarily carry the viral genome. PMID:28186092
Cdk1 Phosphorylates Drosophila Sas-4 to Recruit Polo to Daughter Centrioles and Convert Them to Centrosomes.

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Novak, Zsofia A; Wainman, Alan; Gartenmann, Lisa; Raff, Jordan W

2016-06-20

Centrosomes and cilia are organized by a centriole pair comprising an older mother and a younger daughter. Centriole numbers are tightly regulated, and daughter centrioles (which assemble in S phase) cannot themselves duplicate or organize centrosomes until they have passed through mitosis. It is unclear how this mitotic "centriole conversion" is regulated, but it requires Plk1/Polo kinase. Here we show that in flies, Cdk1 phosphorylates the conserved centriole protein Sas-4 during mitosis. This creates a Polo-docking site that helps recruit Polo to daughter centrioles and is required for the subsequent recruitment of Asterless (Asl), a protein essential for centriole duplication and mitotic centrosome assembly. Point mutations in Sas-4 that prevent Cdk1 phosphorylation or Polo docking do not block centriole disengagement during mitosis, but block efficient centriole conversion and lead to embryonic lethality. These observations can explain why daughter centrioles have to pass through mitosis before they can duplicate and organize a centrosome. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
Loss of γ-tubulin, GCP-WD/NEDD1 and CDK5RAP2 from the Centrosome of Neurons in Developing Mouse Cerebral and Cerebellar Cortex

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Yonezawa, Satoshi; Shigematsu, Momoko; Hirata, Kazuto; Hayashi, Kensuke

2015-01-01

It has been recently reported that the centrosome of neurons does not have microtubule nucleating activity. Microtubule nucleation requires γ-tubulin as well as its recruiting proteins, GCP-WD/NEDD1 and CDK5RAP2 that anchor γ-tubulin to the centrosome. Change in the localization of these proteins during in vivo development of brain, however, has not been well examined. In this study we investigate the localization of γ-tubulin, GCP-WD and CDK5RAP2 in developing cerebral and cerebellar cortex with immunofluorescence. We found that γ-tubulin and its recruiting proteins were localized at centrosomes of immature neurons, while they were lost at centrosomes in mature neurons. This indicated that the loss of microtubule nucleating activity at the centrosome of neurons is due to the loss of γ-tubulin-recruiting proteins from the centrosome. RT-PCR analysis revealed that these proteins are still expressed after birth, suggesting that they have a role in microtubule generation in cell body and dendrites of mature neurons. Microtubule regrowth experiments on cultured mature neurons showed that microtubules are nucleated not at the centrosome but within dendrites. These data indicated the translocation of microtubule-organizing activity from the centrosome to dendrites during maturation of neurons, which would explain the mixed polarity of microtubules in dendrites
Targeting of beta-arrestin2 to the centrosome and primary cilium: role in cell proliferation control.

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Anahi Molla-Herman

Full Text Available The primary cilium is a sensory organelle generated from the centrosome in quiescent cells and found at the surface of most cell types, from where it controls important physiological processes. Specific sets of membrane proteins involved in sensing the extracellular milieu are concentrated within cilia, including G protein coupled receptors (GPCRs. Most GPCRs are regulated by beta-arrestins, betaarr1 and betaarr2, which control both their signalling and endocytosis, suggesting that betaarrs may also function at primary cilium.In cycling cells, betaarr2 was observed at the centrosome, at the proximal region of the centrioles, in a microtubule independent manner. However, betaarr2 did not appear to be involved in classical centrosome-associated functions. In quiescent cells, both in vitro and in vivo, betaarr2 was found at the basal body and axoneme of primary cilia. Interestingly, betaarr2 was found to interact and colocalize with 14-3-3 proteins and Kif3A, two proteins known to be involved in ciliogenesis and intraciliary transport. In addition, as suggested for other centrosome or cilia-associated proteins, betaarrs appear to control cell cycle progression. Indeed, cells lacking betaarr2 were unable to properly respond to serum starvation and formed less primary cilia in these conditions.Our results show that betaarr2 is localized to the centrosome in cycling cells and to the primary cilium in quiescent cells, a feature shared with other proteins known to be involved in ciliogenesis or primary cilium function. Within cilia, betaarr2 may participate in the signaling of cilia-associated GPCRs and, therefore, in the sensory functions of this cell "antenna".
The connections of Wnt pathway components with cell cycle and centrosome: side effects or a hidden logic?

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Bryja, Vítězslav; Červenka, Igor; Čajánek, Lukáš

2017-12-01

Wnt signaling cascade has developed together with multicellularity to orchestrate the development and homeostasis of complex structures. Wnt pathway components - such as β-catenin, Dishevelled (DVL), Lrp6, and Axin-- are often dedicated proteins that emerged in evolution together with the Wnt signaling cascade and are believed to function primarily in the Wnt cascade. It is interesting to see that in recent literature many of these proteins are connected with cellular functions that are more ancient and not limited to multicellular organisms - such as cell cycle regulation, centrosome biology, or cell division. In this review, we summarize the recent literature describing this crosstalk. Specifically, we attempt to find the answers to the following questions: Is the response to Wnt ligands regulated by the cell cycle? Is the centrosome and/or cilium required to activate the Wnt pathway? How do Wnt pathway components regulate the centrosomal cycle and cilia formation and function? We critically review the evidence that describes how these connections are regulated and how they help to integrate cell-to-cell communication with the cell and the centrosomal cycle in order to achieve a fine-tuned, physiological response.
Elevated endogenous expression of the dominant negative basic helix-loop-helix protein ID1 correlates with significant centrosome abnormalities in human tumor cells

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Gutmann Anja

2010-01-01

Full Text Available Abstract Background ID proteins are dominant negative inhibitors of basic helix-loop-helix transcription factors that have multiple functions during development and cellular differentiation. Ectopic (over-expression of ID1 extends the lifespan of primary human epithelial cells. High expression levels of ID1 have been detected in multiple human malignancies, and in some have been correlated with unfavorable clinical prognosis. ID1 protein is localized at the centrosomes and forced (over-expression of ID1 results in errors during centrosome duplication. Results Here we analyzed the steady state expression levels of the four ID-proteins in 18 tumor cell lines and assessed the number of centrosome abnormalities. While expression of ID1, ID2, and ID3 was detected, we failed to detect protein expression of ID4. Expression of ID1 correlated with increased supernumerary centrosomes in most cell lines analyzed. Conclusions This is the first report that shows that not only ectopic expression in tissue culture but endogenous levels of ID1 modulate centrosome numbers. Thus, our findings support the hypothesis that ID1 interferes with centrosome homeostasis, most likely contributing to genomic instability and associated tumor aggressiveness.
Angelman syndrome protein UBE3A interacts with primary microcephaly protein ASPM, localizes to centrosomes and regulates chromosome segregation.

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Pooja Singhmar

Full Text Available Many proteins associated with the phenotype microcephaly have been localized to the centrosome or linked to it functionally. All the seven autosomal recessive primary microcephaly (MCPH proteins localize at the centrosome. Microcephalic osteodysplastic primordial dwarfism type II protein PCNT and Seckel syndrome (also characterized by severe microcephaly protein ATR are also centrosomal proteins. All of the above findings show the importance of centrosomal proteins as the key players in neurogenesis and brain development. However, the exact mechanism as to how the loss-of-function of these proteins leads to microcephaly remains to be elucidated. To gain insight into the function of the most commonly mutated MCPH gene ASPM, we used the yeast two-hybrid technique to screen a human fetal brain cDNA library with an ASPM bait. The analysis identified Angelman syndrome gene product UBE3A as an ASPM interactor. Like ASPM, UBE3A also localizes to the centrosome. The identification of UBE3A as an ASPM interactor is not surprising as more than 80% of Angelman syndrome patients have microcephaly. However, unlike in MCPH, microcephaly is postnatal in Angelman syndrome patients. Our results show that UBE3A is a cell cycle regulated protein and its level peaks in mitosis. The shRNA knockdown of UBE3A in HEK293 cells led to many mitotic abnormalities including chromosome missegregation, abnormal cytokinesis and apoptosis. Thus our study links Angelman syndrome protein UBE3A to ASPM, centrosome and mitosis for the first time. We suggest that a defective chromosome segregation mechanism is responsible for the development of microcephaly in Angelman syndrome.
The presence of centrioles and centrosomes in ovarian mature cystic teratoma cells suggests human parthenotes developed in vitro can differentiate into mature cells without a sperm centriole

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Lee, Bo Yon, E-mail: boyonlee@gmail.com [Department of Obstetrics and Gynecology, Kyung Hee University Hospital, Kyung Hee University, School of Medicine, Seoul (Korea, Republic of); Shim, Sang Woo; Kim, Young Sun; Kim, Seung Bo [Department of Obstetrics and Gynecology, Kyung Hee University Hospital, Kyung Hee University, School of Medicine, Seoul (Korea, Republic of)

2011-11-18

Highlights: Black-Right-Pointing-Pointer The sperm centriole is the progenitor of centrosomes in all somatic cells. Black-Right-Pointing-Pointer Centrioles and centrosomes exist in parthenogenetic ovarian teratoma cells. Black-Right-Pointing-Pointer Without a sperm centriole, parthenogenetic oocytes produce centrioles and centrosomes. Black-Right-Pointing-Pointer Parthenogenetic human oocytes can develop and differentiate into mature cells. -- Abstract: In most animals, somatic cell centrosomes are inherited from the centriole of the fertilizing spermatozoa. The oocyte centriole degenerates during oogenesis, and completely disappears in metaphase II. Therefore, the embryos generated by in vitro parthenogenesis are supposed to develop without any centrioles. Exceptional acentriolar and/or acentrosomal developments are possible in mice and in some experimental cells; however, in most animals, the full developmental potential of parthenogenetic cells in vitro and the fate of their centrioles/centrosomes are not clearly understood. To predict the future of in vitro human parthenogenesis, we explored the centrioles/centrosomes in ovarian mature cystic teratoma cells by immunofluorescent staining and transmission electron microscopy. We confirmed the presence of centrioles and centrosomes in these well-known parthenogenetic ovarian tumor cells. Our findings clearly demonstrate that, even without a sperm centriole, parthenotes that develop from activated oocytes can produce their own centrioles/centrosomes, and can even develop into the well-differentiated mature tissue.
The presence of centrioles and centrosomes in ovarian mature cystic teratoma cells suggests human parthenotes developed in vitro can differentiate into mature cells without a sperm centriole

International Nuclear Information System (INIS)

Lee, Bo Yon; Shim, Sang Woo; Kim, Young Sun; Kim, Seung Bo

2011-01-01

Highlights: ► The sperm centriole is the progenitor of centrosomes in all somatic cells. ► Centrioles and centrosomes exist in parthenogenetic ovarian teratoma cells. ► Without a sperm centriole, parthenogenetic oocytes produce centrioles and centrosomes. ► Parthenogenetic human oocytes can develop and differentiate into mature cells. -- Abstract: In most animals, somatic cell centrosomes are inherited from the centriole of the fertilizing spermatozoa. The oocyte centriole degenerates during oogenesis, and completely disappears in metaphase II. Therefore, the embryos generated by in vitro parthenogenesis are supposed to develop without any centrioles. Exceptional acentriolar and/or acentrosomal developments are possible in mice and in some experimental cells; however, in most animals, the full developmental potential of parthenogenetic cells in vitro and the fate of their centrioles/centrosomes are not clearly understood. To predict the future of in vitro human parthenogenesis, we explored the centrioles/centrosomes in ovarian mature cystic teratoma cells by immunofluorescent staining and transmission electron microscopy. We confirmed the presence of centrioles and centrosomes in these well-known parthenogenetic ovarian tumor cells. Our findings clearly demonstrate that, even without a sperm centriole, parthenotes that develop from activated oocytes can produce their own centrioles/centrosomes, and can even develop into the well-differentiated mature tissue.
E-cadherin is required for centrosome and spindle orientation in Drosophila male germline stem cells.

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Mayu Inaba

2010-08-01

Full Text Available Many adult stem cells reside in a special microenvironment known as the niche, where they receive essential signals that specify stem cell identity. Cell-cell adhesion mediated by cadherin and integrin plays a crucial role in maintaining stem cells within the niche. In Drosophila melanogaster, male germline stem cells (GSCs are attached to niche component cells (i.e., the hub via adherens junctions. The GSC centrosomes and spindle are oriented toward the hub-GSC junction, where E-cadherin-based adherens junctions are highly concentrated. For this reason, adherens junctions are thought to provide a polarity cue for GSCs to enable proper orientation of centrosomes and spindles, a critical step toward asymmetric stem cell division. However, understanding the role of E-cadherin in GSC polarity has been challenging, since GSCs carrying E-cadherin mutations are not maintained in the niche. Here, we tested whether E-cadherin is required for GSC polarity by expressing a dominant-negative form of E-cadherin. We found that E-cadherin is indeed required for polarizing GSCs toward the hub cells, an effect that may be mediated by Apc2. We also demonstrated that E-cadherin is required for the GSC centrosome orientation checkpoint, which prevents mitosis when centrosomes are not correctly oriented. We propose that E-cadherin orchestrates multiple aspects of stem cell behavior, including polarization of stem cells toward the stem cell-niche interface and adhesion of stem cells to the niche supporting cells.
Cep169, a Novel Microtubule Plus-End-Tracking Centrosomal Protein, Binds to CDK5RAP2 and Regulates Microtubule Stability.

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Yusuke Mori

Full Text Available The centrosomal protein, CDK5RAP2, is a microcephaly protein that regulates centrosomal maturation by recruitment of a γ-tubulin ring complex (γ-TuRC onto centrosomes. In this report, we identified a novel human centrosomal protein, Cep169, as a binding partner of CDK5RAP2, a member of microtubule plus-end-tracking proteins (+TIPs. Cep169 interacts directly with CDK5RAP2 through CM1, an evolutionarily conserved domain, and colocalizes at the pericentriolar matrix (PCM around centrioles with CDK5RAP2. In addition, Cep169 interacts with EB1 through SxIP-motif responsible for EB1 binding, and colocalizes with CDK5RAP2 at the microtubule plus-end. EB1-binding-deficient Cep169 abolishes EB1 interaction and microtubule plus-end attachment, indicating Cep169 as a novel member of +TIPs. We further show that ectopic expression of either Cep169 or CDK5RAP2 induces microtubule bundling and acetylation in U2OS cells, and depletion of Cep169 induces microtubule depolymerization in HeLa cells, although Cep169 is not required for assembly of γ-tubulin onto centrosome by CDK5RAP2. These results show that Cep169 targets microtubule tips and regulates stability of microtubules with CDK5RAP2.
Human Embryonic Stem Cells Suffer from Centrosomal Amplification

Czech Academy of Sciences Publication Activity Database

Holubcová, Z.; Matula, P.; Sedláčková, M.; Vinarský, Vladimír; Doležalová, Dáša; Bárta, Tomáš; Dvořák, Petr; Hampl, Aleš

2011-01-01

Roč. 29, č. 1 (2011), s. 46-56 ISSN 1066-5099 R&D Projects: GA ČR GA204/09/2044 Grant - others:GA MŠk(CZ) 1M0538; GA MŠk(CZ) 2B06052; EU FP6 project ESTOOLS(XE) LSHG-CT-2006-018739 Program:1M Institutional research plan: CEZ:AV0Z50390703 Keywords : human embryonic stem cells * centrosome * chromosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.781, year: 2011
Rac1-dependent recruitment of PAK2 to G 2 phase centrosomes and their roles in the regulation of mitotic entry

DEFF Research Database (Denmark)

May, Martin; Schelle, Ilona; Brakebusch, Cord Herbert

2014-01-01

-GTPases Rac/Cdc42. In this study, Rac1 (but not RhoA or Cdc42) is presented to associate with the centrosomes from early G 2 phase until prometaphase in a cell cycle-dependent fashion, as evidenced by western blot analysis of prepared centrosomes and by immunolabeling. PAK associates with the G 2/M......-phase centrosomes in a Rac1-dependent fashion. Furthermore, specific inhibition of Rac1 by C. difficile toxinB-catalyzed glucosylation or by knockout results in inhibited activation of PAK1/2, Aurora A, and the CyclinB/Cdk1 complex in late G 2 phase/prophase and delayed mitotic entry. Inhibition of PAK activation...
Androgen and taxol cause cell type-specific alterations of centrosome and DNA organization in androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cells

Science.gov (United States)

Schatten, H.; Ripple, M.; Balczon, R.; Weindruch, R.; Chakrabarti, A.; Taylor, M.; Hueser, C. N.

2000-01-01

We investigated the effects of androgen and taxol on the androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cell lines. Cells were treated for 48 and 72 h with 0.05-1 nM of the synthetic androgen R1881 and with 100 nM taxol. Treatment of LNCaP cells with 0.05 nM R1881 led to increased cell proliferation, whereas treatment with 1 nM R1881 resulted in inhibited cell division, DNA cycle arrest, and altered centrosome organization. After treatment with 1 nM R1881, chromatin became clustered, nuclear envelopes convoluted, and mitochondria accumulated around the nucleus. Immunofluorescence microscopy with antibodies to centrosomes showed altered centrosome structure. Although centrosomes were closely associated with the nucleus in untreated cells, they dispersed into the cytoplasm after treatment with 1 nM R1881. Microtubules were only faintly detected in 1 nM R1881-treated LNCaP cells. The effects of taxol included microtubule bundling and altered mitochondria morphology, but not DNA organization. As expected, the androgen-independent prostate cancer cell line DU145 was not affected by R1881. Treatment with taxol resulted in bundling of microtubules in both cell lines. Additional taxol effects were seen in DU145 cells with micronucleation of DNA, an indication of apoptosis. Simultaneous treatment with R1881 and taxol had no additional effects on LNCaP or DU145 cells. These results suggest that LNCaP and DU145 prostate cancer cells show differences not only in androgen responsiveness but in sensitivity to taxol as well. Copyright 2000 Wiley-Liss, Inc.
De novo formation of centrosomes in vertebrate cells arrested during S phase

NARCIS (Netherlands)

Khodjakov, A; Rieder, CL; Sluder, G; Cassels, G; Sibon, O; Wang, CL

2002-01-01

The centrosome usually replicates in a semiconservative fashion, i.e., new centrioles form in association with preexisting "maternal" centrioles. De novo formation of centrioles has been reported for a few highly specialized cell types but it has not been seen in vertebrate somatic cells. We find
The presence of centrioles and centrosomes in ovarian mature cystic teratoma cells suggests human parthenotes developed in vitro can differentiate into mature cells without a sperm centriole.

Science.gov (United States)

Lee, Bo Yon; Shim, Sang Woo; Kim, Young Sun; Kim, Seung Bo

2011-11-18

In most animals, somatic cell centrosomes are inherited from the centriole of the fertilizing spermatozoa. The oocyte centriole degenerates during oogenesis, and completely disappears in metaphase II. Therefore, the embryos generated by in vitro parthenogenesis are supposed to develop without any centrioles. Exceptional acentriolar and/or acentrosomal developments are possible in mice and in some experimental cells; however, in most animals, the full developmental potential of parthenogenetic cells in vitro and the fate of their centrioles/centrosomes are not clearly understood. To predict the future of in vitro human parthenogenesis, we explored the centrioles/centrosomes in ovarian mature cystic teratoma cells by immunofluorescent staining and transmission electron microscopy. We confirmed the presence of centrioles and centrosomes in these well-known parthenogenetic ovarian tumor cells. Our findings clearly demonstrate that, even without a sperm centriole, parthenotes that develop from activated oocytes can produce their own centrioles/centrosomes, and can even develop into the well-differentiated mature tissue. Copyright © 2011 Elsevier Inc. All rights reserved.

Critical Importance of Protein 4.1 in Centrosome and Mitiotic Spindle Aberrations in Breast Cancer Pathogenesis

National Research Council Canada - National Science Library

Krauss, Sharon W

2005-01-01

Important pathological hallmarks of many breast cancers include centrosome amplification, spindle pole defects leading to aberrant chromosome segregation, altered nucleoskeletal proteins and perturbed cytokinesis...
3D-structured illumination microscopy provides novel insight into architecture of human centrosomes

Directory of Open Access Journals (Sweden)

Katharina F. Sonnen

2012-08-01

Centrioles are essential for the formation of cilia and flagella. They also form the core of the centrosome, which organizes microtubule arrays important for cell shape, polarity, motility and division. Here, we have used super-resolution 3D-structured illumination microscopy to analyse the spatial relationship of 18 centriole and pericentriolar matrix (PCM components of human centrosomes at different cell cycle stages. During mitosis, PCM proteins formed extended networks with interspersed γ-Tubulin. During interphase, most proteins were arranged at specific distances from the walls of centrioles, resulting in ring staining, often with discernible density masses. Through use of site-specific antibodies, we found the C-terminus of Cep152 to be closer to centrioles than the N-terminus, illustrating the power of 3D-SIM to study protein disposition. Appendage proteins showed rings with multiple density masses, and the number of these masses was strongly reduced during mitosis. At the proximal end of centrioles, Sas-6 formed a dot at the site of daughter centriole assembly, consistent with its role in cartwheel formation. Plk4 and STIL co-localized with Sas-6, but Cep135 was associated mostly with mother centrioles. Remarkably, Plk4 formed a dot on the surface of the mother centriole before Sas-6 staining became detectable, indicating that Plk4 constitutes an early marker for the site of nascent centriole formation. Our study provides novel insights into the architecture of human centrosomes and illustrates the power of super-resolution microscopy in revealing the relative localization of centriole and PCM proteins in unprecedented detail.
The Role of Oncogene/Tumor Suppressor Interaction with the Centrosome Protein Pericentrin in Prostate Tumorigenesis

National Research Council Canada - National Science Library

Chen, Chun-Ting

2006-01-01

.... We believe that these changes may be a result of defects in the centrosome, an essential organelle that organizes spindle poles during mitosis and has important roles in cell proliferation, cell...
The Role of Oncogene/Tumor Suppressor Interaction with the Centrosome Protein Pericentrin in Prostate Tumorigenesis

National Research Council Canada - National Science Library

Chen, Chun-Ting

2007-01-01

.... We believe that these changes may be a result of defects in the centrosome an essential organelle that organizes spindle poles during mitosis and has important roles in cell proliferation cell...
A primary microcephaly protein complex forms a ring around parental centrioles.

Science.gov (United States)

Sir, Joo-Hee; Barr, Alexis R; Nicholas, Adeline K; Carvalho, Ofelia P; Khurshid, Maryam; Sossick, Alex; Reichelt, Stefanie; D'Santos, Clive; Woods, C Geoffrey; Gergely, Fanni

2011-10-09

Autosomal recessive primary microcephaly (MCPH) is characterized by a substantial reduction in prenatal human brain growth without alteration of the cerebral architecture and is caused by biallelic mutations in genes coding for a subset of centrosomal proteins. Although at least three of these proteins have been implicated in centrosome duplication, the nature of the centrosome dysfunction that underlies the neurodevelopmental defect in MCPH is unclear. Here we report a homozygous MCPH-causing mutation in human CEP63. CEP63 forms a complex with another MCPH protein, CEP152, a conserved centrosome duplication factor. Together, these two proteins are essential for maintaining normal centrosome numbers in cells. Using super-resolution microscopy, we found that CEP63 and CEP152 co-localize in a discrete ring around the proximal end of the parental centriole, a pattern specifically disrupted in CEP63-deficient cells derived from patients with MCPH. This work suggests that the CEP152-CEP63 ring-like structure ensures normal neurodevelopment and that its impairment particularly affects human cerebral cortex growth.
Critical Importance of Protein 4.1 in Centrosome and Mitotic Spindle Aberrations in Breast Cancer Pathogenesis

National Research Council Canada - National Science Library

Krauss, Sharon W

2006-01-01

We proposed to test the novel hypothesis that protein 4.1 is of critical importance to centrosome and mitotic spindle aberrations that directly impact aspects of breast cancer pathogenesis. We characterized...
The conserved Wdr8-hMsd1/SSX2IP complex localises to the centrosome and ensures proper spindle length and orientation

International Nuclear Information System (INIS)

Hori, Akiko; Morand, Agathe; Ikebe, Chiho; Frith, David; Snijders, Ambrosius P.; Toda, Takashi

2015-01-01

The centrosome plays a pivotal role in a wide range of cellular processes and its dysfunction is causally linked to many human diseases including cancer and developmental and neurological disorders. This organelle contains more than one hundred components, and yet many of them remain uncharacterised. Here we identified a novel centrosome protein Wdr8, based upon the structural conservation of the fission yeast counterpart. We showed that Wdr8 constitutively localises to the centrosome and super resolution microscopy uncovered that this protein is enriched at the proximal end of the mother centriole. Furthermore, we identified hMsd1/SSX2IP, a conserved spindle anchoring protein, as one of Wdr8 interactors by mass spectrometry. Wdr8 formed a complex and partially colocalised with hMsd1/SSX2IP. Intriguingly, knockdown of Wdr8 or hMsd1/SSX2IP displayed very similar mitotic defects, in which spindle microtubules became shortened and misoriented. Indeed, Wdr8 depletion resulted in the reduced recruitment of hMsd1/SSX2IP to the mitotic centrosome, though the converse is not true. Together, we propose that the conserved Wdr8-hMsd1/SSX2IP complex plays a critical role in controlling proper spindle length and orientation. - Highlights: • Human Wdr8 is a centrosomal protein enriched in the proximal end of the centriole. • Wdr8 and hMsd1/SSX2IP form a complex conserved in fungi. • Depletion of Wdr8 results in shorter, tilted spindle microtubules. • Depletion phenotypes of Wdr8 are very similar to those of hMsd1/SSX2IP knockdown.
The conserved Wdr8-hMsd1/SSX2IP complex localises to the centrosome and ensures proper spindle length and orientation

Energy Technology Data Exchange (ETDEWEB)

Hori, Akiko; Morand, Agathe; Ikebe, Chiho; Frith, David; Snijders, Ambrosius P.; Toda, Takashi, E-mail: takashi-toda@hiroshima-u.ac.jp

2015-12-04

The centrosome plays a pivotal role in a wide range of cellular processes and its dysfunction is causally linked to many human diseases including cancer and developmental and neurological disorders. This organelle contains more than one hundred components, and yet many of them remain uncharacterised. Here we identified a novel centrosome protein Wdr8, based upon the structural conservation of the fission yeast counterpart. We showed that Wdr8 constitutively localises to the centrosome and super resolution microscopy uncovered that this protein is enriched at the proximal end of the mother centriole. Furthermore, we identified hMsd1/SSX2IP, a conserved spindle anchoring protein, as one of Wdr8 interactors by mass spectrometry. Wdr8 formed a complex and partially colocalised with hMsd1/SSX2IP. Intriguingly, knockdown of Wdr8 or hMsd1/SSX2IP displayed very similar mitotic defects, in which spindle microtubules became shortened and misoriented. Indeed, Wdr8 depletion resulted in the reduced recruitment of hMsd1/SSX2IP to the mitotic centrosome, though the converse is not true. Together, we propose that the conserved Wdr8-hMsd1/SSX2IP complex plays a critical role in controlling proper spindle length and orientation. - Highlights: • Human Wdr8 is a centrosomal protein enriched in the proximal end of the centriole. • Wdr8 and hMsd1/SSX2IP form a complex conserved in fungi. • Depletion of Wdr8 results in shorter, tilted spindle microtubules. • Depletion phenotypes of Wdr8 are very similar to those of hMsd1/SSX2IP knockdown.
Transcriptional program of ciliated epithelial cells reveals new cilium and centrosome components and links to human disease.

Directory of Open Access Journals (Sweden)

Ramona A Hoh

Full Text Available Defects in the centrosome and cilium are associated with a set of human diseases having diverse phenotypes. To further characterize the components that define the function of these organelles we determined the transcriptional profile of multiciliated tracheal epithelial cells. Cultures of mouse tracheal epithelial cells undergoing differentiation in vitro were derived from mice expressing GFP from the ciliated-cell specific FOXJ1 promoter (FOXJ1:GFP. The transcriptional profile of ciliating GFP+ cells from these cultures was defined at an early and a late time point during differentiation and was refined by subtraction of the profile of the non-ciliated GFP- cells. We identified 649 genes upregulated early, when most cells were forming basal bodies, and 73 genes genes upregulated late, when most cells were fully ciliated. Most, but not all, of known centrosome proteins are transcriptionally upregulated early, particularly Plk4, a master regulator of centriole formation. We found that three genes associated with human disease states, Mdm1, Mlf1, and Dyx1c1, are upregulated during ciliogenesis and localize to centrioles and cilia. This transcriptome for mammalian multiciliated epithelial cells identifies new candidate centrosome and cilia proteins, highlights similarities between components of motile and primary cilia, and identifies new links between cilia proteins and human disease.
Axin localizes to mitotic spindles and centrosomes in mitotic cells

International Nuclear Information System (INIS)

Kim, Shi-Mun; Choi, Eun-Jin; Song, Ki-Joon; Kim, Sewoon; Seo, Eunjeong; Jho, Eek-Hoon; Kee, Sun-Ho

2009-01-01

Wnt signaling plays critical roles in cell proliferation and carcinogenesis. In addition, numerous recent studies have shown that various Wnt signaling components are involved in mitosis and chromosomal instability. However, the role of Axin, a negative regulator of Wnt signaling, in mitosis has remained unclear. Using monoclonal antibodies against Axin, we found that Axin localizes to the centrosome and along mitotic spindles. This localization was suppressed by siRNA specific for Aurora A kinase and by Aurora kinase inhibitor. Interestingly, Axin over-expression altered the subcellular distribution of Plk1 and of phosphorylated glycogen synthase kinase (GSK3β) without producing any notable changes in cellular phenotype. In the presence of Aurora kinase inhibitor, Axin over-expression induced the formation of cleavage furrow-like structures and of prominent astral microtubules lacking midbody formation in a subset of cells. Our results suggest that Axin modulates distribution of Axin-associated proteins such as Plk1 and GSK3β in an expression level-dependent manner and these interactions affect the mitotic process, including cytokinesis under certain conditions, such as in the presence of Aurora kinase inhibitor
TrkAIII Promotes Microtubule Nucleation and Assembly at the Centrosome in SH-SY5Y Neuroblastoma Cells, Contributing to an Undifferentiated Anaplastic Phenotype

Directory of Open Access Journals (Sweden)

Antonietta R. Farina

2013-01-01

Full Text Available The alternative TrkAIII splice variant is expressed by advanced stage human neuroblastomas (NBs and exhibits oncogenic activity in NB models. In the present study, employing stable transfected cell lines and assays of indirect immunofluorescence, immunoprecipitation, Western blotting, microtubule regrowth, tubulin kinase, and tubulin polymerisation, we report that TrkAIII binds α-tubulin and promotes MT nucleation and assembly at the centrosome. This effect depends upon spontaneous TrkAIII activity, TrkAIII localisation to the centrosome and pericentrosomal area, and the capacity of TrkAIII to bind, phosphorylate, and polymerise tubulin. We propose that this novel role for TrkAIII contributes to MT involvement in the promotion and maintenance of an undifferentiated anaplastic NB cell morphology by restricting and augmenting MT nucleation and assembly at the centrosomal MTOC.
Phosphatase PP2A and microtubule-mediated pulling forces disassemble centrosomes during mitotic exit

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Stephen J. Enos

2018-01-01

Full Text Available Centrosomes are microtubule-nucleating organelles that facilitate chromosome segregation and cell division in metazoans. Centrosomes comprise centrioles that organize a micron-scale mass of protein called pericentriolar material (PCM from which microtubules nucleate. During each cell cycle, PCM accumulates around centrioles through phosphorylation-mediated assembly of PCM scaffold proteins. During mitotic exit, PCM swiftly disassembles by an unknown mechanism. Here, we used Caenorhabditis elegans embryos to determine the mechanism and importance of PCM disassembly in dividing cells. We found that the phosphatase PP2A and its regulatory subunit SUR-6 (PP2ASUR-6, together with cortically directed microtubule pulling forces, actively disassemble PCM. In embryos depleted of these activities, ∼25% of PCM persisted from one cell cycle into the next. Purified PP2ASUR-6 could dephosphorylate the major PCM scaffold protein SPD-5 in vitro. Our data suggest that PCM disassembly occurs through a combination of dephosphorylation of PCM components and force-driven fragmentation of the PCM scaffold.
Ndj1, a telomere-associated protein, regulates centrosome separation in budding yeast meiosis

Science.gov (United States)

Li, Ping; Shao, Yize; Jin, Hui

2015-01-01

Yeast centrosomes (called spindle pole bodies [SPBs]) remain cohesive for hours during meiotic G2 when recombination takes place. In contrast, SPBs separate within minutes after duplication in vegetative cells. We report here that Ndj1, a previously known meiosis-specific telomere-associated protein, is required for protecting SPB cohesion. Ndj1 localizes to the SPB but dissociates from it ∼16 min before SPB separation. Without Ndj1, meiotic SPBs lost cohesion prematurely, whereas overproduction of Ndj1 delayed SPB separation. When produced ectopically in vegetative cells, Ndj1 caused SPB separation defects and cell lethality. Localization of Ndj1 to the SPB depended on the SUN domain protein Mps3, and removal of the N terminus of Mps3 allowed SPB separation and suppressed the lethality of NDJ1-expressing vegetative cells. Finally, we show that Ndj1 forms oligomeric complexes with Mps3, and that the Polo-like kinase Cdc5 regulates Ndj1 protein stability and SPB separation. These findings reveal the underlying mechanism that coordinates yeast centrosome dynamics with meiotic telomere movement and cell cycle progression. PMID:25897084
The conversion of centrioles to centrosomes: essential coupling of duplication with segregation

OpenAIRE

Wang, Won-Jing; Soni, Rajesh Kumar; Uryu, Kunihiro; Bryan Tsou, Meng-Fu

2011-01-01

Centrioles are self-reproducing organelles that form the core structure of centrosomes or microtubule-organizing centers (MTOCs). However, whether duplication and MTOC organization reflect innate activities of centrioles or activities acquired conditionally is unclear. In this paper, we show that newly formed full-length centrioles had no inherent capacity to duplicate or to organize pericentriolar material (PCM) but acquired both after mitosis through a Plk1-dependent modification that occur...
MiCroKit 3.0: an integrated database of midbody, centrosome and kinetochore.

Science.gov (United States)

Ren, Jian; Liu, Zexian; Gao, Xinjiao; Jin, Changjiang; Ye, Mingliang; Zou, Hanfa; Wen, Longping; Zhang, Zhaolei; Xue, Yu; Yao, Xuebiao

2010-01-01

During cell division/mitosis, a specific subset of proteins is spatially and temporally assembled into protein super complexes in three distinct regions, i.e. centrosome/spindle pole, kinetochore/centromere and midbody/cleavage furrow/phragmoplast/bud neck, and modulates cell division process faithfully. Although many experimental efforts have been carried out to investigate the characteristics of these proteins, no integrated database was available. Here, we present the MiCroKit database (http://microkit.biocuckoo.org) of proteins that localize in midbody, centrosome and/or kinetochore. We collected into the MiCroKit database experimentally verified microkit proteins from the scientific literature that have unambiguous supportive evidence for subcellular localization under fluorescent microscope. The current version of MiCroKit 3.0 provides detailed information for 1489 microkit proteins from seven model organisms, including Saccharomyces cerevisiae, Schizasaccharomyces pombe, Caenorhabditis elegans, Drosophila melanogaster, Xenopus laevis, Mus musculus and Homo sapiens. Moreover, the orthologous information was provided for these microkit proteins, and could be a useful resource for further experimental identification. The online service of MiCroKit database was implemented in PHP + MySQL + JavaScript, while the local packages were developed in JAVA 1.5 (J2SE 5.0).
Control of GABARAP-mediated autophagy by the Golgi complex, centrosome and centriolar satellites.

Science.gov (United States)

Joachim, Justin; Tooze, Sharon A

2018-01-01

Within minutes of induction of autophagy by amino-acid starvation in mammalian cells, multiple autophagosomes form throughout the cell cytoplasm. During their formation, the autophagosomes sequester cytoplasmic material and deliver it to lysosomes for degradation. How these organelles can be so rapidly formed and how their formation is acutely regulated are major questions in the autophagy field. Protein and lipid trafficking from diverse cell compartments contribute membrane to, or regulate the formation of the autophagosome. In addition, recruitment of Atg8 (in yeast), and the ATG8-family members (in mammalian cells) to autophagosomes is required for efficient autophagy. Recently, it was discovered that the centrosome and centriolar satellites regulate autophagosome formation by delivery of an ATG8-family member, GABARAP, to the forming autophagosome membrane, the phagophore. We propose that GABARAP regulates phagophore expansion by activating the ULK complex, the amino-acid controlled initiator complex. This finding reveals a previously unknown link between the centrosome, centriolar satellites and autophagy. © 2017 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.
Centrobin-mediated Regulation of the Centrosomal Protein 4.1-associated Protein (CPAP) Level Limits Centriole Length during Elongation Stage*

Science.gov (United States)

Gudi, Radhika; Haycraft, Courtney J.; Bell, P. Darwin; Li, Zihai; Vasu, Chenthamarakshan

2015-01-01

Microtubule-based centrioles in the centrosome mediate accurate bipolar cell division, spindle orientation, and primary cilia formation. Cellular checkpoints ensure that the centrioles duplicate only once in every cell cycle and achieve precise dimensions, dysregulation of which results in genetic instability and neuro- and ciliopathies. The normal cellular level of centrosomal protein 4.1-associated protein (CPAP), achieved by its degradation at mitosis, is considered as one of the major mechanisms that limits centriole growth at a predetermined length. Here we show that CPAP levels and centriole elongation are regulated by centrobin. Exogenous expression of centrobin causes abnormal elongation of centrioles due to massive accumulation of CPAP in the cell. Conversely, CPAP was undetectable in centrobin-depleted cells, suggesting that it undergoes degradation in the absence of centrobin. Only the reintroduction of full-length centrobin, but not its mutant form that lacks the CPAP binding site, could restore cellular CPAP levels in centrobin-depleted cells, indicating that persistence of CPAP requires its interaction with centrobin. Interestingly, inhibition of the proteasome in centrobin-depleted cells restored the cellular and centriolar CPAP expression, suggesting its ubiquitination and proteasome-mediated degradation when centrobin is absent. Intriguingly, however, centrobin-overexpressing cells also showed proteasome-independent accumulation of ubiquitinated CPAP and abnormal, ubiquitin-positive, elongated centrioles. Overall, our results show that centrobin interacts with ubiquitinated CPAP and prevents its degradation for normal centriole elongation function. Therefore, it appears that loss of centrobin expression destabilizes CPAP and triggers its degradation to restrict the centriole length during biogenesis. PMID:25616662
Purification, isolation, crystallization, and preliminary X-ray diffraction study of the BTB domain of the centrosomal protein 190 from Drosophila melanogaster

Science.gov (United States)

Boyko, K. M.; Nikolaeva, A. Yu.; Kachalova, G. S.; Bonchuk, A. N.; Popov, V. O.

2017-11-01

The spatial organization of the genome is controlled by a special class of architectural proteins, including proteins containing BTB domains that are able to dimerize or multimerize. The centrosomal protein 190 is one of such architectural proteins. The purification, crystallization, and preliminary X-ray diffraction study of the BTB domain of the centrosomal protein 190 are reported. The crystallization conditions were found by the vapor-diffusion technique. The crystals diffracted to 1.5 Å resolution and belonged to sp. gr. P3221. The structure was solved by the molecular replacement method. The structure refinement is currently underway.
Talpid3-binding centrosomal protein Cep120 is required for centriole duplication and proliferation of cerebellar granule neuron progenitors.

Directory of Open Access Journals (Sweden)

Chuanqing Wu

Full Text Available Granule neuron progenitors (GNPs are the most abundant neuronal type in the cerebellum. GNP proliferation and thus cerebellar development require Sonic hedgehog (Shh secreted from Purkinje cells. Shh signaling occurs in primary cilia originating from the mother centriole. Centrioles replicate only once during a typical cell cycle and are responsible for mitotic spindle assembly and organization. Recent studies have linked cilia function to cerebellar morphogenesis, but the role of centriole duplication in cerebellar development is not known. Here we show that centrosomal protein Cep120 is asymmetrically localized to the daughter centriole through its interaction with Talpid3 (Ta3, another centrosomal protein. Cep120 null mutant mice die in early gestation with abnormal heart looping. Inactivation of Cep120 in the central nervous system leads to both hydrocephalus, due to the loss of cilia on ependymal cells, and severe cerebellar hypoplasia, due to the failed proliferation of GNPs. The mutant GNPs lack Hedgehog pathway activity. Cell biological studies show that the loss of Cep120 results in failed centriole duplication and consequently ciliogenesis, which together underlie Cep120 mutant cerebellar hypoplasia. Thus, our study for the first time links a centrosomal protein necessary for centriole duplication to cerebellar morphogenesis.
How Does Social Trust Affect Economic Growth?

DEFF Research Database (Denmark)

Bjørnskov, Christian

This paper connects two strands of the literature on social trust by estimating the effects of trust on growth through a set of potential transmission mechanisms directly. It does so by modelling the process using a three-stage least squares estimator on a sample of countries for which a full data...... set is available. The results indicate that trust affects schooling and the rule of law directly. These variables in turn affect the investment rate (schooling) and provide a direct effect (rule of law) on the growth rate. The paper closes with a short discussion of the relevance of the findings....

Centrobin-Centrosomal Protein 4.1-associated Protein (CPAP) Interaction Promotes CPAP Localization to the Centrioles during Centriole Duplication*

Science.gov (United States)

Gudi, Radhika; Zou, Chaozhong; Dhar, Jayeeta; Gao, Qingshen; Vasu, Chenthamarakshan

2014-01-01

Centriole duplication is the process by which two new daughter centrioles are generated from the proximal end of preexisting mother centrioles. Accurate centriole duplication is important for many cellular and physiological events, including cell division and ciliogenesis. Centrosomal protein 4.1-associated protein (CPAP), centrosomal protein of 152 kDa (CEP152), and centrobin are known to be essential for centriole duplication. However, the precise mechanism by which they contribute to centriole duplication is not known. In this study, we show that centrobin interacts with CEP152 and CPAP, and the centrobin-CPAP interaction is critical for centriole duplication. Although depletion of centrobin from cells did not have an effect on the centriolar levels of CEP152, it caused the disappearance of CPAP from both the preexisting and newly formed centrioles. Moreover, exogenous expression of the CPAP-binding fragment of centrobin also caused the disappearance of CPAP from both the preexisting and newly synthesized centrioles, possibly in a dominant negative manner, thereby inhibiting centriole duplication and the PLK4 overexpression-mediated centrosome amplification. Interestingly, exogenous overexpression of CPAP in the centrobin-depleted cells did not restore CPAP localization to the centrioles. However, restoration of centrobin expression in the centrobin-depleted cells led to the reappearance of centriolar CPAP. Hence, we conclude that centrobin-CPAP interaction is critical for the recruitment of CPAP to procentrioles to promote the elongation of daughter centrioles and for the persistence of CPAP on preexisting mother centrioles. Our study indicates that regulation of CPAP levels on the centrioles by centrobin is critical for preserving the normal size, shape, and number of centrioles in the cell. PMID:24700465
Microtubule dynamics of the centrosome-like polar organizers from the basal land plant Marchantia polymorpha.

Science.gov (United States)

Buschmann, Henrik; Holtmannspötter, Michael; Borchers, Agnes; O'Donoghue, Martin-Timothy; Zachgo, Sabine

2016-02-01

The liverwort Marchantia employs both modern and ancestral devices during cell division: it forms preprophase bands and in addition it shows centrosome-like polar organizers. We investigated whether polar organizers and preprophase bands cooperate to set up the division plane. To this end, two novel green fluorescent protein-based microtubule markers for dividing cells of Marchantia were developed. Cells of the apical notch formed polar organizers first and subsequently assembled preprophase bands. Polar organizers were formed de novo from multiple mobile microtubule foci localizing to the nuclear envelope. The foci then became concentrated by bipolar aggregation. We determined the comet production rate of polar organizers and show that microtubule plus ends of astral microtubules polymerize faster than those found on cortical microtubules. Importantly, it was observed that conditions increasing polar organizer numbers interfere with preprophase band formation. The data show that polar organizers have much in common with centrosomes, but that they also have specialized features. The results suggest that polar organizers contribute to preprophase band formation and in this way are involved in controlling the division plane. Our analyses of the basal land plant Marchantia shed new light on the evolution of plant cell division. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
CDKL5 localizes at the centrosome and midbody and is required for faithful cell division.

Science.gov (United States)

Barbiero, Isabella; Valente, Davide; Chandola, Chetan; Magi, Fiorenza; Bergo, Anna; Monteonofrio, Laura; Tramarin, Marco; Fazzari, Maria; Soddu, Silvia; Landsberger, Nicoletta; Rinaldo, Cinzia; Kilstrup-Nielsen, Charlotte

2017-07-24

The cyclin-dependent kinase-like 5 (CDKL5) gene has been associated with rare neurodevelopmental disorders characterized by the early onset of seizures and intellectual disability. The CDKL5 protein is widely expressed in most tissues and cells with both nuclear and cytoplasmic localization. In post-mitotic neurons CDKL5 is mainly involved in dendritic arborization, axon outgrowth, and spine formation while in proliferating cells its function is still largely unknown. Here, we report that CDKL5 localizes at the centrosome and at the midbody in proliferating cells. Acute inactivation of CDKL5 by RNA interference (RNAi) leads to multipolar spindle formation, cytokinesis failure and centrosome accumulation. At the molecular level, we observed that, among the several midbody components we analyzed, midbodies of CDKL5-depleted cells were devoid of HIPK2 and its cytokinesis target, the extrachromosomal histone H2B phosphorylated at S14. Of relevance, expression of the phosphomimetic mutant H2B-S14D, which is capable of overcoming cytokinesis failure in HIPK2-defective cells, was sufficient to rescue spindle multipolarity in CDKL5-depleted cells. Taken together, these results highlight a hitherto unknown role of CDKL5 in regulating faithful cell division by guaranteeing proper HIPK2/H2B functions at the midbody.
How does political instability affect economic growth?

OpenAIRE

Aisen, Ari; Veiga, Francisco José

2011-01-01

The purpose of this paper is to empirically determine the effects of political instability on economic growth. Using the system-GMM estimator for linear dynamic panel data models on a sample covering up to 169 countries, and 5-year periods from 1960 to 2004, we find that higher degrees of political instability are associated with lower growth rates of GDP per capita. Regarding the channels of transmission, we find that political instability adversely affects growth by lowering the rates of pr...
Centrobin-centrosomal protein 4.1-associated protein (CPAP) interaction promotes CPAP localization to the centrioles during centriole duplication.

Science.gov (United States)

Gudi, Radhika; Zou, Chaozhong; Dhar, Jayeeta; Gao, Qingshen; Vasu, Chenthamarakshan

2014-05-30

Centriole duplication is the process by which two new daughter centrioles are generated from the proximal end of preexisting mother centrioles. Accurate centriole duplication is important for many cellular and physiological events, including cell division and ciliogenesis. Centrosomal protein 4.1-associated protein (CPAP), centrosomal protein of 152 kDa (CEP152), and centrobin are known to be essential for centriole duplication. However, the precise mechanism by which they contribute to centriole duplication is not known. In this study, we show that centrobin interacts with CEP152 and CPAP, and the centrobin-CPAP interaction is critical for centriole duplication. Although depletion of centrobin from cells did not have an effect on the centriolar levels of CEP152, it caused the disappearance of CPAP from both the preexisting and newly formed centrioles. Moreover, exogenous expression of the CPAP-binding fragment of centrobin also caused the disappearance of CPAP from both the preexisting and newly synthesized centrioles, possibly in a dominant negative manner, thereby inhibiting centriole duplication and the PLK4 overexpression-mediated centrosome amplification. Interestingly, exogenous overexpression of CPAP in the centrobin-depleted cells did not restore CPAP localization to the centrioles. However, restoration of centrobin expression in the centrobin-depleted cells led to the reappearance of centriolar CPAP. Hence, we conclude that centrobin-CPAP interaction is critical for the recruitment of CPAP to procentrioles to promote the elongation of daughter centrioles and for the persistence of CPAP on preexisting mother centrioles. Our study indicates that regulation of CPAP levels on the centrioles by centrobin is critical for preserving the normal size, shape, and number of centrioles in the cell. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
Centrosome clustering and cyclin D1 gene amplification in double minutes are common events in chromosomal unstable bladder tumors

International Nuclear Information System (INIS)

Rey, Javier del; Prat, Esther; Ponsa, Immaculada; Lloreta, Josep; Gelabert, Antoni; Algaba, Ferran; Camps, Jordi; Miró, Rosa

2010-01-01

Aneuploidy, centrosome abnormalities and gene amplification are hallmarks of chromosome instability (CIN) in cancer. Yet there are no studies of the in vivo behavior of these phenomena within the same bladder tumor. Twenty-one paraffin-embedded bladder tumors were analyzed by conventional comparative genome hybridization and fluorescence in situ hybridization (FISH) with a cyclin D1 gene (CCND1)/centromere 11 dual-color probe. Immunofluorescent staining of α, β and γ tubulin was also performed. Based on the CIN index, defined as the percentage of cells not displaying the modal number for chromosome 11, tumors were classified as CIN-negative and CIN-positive. Fourteen out of 21 tumors were considered CIN-positive. All T1G3 tumors were included in the CIN-positive group whereas the majority of Ta samples were classified as CIN-negative tumors. Centrosome clustering was observed in six out of 12 CIN-positive tumors analyzed. CCND1 amplification in homogeneously staining regions was present in six out of 14 CIN-positive tumors; three of them also showed amplification of this gene in double minutes. Complex in vivo behavior of CCND1 amplicon in bladder tumor cells has been demonstrated by accurate FISH analysis on paraffin-embedded tumors. Positive correlation between high heterogeneity, centrosome abnormalities and CCND1 amplification was found in T1G3 bladder carcinomas. This is the first study to provide insights into the coexistence of CCND1 amplification in homogeneously staining regions and double minutes in primary bladder tumors. It is noteworthy that those patients whose tumors showed double minutes had a significantly shorter overall survival rate (p < 0.001)
Does Political Ideology Affect Economic Growth?

DEFF Research Database (Denmark)

Bjørnskov, Christian

2005-01-01

This paper asks the question whether political ideology affects economic growth. Voters may demand inefficient levels of redistribution and government intervention, and they may care too little for aspects that really matter for the economy. Their norms and perceptions of society might, via...... their political ideology, affect economic performance. The paper presents evidence suggesting that rightwing societies have grown faster in the last decades than other democratic societies. Further analysis suggests that these societies develop better legal systems and less government intervention, which in turn...
Identification of conserved, centrosome-targeting ASH domains in TRAPPII complex subunits and TRAPPC8

DEFF Research Database (Denmark)

Schou, Kenneth Bødtker; Morthorst, Stine Kjær; Christensen, Søren Tvorup

2014-01-01

, the Rab8 guanine nucleotide exchange factor Rabin8, and the transport protein particle (TRAPP) components TRAPPC3, -C9, and -C10, which physically interact with each other and function together with Bardet Biedl syndrome (BBS) proteins in ciliary membrane biogenesis. However, despite recent advances...... confer targeting to the centrosome and cilia, and that TRAPPC8 has cilia-related functions. Further, we propose that the yeast TRAPPII complex and its mammalian counterpart are evolutionarily related to the bacterial periplasmic trafficking chaperone PapD of the usher pili assembly machinery....
A molecular mechanism of mitotic centrosome assembly in Drosophila

Science.gov (United States)

Conduit, Paul T; Richens, Jennifer H; Wainman, Alan; Holder, James; Vicente, Catarina C; Pratt, Metta B; Dix, Carly I; Novak, Zsofia A; Dobbie, Ian M; Schermelleh, Lothar; Raff, Jordan W

2014-01-01

Centrosomes comprise a pair of centrioles surrounded by pericentriolar material (PCM). The PCM expands dramatically as cells enter mitosis, but it is unclear how this occurs. In this study, we show that the centriole protein Asl initiates the recruitment of DSpd-2 and Cnn to mother centrioles; both proteins then assemble into co-dependent scaffold-like structures that spread outwards from the mother centriole and recruit most, if not all, other PCM components. In the absence of either DSpd-2 or Cnn, mitotic PCM assembly is diminished; in the absence of both proteins, it appears to be abolished. We show that DSpd-2 helps incorporate Cnn into the PCM and that Cnn then helps maintain DSpd-2 within the PCM, creating a positive feedback loop that promotes robust PCM expansion around the mother centriole during mitosis. These observations suggest a surprisingly simple mechanism of mitotic PCM assembly in flies. DOI: http://dx.doi.org/10.7554/eLife.03399.001 PMID:25149451
How do mean division shares affect growth and development

Directory of Open Access Journals (Sweden)

Shao Liang Frank

2017-01-01

Full Text Available The Gini coefficient is widely used in academia to discuss how income inequality affects development and growth. However, different Lorenz curves may provide different development and growth outcomes while still leading to the same Gini coefficient. This paper studies the development effects of “mean division shares”, i.e., the share of income (mean income share held by people whose household disposable income per capita is below the mean income and the share of the population (mean population share with this income, using panel data. Our analysis explores how this income share and population share impact development and growth. It shows that the income and population shares affect growth in significantly different ways and that an analysis of these metrics provides substantial value compared to that of the Gini coefficient.
Differential Signature of the Centrosomal MARK4 Isoforms in Glioma

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Ivana Magnani

2011-01-01

Full Text Available Background: MAP/microtubule affinity-regulating kinase 4 (MARK4 is a serine-threonine kinase expressed in two spliced isoforms, MARK4L and MARK4S, of which MARK4L is a candidate for a role in neoplastic transformation. Methods: We performed mutation analysis to identify sequence alterations possibly affecting MARK4 expression. We then investigated the MARK4L and MARK4S expression profile in 21 glioma cell lines and 36 tissues of different malignancy grades, glioblastoma-derived cancer stem cells (GBM CSCs and mouse neural stem cells (NSCs by real-time PCR, immunoblotting and immunohistochemistry. We also analyzed the sub-cellular localisation of MARK4 isoforms in glioma and normal cell lines by immunofluorescence. Results: Mutation analysis rules out sequence variations as the cause of the altered MARK4 expression in glioma. Expression profiling confirms that MARK4L is the predominant isoform, whereas MARK4S levels are significantly decreased in comparison and show an inverse correlation with tumour grade. A high MARK4L/MARK4S ratio also characterizes undifferentiated cells, such as GBM CSCs and NSCs. Accordingly, only MARK4L is expressed in brain neurogenic regions. Moreover, while both MARK4 isoforms are localised to the centrosome and midbody in glioma and normal cells, the L isoform exhibits an additional nucleolar localisation in tumour cells. Conclusions: The observed switch towards MARK4L suggests that the balance between the MARK4 isoforms is carefully guarded during neural differentiation but may be subverted in gliomagenesis. Moreover, the MARK4L nucleolar localisation in tumour cells features this MARK4 isoform as a nucleolus-associated tumour marker.
53BP1 and USP28 mediate p53-dependent cell cycle arrest in response to centrosome loss and prolonged mitosis.

Science.gov (United States)

Fong, Chii Shyang; Mazo, Gregory; Das, Tuhin; Goodman, Joshua; Kim, Minhee; O'Rourke, Brian P; Izquierdo, Denisse; Tsou, Meng-Fu Bryan

2016-07-02

Mitosis occurs efficiently, but when it is disturbed or delayed, p53-dependent cell death or senescence is often triggered after mitotic exit. To characterize this process, we conducted CRISPR-mediated loss-of-function screens using a cell-based assay in which mitosis is consistently disturbed by centrosome loss. We identified 53BP1 and USP28 as essential components acting upstream of p53, evoking p21-dependent cell cycle arrest in response not only to centrosome loss, but also to other distinct defects causing prolonged mitosis. Intriguingly, 53BP1 mediates p53 activation independently of its DNA repair activity, but requiring its interacting protein USP28 that can directly deubiquitinate p53 in vitro and ectopically stabilize p53 in vivo. Moreover, 53BP1 can transduce prolonged mitosis to cell cycle arrest independently of the spindle assembly checkpoint (SAC), suggesting that while SAC protects mitotic accuracy by slowing down mitosis, 53BP1 and USP28 function in parallel to select against disturbed or delayed mitosis, promoting mitotic efficiency.
How Does Social Trust Affect Economic Growth?

DEFF Research Database (Denmark)

Bjørnskov, Christian

Social capital in the form of generalized trust has been shown to be a determinant of economic growth in a number of studies. Other studies have explored other consequences of trust, such as its effects on governance, corruption, education and investment. This paper connects the two strands...... of literature by estimating the effects of trust on growth through a set of potential transmission mechanisms directly. It does so by modelling the process using a three-stage least squares estimator on a sample of countries for which a full data set is available. The results indicate that trust affects...
The affective tone of narration and posttraumatic growth in organ transplant recipients

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Zięba Mariusz

2015-09-01

Full Text Available The aim of the study was to verify the hypothesis that positive affective tone of narratives is connected to the experience of posttraumatic growth among transplant patients. Kidney transplant patients (N = 51 and liver transplant patients (N = 48 participated in the study. In the first stage, about 10 weeks after transplant, the participants told two stories about important, freely chosen events from their lives. During the second meeting 10-12 months later we measured posttraumatic growth. Results indicated that the affective tone of narratives about past events was associated with the level of post-traumatic growth measured 10-12 months later. This proves that the affective tone of narratives about life, understood as a relatively constant individual characteristic, promote posttraumatic growth.
How Stock Markets Development Affect Endogenous Growth Theory

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Najeb Masoud

2013-10-01

Full Text Available This paper can bedescribed as a significant exploratory study that will provide a significantcontribution to knowledge to consider crucial issues which need to be barriersto understanding or a temptation/ requirement to judge some practices as‘better’ than others for stock market development effective approach andimplement successful stock market performance and economic growth. Recentanalysis of the link between financial development and growth, gained frominsights acquired as a result of using the technique of endogenous growthmodels, has illustrated that growth without exogenous technical progress andthat growth rates could be related to technology, income distribution andinstitutional arrangements. This provides the theoretical background thatempirical studies have lacked; illustrating that financial intermediationaffects the level of economic growth. Resulting models have provided newimpetus to empirical research of the effects of financial development. Thebirth of the new endogenous growth theory has facilitated the development ofimproved growth models where the long-term rate could be affected by a numberof elements. These included technology, education and health policies in theprocess of economic development, capital accumulation, government policies andinstitutional activities in the role of financial development in economicgrowth.
Mechanisms and pathways of growth failure in primordial dwarfism.

Science.gov (United States)

Klingseisen, Anna; Jackson, Andrew P

2011-10-01

The greatest difference between species is size; however, the developmental mechanisms determining organism growth remain poorly understood. Primordial dwarfism is a group of human single-gene disorders with extreme global growth failure (which includes Seckel syndrome, microcephalic osteodysplastic primordial dwarfism I [MOPD] types I and II, and Meier-Gorlin syndrome). Ten genes have now been identified for microcephalic primordial dwarfism, encoding proteins involved in fundamental cellular processes including genome replication (ORC1 [origin recognition complex 1], ORC4, ORC6, CDT1, and CDC6), DNA damage response (ATR [ataxia-telangiectasia and Rad3-related]), mRNA splicing (U4atac), and centrosome function (CEP152, PCNT, and CPAP). Here, we review the cellular and developmental mechanisms underlying the pathogenesis of these conditions and address whether further study of these genes could provide novel insight into the physiological regulation of organism growth.
Does Foreign Direct Investment Affect Green Growth? Evidence from China’s Experience

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Shujing Yue

2016-02-01

Full Text Available Foreign Direct Investment (FDI not only affects the economic growth but also affects the environmental protection of the host country. With China’s background of pursuing green growth, we need to consider the performance of FDI from the economic and environmental benefit aspects. On this basis, using slacks-based measure directional distance function (SBMDDF to build up green growth efficiency, economic efficiency and environmental efficiency indexes, empirical research on FDI in 104 Chinese cities from 2004 to 2011 has shown that: (1 Different cities have differences in their green growth efficiency. Shenzhen city is always efficient in green economic growth. (2 Overall, FDI is positive on Chinese cities’ green growth. (3 When the green growth efficiency is broken down into economic efficiency and environmental efficiency, FDI promotes China’s economic green growth through both environmental benefits and economic benefits. (4 The effect of FDI differs in different sectors. FDI in the emission-intensive sector promotes green efficiency mainly through the improvement of economic efficiency. FDI in the non-emission-intensive sector promotes economic efficiency, environmental efficiency and green efficiency.
Beclin 1 and UVRAG confer protection from radiation-induced DNA damage and maintain centrosome stability in colorectal cancer cells.

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Jae Myung Park

Full Text Available Beclin 1 interacts with UV-irradiation-resistance-associated gene (UVRAG to form core complexes that induce autophagy. While cells with defective autophagy are prone to genomic instability that contributes to tumorigenesis, it is unknown whether Beclin1 or UVRAG can regulate the DNA damage/repair response to cancer treatment in established tumor cells. We found that siRNA knockdown of Beclin 1 or UVRAG can increase radiation-induced DNA double strand breaks (DSBs, shown by pATM and γH2Ax, and promote colorectal cancer cell death. Furthermore, knockdown of Beclin 1, UVRAG or ATG5 increased the percentage of irradiated cells with nuclear foci expressing 53BP1, a marker of nonhomologous end joining but not RAD51 (homologous recombination, compared to control siRNA. Beclin 1 siRNA was shown to attenuate UVRAG expression. Cells with a UVRAG deletion mutant defective in Beclin 1 binding showed increased radiation-induced DSBs and cell death compared to cells with ectopic wild-type UVRAG. Knockdown of Beclin 1 or UVRAG, but not ATG5, resulted in a significant increase in centrosome number (γ-tubulin staining in irradiated cells compared to control siRNA. Taken together, these data indicate that Beclin 1 and UVRAG confer protection against radiation-induced DNA DSBs and may maintain centrosome stability in established tumor cells.
Non-genetic factors affecting growth performance and carcass ...

African Journals Online (AJOL)

South African Journal of Animal Science ... This study was based on 20 079 and 12 169 growth and 5 406 and 2 533 carcass data collected on performance tested pigs between 1990 and 2008 from Large White and Landrace breeds ... Herd of origin, year of testing and their interaction significantly affected all traits.
The conversion of centrioles to centrosomes: essential coupling of duplication with segregation.

Science.gov (United States)

Wang, Won-Jing; Soni, Rajesh Kumar; Uryu, Kunihiro; Tsou, Meng-Fu Bryan

2011-05-16

Centrioles are self-reproducing organelles that form the core structure of centrosomes or microtubule-organizing centers (MTOCs). However, whether duplication and MTOC organization reflect innate activities of centrioles or activities acquired conditionally is unclear. In this paper, we show that newly formed full-length centrioles had no inherent capacity to duplicate or to organize pericentriolar material (PCM) but acquired both after mitosis through a Plk1-dependent modification that occurred in early mitosis. Modified centrioles initiated PCM recruitment in G1 and segregated equally in mitosis through association with spindle poles. Conversely, unmodified centrioles segregated randomly unless passively tethered to modified centrioles. Strikingly, duplication occurred only in centrioles that were both modified and disengaged, whereas unmodified centrioles, engaged or not, were "infertile," indicating that engagement specifically blocks modified centrioles from reduplication. These two requirements, centriole modification and disengagement, fully exclude unlimited duplication in one cell cycle. We thus uncovered a Plk1-dependent mechanism whereby duplication and segregation are coupled to maintain centriole homeostasis.

Canopy gaps affect long-term patterns of tree growth and mortality in mature and old-growth forests in the Pacific Northwest

Science.gov (United States)

Andrew N. Gray; Thomas A. Spies; Robert J. Pabst

2012-01-01

Canopy gaps created by tree mortality can affect the speed and trajectory of vegetation growth. Speciesâ population dynamics, and spatial heterogeneity in mature forests. Most studies focus on plant development within gaps, yet gaps also affect the mortality and growth of surrounding trees, which influence shading and root encroachment into gaps and determine whether,...
Using sea urchin gametes and zygotes to investigate centrosome duplication.

Science.gov (United States)

Sluder, Greenfield

2016-01-01

Centriole structure and function in the sea urchin zygote parallel those in mammalian somatic cells. Here, I briefly introduce the properties and attributes of the sea urchin system that make it an attractive platform for the study of centrosome and centriole duplication. These attributes apply to all echinoderms readily available from commercial suppliers: sea urchins, sand dollars, and starfish. I list some of the practical aspects of the system that make it a cost- and time-effective system for experimental work and then list properties that are a "tool kit" that can be used to conduct studies that would not be practical, or in some cases not possible, with mammalian somatic cells. Since centrioles organize and localize the pericentriolar material that nucleates the astral arrays of microtubules (Bobinnec et al. in J Cell Biol 143(6):1575-1589, 1998), the pattern of aster duplication over several cell cycles can be used as a reliable measure for centriole duplication (Sluder and Rieder in J Cell Biol 100(3):887-896, 1985). Descriptions of the methods my laboratory has used to handle and image echinoderm zygotes are reviewed in Sluder et al. (Methods Cell Biol 61:439-472, 1999). Also included is a bibliography of papers that describe additional methods.
CEP128 Localizes to the Subdistal Appendages of the Mother Centriole and Regulates TGF-β/BMP Signaling at the Primary Cilium

DEFF Research Database (Denmark)

Mönnich, Maren; Borgeskov, Louise; Breslin, Loretta

2018-01-01

The centrosome is the main microtubule-organizing center in animal cells and comprises a mother and daughter centriole surrounded by pericentriolar material. During formation of primary cilia, the mother centriole transforms into a basal body that templates the ciliary axoneme. Ciliogenesis depends...... on mother centriole-specific distal appendages, whereas the role of subdistal appendages in ciliary function is unclear. Here, we identify CEP128 as a centriole subdistal appendage protein required for regulating ciliary signaling. Loss of CEP128 did not grossly affect centrosomal or ciliary structure...... but caused impaired transforming growth factor-β/bone morphogenetic protein (TGF-β/BMP) signaling in zebrafish and at the primary cilium in cultured mammalian cells. This phenotype is likely the result of defective vesicle trafficking at the cilium as ciliary localization of RAB11 was impaired upon loss...
Breed effect and non-genetic factors affecting growth performance of ...

African Journals Online (AJOL)

SARAH

2013-07-30

Jul 30, 2013 ... Methodology and results: Data on birth weight (BWT), 90-day weaning ... Pre and post-weaning growth rates were significantly (P<0.05) affected by all the factors examined ... The majority of the sheep population of the semi-.
A designated centre for people with disabilities operated by Health Service Executive, Wexford

LENUS (Irish Health Repository)

2010-11-15

DNA damage can induce centrosome overduplication in a manner that requires G2-to-M checkpoint function, suggesting that genotoxic stress can decouple the centrosome and chromosome cycles. How this happens is unclear. Using live-cell imaging of cells that express fluorescently tagged NEDD1\\/GCP-WD and proliferating cell nuclear antigen, we found that ionizing radiation (IR)-induced centrosome amplification can occur outside S phase. Analysis of synchronized populations showed that significantly more centrosome amplification occurred after irradiation of G2-enriched populations compared with G1-enriched or asynchronous cells, consistent with G2 phase centrosome amplification. Irradiated and control populations of G2 cells were then fused to test whether centrosome overduplication is allowed through a diffusible stimulatory signal, or the loss of a duplication-inhibiting signal. Irradiated G2\\/irradiated G2 cell fusions showed significantly higher centrosome amplification levels than irradiated G2\\/unirradiated G2 fusions. Chicken-human cell fusions demonstrated that centrosome amplification was limited to the irradiated partner. Our finding that only the irradiated centrosome can duplicate supports a model where a centrosome-autonomous inhibitory signal is lost upon irradiation of G2 cells. We observed centriole disengagement after irradiation. Although overexpression of dominant-negative securin did not affect IR-induced centrosome amplification, Plk1 inhibition reduced radiation-induced amplification. Together, our data support centriole disengagement as a licensing signal for DNA damage-induced centrosome amplification.
Polo-like kinase phosphorylation determines Caenorhabditis elegans centrosome size and density by biasing SPD-5 toward an assembly-competent conformation

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Oliver Wueseke

2016-10-01

Full Text Available Centrosomes are major microtubule-organizing centers composed of centrioles surrounded by an extensive proteinacious layer called the pericentriolar material (PCM. In Caenorhabditis elegans embryos, the mitotic PCM expands by Polo-like kinase 1 (PLK-1 phosphorylation-accelerated assembly of SPD-5 molecules into supramolecular scaffolds. However, how PLK-1 phosphorylation regulates SPD-5 assembly is not known. We found that a mutant version of SPD-5 that is insensitive to PLK-1 phosphorylation (SPD-54A could localize to PCM but was unable to rescue the reduction in PCM size and density when wild-type SPD-5 levels were decreased. In vitro, purified SPD-54A self-assembled into functional supramolecular scaffolds over long time scales, suggesting that phosphorylation only controls the rate of SPD-5 scaffold assembly. Furthermore, the SPD-5 scaffold, once assembled, remained intact and supported microtubule nucleation in the absence of PLK-1 activity in vivo. We conclude that PLK-1 is required for rapid assembly of the PCM scaffold but not for scaffold maintenance or function. Based on this idea, we developed a theoretical model that adequately predicted PCM growth rates in different mutant conditions in vivo. We propose that PLK-1 phosphorylation-dependent conversion of SPD-5 into an assembly-competent form underlies PCM formation in vivo and that the rate of this conversion determines final PCM size and density.
Environmental Growth Conditions of Trichoderma spp. Affects Indole Acetic Acid Derivatives, Volatile Organic Compounds, and Plant Growth Promotion

Science.gov (United States)

Nieto-Jacobo, Maria F.; Steyaert, Johanna M.; Salazar-Badillo, Fatima B.; Nguyen, Dianne Vi; Rostás, Michael; Braithwaite, Mark; De Souza, Jorge T.; Jimenez-Bremont, Juan F.; Ohkura, Mana; Stewart, Alison

2017-01-01

Trichoderma species are soil-borne filamentous fungi widely utilized for their many plant health benefits, such as conferring improved growth, disease resistance and abiotic stress tolerance to their hosts. Many Trichoderma species are able to produce the auxin phytohormone indole-3-acetic acid (IAA), and its production has been suggested to promote root growth. Here we show that the production of IAA is strain dependent and diverse external stimuli are associated with its production. In in vitro assays, Arabidopsis primary root length was negatively affected by the interaction with some Trichoderma strains. In soil experiments, a continuum effect on plant growth was shown and this was also strain dependent. In plate assays, some strains of Trichoderma spp. inhibited the expression of the auxin reporter gene DR5 in Arabidopsis primary roots but not secondary roots. When Trichoderma spp. and A. thaliana were physically separated, enhancement of both shoot and root biomass, increased root production and chlorophyll content were observed, which strongly suggested that volatile production by the fungus influenced the parameters analyzed. Trichoderma strains T. virens Gv29.8, T. atroviride IMI206040, T. sp. “atroviride B” LU132, and T. asperellum LU1370 were demonstrated to promote plant growth through volatile production. However, contrasting differences were observed with LU1370 which had a negative effect on plant growth in soil but a positive effect in plate assays. Altogether our results suggest that the mechanisms and molecules involved in plant growth promotion by Trichoderma spp. are multivariable and are affected by the environmental conditions. PMID:28232840
Some factors that will affect the next generation of forest growth models

International Nuclear Information System (INIS)

Leary, R.A.

1988-01-01

This paper discusses several types of factors that affect the form and referents of future growth models. These include philosophical, scientific, technological, educational, and organizational factors. Each factor is presented individually
The growth and photosynthesis of Typha in oil sands process affected material and water

Energy Technology Data Exchange (ETDEWEB)

Foote, L. [Alberta Univ., Edmonton, AB (Canada); Hornung, J. [Petro-Canada, Calgary, AB (Canada)

2007-07-01

Aquatic plants such as cattail contribute substantially to the energy flow in wetlands. Since Typha (cattail) plants acquire and cycle carbon and nutrients through wetlands, their growth and recycling of captured nutrients are an important part of natural, healthy wetland ecosystems. Cattail are pervasive and satisfy many of the criteria to be used as indicators of wetland integrity. This study investigated if cattail growth and carbon accrual were influenced by oil sands process materials (OSPM) such as consolidated tailings (CT). The purpose was to facilitate land reclamation initiatives by evaluating the impact that constituents of oil sands process material have on aquatic plant growth. The study was conducted at Suncor's experimental trenches. Six lined basins were used, of which 3 were filled with natural water and 3 were filled with trench water. Cattail were planted in different growth medium combinations, including CT over CT; soil over soil; soil over CT; and soil over sterilized sand. All leaf lengths and widths were measured along with the photosynthesis of the leaves and root and plant biomass at planting and after 2-years growth. A larger leaf area was observed under oil sands process influence, which may indicate increased carbon accrual above ground. Leaf area data suggested that CT affected plants are quite productive. The study also indicated that oil sands affected water may reduce plant fitness, and therefore could influence the overall oil sands reclamation timelines. Conversely, cattail grown in soil capped process affected material had a much larger leaf area compared to those grown in soil capped sand, most likely due to the higher levels of ammonia in process affected material.
Cdc14 phosphatase directs centrosome re-duplication at the meiosis I to meiosis II transition in budding yeast [version 2; referees: 3 approved, 1 approved with reservations

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Colette Fox

2017-02-01

Full Text Available Background Gametes are generated through a specialized cell division called meiosis, in which ploidy is reduced by half because two consecutive rounds of chromosome segregation, meiosis I and meiosis II, occur without intervening DNA replication. This contrasts with the mitotic cell cycle where DNA replication and chromosome segregation alternate to maintain the same ploidy. At the end of mitosis, cyclin-dependent kinases (CDKs are inactivated. This low CDK state in late mitosis/G1 allows for critical preparatory events for DNA replication and centrosome/spindle pole body (SPB duplication. However, their execution is inhibited until S phase, where further preparatory events are also prevented. This “licensing” ensures that both the chromosomes and the centrosomes/SPBs replicate exactly once per cell cycle, thereby maintaining constant ploidy. Crucially, between meiosis I and meiosis II, centrosomes/SPBs must be re-licensed, but DNA re-replication must be avoided. In budding yeast, the Cdc14 protein phosphatase triggers CDK down regulation to promote exit from mitosis. Cdc14 also regulates the meiosis I to meiosis II transition, though its mode of action has remained unclear. Methods Fluorescence and electron microscopy was combined with proteomics to probe SPB duplication in cells with inactive or hyperactive Cdc14. Results We demonstrate that Cdc14 ensures two successive nuclear divisions by re-licensing SPBs at the meiosis I to meiosis II transition. We show that Cdc14 is asymmetrically enriched on a single SPB during anaphase I and provide evidence that this enrichment promotes SPB re-duplication. Cells with impaired Cdc14 activity fail to promote extension of the SPB half-bridge, the initial step in morphogenesis of a new SPB. Conversely, cells with hyper-active Cdc14 duplicate SPBs, but fail to induce their separation. Conclusion Our findings implicate reversal of key CDK-dependent phosphorylations in the differential licensing of
Does Misaligned Currency Affect Economic Growth? – Evidence from Croatia

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Tonći Svilokos

2014-12-01

Full Text Available The main objective of this paper is to measure the currency misalignment of the Croatian kuna and to reveal whether it affects economic growth for the period 2001 (Q1 to 2013 (Q3. The estimate relies on recent cointegration techniques, VAR models and Granger causality tests. The findings show that there are two misalignment sub-periods for the Croatian kuna: undervaluation in the period from 2000Q1 to 2007Q4 and overvaluation in the period from 2008Q1 to 2013Q3. The evidence reveals that for the whole sample period, the Granger causality goes from misalignments (MISA to GDP growth under the 10 percent significance level. However, for the two sub-periods no evidence of Granger causality from MISA to GDP growth or vice versa is found. The research also reveals that the currency misalignments in the observed period are relatively small.
DISC1, PDE4B, and NDE1 at the centrosome and synapse

International Nuclear Information System (INIS)

Bradshaw, Nicholas J.; Ogawa, Fumiaki; Antolin-Fontes, Beatriz; Chubb, Jennifer E.; Carlyle, Becky C.; Christie, Sheila; Claessens, Antoine; Porteous, David J.; Millar, J. Kirsty

2008-01-01

Disrupted-In-Schizophrenia 1 (DISC1) is a risk factor for schizophrenia and other major mental illnesses. Its protein binding partners include the Nuclear Distribution Factor E Homologs (NDE1 and NDEL1), LIS1, and phosphodiesterases 4B and 4D (PDE4B and PDE4D). We demonstrate that NDE1, NDEL1 and LIS1, together with their binding partner dynein, associate with DISC1, PDE4B and PDE4D within the cell, and provide evidence that this complex is present at the centrosome. LIS1 and NDEL1 have been previously suggested to be synaptic, and we now demonstrate localisation of DISC1, NDE1, and PDE4B at synapses in cultured neurons. NDE1 is phosphorylated by cAMP-dependant Protein Kinase A (PKA), whose activity is, in turn, regulated by the cAMP hydrolysis activity of phosphodiesterases, including PDE4. We propose that DISC1 acts as an assembly scaffold for all of these proteins and that the NDE1/NDEL1/LIS1/dynein complex is modulated by cAMP levels via PKA and PDE4.
Fusarium oxysporum volatiles enhance plant growth via affecting auxin transport and signaling

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Vasileios eBitas

2015-11-01

Full Text Available Volatile organic compounds (VOCs have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption.
ZnO Nanoparticles Affect Bacillus subtilis Cell Growth and Biofilm Formation.

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Yi-Huang Hsueh

Full Text Available Zinc oxide nanoparticles (ZnO NPs are an important antimicrobial additive in many industrial applications. However, mass-produced ZnO NPs are ultimately disposed of in the environment, which can threaten soil-dwelling microorganisms that play important roles in biodegradation, nutrient recycling, plant protection, and ecological balance. This study sought to understand how ZnO NPs affect Bacillus subtilis, a plant-beneficial bacterium ubiquitously found in soil. The impact of ZnO NPs on B. subtilis growth, FtsZ ring formation, cytosolic protein activity, and biofilm formation were assessed, and our results show that B. subtilis growth is inhibited by high concentrations of ZnO NPs (≥ 50 ppm, with cells exhibiting a prolonged lag phase and delayed medial FtsZ ring formation. RedoxSensor and Phag-GFP fluorescence data further show that at ZnO-NP concentrations above 50 ppm, B. subtilis reductase activity, membrane stability, and protein expression all decrease. SDS-PAGE Stains-All staining results and FT-IR data further demonstrate that ZnO NPs negatively affect exopolysaccharide production. Moreover, it was found that B. subtilis biofilm surface structures became smooth under ZnO-NP concentrations of only 5-10 ppm, with concentrations ≤ 25 ppm significantly reducing biofilm formation activity. XANES and EXAFS spectra analysis further confirmed the presence of ZnO in co-cultured B. subtilis cells, which suggests penetration of cell membranes by either ZnO NPs or toxic Zn+ ions from ionized ZnO NPs, the latter of which may be deionized to ZnO within bacterial cells. Together, these results demonstrate that ZnO NPs can affect B. subtilis viability through the inhibition of cell growth, cytosolic protein expression, and biofilm formation, and suggest that future ZnO-NP waste management strategies would do well to mitigate the potential environmental impact engendered by the disposal of these nanoparticles.
Growth of bean and tomato plants as affected by root absorbed growth substances and atmospheric carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Tognoni, F; Halevy, A H; Wittwer, S H

1967-01-01

Bean and tomato plants were grown in solution culture root media containing pre-determined concentrations of gibberellin A/sub 3/ (GA), 1-naphthalene-acetic acid (NAA), N/sup 6/-benzyladenine (BA), (2-chloroethyl)trimethylammonium chloride (CCC), and at atmospheric levels of 300 and 1000 ppm of CO/sub 2/. Net assimilation rates (NAR), relative growth rates (RGR), leaf area ratios (LAR), root to top dry weight ratios (R/T) and changes in dry weight, size, and form of each organ were recorded. Gibberellin had no effect on RGR of either plant species but increased the NAR of tomatoes at 1000 ppm CO/sub 2/. Total dry weight was only slightly affected by GA but root growth and R/T were markedly depressed. CCC had no effect on NAR, but decreased RGR and LAR. Root growth of beans and R/T in both plants were promoted by CCC. NAR and RGR were strongly inhibited by BA and NAA. Inhibition of stem and leaf growth by CCC and NAA was greater than that for roots; thus, R/T ratios were increased. Root branching was promoted by NAA. High (1000 ppm), compared to the low (300 ppm), atmospheric levels of CO/sub 2/ generally promoted root growth and produced an increase in the R/T, both in the absence and presence of chemical treatment. The multiplicity of effects of the root-absorbed chemical growth substances and CO/sub 2/ on growth and photosynthesis is discussed.
Cep70 and Cep131 contribute to ciliogenesis in zebrafish embryos

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Carl Matthias

2009-03-01

Full Text Available Abstract Background The centrosome is the cell's microtubule organising centre, an organelle with important roles in cell division, migration and polarity. However, cells can divide and flies can, for a large part of development, develop without them. Many centrosome proteins have been identified but the roles of most are still poorly understood. The centrioles of the centrosome are similar to the basal bodies of cilia, hair-like extensions of many cells that have important roles in cell signalling and development. In a number of human diseases, such Bardet-Biedl syndrome, centrosome/cilium proteins are mutated, leading to polycystic kidney disease, situs inversus, and neurological problems, amongst other symptoms. Results We describe zebrafish (Danio rerio embryos depleted for two uncharacterised, centrosome proteins, Cep70 and Cep131. The phenotype of these embryos resembles that of zebrafish mutants for intraflagellar transport proteins (IFTs, with kidney and ear development affected and left-right asymmetry randomised. These organs and processes are those affected in Bardet-Biedl syndrome and other similar diseases. Like these diseases, the root cause of the phenotype lies, in fact, in dysfunctional cilia, which are shortened but not eliminated in several tissues in the morphants. Centrosomes and basal bodies, on the other hand, are present. Both Cep70 and Cep131 possess a putative HDAC (histone deacetylase interacting domain. However, we could not detect in yeast two-hybrid assays any interaction with the deacetylase that controls cilium length, HDAC6, or any of the IFTs that we tested. Conclusion Cep70 and Cep131 contribute to ciliogenesis in many tissues in the zebrafish embryo: cilia are made in cep70 and cep131 morphant zebrafish embryos but are shortened. We propose that the role of these centrosomal/basal body proteins is in making the cilium and that they are involved in determination of the length of the axoneme.
Role of the placental Vitamin D receptor in modulating feto-placental growth in Fetal growth restriction and Preeclampsia-affected pregnancies.

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Padma eMurthi

2016-02-01

Full Text Available Fetal growth restriction (FGR is a common pregnancy complication that affects up to 5% of pregnancies worldwide. Recent studies demonstrate that Vitamin D deficiency is implicated in reduced fetal growth, which may be rescued by supplementation of Vitamin D. Despite this, the pathway(s by which Vitamin D modulate fetal growth remains to be investigated. Our own studies demonstrate that the Vitamin D receptor (VDR is significantly decreased in placentae from human pregnancies complicated by FGR and contributes to abnormal placental trophoblast apoptosis and differentiation and regulation of cell-cycle genes in vitro. Thus, Vitamin D signalling is important for normal placental function and fetal growth. This review discusses the association of Vitamin D with fetal growth, the function of Vitamin D and its receptor in pregnancy, as well as the functional significance of a placental source of Vitamin D in FGR. Additionally, we propose that for Vitamin D to be clinically effective to prevent and manage FGR, the molecular mechanisms of Vitamin D and its receptor in modulating fetal growth requires further investigation.
Do plastic particles affect microalgal photosynthesis and growth?

Science.gov (United States)

Sjollema, Sascha B; Redondo-Hasselerharm, Paula; Leslie, Heather A; Kraak, Michiel H S; Vethaak, A Dick

2016-01-01

The unbridled increase in plastic pollution of the world's oceans raises concerns about potential effects these materials may have on microalgae, which are primary producers at the basis of the food chain and a major global source of oxygen. Our current understanding about the potential modes and mechanisms of toxic action that plastic particles exert on microalgae is extremely limited. How effects might vary with particle size and the physico-chemical properties of the specific plastic material in question are equally unelucidated, but may hold clues to how toxicity, if observed, is exerted. In this study we selected polystyrene particles, both negatively charged and uncharged, and three different sizes (0.05, 0.5 and 6μm) for testing the effects of size and material properties. Microalgae were exposed to different polystyrene particle sizes and surface charges for 72h. Effects on microalgal photosynthesis and growth were determined by pulse amplitude modulation fluorometry and flow cytometry, respectively. None of the treatments tested in these experiments had an effect on microalgal photosynthesis. Microalgal growth was negatively affected (up to 45%) by uncharged polystyrene particles, but only at high concentrations (250mg/L). Additionally, these adverse effects were demonstrated to increase with decreasing particle size. Copyright © 2015 Elsevier B.V. All rights reserved.
Temperature and salinity affect the germination and growth of Silybum marianum Gaertn and Avena fatua

International Nuclear Information System (INIS)

Kashmir, S.; Khan, M. A.; Shad, A.

2016-01-01

Two troublesome weeds like Silybum marianum and Avena fatua were exposed to different levels of temperature and salinity. Laboratory based experimented were conducted in the Department of Weed Science, The University of Agriculture Peshawar during 2015. Sterilized seeds of S. marianum and A. fatua were placed in petri-dishes in a growth chamber. The temperature levels studied were 15, 25 and 40 degree C while the NaCl concentrations were 0, 100, 200, 300, 400, 500 and 600 mM. Data revealed that germination and growth related traits responded differently to different levels of temperature and salinity. Optimum temperature (25 degree C) resulted in higher germination and growth of both the weed species. While highest temperature used (40 degree C) or lower temperature (15 degree C) resulted in poor germination and growth of S. marianum and A. fatua. Salinity level up to 100 mM did not affect the seed germination of S. marianum and A. fatua. NaCl concentration above 100 mM significantly decreased germination and ceased the germination of both the weeds at 600 mM. Like germination, the growth related variables were also decreased at very low or very high temperature and higher concentrations of NaCl. It is concluded that temperature and NaCl can affect establishment, growth and seed production potential of S. marianum and A. fatua. (author)
Centriole amplification by mother and daughter centrioles differs in multiciliated cells.

Science.gov (United States)

Al Jord, Adel; Lemaître, Anne-Iris; Delgehyr, Nathalie; Faucourt, Marion; Spassky, Nathalie; Meunier, Alice

2014-12-04

The semi-conservative centrosome duplication in cycling cells gives rise to a centrosome composed of a mother and a newly formed daughter centriole. Both centrioles are regarded as equivalent in their ability to form new centrioles and their symmetric duplication is crucial for cell division homeostasis. Multiciliated cells do not use the archetypal duplication program and instead form more than a hundred centrioles that are required for the growth of motile cilia and the efficient propelling of physiological fluids. The majority of these new centrioles are thought to appear de novo, that is, independently from the centrosome, around electron-dense structures called deuterosomes. Their origin remains unknown. Using live imaging combined with correlative super-resolution light and electron microscopy, we show that all new centrioles derive from the pre-existing progenitor cell centrosome through multiple rounds of procentriole seeding. Moreover, we establish that only the daughter centrosomal centriole contributes to deuterosome formation, and thus to over ninety per cent of the final centriole population. This unexpected centriolar asymmetry grants new perspectives when studying cilia-related diseases and pathological centriole amplification observed in cycling cells and associated with microcephaly and cancer.

Soil type affects Pinus ponderosa var. scopulorum (Pinaceae) seedling growth in simulated drought experiments.

Science.gov (United States)

Lindsey, Alexander J; Kilgore, Jason S

2013-08-01

Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. • Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering) produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. • Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies.
Exploring posttraumatic growth in Tamil children affected by the Indian Ocean Tsunami in 2004.

Science.gov (United States)

Exenberger, Silvia; Ramalingam, Panch; Höfer, Stefan

2016-10-13

Few studies explore posttraumatic growth (PTG) in children from Eastern cultures. To help address this gap, the present study examined PTG among 177 South Indian children aged 8-17 years who were affected by the 2004 Tsunami. The study identifies the underlying factor structure of the Tamil version of the Revised Posttraumatic Growth Inventory for Children (PTGI-C-R), and aims to explore the prevalence of PTG, the relationship between distress and growth, and gender and age differences in PTG. The results of the principal component analysis indicated a two-factor structure with an interpersonal and a person-centred dimension of growth. The total scores of the Tamil PTGI-C-R were positively associated with posttraumatic stress symptoms (PTSS) and age. Moreover, there was a significant relationship between age and the person-centred growth subscale. Non-parametric tests found no gender differences in perceived growth. The role of socio-cultural factors on the nature of PTG is discussed. © 2016 International Union of Psychological Science.
Review of factors affecting the growth and survival of follicular grafts

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William M Parsley

2010-01-01

Full Text Available Great strides have been made in hair restoration over the past 20 years. A better understanding of natural balding and non-balding patterns along with more respect for ageing has helped guide proper hairline design. Additionally, the use of smaller grafts has created a significantly improved natural appearance to the transplanted grafts. Inconsistent growth and survival of follicular grafts, however, has continued to be a problem that has perplexed hair restoration surgeons. This review attempts to explore the stresses affecting grafts during transplantation and some of the complexities involved in graft growth and survival. These authors reviewed the literature to determine the primary scope of aspects influencing growth and survival of follicular grafts. This scope includes patient selection, operating techniques, graft care, storage solutions and additives. The primary focus of the hair restoration surgeons should first be attention to the fundamentals of hair care, hydration, temperature, time out of body and gentle handling. Factors such as advanced storage solutions and additives can be helpful once the fundamentals have been addressed.
Color of illumination during growth affects LHCII chiral macroaggregates in pea plant leaves.

Science.gov (United States)

Gussakovsky, Eugene E; Shahak, Yosepha; Schroeder, Dana F

2007-02-01

To determine whether the color of illumination under which plants are grown, affects the structure of photosynthetic antennae, pea plants were grown under either blue-enriched, red-enriched, or white light. Carotenoid content of isolated chloroplasts was found to be insensitive to the color of illumination during growth, while chlorophyll a/b ratio in chloroplasts isolated from young illuminated leaves showed susceptibility to color. Color of illumination affects the LHCII chiral macroaggregates in intact leaves and isolated chloroplasts, providing light-induced alteration of the handedness of the LHCII chiral macroaggregate, as measured with circular dichroism and circularly polarized luminescence. The susceptibility of handedness to current illumination (red light excitation of chlorophyll fluorescence) is dependent on the color under which the plants were grown, and was maximal for the red-enriched illumination. We propose the existence of a long-term (growth period) color memory, which influences the susceptibility of the handedness of LHCII chiral macroaggregates to current light.
Numerical study of how creep and progressive stiffening affect the growth stress formation in trees

DEFF Research Database (Denmark)

Ormarsson, Sigurdur; Dahlblom, O.; Johansson, M.

2010-01-01

It is not fully understood how much growth stresses affect the final quality of solid timber products in terms of e.g. shape stability. It is for example difficult to predict the internal growth stress field within the tree stem. Growth stresses are progressively generated during the tree growth...... and they are highly influenced by climate, biologic and material related factors. To increase the knowledge of the stress formation a finite element model was created to study how the growth stresses develop during the tree growth. The model is an axisymmetric general plane strain model where material for all new...... annual rings is progressively added to the tree during the analysis. The material model used is based on the theory of small strains (where strains refer to the undeformed configuration which is good approximation for strains less than 4%) where so-called biological maturation strains (growth...
Soil Type Affects Pinus ponderosa var. scopulorum (Pinaceae Seedling Growth in Simulated Drought Experiments

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Alexander J. Lindsey

2013-07-01

Full Text Available Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite, a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. Conclusions: Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies.
The centrosome protein NEDD1 as a potential pharmacological target to induce cell cycle arrest

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Etievant Chantal

2009-02-01

Full Text Available Abstract Background NEDD1 is a protein that binds to the gamma-tubulin ring complex, a multiprotein complex at the centrosome and at the mitotic spindle that mediates the nucleation of microtubules. Results We show that NEDD1 is expressed at comparable levels in a variety of tumor-derived cell lines and untransformed cells. We demonstrate that silencing of NEDD1 expression by treatment with siRNA has differential effects on cells, depending on their status of p53 expression: p53-positive cells arrest in G1, whereas p53-negative cells arrest in mitosis with predominantly aberrant monopolar spindles. However, both p53-positive and -negative cells arrest in mitosis if treated with low doses of siRNA against NEDD1 combined with low doses of the inhibitor BI2536 against the mitotic kinase Plk1. Simultaneous reduction of NEDD1 levels and inhibition of Plk1 act in a synergistic manner, by potentiating the anti-mitotic activity of each treatment. Conclusion We propose that NEDD1 may be a promising target for controlling cell proliferation, in particular if targeted in combination with Plk1 inhibitors.
Plasmid Transfer of Plasminogen K1-5 Reduces Subcutaneous Hepatoma Growth by Affecting Inflammatory Factors

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Lea A. Koch

2014-01-01

Full Text Available There is evidence that plasminogen K1-5 (PlgK1-5 directly affects tumour cells and inflammation. Therefore, we analysed if PlgK1-5 has immediate effects on hepatoma cells and inflammatory factors in vitro and in vivo. In vitro, effects of plasmid encoding PlgK1-5 (pK1-5 on Hepa129, Hepa1-6, and HuH7 cell viability, apoptosis, and proliferation as well as VEGF and TNF-alpha expression and STAT3-phosphorylation were investigated. In vivo, tumour growth, proliferation, vessel density, and effects on vascular endothelial growth factor (VEGF and tumour necrosis factor alpha (TNF-alpha expression were examined following treatment with pK1-5. In vivo, pK1-5 halved cell viability; cell death was increased by up to 15% compared to the corresponding controls. Proliferation was not affected. VEGF, TNF-alpha, and STAT3-phosphorylation were affected following treatment with pK1-5. In vivo, ten days after treatment initiation, pK1-5 reduced subcutaneous tumour growth by 32% and mitosis by up to 77% compared to the controls. Vessel density was reduced by 50%. TNF-alpha levels in tumour and liver tissue were increased, whereas VEGF levels in tumours and livers were reduced after pK1-5 treatment. Taken together, plasmid gene transfer of PlgK1-5 inhibits hepatoma (cell growth not only by reducing vessel density but also by inducing apoptosis, inhibiting proliferation, and triggering inflammation.
Pleiotropic Genes Affecting Carcass Traits in Bos indicus (Nellore Cattle Are Modulators of Growth.

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Anirene G T Pereira

Full Text Available Two complementary methods, namely Multi-Trait Meta-Analysis and Versatile Gene-Based Test for Genome-wide Association Studies (VEGAS, were used to identify putative pleiotropic genes affecting carcass traits in Bos indicus (Nellore cattle. The genotypic data comprised over 777,000 single-nucleotide polymorphism markers scored in 995 bulls, and the phenotypic data included deregressed breeding values (dEBV for weight measurements at birth, weaning and yearling, as well visual scores taken at weaning and yearling for carcass finishing precocity, conformation and muscling. Both analyses pointed to the pleomorphic adenoma gene 1 (PLAG1 as a major pleiotropic gene. VEGAS analysis revealed 224 additional candidates. From these, 57 participated, together with PLAG1, in a network involved in the modulation of the function and expression of IGF1 (insulin like growth factor 1, IGF2 (insulin like growth factor 2, GH1 (growth hormone 1, IGF1R (insulin like growth factor 1 receptor and GHR (growth hormone receptor, suggesting that those pleiotropic genes operate as satellite regulators of the growth pathway.
Factors affecting the course of body and kidney growth in infants with urolithiasis: A critical long-term evaluation

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Kemal Sarica

2016-12-01

Full Text Available Objective: To investigate the possible effects of dietary, patient and stone related factors on the clinical course of the stone disease as well as the body and renal growth status of the infants. Patients and Methods: A total of 50 children with an history of stone disease during infancy period were studied. Patient (anatomical abnormalities, urinary tract infection - UTI, associated morbidities, stone (obstruction, UTI and required interventions and lastly dietary (duration of sole breast feeding, formula feeding related factors which may affect the clinical course of the disease were all evaluated for their effects on the body and renal growth during long-term follow-up. Results: Mean age of the children was 2.40 ± 2.65 years. Our findings demonstrated that infants receiving longer period of breast feeding without formula addition seemed to have a higher rate of normal growth percentile values when compared with the other children. Again, higher frequency of UTI and stone attacks affected the growth status of the infants in a remarkable manner than the other cases. Our findings also demonstrated that thorough a close follow-up and appropriately taken measures; the possible growth retardation as well as renal growth problems could be avoided in children beginning to suffer from stone disease during infancy period. Conclusions: Duration of breast feeding, frequency of UTI, number of stone attacks and stone removal procedures are crucial factors for the clinical course of stone disease in infants that may affect the body as well as kidney growth during long-term follow-up.
Role of CAP350 in centriolar tubule stability and centriole assembly.

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Mikael Le Clech

Full Text Available BACKGROUND: Centrioles are microtubule-based cylindrical structures composed of nine triplet tubules and are required for the formation of the centrosome, flagella and cilia. Despite theirs importance, centriole biogenesis is poorly understood. Centrosome duplication is initiated at the G1/S transition by the sequential recruitment of a set of conserved proteins under the control of the kinase Plk4. Subsequently, the procentriole is assembled by the polymerization of centriolar tubules via an unknown mechanism involving several tubulin paralogs. METHODOLOGY/PRINCIPAL FINDINGS: Here, we developed a cellular assay to study centrosome duplication and procentriole stability based on its sensitivity to the microtubule-depolymerizing drug nocodazole. By using RNA interference experiments, we show that the stability of growing procentrioles is regulated by the microtubule-stabilizing protein CAP350, independently of hSAS-6 and CPAP which initiate procentriole growth. Furthermore, our analysis reveals the critical role of centriolar tubule stability for an efficient procentriole growth. CONCLUSIONS/SIGNIFICANCE: CAP350 belongs to a new class of proteins which associate and stabilize centriolar tubules to control centriole duplication.
Lichen secondary metabolites affect growth of Physcomitrella patens by allelopathy.

Science.gov (United States)

Goga, Michal; Antreich, Sebastian J; Bačkor, Martin; Weckwerth, Wolfram; Lang, Ingeborg

2017-05-01

Lichen secondary metabolites can function as allelochemicals and affect the development and growth of neighboring bryophytes, fungi, vascular plants, microorganisms, and even other lichens. Lichen overgrowth on bryophytes is frequently observed in nature even though mosses grow faster than lichens, but there is still little information on the interactions between lichens and bryophytes.In the present study, we used extracts from six lichen thalli containing secondary metabolites like usnic acid, protocetraric acid, atranorin, lecanoric acid, nortistic acid, and thamnolic acid. To observe the influence of these metabolites on bryophytes, the moss Physcomitrella patens was cultivated for 5 weeks under laboratory conditions and treated with lichen extracts. Toxicity of natural mixtures of secondary metabolites was tested at three selected doses (0.001, 0.01, and 0.1 %). When the mixture contained substantial amounts of usnic acid, we observed growth inhibition of protonemata and reduced development of gametophores. Significant differences in cell lengths and widths were also noticed. Furthermore, usnic acid had a strong effect on cell division in protonemata suggesting a strong impact on the early stages of bryophyte development by allelochemicals contained in the lichen secondary metabolites.Biological activities of lichen secondary metabolites were confirmed in several studies such as antiviral, antibacterial, antitumor, antiherbivore, antioxidant, antipyretic, and analgetic action or photoprotection. This work aimed to expand the knowledge on allelopathic effects on bryophyte growth.
Soil type affects Pinus ponderosa var. scopulorum (Pinaceae) seedling growth in simulated drought experiments1

Science.gov (United States)

Lindsey, Alexander J.; Kilgore, Jason S.

2013-01-01

• Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. • Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering) produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. • Conclusions: Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies. PMID:25202578
Mastication markedly affects mandibular condylar cartilage growth, gene expression, and morphology.

Science.gov (United States)

Enomoto, Akiko; Watahiki, Junichi; Nampo, Tomoki; Irie, Tarou; Ichikawa, Yuuta; Tachikawa, Tetsuhiko; Maki, Koutaro

2014-09-01

Mandibular growth is believed to be strongly related to mastication. Furthermore, mandibular condylar cartilage is known to be derived from neural crest cells. We examined whether the degree of chewing affects condylar cartilage growth of the mandible. Mice were fed diets with varying hardness. Genes specific to neural crest-derived cells were measured by real-time polymerase chain reaction to compare the expression changes between the mandibular and tibia cartilages. The mandibular condylar cartilage was then evaluated histologically, and proliferation was evaluated using proliferating cell nuclear antigen. Immunostaining was conducted for osteopontin, type X collagen, and Musashi1, and real-time polymerase chain reaction was used to assess the expression levels of osteopontin and type X collagen. Markers including P75, Wnt-1, Musashi1, and Nestin were upregulated in the mandibular condylar cartilage as compared with the tibial cartilage. Histologic assessment of the mandibular cartilage showed that the hypertrophic chondrocyte zone was statistically significantly thicker in mice fed a hard diet. Chondrocyte proliferation and Musashi1 expression were lower in mice fed a hard diet. After 4 weeks, numerous osteopontin and type X collagen-positive cells were observed in mice fed a mixed diet. Mastication affects the balance between differentiation and proliferation in the mandibular condylar cartilage. This phenomenon might be attributed to the presence of neural crest-derived cells. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Parameters affecting TGO growth rate and the lifetime of TBC systems with MCrAlY-bondcoats

Energy Technology Data Exchange (ETDEWEB)

Toscano, J.; Naumenko, D.; Singheiser, L.; Quadakkers, W.J. [Forschungszentrum Juelich GmbH, IEF 2, Juelich (Germany); Gil, A. [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Krakow (Poland)

2008-06-15

In the present work different parameters which affect the oxide growth on MCrAlY-bondcoats have been studied, in an attempt to find a reliable way to define the critical oxide thickness to failure of an EB-PVD thermal barrier coatings (TBC). It was found that the variation of selected parameters such as oxidation temperature, surface roughness, and bondcoat thickness certainly alters the thermally grown oxide (TGO) growth rate. However, simultaneously the morphology, composition, and/or microstructure of the oxide are changed, which can affect the critical TGO thickness to failure in a TBC system. In contrast, the variation of the oxygen partial pressure of the oxidizing atmosphere led to different TGO growth rates without significantly changing the oxide morphology and composition. Comparing the TGOs grown at different rates in the specimens exposed to high pO{sub 2} and low pO{sub 2} atmospheres, it was estimated that at failure the oxide scales in both specimens have reached a similar critical thickness. (Abstract Copyright [2008], Wiley Periodicals, Inc.)
Rearing Tenebrio molitor in BLSS: Dietary fiber affects larval growth, development, and respiration characteristics

Science.gov (United States)

Li, Leyuan; Stasiak, Michael; Li, Liang; Xie, Beizhen; Fu, Yuming; Gidzinski, Danuta; Dixon, Mike; Liu, Hong

2016-01-01

Rearing of yellow mealworm (Tenebrio molitor L.) will provide good animal nutrition for astronauts in a bioregenerative life support system. In this study, growth and biomass conversion data of T. molitor larvae were tested for calculating the stoichiometric equation of its growth. Result of a respiratory quotient test proved the validity of the equation. Fiber had the most reduction in mass during T. molitor‧s consumption, and thus it is speculated that fiber is an important factor affecting larval growth of T. molitor. In order to further confirm this hypothesis and find out a proper feed fiber content, T. molitor larvae were fed on diets with 4 levels of fiber. Larval growth, development and respiration in each group were compared and analyzed. Results showed that crude-fiber content of 5% had a significant promoting effect on larvae in early instars, and is beneficial for pupa eclosion. When fed on feed of 5-10% crude-fiber, larvae in later instars reached optimal levels in growth, development and respiration. Therefore, we suggest that crude fiber content in feed can be controlled within 5-10%, and with the consideration of food palatability, a crude fiber of 5% is advisable.
The zebrafish maternal-effect gene cellular atoll encodes the centriolar component sas-6 and defects in its paternal function promote whole genome duplication.

Science.gov (United States)

Yabe, Taijiro; Ge, Xiaoyan; Pelegri, Francisco

2007-12-01

A female-sterile zebrafish maternal-effect mutation in cellular atoll (cea) results in defects in the initiation of cell division starting at the second cell division cycle. This phenomenon is caused by defects in centrosome duplication, which in turn affect the formation of a bipolar spindle. We show that cea encodes the centriolar coiled-coil protein Sas-6, and that zebrafish Cea/Sas-6 protein localizes to centrosomes. cea also has a genetic paternal contribution, which when mutated results in an arrested first cell division followed by normal cleavage. Our data supports the idea that, in zebrafish, paternally inherited centrosomes are required for the first cell division while maternally derived factors are required for centrosomal duplication and cell divisions in subsequent cell cycles. DNA synthesis ensues in the absence of centrosome duplication, and the one-cycle delay in the first cell division caused by cea mutant sperm leads to whole genome duplication. We discuss the potential implications of these findings with regards to the origin of polyploidization in animal species. In addition, the uncoupling of developmental time and cell division count caused by the cea mutation suggests the presence of a time window, normally corresponding to the first two cell cycles, which is permissive for germ plasm recruitment.
Survivin inhibits anti-growth effect of p53 activated by aurora B

International Nuclear Information System (INIS)

Jung, Ji-Eun; Kim, Tae-Kyung; Lee, Joong-Seob; Oh, Se-Yeong; Kwak, Sungwook; Jin, Xun; Sohn, Jin-Young; Song, Min-Keun; Sohn, Young-Woo; Lee, Soo-Yeon; Pian, Xumin; Lee, Jang-Bo; Chung, Yong Gu; Choi, Young Ki; You, Seungkwon; Kim, Hyunggee

2005-01-01

Genomic instability and apoptosis evasion are hallmarks of cancer, but the molecular mechanisms governing these processes remain elusive. Here, we found that survivin, a member of the apoptosis-inhibiting gene family, and aurora B kinase, a chromosomal passenger protein, were co-overexpressed in the various glioblastoma cell lines and tumors. Notably, exogenous introduction of the aurora B in human BJ cells was shown to decrease cell growth and increase the senescence-associated β-galactosidase activity by activation of p53 tumor suppressor. However, aurora B overexpression failed to inhibit cell proliferation in BJ and U87MG cells transduced with dominant-negative p53 as well as in p53 -/- mouse astrocytes. Aurora B was shown to increase centrosome amplification in the p53 -/- astrocytes. Survivin was shown to induce anchorage-independent growth and inhibit anti-proliferation and drug-sensitive apoptosis caused by aurora B. Overexpression of both survivin and aurora B further accelerated the proliferation of BJ cells. Taken together, the present study indicates that survivin should accelerate tumorigenesis by inhibiting the anti-proliferative effect of p53 tumor suppressor that is activated by aurora B in normal and glioblastoma cells containing intact p53
Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

International Nuclear Information System (INIS)

Maneckjee, R.; Minna, J.D.

1990-01-01

Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for μ, δ, and κ opioid agonists and for nicotine and α-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas μ, δ, and κ opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides (β-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer
Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

Energy Technology Data Exchange (ETDEWEB)

Maneckjee, R.; Minna, J.D. (National Cancer Institute-Navy Medical Oncology Branch, Bethesda, MD (USA) Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

1990-05-01

Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for {mu}, {delta}, and {kappa} opioid agonists and for nicotine and {alpha}-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas {mu}, {delta}, and {kappa} opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides ({beta}-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer.

The cytoskeleton of Drosophila-derived Schneider line-1 and Kc23 cells undergoes significant changes during long-term culture

Science.gov (United States)

Schatten, H.; Hedrick, J.; Chakrabarti, A.

1998-01-01

Insect cell cultures derived from Drosophila melanogaster are increasingly being used as an alternative system to mammalian cell cultures, as they are amenable to genetic manipulation. Although Drosophila cells are an excellent tool for the study of genes and expression of proteins, culture conditions have to be considered in the interpretation of biochemical results. Our studies indicate that significant differences occur in cytoskeletal structure during the long-term culture of the Drosophila-derived cell lines Schneider Line-1 (S1) and Kc23. Scanning, transmission-electron, and immunofluorescence microscopy studies reveal that microfilaments, microtubules, and centrosomes become increasingly different during the culture of these cells from 24 h to 7-14 days. Significant cytoskeletal changes are observed at the cell surface where actin polymerizes into microfilaments, during the elongation of long microvilli. Additionally, long protrusions develop from the cell surface; these protrusions are microtubule-based and establish contact with neighboring cells. In contrast, the microtubule network in the interior of the cells becomes disrupted after four days of culture, resulting in altered transport of mitochondria. Microtubules and centrosomes are also affected in a small percent of cells during cell division, indicating an instability of centrosomes. Thus, the cytoskeletal network of microfilaments, microtubules, and centrosomes is affected in Drosophila cells during long-term culture. This implies that gene regulation and post-translational modifications are probably different under different culture conditions.
A review on the factors affecting mite growth in stored grain commodities.

Science.gov (United States)

Collins, D A

2012-03-01

A thorough review of the literature has identified the key factors and interactions that affect the growth of mite pests on stored grain commodities. Although many factors influence mite growth, the change and combinations of the physical conditions (temperature, relative humidity and/or moisture content) during the storage period are likely to have the greatest impact, with biological factors (e.g. predators and commodity) playing an important role. There is limited information on the effects of climate change, light, species interactions, local density dependant factors, spread of mycotoxins and action thresholds for mites. A greater understanding of these factors may identify alternative control techniques. The ability to predict mite population dynamics over a range of environmental conditions, both physical and biological, is essential in providing an early warning of mite infestations, advising when appropriate control measures are required and for evaluating control measures. This information may provide a useful aid in predicting and preventing mite population development as part of a risk based decision support system.
Does the titanium plate fixation of symphyseal fracture affect mandibular growth?

Science.gov (United States)

Bayram, Burak; Yilmaz, Alev Cetinsahin; Ersoz, Esra; Uckan, Sina

2012-11-01

The effect of metallic fixation on growth is a major concern in children and is not yet clear. The aim of this study was to evaluate the effect of metallic fixation of mandibular symphyseal fracture on mandibular growth.Eighteen 90-day-old growing white New Zealand rabbits weighing 1.6 to 2.5 kg were included in this study and divided into 2 groups of 9 subjects. In the experimental group, animals underwent mandibular osteotomy, simulating a symphyseal fracture on the midline of mandibular symphysis. The bone segments were fixed with microplates and microscrews (1.6 mm).In the control group, the same surgical incision without performing symphyseal osteotomy was conducted, and 2 screws were inserted on each side of the symphyseal midline.Digital cephalometric and submentovertex radiographs were taken before the operation and at postoperative 6 months for each animal in 2 groups, and cephalometric measurements were performed. The distance between the centers of the head of 2 screws measured at the end of surgery in the control group was compared with measurements at 6 months after surgery. Obtained data were statistically analyzed.There is no statistically significant difference between the 2 groups for growth amount of both sides of the mandible. Difference of ANS-Id (the most anterior points of nasal bone, the most anterior point on the alveolar bone between the lower incisors) and Cd-Id (the uppermost and most distal point of the mandibular condyle, the most anterior point on the alveolar bone between the lower incisors) values of the 2 groups is not statistically significant (P > 0.05).The distance between the 2 screws at the first application significantly increased at the postoperative sixth month (P mandibular symphyseal fracture does not affect the vertical and sagittal mandibular growth in growing rabbits.
Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof

Energy Technology Data Exchange (ETDEWEB)

Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy, E-mail: jlundholm@smu.ca

2016-05-15

Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%–26% volumetric moisture content) and temperature (21 °C–36 °C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat
Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof

International Nuclear Information System (INIS)

Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

2016-01-01

Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%–26% volumetric moisture content) and temperature (21 °C–36 °C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat
Remnant trees affect species composition but not structure of tropical second-growth forest.

Science.gov (United States)

Sandor, Manette E; Chazdon, Robin L

2014-01-01

Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.
Two Novel SNPs of PPARγ Significantly Affect Weaning Growth Traits of Nanyang Cattle.

Science.gov (United States)

Huang, Jieping; Chen, Ningbo; Li, Xin; An, Shanshan; Zhao, Minghui; Sun, Taihong; Hao, Ruijie; Ma, Yun

2018-01-02

Peroxisome-proliferator-activated receptor gamma (PPARγ) is a key transcription factor that controls adipocyte differentiation and energy in mammals. Therefore, PPARγ is a potential factor influencing animal growth traits. This study primarily evaluates PPARγ as candidate gene for growth traits of cattle and identifies potential molecular marker for cattle breeding. Per previous studies, PPARγ mRNA was mainly expressed at extremely high levels in adipose tissues as shown by quantitative real-time polymerase chain reaction analysis. Three novel SNPs of the bovine PPARγ gene were identified in 514 individuals from six Chinese cattle breeds: SNP1 (AC_000179.1 g.57386668 C > G) in intron 2 and SNP2 (AC_000179.1 g.57431964 C > T) and SNP3 (AC_000179.1 g.57431994 T > C) in exon 7. The present study also investigated genetic characteristics of these SNP loci in six populations. Association analysis showed that SNP1 and SNP3 loci significantly affect weaning growth traits, especially body weight of Nanyang cattle. These results revealed that SNP1 and SNP3 are potential molecular markers for cattle breeding.
How do Labor Market Institutions affect the Link between Growth and Unemployment: the case of the European countries

Directory of Open Access Journals (Sweden)

Langot, François

2010-12-01

Full Text Available This paper analyzes how the frictions in the labor market simultaneously affect the economic growth and the long run unemployment. To this goal, we develop a schumpeterian model of endogenous growth: agents have the choice between employment and R and D activities. Unemployment is caused by the wage-setting behavior of unions. We show that: (i Increases in the labor costs or in the power of trade unions lead to higher unemployment and lower economic growth. (ii Efficient bargain allows to increase employment, at the price of a lower growth rate. These theoretical predictions are consistent with the insights from our empirical analysis based on 183 European Regions, between 1980-2003
Do soil fertilization and forest canopy foliage affect the growth and photosynthesis of Amazonian saplings?

Directory of Open Access Journals (Sweden)

Nilvanda dos Santos Magalhães

2014-02-01

Full Text Available Most Amazonian soils are highly weathered and poor in nutrients. Therefore, photosynthesis and plant growth should positively respond to the addition of mineral nutrients. Surprisingly, no study has been carried out in situ in the central Amazon to address this issue for juvenile trees. The objective of this study was to determine how photosynthetic rates and growth of tree saplings respond to the addition of mineral nutrients, to the variation in leaf area index of the forest canopy, and to changes in soil water content associated with rainfall seasonality. We assessed the effect of adding a slow-release fertilizer. We determined plant growth from 2010 to 2012 and gas exchange in the wet and dry season of 2012. Rainfall seasonality led to variations in soil water content, but it did not affect sapling growth or leaf gas exchange parameters. Although soil amendment increased phosphorus content by 60 %, neither plant growth nor the photosynthetic parameters were influenced by the addition of mineral nutrients. However, photosynthetic rates and growth of saplings decreased as the forest canopy became denser. Even when Amazonian soils are poor in nutrients, photosynthesis and sapling growth are more responsive to slight variations in light availability in the forest understory than to the availability of nutrients. Therefore, the response of saplings to future increases in atmospheric [CO2] will not be limited by the availability of mineral nutrients in the soil.
SCC growth behavior of stainless steel weld heat-affected zone in hydrogenated high temperature water

International Nuclear Information System (INIS)

Yamada, Takuyo; Terachi, Takumi; Miyamoto, Tomoki; Arioka, Koji

2010-01-01

It is known that the SCC growth rate of stainless steels in high-temperature water is accelerated by cold-work (CW). The weld heat-affected-zone (HAZ) of stainless steels is also deformed by weld shrinkage. However, only little have been reported on the SCC growth of weld HAZ of SUS316 and SUS304 in hydrogenated high-temperature water. Thus, in this present study, SCC growth experiments were performed using weld HAZ of stainless steels, especially to obtain data on the dependence of SCC growth on (1) temperature and (2) hardness in hydrogenated water at temperatures from 250degC to 340degC. And then, the SCC growth behaviors were compared between weld HAZ and CW stainless steels. The following results have been obtained. Significant SCC growth were observed in weld HAZ (SUS316 and SUS304) in hydrogenated water at 320degC. The SCC growth rates of the HAZ are similar to that of 10% CW non-sensitized SUS316, in accordance with that the hardness of weld HAZ is also similar to that of 10% CW SUS316. Temperature dependency of SCC growth of weld HAZ (SUS316 and SUS304) is also similar to that of 10% CW non-sensitized SUS316. That is, no significant SCC were observed in the weld HAZ (SUS316 and SUS304) in hydrogenated water at 340degC. This suggests that SCC growth behaviors of weld HAZ and CW stainless steels are similar and correlated with the hardness or yield strength of the materials, at least in non-sensitized regions. And the similar temperature dependence between the HAZ and CW stainless steels suggests that the SCC growth behaviors are also attributed to the common mechanism. (author)
Simulations of centriole of polarized centrosome as a monopole antenna in immune and viral synapses.

Science.gov (United States)

Dvorak, Josef; Melichar, Bohuslav; Filipova, Alzbeta; Grimova, Jana; Grimova, Nela; Rozsypalova, Aneta; Buka, David; Voboril, Rene; Zapletal, Radek; Buchler, Tomas; Richter, Igor; Buka, David

2018-01-01

The immune synapse (IS) is a temporary interface between an antigen-presenting cell and an effector lymphocyte. Viral synapse is a molecularly organized cellular junction that is structurally similar to the IS. Primary cilium is considered as a functional homologue of the IS due to the morphological and functional similarities in architecture between both micotubule structures. It has been hypothesized that endogenous electromagnetic field in the cell is generated by a unique cooperating system between mitochondria and microtubules. We are extending this prior hypothesis of the endogenous electromagnetic field in the cell postulating that polarized centriole in immune and viral synapse could serve as a monopole antenna. This is an addition to our hypothesis that primary cilium could serve as a monopole antenna. We simulated the distribution of electric field of centriole of polarized centrosome as a monopole antenna in immune and viral synapse. Very weak electromagnetic field of polarized centriole of CD8+ T lymphocyte in IS can contribute to the transport of cytolytic granules into the attacked (cancer) cell. Analogically, very weak electromagnetic field of polarized centriole in viral synapse of infected CD4 cells can aid the transport of viruses (human immunodeficiency virus) to non-infected CD4 cells. We hypothesized that healthy organisms need these monopole antennas. If, during the neoplastic transformation, healthy cells lose monopole antennas in form of primary cilia, the IS aims to replace them by monopole antennas of polarized centrioles in IS to restore homeostasis.
Does the water reuse affect the fish growth, welfare quality?

Directory of Open Access Journals (Sweden)

Štěpán Lang

2012-01-01

Full Text Available The fish production in aquaculture is growing from year to year. However capacities of current aquaculture facilities are limited. So the need of intensification of old facilities and building new intensive facilities is obvious. The high intensity of fish culture generates some questions. Could water reuse affect fish growth, welfare, health or quality of final product? A lot of research was performed for this issue but just a few works compared water reuse systems (RAS versus flow thru systems (FTS. A problem with CO2 oversaturation was solved by shallow diffusers. Fin erosion seems to be a problem of high stocking density and system hygienic but it is not related directly to water reuse. A few papers were written about biochemical blood stress markers but it was mostly aimed to acute crowding or changes were found at extreme stocking densities over 124 kg.m3 for rainbow trout and 70 kg.m3 for sea bass. The fish are able to accustom to increased noise produced by RAS equipment very fast so it don’t affect fish negatively. There wasn’t found any prove of main water reuse to fish influence in the available literature. All results indicates that if the ecological parameters are kept in natural range for the fish reared in RAS, there is no negative effect of water reuse on fish.
Eastern Baltic cod : Perspectives from existing data on processes affecting growth and survival of eggs and larvae

DEFF Research Database (Denmark)

MacKenzie, Brian; St. John, Michael; Wieland, Kai

1996-01-01

exist in our knowledge of processes affecting egg and larval growth and survival, but some promising areas of research are indicated. In particular the seasonality of spawning, deep water oxygen concentrations, predation on eggs, and larval food production require further investigation....... surveys have described food concentrations at appropriate scales for cod larvae, and the species composition of larval diets is unknown. Growth rates for Baltic cod larvae have not been measured and cannot be compared with rates in other areas or to variations in biotic and abiotic factors. Large gaps...
Chapter 10 the primary cilium coordinates signaling pathways in cell cycle control and migration during development and tissue repair

DEFF Research Database (Denmark)

Christensen, Søren T; Pedersen, Stine F; Satir, Peter

2008-01-01

Cell cycle control and migration are critical processes during development and maintenance of tissue functions. Recently, primary cilia were shown to take part in coordination of the signaling pathways that control these cellular processes in human health and disease. In this review, we present...... an overview of the function of primary cilia and the centrosome in the signaling pathways that regulate cell cycle control and migration with focus on ciliary signaling via platelet-derived growth factor receptor alpha (PDGFRalpha). We also consider how the primary cilium and the centrosome interact...... with the extracellular matrix, coordinate Wnt signaling, and modulate cytoskeletal changes that impinge on both cell cycle control and cell migration....
Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

NARCIS (Netherlands)

Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Doerfler, Arnd; Kinning, Esther; Megarbane, Andre; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Doerr, Helmuth-Guenther; Reis, Andre

2008-01-01

Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss- of- function mutations in the centrosomal pericentrin ( PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial
Breakage or uprooting: How tree death type affects hillslope processes in old-growth temperate forests

Science.gov (United States)

Šamonil, Pavel; Daněk, Pavel; Adam, Dušan; Phillips, Jonathan D.

2017-12-01

Tree breakage and uprooting are two possible scenarios of tree death that have differing effects on hillslope processes. In this study we aimed to (i) reveal the long-term structure of the biomechanical effects of trees (BETs) in relation to their radial growth and tree death types in four old-growth temperate forests in four different elevation settings with an altitudinal gradient of 152-1105 m a.s.l., (ii) quantify affected areas and soil volumes associated with the studied BETs in reserves, and (iii) derive a general model of the role of BETs in hillslope processes in central European temperate forests. We analyzed the individual dynamics of circa 55,000 trees in an area of 161 ha within four old-growth forests over 3-4 decades. Basal tree censuses established in all sites in the 1970s and repeated tree censuses in the 1990s and 2000s provided detailed information about the radial growth of each tree of DBH ≥ 10 cm as well as about types of tree death. We focused on the quantification of: (i) surviving still-living trees, (ii) new recruits, (iii) standing dead trees, (iv) uprooted trees, and (v) broken trees. Frequencies of phenomena were related to affected areas and volumes of soil using individual statistical models. The elevation contrasts were a significant factor in the structure of BETs. Differences between sites increased from frequencies of events through affected areas to volumes of soil associated with BETs. An average 2.7 m3 ha-1 year-1 was associated with all BETs of the living and dying trees in lowlands, while there was an average of 7.8 m3 ha-1 year-1 in the highest mountain site. Differences were caused mainly by the effects of dying trees. BETs associated with dead trees were 7-8 times larger in the mountains. Effects of dying trees and particularly treethrows represented about 70% of all BETs at both mountain sites, while it was 58% at the highland site and only 32% at the lowland site. Our results show a more significant role of BETs in
Warming and neighbor removal affect white spruce seedling growth differently above and below treeline.

Science.gov (United States)

Okano, Kyoko; Bret-Harte, M Syndonia

2015-01-01

Climate change is expected to be pronounced towards higher latitudes and altitudes. Warming triggers treeline and vegetation shifts, which may aggravate interspecific competition and affect biodiversity. This research tested the effects of a warming climate, habitat type, and neighboring plant competition on the establishment and growth of white spruce (Picea glauca (Moench) Voss) seedlings in a subarctic mountain region. P. glauca seedlings were planted in June 2010 under 4 different treatments (high/control temperatures, with/without competition) in 3 habitats (alpine ridge above treeline/tundra near treeline /forest below treeline habitats). After two growing seasons in 2011, growth, photosynthesis and foliar C and N data were obtained from a total of 156, one-and-a-half year old seedlings that had survived. Elevated temperatures increased growth and photosynthetic rates above and near treeline, but decreased them below treeline. Competition was increased by elevated temperatures in all habitat types. Our results suggest that increasing temperatures will have positive effects on the growth of P. glauca seedlings at the locations where P. glauca is expected to expand its habitat, but increasing temperatures may have negative effects on seedlings growing in mature forests. Due to interspecific competition, possibly belowground competition, the upslope expansion of treelines may not be as fast in the future as it was the last fifty years.
An overview of microstructural and experimental factors that affect the irradiation growth behavior of zirconium alloys

International Nuclear Information System (INIS)

Fidleris, V.; Tucker, R.P.; Adamson, R.B.

1987-01-01

This paper presents an overview of factors affecting irradiation growth of zirconium alloys. Recent data obtained from irradiation programs in EBR-II, ATR, and NRU reactors are used to illustrate the effects of various microstructural and experimental factors on the growth of Zircaloy, zirconium, and zirconium-biobium alloys irradiated to fluences up to 2 X 10 26 nm -2 (E > 1 MeV) over the temperature range 330 to 720 K. Open literature results are also used to confirm or illustrate various effects. Important factors are texture, grain boundary parameters, residual stresses, original dislocation density, microstructure evolution, temperature during irradiation, solute effects, and fluence
Statistical aspects of fatigue crack growth life of base metal, weld metal and heat affected zone in FSWed 7075-T651aluminum alloy

International Nuclear Information System (INIS)

Sohn, Hye Jeong; Haryadi, Gunawan Dwi; Kim, Seon Jin

2014-01-01

The statistical aspects of fatigue crack growth life of base metal (BM), weld metal (WM) and heat affected zone (HAZ) in friction stir welded (FSWed) 7075-T651 aluminum alloy has been studied by Weibull statistical analysis. The fatigue crack growth tests were performed at room temperature on ASTM standard CT specimens under three different constant stress intensity factor range controls. The main objective of this paper is to investigate the effects of statistical aspects of fatigue crack growth life on stress intensity factor ranges and material properties, namely BM, WM and HAZ specimens. In this work, the Weibull distribution was employed to estimate the statistical aspects of fatigue crack growth life. The shape parameter of Weibull distribution for fatigue crack growth life was significantly affected by material properties and the stress intensity factor range. The scale parameter of WM specimen exhibited the lowest value at all stress intensity factor ranges.
Pyrrolizidine alkaloids from Senecio jacobaea affect fungal growth

NARCIS (Netherlands)

Hol, W.H.G.; Van Veen, J.A.

2002-01-01

We investigated the growth-reducing effects of pyrrolizidine alkaloids (PAs) from Senecio jacobaea on nine plant-associated fungi (five strains of Fusarium oxysporum, two of F. sambucinum, and two of Trichoderma sp). Fungal growth was monitored on water agar media containing different concentrations

Azadirachtin Affects the Growth of Spodoptera litura Fabricius by Inducing Apoptosis in Larval Midgut.

Science.gov (United States)

Shu, Benshui; Zhang, Jingjing; Cui, Gaofeng; Sun, Ranran; Yi, Xin; Zhong, Guohua

2018-01-01

Azadirachtin, the environmentally friendly botanical pesticide, has been used as an antifeedant and pest growth regulator in integrated pest management for decades. It has shown strong biological activity against Spodoptera litura , but the mechanism of toxicity remains unclear. The present study showed that azadirachtin inhibited the growth of S. litura larvae, which was resulted by structure destroy and size inhibition of the midgut. Digital gene expression (DGE) analysis of midgut suggested that azadirachtin regulated the transcriptional level of multiple unigenes involved in mitogen-activated protein kinase (MAPK) and calcium apoptotic signaling pathways. Simultaneously, the expression patterns of some differentially expressed unigenes were verified by quantitative real time-PCR (qRT-PCR). In addition, the enhanced terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining, the increased expression of caspase family members and apoptosis-binding motif 1 (IBM1) on both gene and protein level and the release of cytochrome c from mitochondria to cytoplasm were induced in midgut after azadirachtin treatment. These results demonstrated that azadirachtin induced structural alteration in S. litura larval midgut by apoptosis activation. These alterations may affect the digestion and absorption of nutrients and eventually lead to the growth inhibition of larvae.
Responding to chromosomal breakage during M-phase: insights from a cell-free system

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Costanzo Vincenzo

2009-07-01

Full Text Available Abstract DNA double strand breaks (DSBs activate ATM and ATR dependent checkpoints that prevent the onset of mitosis. However, how cells react to DSBs occurring when they are already in mitosis is poorly understood. The Xenopus egg extract has been utilized to study cell cycle progression and DNA damage checkpoints. Recently this system has been successfully used to uncover an ATM and ATR dependent checkpoint affecting centrosome driven spindle assembly. These studies have led to the identification of XCEP63 as major target of this pathway. XCEP63 is a coiled-coil rich protein localized at centrosome essential for proper spindle assembly. ATM and ATR directly phosphorylate XCEP63 on serine 560 inducing its delocalization from centrosome, which in turn delays spindle assembly. This pathway might contribute to regulate DNA repair or mitotic cell survival in the presence of chromosome breakage.
An ultraviolet B condition that affects growth and defense in Arabidopsis.

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Vandenbussche, Filip; Yu, Na; Li, Weidong; Vanhaelewyn, Lucas; Hamshou, Mohamad; Van Der Straeten, Dominique; Smagghe, Guy

2018-03-01

Ultraviolet B light (UV-B, 280-315 nm) is the shortest wavelength of the solar spectrum reaching the surface of the Earth. It has profound effects on plants, ranging from growth regulation to severe metabolic changes. Low level UV-B mainly causes photomorphogenic effects while higher levels can induce stress, yet these effects tend to overlap. Here we identified a condition that allows growth reduction without obvious detrimental stress in wild type Arabidopsis rosette plants. This condition was used to study the effects of a daily UV-B dose on plant characteristics of UV-B adapted plants in detail. Exploration of the transcriptome of developing leaves indicated downregulation of genes involved in stomata formation by UV-B, while at the same time genes involved in photoprotective pigment biosynthesis were upregulated. These findings correspond with a decreased stomatal density and increased UV-B absorbing pigments. Gene ontology analysis revealed upregulation of defense related genes and meta-analysis showed substantial overlap of the UV-B regulated transcriptome with transcriptomes of salicylate and jasmonate treated as well as herbivore exposed plants. Feeding experiments showed that caterpillars of Spodoptera littoralis are directly affected by UV-B, while performance of the aphid Myzus persicae is diminished by a plant mediated process. Copyright © 2017 Elsevier B.V. All rights reserved.
The Fat-Dachsous signaling pathway regulates growth of horns in Trypoxylus dichotomus, but does not affect horn allometry.

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Hust, James; Lavine, Mark D; Worthington, Amy M; Zinna, Robert; Gotoh, Hiroki; Niimi, T; Lavine, Laura

Males of the Asian rhinoceros beetle, Trypoxylus dichotomus, possess exaggerated head and thoracic horns that scale dramatically out of proportion to body size. While studies of insulin signaling suggest that this pathway regulates nutrition-dependent growth including exaggerated horns, what regulates disproportionate growth has yet to be identified. The Fat signaling pathway is a potential candidate for regulating disproportionate growth of sexually-selected traits, a hypothesis we advanced in a previous paper (Gotoh et al., 2015). To investigate the role of Fat signaling in the growth and scaling of the sexually dimorphic, condition-dependent traits of the in the Asian rhinoceros beetle T. dichotomus, we used RNA interference to knock down expression of fat and its co-receptor dachsous. Knockdown of fat, and to a lesser degree dachsous, caused shortening and widening of appendages, including the head and thoracic horns. However, scaling of horns to body size was not affected. Our results show that Fat signaling regulates horn growth in T. dichotomus as it does in appendage growth in other insects. However, we provide evidence that Fat signaling does not mediate the disproportionate, positive allometric growth of horns in T. dichotomus. Copyright © 2018 Elsevier Ltd. All rights reserved.
Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

NARCIS (Netherlands)

Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Dörfler, Arnd; Kinning, Esther; Megarbane, André; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Dörr, Helmuth-Günther; Reis, André

2008-01-01

Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss-of-function mutations in the centrosomal pericentrin (PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial dwarfism
Factors affecting quality and health promoting compounds during growth and postharvest life of sweet cherry (Prunus avium L.)

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Correia, Sofia; Schouten, Rob; Silva, Ana P.; Gonçalves, Berta

2017-01-01

Sweet cherries are attractive fruits due to their taste, color, nutritional value, and beneficial health effects. Sweet cherry is a highly perishable fruit and all quality attributes and the level of health promoting compounds are affected by growth conditions, picking, packing, transport, and
ANALYSIS OF FACTORS WHICH AFFECTING THE ECONOMIC GROWTH

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Suparna Wijaya

2017-03-01

Full Text Available High economic growth and sustainable process are main conditions for sustainability of economic country development. They are also become measures of the success of the country's economy. Factors which tested in this study are economic and non-economic factors which impacting economic development. This study has a goal to explain the factors that influence on macroeconomic Indonesia. It used linear regression modeling approach. The analysis result showed that Tax Amnesty, Exchange Rate, Inflation, and interest rate, they jointly can bring effect which amounted to 77.6% on economic growth whereas the remaining 22.4% is the influenced by other variables which not observed in this study. Keywords: tax amnesty, exchange rates, inflation, SBI and economic growth
Aluminium Toxicity to Plants as Influenced by the Properties of the Root Growth Environment Affected by Other Co-Stressors: A Review.

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Siecińska, Joanna; Nosalewicz, Artur

Aluminium toxicity to crops depends on the acidity of the soil and specific plant resistance. However, it is also strongly affected by other environmental factors that have to be considered to properly evaluate the resultant effects on plants. Observed weather perturbations and predicted climate changes will increase the probability of co-occurrence of aluminium toxicity and other abiotic stresses.In this review the mechanisms of plant-aluminium interactions are shown to be influenced by soil mineral nutrients, heavy metals, organic matter, oxidative stress and drought. Described effects of aluminium toxicity include: root growth inhibition, reduction in the uptake of mineral nutrients resulting from the inhibition of transport processes through ion channels; epigenetic changes to DNA resulting in gene silencing. Complex processes occurring in the rhizosphere are highlighted, including the role of soil organic matter and aluminium detoxification by mucilage.There is a considerable research gap in the understanding of root growth in the soil environment in the presence of toxic aluminium concentrations as affected by interactions with abiotic stressors. This knowledge is important for the selection of feasible methods aimed at the reduction of negative consequences of crop production in acidic soils affected by adverse growth environment.
RNAi mediated acute depletion of Retinoblastoma protein (pRb promotes aneuploidy in human primary cells via micronuclei formation

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Iovino Flora

2009-11-01

Full Text Available Abstract Background Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Results Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Conclusion Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger
The garlic allelochemical diallyl disulfide affects tomato root growth by influencing cell division, phytohormone balance and expansin gene expression

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Fang Cheng

2016-08-01

Full Text Available Diallyl disulfide (DADS is a volatile organosulfur compound derived from garlic (Allium sativum L., and it is known as an allelochemical responsible for the strong allelopathic potential of garlic. The anticancer properties of DADS have been studied in experimental animals and various types of cancer cells, but to date, little is known about its mode of action as an allelochemical at the cytological level. The current research presents further studies on the effects of DADS on tomato (Solanum lycopersicum L. seed germination, root growth, mitotic index and cell size in root meristem, as well as the phytohormone levels and expression profile of auxin biosynthesis genes (FZYs, auxin transport genes (SlPINs and expansin genes (EXPs in tomato root. The results showed a biphasic, dose-dependent effect on tomato seed germination and root growth under different DADS concentrations. Lower concentrations (0.01-0.62 mM of DADS significantly promoted root growth, whereas higher levels (6.20-20.67 mM showed inhibitory effects. Cytological observations showed that the cell length of root meristem was increased and that the mitotic activity of meristematic cells in seedling root tips was enhanced at lower concentrations of DADS. In contrast, DADS at higher concentrations inhibited root growth by affecting both the length and division activity of meristematic cells. However, the cell width of the root meristem was not affected. Additionally, DADS increased the IAA and ZR contents of seedling roots in a dose-dependent manner. The influence on IAA content may be mediated by the up-regulation of FZYs and PINs. Further investigation into the underlying mechanism revealed that the expression levels of tomato EXPs were significantly affected by DADS. The expression levels of EXPB2 and beta-expansin precursor were increased after 3 d, and those of EXP1, EXPB3 and EXLB1 were increased after 5 d of DADS treatment (0.41 mM. This result suggests that tomato root growth
Growth

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John R. Jones; George A. Schier

1985-01-01

This chapter considers aspen growth as a process, and discusses some characteristics of the growth and development of trees and stands. For the most part, factors affecting growth are discussed elsewhere, particularly in the GENETICS AND VARIATION chapter and in chapters in PART 11. ECOLOGY. Aspen growth as it relates to wood production is examined in the WOOD RESOURCE...
Effect of exo-polysaccharides producing bacterial inoculation on growth of roots of wheat(Triticum aestivum L. ) plants grown in a salt-affected soil

International Nuclear Information System (INIS)

Ashraf, M.; Hasnain, S.; Berge, O.

2006-01-01

Effect of soil salinity on physico-chemical and biological properties renders the salt-affected soils unsuitable for soil microbial processes and growth of the crop plants. Soil aggregation around roots of the plants is a function of the bacterial exo-polysaccharides, however, such a role of the EPS-producing bacteria in the saline environments has rarely been investigated. Pot experiments were conducted to observe the effects of inoculating six strains of exo-polysaccharides-producing bacteria on growth of primary (seminal) roots and its relationship with saccharides, cations (Ca 2+, Na +, K +) contents and mass of rhizosheath soils of roots of the wheat plants grown in a salt-affected soil. A strong positive relationship of RS with different root growth parameters indicated that an integrated influence of various biotic and abiotic RS factors would have controlled and promoted growth of roots of the inoculated wheat plants. The increase in root growth in turn could help inoculated wheat plants to withstand the negative effects of soil salinity through an enhanced soil water uptake, a restricted Na +i nflux in the plants and the accelerated soil microbial process involved in cycling and availability of the soil nutrients to the plants. It was concluded that inoculation of the exo- polysaccharides producing would be a valuable tool for amelioration and increasing crop productivity of the salt-affected soils
contribution to carcinogenesis

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Aneta Białkowska

2014-01-01

Full Text Available The centrosomes are subcellular organelles composed of two centrioles surrounded by a pericentriolar material. In animal cells they are responsible for the organization of the interphase microtubule cytoskeleton including microtubule nucleation and elongation, their attachment and release. The centrosomes are also involved in the construction of the mitotic spindle and chromosome segregation. More than a century ago it was suggested that these structures might be involved in human diseases, including cancer. Cancer cells show a high frequency of centrosome aberrations, especially amplification. Centrosome defects may increase the incidence of multipolar mitoses that lead to chromosomal segregation abnormalities and aneuploidy, which is the predominant type of genomic instability found in human solid tumors. The number of these organelles in cells is strictly controlled and is dependent on the proper process of centrosome duplication. Multiple genes that are frequently found mutated in cancers encode proteins which participate in the regulation of centrosome duplication and the numeral integrity of centrosomes. In recent years there has been growing interest in the potential participation of centrosomes in the process of carcinogenesis, especially because centrosome abnormalities are observed in premalignant stages of cancer development. The common presence of abnormal centrosomes in cancer cells and the role these organelles play in the cells suggest that the factors controlling the number of centrosomes may be potential targets for cancer therapy.
microRNA 21-mediated suppression of Sprouty1 by Pokemon affects liver cancer cell growth and proliferation.

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Jin, Xiu-Li; Sun, Qin-Sheng; Liu, Feng; Yang, Hong-Wei; Liu, Min; Liu, Hong-Xia; Xu, Wei; Jiang, Yu-Yang

2013-07-01

Transcriptional repressor Pokemon is a critical factor in embryogenesis, development, cell proliferation, differentiation, and oncogenesis, thus behaving as an oncogene. Oncomine database suggests a potential correlation between the expressions of Pokemon and Sprouty1. This study investigated the regulatory role of Pokemon in Sprouty1 expression and the effect on liver cancer cell growth and proliferation, revealing a novel miR-21-mediated regulatory circuit. In normal (HL-7702) and cancer (QGY-7703) liver cell lines, Sprouty1 expression is inversely correlated with Pokemon levels. Targeted expression or siRNA-mediated silencing showed that Pokemon is a repressor of Sprouty1 expression at both mRNA and protein levels, but Pokemon cannot affect the promoter activity of Sprouty1. Sprouty1 is a target of miR-21 and interestingly, we found that miR-21 is up-regulated by Pokemon in liver cancer cells. Luciferase reporter assays showed that Pokemon up-regulated miR-21 transcription in a dose-dependent manner, and ChIP assay exhibited a direct binding of Pokemon to the miR-21 promoter at -747 to -399 bp. Site-directed mutagenesis of the GC boxes at -684 to -679 bp and -652 to -647 bp of miR-21 promoter abolished the regulatory activity by Pokemon. Furthermore, we found that the modulation of Pokemon and miR-21 expression affected the growth and proliferation of liver cancer cells QGY-7703. In summary, our findings demonstrate that Pokemon suppresses Sprouty1 expression through a miR-21-mediated mechanism, affecting the growth and proliferation of liver cancer cells. This study recognized miR-21 and Sprouty1 as novel targets of the Pokemon regulatory network. Copyright © 2013 Wiley Periodicals, Inc.
Azadirachtin Affects the Growth of Spodoptera litura Fabricius by Inducing Apoptosis in Larval Midgut

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Benshui Shu

2018-02-01

Full Text Available Azadirachtin, the environmentally friendly botanical pesticide, has been used as an antifeedant and pest growth regulator in integrated pest management for decades. It has shown strong biological activity against Spodoptera litura, but the mechanism of toxicity remains unclear. The present study showed that azadirachtin inhibited the growth of S. litura larvae, which was resulted by structure destroy and size inhibition of the midgut. Digital gene expression (DGE analysis of midgut suggested that azadirachtin regulated the transcriptional level of multiple unigenes involved in mitogen-activated protein kinase (MAPK and calcium apoptotic signaling pathways. Simultaneously, the expression patterns of some differentially expressed unigenes were verified by quantitative real time-PCR (qRT-PCR. In addition, the enhanced terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL staining, the increased expression of caspase family members and apoptosis-binding motif 1 (IBM1 on both gene and protein level and the release of cytochrome c from mitochondria to cytoplasm were induced in midgut after azadirachtin treatment. These results demonstrated that azadirachtin induced structural alteration in S. litura larval midgut by apoptosis activation. These alterations may affect the digestion and absorption of nutrients and eventually lead to the growth inhibition of larvae.
Mutations in CDK5RAP2 cause Seckel syndrome.

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Yigit, Gökhan; Brown, Karen E; Kayserili, Hülya; Pohl, Esther; Caliebe, Almuth; Zahnleiter, Diana; Rosser, Elisabeth; Bögershausen, Nina; Uyguner, Zehra Oya; Altunoglu, Umut; Nürnberg, Gudrun; Nürnberg, Peter; Rauch, Anita; Li, Yun; Thiel, Christian Thomas; Wollnik, Bernd

2015-09-01

Seckel syndrome is a heterogeneous, autosomal recessive disorder marked by prenatal proportionate short stature, severe microcephaly, intellectual disability, and characteristic facial features. Here, we describe the novel homozygous splice-site mutations c.383+1G>C and c.4005-9A>G in CDK5RAP2 in two consanguineous families with Seckel syndrome. CDK5RAP2 (CEP215) encodes a centrosomal protein which is known to be essential for centrosomal cohesion and proper spindle formation and has been shown to be causally involved in autosomal recessive primary microcephaly. We establish CDK5RAP2 as a disease-causing gene for Seckel syndrome and show that loss of functional CDK5RAP2 leads to severe defects in mitosis and spindle organization, resulting in cells with abnormal nuclei and centrosomal pattern, which underlines the important role of centrosomal and mitotic proteins in the pathogenesis of the disease. Additionally, we present an intriguing case of possible digenic inheritance in Seckel syndrome: A severely affected child of nonconsanguineous German parents was found to carry heterozygous mutations in CDK5RAP2 and CEP152. This finding points toward a potential additive genetic effect of mutations in CDK5RAP2 and CEP152.
Mutations in CDK5RAP2 cause Seckel syndrome

Science.gov (United States)

Yigit, Gökhan; Brown, Karen E; Kayserili, Hülya; Pohl, Esther; Caliebe, Almuth; Zahnleiter, Diana; Rosser, Elisabeth; Bögershausen, Nina; Uyguner, Zehra Oya; Altunoglu, Umut; Nürnberg, Gudrun; Nürnberg, Peter; Rauch, Anita; Li, Yun; Thiel, Christian Thomas; Wollnik, Bernd

2015-01-01

Seckel syndrome is a heterogeneous, autosomal recessive disorder marked by prenatal proportionate short stature, severe microcephaly, intellectual disability, and characteristic facial features. Here, we describe the novel homozygous splice-site mutations c.383+1G>C and c.4005-9A>G in CDK5RAP2 in two consanguineous families with Seckel syndrome. CDK5RAP2 (CEP215) encodes a centrosomal protein which is known to be essential for centrosomal cohesion and proper spindle formation and has been shown to be causally involved in autosomal recessive primary microcephaly. We establish CDK5RAP2 as a disease-causing gene for Seckel syndrome and show that loss of functional CDK5RAP2 leads to severe defects in mitosis and spindle organization, resulting in cells with abnormal nuclei and centrosomal pattern, which underlines the important role of centrosomal and mitotic proteins in the pathogenesis of the disease. Additionally, we present an intriguing case of possible digenic inheritance in Seckel syndrome: A severely affected child of nonconsanguineous German parents was found to carry heterozygous mutations in CDK5RAP2 and CEP152. This finding points toward a potential additive genetic effect of mutations in CDK5RAP2 and CEP152. PMID:26436113
Understanding and Targeting Cell Growth Networks in Breast Cancer

Science.gov (United States)

2013-04-01

formic acid–33.3% silver nitrate solution in 0.66% gelatin and mounted onto slides with Vectashield (Vector Labs). Subcellular protein fractionation...Characterization of centrosomal association of nucleophos- min/B23 linked to Crm1 activity. FEBS Lett 579: 6621–6634. Spector DL, Ochs RL, Busch H. (1984). Silver ...nucleoli was not due to decreased protein expression levels for either NPM or fibrillarin (Fig. 10B). Furthermore, silver staining for nucleolar organizing
L-carnosine affects the growth of Saccharomyces cerevisiae in a metabolism-dependent manner.

Science.gov (United States)

Cartwright, Stephanie P; Bill, Roslyn M; Hipkiss, Alan R

2012-01-01

The dipeptide L-carnosine (β-alanyl-L-histidine) has been described as enigmatic: it inhibits growth of cancer cells but delays senescence in cultured human fibroblasts and extends the lifespan of male fruit flies. In an attempt to understand these observations, the effects of L-carnosine on the model eukaryote, Saccharomyces cerevisiae, were examined on account of its unique metabolic properties; S. cerevisiae can respire aerobically, but like some tumor cells, it can also exhibit a metabolism in which aerobic respiration is down regulated. L-Carnosine exhibited both inhibitory and stimulatory effects on yeast cells, dependent upon the carbon source in the growth medium. When yeast cells were not reliant on oxidative phosphorylation for energy generation (e.g. when grown on a fermentable carbon source such as 2% glucose), 10-30 mM L-carnosine slowed growth rates in a dose-dependent manner and increased cell death by up to 17%. In contrast, in media containing a non-fermentable carbon source in which yeast are dependent on aerobic respiration (e.g. 2% glycerol), L-carnosine did not provoke cell death. This latter observation was confirmed in the respiratory yeast, Pichia pastoris. Moreover, when deletion strains in the yeast nutrient-sensing pathway were treated with L-carnosine, the cells showed resistance to its inhibitory effects. These findings suggest that L-carnosine affects cells in a metabolism-dependent manner and provide a rationale for its effects on different cell types.
L-carnosine affects the growth of Saccharomyces cerevisiae in a metabolism-dependent manner.

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Stephanie P Cartwright

Full Text Available The dipeptide L-carnosine (β-alanyl-L-histidine has been described as enigmatic: it inhibits growth of cancer cells but delays senescence in cultured human fibroblasts and extends the lifespan of male fruit flies. In an attempt to understand these observations, the effects of L-carnosine on the model eukaryote, Saccharomyces cerevisiae, were examined on account of its unique metabolic properties; S. cerevisiae can respire aerobically, but like some tumor cells, it can also exhibit a metabolism in which aerobic respiration is down regulated. L-Carnosine exhibited both inhibitory and stimulatory effects on yeast cells, dependent upon the carbon source in the growth medium. When yeast cells were not reliant on oxidative phosphorylation for energy generation (e.g. when grown on a fermentable carbon source such as 2% glucose, 10-30 mM L-carnosine slowed growth rates in a dose-dependent manner and increased cell death by up to 17%. In contrast, in media containing a non-fermentable carbon source in which yeast are dependent on aerobic respiration (e.g. 2% glycerol, L-carnosine did not provoke cell death. This latter observation was confirmed in the respiratory yeast, Pichia pastoris. Moreover, when deletion strains in the yeast nutrient-sensing pathway were treated with L-carnosine, the cells showed resistance to its inhibitory effects. These findings suggest that L-carnosine affects cells in a metabolism-dependent manner and provide a rationale for its effects on different cell types.

Does temperature and oxygen affect duration of intramarsupial development and juvenile growth in the terrestrial isopod Porcellio scaber (Crustacea, Malacostraca?

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Terézia Horváthová

2015-07-01

Full Text Available According to the temperature-size rule (TSR, ectotherms developing under cold conditions experience slower growth as juveniles but reach a larger size at maturity. Whether temperature alone causes this phenomenon is unknown, but oxygen limitation can play a role in the temperature-size relationship. Oxygen may become limited under warm conditions when the resulting higher metabolism creates a greater demand for oxygen, especially in larger individuals. We examined the independent effects of oxygen concentration (10% and 22% O2 and temperature (15 °C and 22 °C on duration of ontogenic development, which takes place within the maternal brood pouch (marsupium, and juvenile growth in the terrestrial isopod common rough woodlouse (Porcellio scaber. Individuals inside the marsupium undergo the change from the aqueous to the gaseous environment. Under hypoxia, woodlice hatched from the marsupium sooner, but their subsequent growth was not affected by the level of oxygen. Marsupial development and juvenile growth were almost three times slower at low temperature, and marsupial development was longer in larger females but only in the cold treatment. These results show that temperature and oxygen are important ecological factors affecting developmental time and that the strength of the effect likely depends on the availability of oxygen in the environment.
Austenite grain growth and microstructure control in simulated heat affected zones of microalloyed HSLA steel

Energy Technology Data Exchange (ETDEWEB)

Zhang, Lei [Department of Machine Tools and Factory Management, Technical University of Berlin, Pascalstraße 8 – 9, 10587, Berlin (Germany); Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12205, Berlin (Germany); Kannengiesser, Thomas [Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12205, Berlin (Germany); Institute of Materials and Joining Technology, Otto von Guericke University Magdeburg, Universitetsplatz 2, 39106, Magdeburg (Germany)

2014-09-08

The roles of microalloying niobium, titanium and vanadium for controlling austenite grain growth, microstructure evolution and hardness were investigated at different simulated heat affected zones (HAZ) for high strength low alloy (HSLA) S690QL steel. High resolution FEG-SEM has been used to characterize fine bainitic ferrite, martensite and nanosized second phases at simulated coarse and fine grain HAZs. It was found that for Ti bearing steel (Ti/N ratio is 2) austenite grain had the slowest growth rate due to the presence of most stable TiN. The fine cuboidal particles promoted intragranular acicular ferrite (IGF) formation. Nb bearing steel exhibited relatively weaker grain growth retardation compared with titanium bearing steels and a mixed microstructure of bainite and martensite was present for all simulated HAZs. IGF existed at coarse grain HAZ of Ti+V bearing steel but it was totally replaced by bainite at fine grain HAZs. Hardness result was closely related to the morphology of bainitic ferrite, intragranular ferrite and second phases within ferrite. The microstructure and hardness results of different simulated HAZs were in good agreement with welded experimental results.
Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

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Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

2016-05-15

Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat
Organizational Career Growth, Affective Occupational Commitment and Turnover Intentions

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Weng, Qingxiong; McElroy, James C.

2012-01-01

Survey data, collected from the People's Republic of China, were used to test Weng's (2010) four facet model of career growth and to examine its effect on occupational commitment and turnover intentions. Weng conceptualized career growth as consisting of four factors: career goal progress, professional ability development, promotion speed, and…
Leptin administration affects growth and skeletal development in a rat intrauterine growth restriction model: preliminary study.

Science.gov (United States)

Bar-El Dadon, Shimrit; Shahar, Ron; Katalan, Vered; Monsonego-Ornan, Efrat; Reifen, Ram

2011-09-01

Skeletal abnormalities are one of the hallmarks of growth delay during gestation. The aim of this study was to determine changes induced by leptin in skeletal growth and development in a rat model of intrauterine growth retardation (IUGR) and to elucidate the possible underlying mechanisms. Intrauterine growth retardation was induced prepartum and the effects of leptin to mothers prenatally or to offspring postnatally were studied. Radii were harvested and tested mechanically and structurally. Tibias were evaluated for growth-plate morphometry. On day 40 postpartum, total bone length and mineral density and tibial growth-plate width and numbers of cells within its zones of offspring treated with leptin were significantly greater than in the control group. Postnatal leptin administration in an IUGR model improves the structural properties and elongation rate of bone. These findings could pave the way to preventing some phenotypic presentations of IUGR. Copyright © 2011 Elsevier Inc. All rights reserved.
The subcellular localization of IGFBP5 affects its cell growth and migration functions in breast cancer

International Nuclear Information System (INIS)

Akkiprik, Mustafa; Hu, Limei; Sahin, Aysegul; Hao, Xishan; Zhang, Wei

2009-01-01

Insulin-like growth factor binding protein 5 (IGFBP5) has been shown to be associated with breast cancer metastasis in clinical marker studies. However, a major difficulty in understanding how IGFBP5 functions in this capacity is the paradoxical observation that ectopic overexpression of IGFBP5 in breast cancer cell lines results in suppressed cellular proliferation. In cancer tissues, IGFBP5 resides mainly in the cytoplasm; however, in transfected cells, IGFBP5 is mainly located in the nucleus. We hypothesized that subcellular localization of IGFBP5 affects its functions in host cells. To test this hypothesis, we generated wild-type and mutant IGFBP5 expression constructs. The mutation occurs within the nuclear localization sequence (NLS) of the protein and is generated by site-directed mutagenesis using the wild-type IGFBP5 expression construct as a template. Next, we transfected each expression construct into MDA-MB-435 breast cancer cells to establish stable clones overexpressing either wild-type or mutant IGFBP5. Functional analysis revealed that cells overexpressing wild-type IGFBP5 had significantly lower cell growth rate and motility than the vector-transfected cells, whereas cells overexpressing mutant IGFBP5 demonstrated a significantly higher ability to proliferate and migrate. To illustrate the subcellular localization of the proteins, we generated wild-type and mutant IGFBP5-pDsRed fluorescence fusion constructs. Fluorescence microscopy imaging revealed that mutation of the NLS in IGFBP5 switched the accumulation of IGFBP5 from the nucleus to the cytoplasm of the protein. Together, these findings imply that the mutant form of IGFBP5 increases proliferation and motility of breast cancer cells and that mutation of the NLS in IGFBP5 results in localization of IGFBP5 in the cytoplasm, suggesting that subcellular localization of IGFBP5 affects its cell growth and migration functions in the breast cancer cells
Developmental light level affects growth, morphology, and leaf physiology of young carambola trees

International Nuclear Information System (INIS)

Marler, T.E.; Schaffer, B.; Crane, J.H.

1994-01-01

Growth and leaf physiology responses of container-grown 'Arkin' carambola (Averrhoa carambola L.) trees to long-term exposure of approximately 25%, approximately 50%, or 100% sunlight were studied in four experiments in Guam and Florida. Shading increased rachis length and leaflet area, and decreased leaflet thickness. Shaded trees also had a more horizontal branch orientation. Shading reduced dark respiration (Rd) and light compensation and saturation points but increased chlorophyll concentration and N-use efficiency. Light-saturated net CO2 assimilation (A) was not affected by developmental light level. Trees in full sun had smaller total leaf area, canopy diameter, and shoot:root ratio and exhibited leaflet movement to avoid direct solar radiation. Also, trees grown in 100% sunlight had a more vertical branch orientation and greater stomatal density than shaded trees. The ratio of variable to maximum fluorescence (Fv/Fm) declined during midday in 100% sunlight trees. This pattern was accompanied by a midday suppression of A in 100% sunlight-grown trees in Guam. 'Arkin' carambola trees exposed to approximately 25%, approximately 50%, or 100% sunlight for up to 39 weeks exhibited physiological and morphological adaptations that resulted in similar growth. These results indicate that carambola efficiently adapts to different developmental light intensities
Exome capture reveals ZNF423 and CEP164 mutations, linking renal ciliopathies to DNA damage response signaling

DEFF Research Database (Denmark)

Chaki, Moumita; Airik, Rannar; Ghosh, Amiya K

2012-01-01

Nephronophthisis-related ciliopathies (NPHP-RC) are degenerative recessive diseases that affect kidney, retina, and brain. Genetic defects in NPHP gene products that localize to cilia and centrosomes defined them as "ciliopathies." However, disease mechanisms remain poorly understood. Here, we id...
Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

Science.gov (United States)

Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

2016-01-01

Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions. PMID:26735689
Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

Science.gov (United States)

Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

2016-01-01

Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.
Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

Directory of Open Access Journals (Sweden)

Mo-Zhu Wang

Full Text Available Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.
Analysis of algae growth mechanism and water bloom prediction under the effect of multi-affecting factor.

Science.gov (United States)

Wang, Li; Wang, Xiaoyi; Jin, Xuebo; Xu, Jiping; Zhang, Huiyan; Yu, Jiabin; Sun, Qian; Gao, Chong; Wang, Lingbin

2017-03-01

The formation process of algae is described inaccurately and water blooms are predicted with a low precision by current methods. In this paper, chemical mechanism of algae growth is analyzed, and a correlation analysis of chlorophyll-a and algal density is conducted by chemical measurement. Taking into account the influence of multi-factors on algae growth and water blooms, the comprehensive prediction method combined with multivariate time series and intelligent model is put forward in this paper. Firstly, through the process of photosynthesis, the main factors that affect the reproduction of the algae are analyzed. A compensation prediction method of multivariate time series analysis based on neural network and Support Vector Machine has been put forward which is combined with Kernel Principal Component Analysis to deal with dimension reduction of the influence factors of blooms. Then, Genetic Algorithm is applied to improve the generalization ability of the BP network and Least Squares Support Vector Machine. Experimental results show that this method could better compensate the prediction model of multivariate time series analysis which is an effective way to improve the description accuracy of algae growth and prediction precision of water blooms.
Human cytomegalovirus infant infection adversely affects growth and development in maternally HIV-exposed and unexposed infants in Zambia.

Science.gov (United States)

Gompels, U A; Larke, N; Sanz-Ramos, M; Bates, M; Musonda, K; Manno, D; Siame, J; Monze, M; Filteau, S

2012-02-01

Human immunodeficiency virus (HIV) and human cytomegalovirus (HCMV) coinfections have been shown to increase infant morbidity, mortality, and AIDS progression. In HIV-endemic regions, maternal HIV-exposed but HIV-uninfected infants, which is the majority of children affected by HIV, also show poor growth and increased morbidity. Although nutrition has been examined, the effects of HCMV infection have not been evaluated. We studied the effects of HCMV infection on the growth, development, and health of maternally HIV-exposed and unexposed infants in Zambia. Infants were examined in a cohort recruited to a trial of micronutrient-fortified complementary foods. HIV-infected mothers and infants had received perinatal antiretroviral therapy to prevent mother-to-child HIV transmission. Growth, development, and morbidity were analyzed by linear regression analyses in relation to maternal HIV exposure and HCMV infection, as screened by sera DNA for viremia at 6 months of age and by antibody for infection at 18 months. All HCMV-seropositive infants had decreased length-for-age by 18 months compared with seronegative infants (standard deviation [z]-score difference: -0.44 [95% confidence interval {CI}, -.72 to -.17]; P = .002). In HIV-exposed infants, those who were HCMV positive compared with those who were negative, also had reduced head size (mean z-score difference: -0.72 [95% CI, -1.23 to -.22]; P = .01) and lower psychomotor development (Bayley test score difference: -4.1 [95% CI, -7.8 to -.5]; P = .03). HIV-exposed, HCMV-viremic infants were more commonly referred for hospital treatment than HCMV-negative infants. The effects of HCMV were unaffected by micronutrient fortification. HCMV affects child growth, development, and morbidity of African infants, particularly in those maternally exposed to HIV. HCMV is therefore a risk factor for child health in this region.
Assembly and control of large microtubule complexes

Science.gov (United States)

Korolev, Kirill; Ishihara, Keisuke; Mitchison, Timothy

Motility, division, and other cellular processes require rapid assembly and disassembly of microtubule structures. We report a new mechanism for the formation of asters, radial microtubule complexes found in very large cells. The standard model of aster growth assumes elongation of a fixed number of microtubules originating from the centrosomes. However, aster morphology in this model does not scale with cell size, and we found evidence for microtubule nucleation away from centrosomes. By combining polymerization dynamics and auto-catalytic nucleation of microtubules, we developed a new biophysical model of aster growth. The model predicts an explosive transition from an aster with a steady-state radius to one that expands as a travelling wave. At the transition, microtubule density increases continuously, but aster growth rate discontinuously jumps to a nonzero value. We tested our model with biochemical perturbations in egg extract and confirmed main theoretical predictions including the jump in the growth rate. Our results show that asters can grow even though individual microtubules are short and unstable. The dynamic balance between microtubule collapse and nucleation could be a general framework for the assembly and control of large microtubule complexes. NIH GM39565; Simons Foundation 409704; Honjo International 486 Scholarship Foundation.
Galanin does not affect the growth hormone-releasing hormone-stimulated growth hormone secretion in patients with hyperthyroidism.

Science.gov (United States)

Giustina, A; Bussi, A R; Legati, F; Bossoni, S; Licini, M; Schettino, M; Zuccato, F; Wehrenberg, W B

1992-12-01

Patients with hyperthyroidism have reduced spontaneous and stimulated growth hormone (GH) secretion. The aim of our study was to evaluate the effects of galanin, a novel neuropeptide which stimulates GH secretion in man, on the GH response to GHRH in patients with hyperthyroidism. Eight untreated hyperthyroid patients with Graves' disease (6F, 2M, aged 25-50 years) and six healthy volunteers (3F, 3M, aged 27-76 years) underwent from -10 to 30 min in random order: (i) porcine galanin, iv, 500 micrograms in 100 ml saline; or (ii) saline, iv, 100 ml. A bolus of human GHRH(1-29)NH2, 100 micrograms, was injected iv at 0 min. Hyperthyroid patients showed blunted GH peaks after GHRH+saline (10.2 +/- 2.5 micrograms/l) compared to normal subjects (20.7 +/- 4.8 micrograms/l, p hyperthyroid subjects (12.5 +/- 3 micrograms/l) compared to normal subjects (43.8 +/- 6 micrograms/l, p hyperthyroidism suggests that hyperthyroxinemia may either increase the somatostatin release by the hypothalamus or directly affect the pituitary GH secretory capacity.
Do Corruption and Social Trust affect Economic Growth? A Review

DEFF Research Database (Denmark)

Serritzlew, Søren; Sønderskov, Kim Mannemar; Svendsen, Gert Tinggaard

2014-01-01

Two separate literatures suggest that corruption and social trust, respectively, are related to economic growth, although the strengths of the relationships, and the direction of causality, are still debated. In this paper, we review these literatures and evaluate the evidence for causal effects...... of corruption and trust on economic growth, and discuss how corruption and trust are interrelated. The reviews show that absence of corruption and high levels of social trust foster economic growth. The literatures also indicate that corruption has a causal effect on social trust, while the opposite effect...... is more uncertain. In the conclusion, we offer the suggestion that fighting corruption may yield a “double dividend”, as reduced corruption is likely to have both direct and indirect effects on growth....
Survivin inhibitor YM155 suppresses gastric cancer xenograft growth in mice without affecting normal tissues.

Science.gov (United States)

Cheng, Xiao Jiao; Lin, Jia Cheng; Ding, Yan Fei; Zhu, Liming; Ye, Jing; Tu, Shui Ping

2016-02-09

Survivin overexpression is associated with poor prognosis of human gastric cancer, and is a target for gastric cancer therapy. YM155 is originally identified as a specific inhibitor of survivin. In this study, we investigated the antitumor effect of YM155 on human gastric cancer. Our results showed that YM155 treatment significantly inhibited cell proliferation, reduced colony formation and induced apoptosis of gastric cancer cells in a dose-dependent manner. Accordingly, YM155 treatment significantly decreased survivin expression without affecting XIAP expression and increased the cleavage of apoptosis-associated proteins caspase 3, 7, 8, 9. YM155 significantly inhibited sphere formation of gastric cancer cells, suppressed expansion and growth of the formed spheres (cancer stem cell-like cells, CSCs) and downregulated the protein levels of β-catenin, c-Myc, Cyclin D1 and CD44 in gastric cancer cells. YM155 infusion at 5 mg/kg/day for 7 days markedly inhibited growth of gastric cancer xenograft in a nude mouse model. Immunohistochemistry staining and Western Blot showed that YM155 treatment inhibited expression of survivin and CD44, induced apoptosis and reduced CD44+ CSCs in xenograft tumor tissues in vivo. No obvious pathological changes were observed in organs (e.g. heart, liver, lung and kidney) in YM155-treated mice. Our results demonstrated that YM155 inhibits cell proliferation, induces cell apoptosis, reduces cancer stem cell expansion, and inhibits xenograft tumor growth in gastric cancer cells. Our results elucidate a new mechanism by which YM155 inhibits gastric cancer growth by inhibition of CSCs. YM155 may be a promising agent for gastric cancer treatment.
Luminal epithelium in endometrial fragments affects their vascularization, growth and morphological development into endometriosis-like lesions in mice.

Science.gov (United States)

Feng, Dilu; Menger, Michael D; Wang, Hongbo; Laschke, Matthias W

2014-02-01

In endometriosis research, endometriosis-like lesions are usually induced in rodents by transplantation of isolated endometrial tissue fragments to ectopic sites. In the present study, we investigated whether this approach is affected by the cellular composition of the grafts. For this purpose, endometrial tissue fragments covered with luminal epithelium (LE(+)) and without luminal epithelium (LE(-)) were transplanted from transgenic green-fluorescent-protein-positive (GFP(+)) donor mice into the dorsal skinfold chamber of GFP(-) wild-type recipient animals to analyze their vascularization, growth and morphology by means of repetitive intravital fluorescence microscopy, histology and immunohistochemistry during a 14-day observation period. LE(-) fragments developed into typical endometriosis-like lesions with cyst-like dilated endometrial glands and a well-vascularized endometrial stroma. In contrast, LE(+) fragments exhibited a polypoid morphology and a significantly reduced blood perfusion after engraftment, because the luminal epithelium prevented the vascular interconnection with the microvasculature of the surrounding host tissue. This was associated with a markedly decreased growth rate of LE(+) lesions compared with LE(-) lesions. In addition, we found that many GFP(+) microvessels grew outside the LE(-) lesions and developed interconnections to the host microvasculature, indicating that inosculation is an important mechanism in the vascularization process of endometriosis-like lesions. Our findings demonstrate that the luminal epithelium crucially affects the vascularization, growth and morphology of endometriosis-like lesions. Therefore, it is of major importance to standardize the cellular composition of endometrial grafts in order to increase the validity and reliability of pre-clinical rodent studies in endometriosis research.
Luminal epithelium in endometrial fragments affects their vascularization, growth and morphological development into endometriosis-like lesions in mice

Directory of Open Access Journals (Sweden)

Dilu Feng

2014-02-01

Full Text Available In endometriosis research, endometriosis-like lesions are usually induced in rodents by transplantation of isolated endometrial tissue fragments to ectopic sites. In the present study, we investigated whether this approach is affected by the cellular composition of the grafts. For this purpose, endometrial tissue fragments covered with luminal epithelium (LE+ and without luminal epithelium (LE− were transplanted from transgenic green-fluorescent-protein-positive (GFP+ donor mice into the dorsal skinfold chamber of GFP− wild-type recipient animals to analyze their vascularization, growth and morphology by means of repetitive intravital fluorescence microscopy, histology and immunohistochemistry during a 14-day observation period. LE− fragments developed into typical endometriosis-like lesions with cyst-like dilated endometrial glands and a well-vascularized endometrial stroma. In contrast, LE+ fragments exhibited a polypoid morphology and a significantly reduced blood perfusion after engraftment, because the luminal epithelium prevented the vascular interconnection with the microvasculature of the surrounding host tissue. This was associated with a markedly decreased growth rate of LE+ lesions compared with LE− lesions. In addition, we found that many GFP+ microvessels grew outside the LE− lesions and developed interconnections to the host microvasculature, indicating that inosculation is an important mechanism in the vascularization process of endometriosis-like lesions. Our findings demonstrate that the luminal epithelium crucially affects the vascularization, growth and morphology of endometriosis-like lesions. Therefore, it is of major importance to standardize the cellular composition of endometrial grafts in order to increase the validity and reliability of pre-clinical rodent studies in endometriosis research.
Insights into embryo defenses of the invasive apple snail Pomacea canaliculata: egg mass ingestion affects rat intestine morphology and growth.

Science.gov (United States)

Dreon, Marcos S; Fernández, Patricia E; Gimeno, Eduardo J; Heras, Horacio

2014-06-01

The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology. Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing rats. PVF-supplemented diet induced the appearance of shorter and wider villi as well as fused villi. This was associated with changes in glycoconjugate expression, increased cell proliferation at crypt base, and hypertrophic mucosal growth. This resulted in a decreased absorptive surface after 3 days of treatment and a diminished rat growth rate that reverted to normal after the fourth day of treatment. Longer exposure to PVF induced a time-dependent lengthening of the small intestine while switching to a control diet restored intestine length and morphology after 4 days. Ingestion of PVF rapidly limits the ability of potential predators to absorb nutrients by inducing large, reversible changes in intestinal morphology and growth rate. The occurrence of toxins that affect intestinal morphology and absorption is a strategy against predation not recognized among animals before. Remarkably, this defense is rather similar to the toxic effect of plant antipredator strategies. This defense

Insights into embryo defenses of the invasive apple snail Pomacea canaliculata: egg mass ingestion affects rat intestine morphology and growth.

Directory of Open Access Journals (Sweden)

Marcos S Dreon

2014-06-01

Full Text Available The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF ingestion on the rat small intestine morphology and physiology.Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing rats. PVF-supplemented diet induced the appearance of shorter and wider villi as well as fused villi. This was associated with changes in glycoconjugate expression, increased cell proliferation at crypt base, and hypertrophic mucosal growth. This resulted in a decreased absorptive surface after 3 days of treatment and a diminished rat growth rate that reverted to normal after the fourth day of treatment. Longer exposure to PVF induced a time-dependent lengthening of the small intestine while switching to a control diet restored intestine length and morphology after 4 days.Ingestion of PVF rapidly limits the ability of potential predators to absorb nutrients by inducing large, reversible changes in intestinal morphology and growth rate. The occurrence of toxins that affect intestinal morphology and absorption is a strategy against predation not recognized among animals before. Remarkably, this defense is rather similar to the toxic effect of plant antipredator strategies
Predation risk affects growth and reproduction of an invasive snail and its lethal effect depends on prey size

Science.gov (United States)

Guo, Jing; Martín, Pablo R.; Zhang, Chunxia

2017-01-01

The behavior of invasive species under predation risk has been studied extensively, but their growth and reproductive responses have rarely been investigated. We conducted experiments with juveniles and adults of the invasive freshwater snail Pomacea canaliculata, and we observed changes in growth and reproduction in response to predation risk from a caged predator (Trachemys scripta elegans). P. canaliculata produced eggs earlier in the presence of predators and injured conspecifics compared with the control group (no risk), although the total number of egg masses laid by per female was exceeded by that of the controls after 15 days. Egg hatching success noticeably decreased under predation risk, and the incubation period was significantly prolonged; however, the oviposition height of the snails was not affected. A lethal effect of predation risk was detected in juvenile snails but not in adults. The growth of juvenile P. canaliculata was inhibited under predation risk, probably due to a reduction in food intake. Adult females exhibited a greater reduction in growth under predation risk than males, which likely resulted in part from the high reproductive investment of females in egg laying. These results indicate that P. canaliculata snails under predation risk face a trade-off between predator avoidance and growth and reproduction, where the lethal effect of predation risk is linked to the size of the prey. PMID:29136660
Predation risk affects growth and reproduction of an invasive snail and its lethal effect depends on prey size.

Directory of Open Access Journals (Sweden)

Jing Guo

Full Text Available The behavior of invasive species under predation risk has been studied extensively, but their growth and reproductive responses have rarely been investigated. We conducted experiments with juveniles and adults of the invasive freshwater snail Pomacea canaliculata, and we observed changes in growth and reproduction in response to predation risk from a caged predator (Trachemys scripta elegans. P. canaliculata produced eggs earlier in the presence of predators and injured conspecifics compared with the control group (no risk, although the total number of egg masses laid by per female was exceeded by that of the controls after 15 days. Egg hatching success noticeably decreased under predation risk, and the incubation period was significantly prolonged; however, the oviposition height of the snails was not affected. A lethal effect of predation risk was detected in juvenile snails but not in adults. The growth of juvenile P. canaliculata was inhibited under predation risk, probably due to a reduction in food intake. Adult females exhibited a greater reduction in growth under predation risk than males, which likely resulted in part from the high reproductive investment of females in egg laying. These results indicate that P. canaliculata snails under predation risk face a trade-off between predator avoidance and growth and reproduction, where the lethal effect of predation risk is linked to the size of the prey.
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.
Finding the Cell Center by a Balance of Dynein and Myosin Pulling and Microtubule Pushing: A Computational Study

Science.gov (United States)

Zhu, Jie; Burakov, Anton; Rodionov, Vladimir

2010-01-01

The centrosome position in many types of interphase cells is actively maintained in the cell center. Our previous work indicated that the centrosome is kept at the center by pulling force generated by dynein and actin flow produced by myosin contraction and that an unidentified factor that depends on microtubule dynamics destabilizes position of the centrosome. Here, we use modeling to simulate the centrosome positioning based on the idea that the balance of three forces—dyneins pulling along microtubule length, myosin-powered centripetal drag, and microtubules pushing on organelles—is responsible for the centrosome displacement. By comparing numerical predictions with centrosome behavior in wild-type and perturbed interphase cells, we rule out several plausible hypotheses about the nature of the microtubule-based force. We conclude that strong dynein- and weaker myosin-generated forces pull the microtubules inward competing with microtubule plus-ends pushing the microtubule aster outward and that the balance of these forces positions the centrosome at the cell center. The model also predicts that kinesin action could be another outward-pushing force. Simulations demonstrate that the force-balance centering mechanism is robust yet versatile. We use the experimental observations to reverse engineer the characteristic forces and centrosome mobility. PMID:20980619
Housing conditions affecting interior moisture levels: links to mould growth and children's respiratory health

Energy Technology Data Exchange (ETDEWEB)

Wells, John A. [Crosier Kilgour and Partners Ltd. (Canada)], email: john.w@ckpeng.com; Polyzois, Dimos [Department of Civil Engineering, University of Manitoba (Canada)], email: polyzoi@cc.umanitoba.ca; Polyzoi, Eleoussa [Faculty of Education, University of Winnipeg (Canada)], email: l.polyzoi@uwinnipeg.ca

2011-07-01

Previous research has demonstrated that a person's respiratory health is affected by high indoor moisture content in their house. The aim of this paper is to provide a better understanding of the link between housing conditions and respiratory health, so that strategies can be implemented to improve the quality of life of children. This study was carried out through the completion of a survey by 3,423 parents in Winnipeg, Canada, the collection of 715 air samples from the residences of 715 parents, and an engineering audit of their homes. This study showed that a strong relationship exists between building moisture content and common home maintenance and that routine maintenance is efficient in significantly reducing the growth of mould which impacts children's respiratory health. This paper provided useful information on the relation between housing conditions and respiratory health problems and the rest of the study will aim at determining which building conditions impact mould growth most.
Growth and development of moringa (Moringa oleifera L. stem cuttings as affected by diameter magnitude, growth media, and indole-3-butyric acid

Directory of Open Access Journals (Sweden)

Shamsuddeen Rufai

2016-12-01

chlorophyll content were found to be non-significantly (P>0.05 influenced. The MB growth media was observed to significantly affect the plant height, percentage root number, and root length as compared to the M growth media. For a successful vegetative propagation and subsequent domestication, the MB growth media coupled with a higher stem diameter size are recommended.
Aromatase inhibitor (anastrozole) affects growth of endometrioma cells in culture.

Science.gov (United States)

Badawy, Shawky Z A; Brown, Shereene; Kaufman, Lydia; Wojtowycz, Martha A

2015-05-01

To study the effects of aromatase inhibitor (anastrozole) on the growth and estradiol secretion of endometrioma cells in culture. Endometrioma cells are grown in vitro until maximum growth before used in this study. This was done in the research laboratory for tissue culture, in an academic hospital. Testosterone at a concentration of 10 μg/mL was added as a substrate for the intracellular aromatase. In addition, aromatase inhibitor was added at a concentration of 200 and 300 μg/mL. The effect on cell growth and estradiol secretion is evaluated using Student's t-test. The use of testosterone increased estradiol secretion by endometrioma cells in culture. The use of aromatase inhibitor significantly inhibited the growth of endometrioma cells, and estradiol secretion. Aromatase inhibitor (anastrozole) may be an effective treatment for endometriosis due to inhibition of cellular aromatase. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Growth and Growth hormone - Insulin Like Growth Factor -I (GH-IGF-I) Axis in Chronic Anemias.

Science.gov (United States)

Soliman, Ashraf T; De Sanctis, Vincenzo; Yassin, Mohamed; Adel, Ashraf

2017-04-28

Anaemia is a global public health problem affecting both developing and developed countries with major consequences for human health as well as social and economic development. It occurs at all stages of the life cycle, but is more prevalent in pregnant women and young children. Iron deficiency anaemia (IDA) was considered to be among the most important contributing factors to the global burden of disease. Prolonged and/or chronic anemia has a negative effect on linear growth especially during the rapid phases (infancy and puberty). Additionally infants with chronic IDA have delayed cognitive, motor, and affective development that may be long-lasting. In view of the significant impact of chronic anemias on growth, pediatricians endocrinologists and hematologists should advocate primary prevention and screening for growth disturbance in these forms of anemias. The extent of the negative effect of different forms of chronic anemias on linear growth and its possible reversibilty is addressed in this review. The possible mechanisms that may impair growth in the different forms of anemias are addressed with special attention to their effect on the growth hormone (GH) - insulin like growth factor -I (IGF-I).
Individual heterogeneity and offspring sex affect the growth-reproduction trade-off in a mammal with indeterminate growth.

Science.gov (United States)

Gélin, Uriel; Wilson, Michelle E; Cripps, Jemma; Coulson, Graeme; Festa-Bianchet, Marco

2016-04-01

Reproduction can lead to a trade-off with growth, particularly when individuals reproduce before completing body growth. Kangaroos have indeterminate growth and may always face this trade-off. We combined an experimental manipulation of reproductive effort and multi-year monitoring of a large sample size of marked individuals in two populations of eastern grey kangaroos to test the predictions (1) that reproduction decreases skeletal growth and mass gain and (2) that mass loss leads to reproductive failure. We also tested if sex-allocation strategies influenced these trade-offs. Experimental reproductive suppression revealed negative effects of reproduction on mass gain and leg growth from 1 year to the next. Unmanipulated females, however, showed a positive correlation between number of days lactating and leg growth over periods of 2 years and longer, suggesting that over the long term, reproductive costs were masked by individual heterogeneity in resource acquisition. Mass gain was necessary for reproductive success the subsequent year. Although mothers of daughters generally lost more mass than females nursing sons, mothers in poor condition experienced greater mass gain and arm growth if they had daughters than if they had sons. The strong links between individual mass changes and reproduction suggest that reproductive tactics are strongly resource-dependent.
Specific protein supplementation using soya, casein or whey differentially affects regional gut growth and luminal growth factor bioactivity in rats; implications for the treatment of gut injury and stimulating repair.

Science.gov (United States)

Marchbank, Tania; Mandir, Nikki; Calnan, Denis; Goodlad, Robert A; Podas, Theo; Playford, Raymond J

2018-01-24

Modulation of regional growth within specific segments of the bowel may have clinical value for several gastrointestinal conditions. We therefore examined the effects of different dietary protein sources on regional gut growth and luminal growth factor bioactivity as potential therapies. Rats were fed for 14 days on isonitrogenous and isocaloric diets comprising elemental diet (ED) alone (which is known to cause gut atrophy), ED supplemented with casein or whey or a soya protein-rich feed. Effects on regional gut growth and intraluminal growth factor activity were then determined. Despite calorie intake being similar in all groups, soya rich feed caused 20% extra total body weight gain. Stomach weight was highest on soya and casein diets. Soya enhanced diet caused greatest increase in small intestinal weight and preserved luminal growth factor activity at levels sufficient to increase proliferation in vitro. Regional small intestinal proliferation was highest in proximal segment in ED fed animals whereas distal small intestine proliferation was greater in soya fed animals. Colonic weight and proliferation throughout the colon was higher in animals receiving soya or whey supplemented feeds. We conclude that specific protein supplementation with either soya, casein or whey may be beneficial to rest or increase growth in different regions of the bowel through mechanisms that include differentially affecting luminal growth factor bioactivity. These results have implications for targeting specific regions of the bowel for conditions such as Crohn's disease and chemotherapy.
Live imaging of spindle pole disorganization in docetaxel-treated multicolor cells

International Nuclear Information System (INIS)

Sakaushi, Shinji; Nishida, Kumi; Minamikawa, Harumi; Fukada, Takashi; Oka, Shigenori; Sugimoto, Kenji

2007-01-01

Treatment of cells with docetaxel at low concentrations induces aberrant bipolar spindles of which two centrosomes stay at only one pole, and also induces multipolar spindles. To gain insight into the relations between centrosome impairment and structural defects of the spindle, live-cell imaging was performed on a human MDA Auro/imp/H3 cell line in which centrosomes/mitotic spindles, nuclear membrane and chromatin were simultaneously visualized by fluorescent proteins. In the presence of docetaxel at IC 50 concentration, the centrosomes did not segregate, and multiple aster-like structures ectopically arose around the disappearing nuclear membrane. Those ectopic structures formed an acentrosomal pole opposing to the two-centrosomes-containing pole. In late metaphase, one pole often fragmented into multiple spindle poles, leading multipolar division. These results suggest that spindle pole fragility may be induced by centrosome impairment, and collapse of the pole may contribute to induction of aneuploid daughter cells
How Will Global Environmental Changes Affect the Growth of Alien Plants?

Directory of Open Access Journals (Sweden)

Jujie Jia

2016-11-01

Full Text Available Global environmental changes can create novel habitats, promoting the growth of alien plants that often exhibit broad environmental tolerance and high phenotypic plasticity. However, the mechanisms underlying these growth promotory effects are unknown at present. Here, we conducted a phylogenetically controlled meta-analysis using data from 111 published studies encompassing the responses of 129 alien plants to global warming, increased precipitation, N deposition, and CO2 enrichment. We compared the differences in the responses of alien plants to the four global environmental change factors across six categories of functional traits between woody and non-woody life forms as well as C3 and C4 photosynthetic pathways. Our results showed that all four global change factors promote alien plant growth. Warming had a more positive effect on C4 than C3 plants. Although the effects of the four factors on the functional traits of alien plants were variable, plant growth was mainly promoted via an increase in growth rate and size. Our data suggest that potential future global environmental changes could further facilitate alien plant growth.
Organic matter loading affects lodgepole pine seedling growth.

Science.gov (United States)

Wei, Xiaohua; Li, Qinglin; Waterhouse, M J; Armleder, H M

2012-06-01

Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability.
Factors affecting the growth of Didymosphenia geminata in New Zealand rivers: Flow, bed disturbance, nutrients, light, and seasonal dynamics. (Invited)

Science.gov (United States)

Cullis, J. D.; Gillis, C.; Drummond, J. D.; Garcia, T.; Kilroy, C.; Larned, S.; Hassan, M. A.

2010-12-01

Didymosphenia geminata (didymo) was introduced into a New Zealand river in 2004, and since then has dramatically spread to cover the beds of many rivers with extremely dense and extensive mats. Successful management is hampered by the fact that much is still unknown about the factors affecting the growth of this nuisance species. We synthesized available data on the distribution of D. geminata in New Zealand rivers to determine how physical and chemical system conditions (flow, bed disturbance, nutrients, and light) affect the growth and persistence of this organism. Here we assess results from bi-weekly surveys performed over a full year on two rivers where didymo was first observed in New Zealand; the Oreti and Mararoa. We used the data to test the hypotheses that the development of thick, dense mats requires high light levels but is inversely proportional to nutrient levels, and that mat persistence is controlled by the frequency of flow events that produce bed sediment transport. Observed regrowth between disturbance events was found to be inversely correlated with nutrient availability. The seasonal availability of light did not correlate with variations in growth rate, but this did not account for specific characteristics of the different sites such as aspect, shading, flow depth and turbidity that will all impact on the amount of available light reaching the streambed. The results clearly indicate that the time-history of flow and nutrient levels is critical to evaluating the growth and persistence of D. geminata and that additional site specific information is necessary to determine the role of bed stability and the amount of available light reaching the streambed.
Environmental logistics performance indicators affecting per capita income and sectoral growth: evidence from a panel of selected global ranked logistics countries.

Science.gov (United States)

Khan, Syed Abdul Rehman; Qianli, Dong; SongBo, Wei; Zaman, Khalid; Zhang, Yu

2017-01-01

The objective of the study is to examine the long-run and causal relationship between environmental logistics performance indicators (ELPI) and growth-specific factors in a panel of 15 selected global ranked logistics countries over a period of 2007-2015. This study is exclusive as we utilized a number of LPI factors including logistics performance, logistics competence, and logistics infrastructure with mediation of sustainable factors, i.e., carbon dioxide (CO 2 ), fossil fuel, and greenhouse gas (GHG) emissions in a region. The results show that the per capita income, industry, manufacturing, and service share to GDP is affected by CO 2 emissions and GHG emissions. Logistics competence and infrastructure promote economic growth and sectoral value added, while energy demand and FDI inflows both are prerequisite for sustainable agriculture in a region. The causal relationships confirm that more energy demand results in an increase in economic growth, industry value added, and the service sector (i.e., feedback hypothesis), while the sustainable supply chain system improves energy demand, FDI inflows, economic growth, and sectoral growth (i.e., conservation hypothesis) in a panel of countries.
Growth hormone and insulin-like growth factor 1 affect the severity of Graves' disease.

Science.gov (United States)

Di Cerbo, Alfredo; Pezzuto, Federica; Di Cerbo, Alessandro

2017-01-01

Graves' disease, the most common form of hyperthyroidism in iodine-replete countries, is associated with the presence of immunoglobulins G (IgGs) that are responsible for thyroid growth and hyperfunction. In this article, we report the unusual case of a patient with acromegaly and a severe form of Graves' disease. Here, we address the issue concerning the role of growth hormone (GH) and insulin-like growth factor 1 (IGF1) in influencing thyroid function. Severity of Graves' disease is exacerbated by coexistent acromegaly and both activity indexes and symptoms and signs of Graves' disease improve after the surgical remission of acromegaly. We also discuss by which signaling pathways GH and IGF1 may play an integrating role in regulating the function of the immune system in Graves' disease and synergize the stimulatory activity of Graves' IgGs. Clinical observations have demonstrated an increased prevalence of euthyroid and hyperthyroid goiters in patients with acromegaly.The coexistence of acromegaly and Graves' disease is a very unusual event, the prevalence being Graves' disease associated with acromegaly and show that surgical remission of acromegaly leads to a better control of symptoms of Graves' disease.
Merkel cell polyomavirus small T antigen induces genome instability by E3 ubiquitin ligase targeting.

Science.gov (United States)

Kwun, H J; Wendzicki, J A; Shuda, Y; Moore, P S; Chang, Y

2017-12-07

The formation of a bipolar mitotic spindle is an essential process for the equal segregation of duplicated DNA into two daughter cells during mitosis. As a result of deregulated cellular signaling pathways, cancer cells often suffer a loss of genome integrity that might etiologically contribute to carcinogenesis. Merkel cell polyomavirus (MCV) small T (sT) oncoprotein induces centrosome overduplication, aneuploidy, chromosome breakage and the formation of micronuclei by targeting cellular ligases through a sT domain that also inhibits MCV large T oncoprotein turnover. These results provide important insight as to how centrosome number and chromosomal stability can be affected by the E3 ligase targeting capacity of viral oncoproteins such as MCV sT, which may contribute to Merkel cell carcinogenesis.
Does overhead irrigation with salt affect growth, yield, and phenolic content of lentil plants?

Directory of Open Access Journals (Sweden)

Giannakoula Anastasia

2012-01-01

Full Text Available Overhead irrigation of lentil plants with salt (100 mM NaCl did not have any significant impact on plant growth, while chlorophyll content and chlorophyll fluorescence parameter Fv/Fm were affected. Under such poor irrigation water quality, the malondialdehyde content in leaves was increased due to the lipid peroxidation of membranes. In seeds, the total phenolic content (TPC was correlated to their total antioxidant capacity (TAC. High performance liquid chromatography-mass spectrometry (HPLC-MS detection showed that flavonoids (catechin, epicatechin, rutin, p-coumaric acid, quercetin, kaempferol, gallic acid and resveratrol appear to be the compounds with the greatest influence on the TAC values. Catechin is the most abundant phenolic compound in lentil seeds. Overhead irrigation with salt reduced the concentration of almost all phenolic compounds analyzed from lentil seed extracts.
Shade periodicity affects growth of container grown dogwoods

Science.gov (United States)

Container-grown dogwoods rank third in the US in nursery sales of ornamental trees. However, Dogwoods are a challenging crop to produce in container culture, especially when bare root liners are used as the initial transplant into containers due unacceptable levels of mortality and poor growth. This...

Insulin Like Growth Factor System: How Does it Affect Neonatal Anthropometry?

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Emine Kacar

2016-09-01

Full Text Available Aim: The present study aims to clarify the role of insulin like growth factor-1 (IGF-1, insulin like growth factor binding protein-3 (IGFBP-3, ghrelin, and insulin in fetal growth. Material and Method: Based on Turkish standards, 14 newborns were defined as small for gestational age (SGA, 33 newborns were described as appropriate for gestational age (AGA, and 13 newborns were identified as large for gestational age (LGA. IGF-1, IGFBP-3, ghrelin, and insulin levels were measured in umbilical cord and maternal serum. Results: The LGA group had significantly higher levels of IGF-1, IGFBP-3, ghrelin, and insulin in umbilical cord and maternal serum than the SGA group. Umbilical cord and maternal serum levels of IGF-1 and IGFBP-3 correlated significantly and positively with body weight, body length, head circumference, and abdominal circumference of the neonates. Discussion: Based on the findings of the present study, it may be postulated that insulin like growth factor system has a role in fetal growth.
Factors affecting growth and pigmentation of Penicillium caseifulvum

DEFF Research Database (Denmark)

Suhr, Karin Isabel; Haasum, I.; Steenstrup, L.D.

2002-01-01

Color formation, metabolite production and growth of Penicillium caseifulvum were studied in order to elucidate factors contributing to. yellow discoloration of Blue Cheese caused by the mold. A screening experiment was set up to study the effect of pH, concentration of salt (NaCl), P, K, N, S, Mg...
Non-Overlapping Distributions and Functions of the VDAC Family in Ciliogenesis

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Shubhra Majumder

2015-07-01

Full Text Available Centrosomes are major microtubule-organizing centers of animal cells that consist of two centrioles. In mitotic cells, centrosomes are duplicated to serve as the poles of the mitotic spindle, while in quiescent cells, centrosomes move to the apical membrane where the oldest centriole is transformed into a basal body to assemble a primary cilium. We recently showed that mitochondrial outer membrane porin VDAC3 localizes to centrosomes where it negatively regulates ciliogenesis. We show here that the other two family members, VDAC1 and VDAC2, best known for their function in mitochondrial bioenergetics, are also found at centrosomes. Like VDAC3, centrosomal VDAC1 is predominantly localized to the mother centriole, while VDAC2 localizes to centriolar satellites in a microtubule-dependent manner. Down-regulation of VDAC1 leads to inappropriate ciliogenesis, while its overexpression suppresses cilia formation, suggesting that VDAC1 and VDAC3 both negatively regulate ciliogenesis. However, this negative effect on ciliogenesis is not shared by VDAC2, which instead appears to promote maturation of primary cilia. Moreover, because overexpression of VDAC3 cannot compensate for depletion of VDAC1, our data suggest that while the entire VDAC family localizes to centrosomes, they have non-redundant functions in cilogenesis.
Gamma-tubulin-containing abnormal centrioles are induced by insufficient Plk4 in human HCT116 colorectal cancer cells.

Science.gov (United States)

Kuriyama, Ryoko; Bettencourt-Dias, Monica; Hoffmann, Ingrid; Arnold, Marc; Sandvig, Lisa

2009-06-15

Cancer cells frequently induce aberrant centrosomes, which have been implicated in cancer initiation and progression. Human colorectal cancer cells, HCT116, contain aberrant centrioles composed of disorganized cylindrical microtubules and displaced appendages. These cells also express unique centrosome-related structures associated with a subset of centrosomal components, including gamma-tubulin, centrin and PCM1. During hydroxyurea treatment, these abnormal structures become more abundant and undergo a change in shape from small dots to elongated fibers. Although gamma-tubulin seems to exist as a ring complex, the abnormal structures do not support microtubule nucleation. Several lines of evidence suggest that the fibers correspond to a disorganized form of centriolar microtubules. Plk4, a mammalian homolog of ZYG-1 essential for initiation of centriole biogenesis, is not associated with the gamma-tubulin-specific abnormal centrosomes. The amount of Plk4 at each centrosome was less in cells with abnormal centrosomes than cells without gamma-tubulin-specific abnormal centrosomes. In addition, the formation of abnormal structures was abolished by expression of exogenous Plk4, but not SAS6 and Cep135/Bld10p, which are downstream regulators required for the organization of nine-triplet microtubules. These results suggest that HCT116 cells fail to organize the ninefold symmetry of centrioles due to insufficient Plk4.
Growth and Accumulation of Secondary Metabolites in Perilla as Affected by Photosynthetic Photon Flux Density and Electrical Conductivity of the Nutrient Solution

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Na Lu

2017-05-01

Full Text Available The global demand for medicinal plants is increasing. The quality of plants grown outdoors, however, is difficult to control. Myriad environmental factors influence plant growth and directly impact biosynthetic pathways, thus affecting the secondary metabolism of bioactive compounds. Plant factories use artificial lighting to increase the quality of medicinal plants and stabilize production. Photosynthetic photon flux density (PPFD and electrical conductivity (EC of nutrient solutions are two important factors that substantially influence perilla (Perilla frutescens, Labiatae plant growth and quality. To identify suitable levels of PPFD and EC for perilla plants grown in a plant factory, the growth, photosynthesis, and accumulation of secondary metabolites in red and green perilla plants were measured at PPFD values of 100, 200, and 300 μmol m-2 s-1 in nutrient solutions with EC values of 1.0, 2.0, and 3.0 dS m-1. The results showed significant interactive effects between PPFD and EC for both the fresh and dry weights of green perilla, but not for red perilla. The fresh and dry weights of shoots and leafy areas were affected more by EC than by PPFD in green perilla, whereas they were affected more by PPFD than by EC in red perilla. Leaf net photosynthetic rates were increased as PPFD increased in both perilla varieties, regardless of EC. The perillaldehyde concentration (mg g-1 in red perilla was unaffected by the treatments, but accumulation in plants (mg per plant was significantly enhanced as the weight of dry leaves increased. Perillaldehyde concentrations in green perilla showed significant differences between combinations of the highest PPFD with the highest EC and the lowest PPFD with the lowest EC. Rosmarinic acid concentration (mg g-1 was increased in a combination of low EC and high PPFD conditions. Optimal cultivation conditions of red and green perilla in plant factory will be discussed in terms of plant growth and contents of
How wind affects growth in treeline Picea abies

Czech Academy of Sciences Publication Activity Database

Kašpar, J.; Hošek, Jiří; Treml, V.

2017-01-01

Roč. 127, č. 2 (2017), s. 1-12 ISSN 1664-2201 Institutional support: RVO:68378289 Keywords : height increment * picea abies * radial growth * thigmomorphogenesis * tree rings Subject RIV: GK - Forestry OBOR OECD: Forestry Impact factor: 2.281, year: 2016 https://link.springer.com/content/pdf/10.1007%2Fs00035-017-0186-x.pdf
SECTORAL SHARES AND ECONOMIC GROWTH

DEFF Research Database (Denmark)

Ahmad, Nisar; Naveed, Amjad; Naz, Amber

2013-01-01

believe that structural change is an unimportant side effect of the economic development. On the contrary, economists associated with the World Bank and some others posit that growth is brought about by the changes in sectoral composition. The objective of this study is to empirically test...... the relationship between sectoral shares and economic growth by using the panel data for 20 developed countries. The results of the granger causality suggest that both services and agriculture sectors do granger cause economic growth, whereas industrial sector does not granger cause growth. Reverse causality does...... not hold for any of the three sectors. The results of Barro and Non-Barro regressions along with the set of control variables have suggested that services sector is negatively affecting growth, whereas both industrial and agriculture shares are positively affect economic growth....
Early kit mortality and growth in farmed mink are affected by litter size rather than nest climate.

Science.gov (United States)

Schou, T M; Malmkvist, J

2017-09-01

We investigated the effects of nest box climate on early mink kit mortality and growth. We hypothesised that litters in warm nest boxes experience less hypothermia-induced mortality and higher growth rates during the 1st week of life. This study included data from 749, 1-year-old breeding dams with access to nesting materials. Kits were weighed on days 1 and 7, dead kits were collected daily from birth until day 7 after birth, and nest climate was measured continuously from days 1 to 6. We tested the influences of the following daily temperature (T) and humidity (H) parameters on the number of live-born kit deaths and kit growth: T mean, T min, T max, T var (fluctuation) and H mean. The nest microclimate experienced by the kits was buffered against the ambient climate, with higher temperatures and reduced climate fluctuation. Most (77.0%) live-born kit deaths in the 1st week occurred on days 0 and 1. Seven of 15 climate parameters on days 1 to 3 had significant effects on live-born kit mortality. However, conflicting effects among days, marginal effects and late effects indicated that climate was not the primary cause of kit mortality. Five of 30 climate parameters had significant effects on kit growth. Few and conflicting effects indicated that the climate effect on growth was negligible. One exception was that large nest temperature fluctuations on day 1 were associated with reduced deaths of live-born kit (P<0.001) and increased kit growth (P=0.003). Litter size affected kit vitality; larger total litter size at birth was associated with greater risks of kit death (P<0.001) and reduced growth (P<0.001). The number of living kits in litters had the opposite effect, as kits in large liveborn litters had a reduced risk of death (P<0.001) and those with large mean litter size on days 1 to 7 had increased growth (P=0.026). Nest box temperature had little effect on early kit survival and growth, which could be due to dams' additional maternal behaviour. Therefore, we
Digestive efficiency, free amino acid pools and quality of growth performance in Atlantic salmon (Salmo salar L.) affected by light regimes and vaccine types.

Science.gov (United States)

Rungruangsak-Torrissen, Krisna; Sunde, Jan; Berg, Arne Erik; Nordgarden, Ulla; Fjelldal, Per Gunnar; Oppedal, Frode

2009-06-01

This study comprised the results of three different seawater trials using unique combination of techniques to study protease digestive efficiency and growth performance quality to illustrate the effects of light regimes and vaccine types in Atlantic salmon (Salmo salar L.). Fish with higher growth had higher trypsin (T) and chymotrypsin (C) specific activities with higher T/C ratio or slope T/C ratio [calculated from the regression between trypsin (y) and chymotrypsin (x) specific activities] in the pyloric caeca. The T/C ratios indicated fish growth rates over a period of 1-2 months, while the slope T/C ratios indicated fish growth rates at sampling. Adaptation period for adjustment to the new environment of continuous light was 70 days, indicated by the differences in trypsin specific activities and the crossing of slope T/C ratio regressions following with the changes in growth rate directions between the control and the treated group. Vaccine types affected fish vertebral growth, and additional continuous light enhanced the impact of vaccines on fish growth during springtime, indicated by differences in slope T/C ratios. Continuous light stimulated fish growth during winter to spring, when the natural day length was short, without significantly changing white muscle and oocyte qualities in the fish of about 500 g, except for significantly increased white muscle RNA concentration. Continuous light also reduced fish growth rate later during summer, when the natural day length was long, by precedently decreasing the T/C ratio in late spring. Interestingly, plasma levels of free lysine related to tryptic digestion were correlated with trypsin specific activity levels. Continuous light caused higher levels of most free amino acids (FAA) involved in nitrogen metabolism, higher incorporation of essential FAA for protein synthesis, and higher protein turnover rate (free hydroxyproline levels) in both plasma and white muscle. However, continuous light did not affect
Divergence for residual feed intake of Holstein-Friesian cattle during growth did not affect production and reproduction during lactation.

Science.gov (United States)

Macdonald, K A; Thomson, B P; Waghorn, G C

2016-11-01

Residual feed intake (RFI) is the difference between actual and predicted dry matter intake (DMI) of individual animals. Recent studies with Holstein-Friesian calves have identified an ~20% difference in RFI during growth (calf RFI) and these groups remained divergent in RFI during lactation. The objective of the experiment described here was to determine if cows selected for divergent RFI as calves differed in milk production, reproduction or in the profiles of BW and body condition score (BCS) change during lactation, when grazing pasture. The cows used in the experiment (n=126) had an RFI of -0.88 and +0.75 kg DM intake/day for growth as calves (efficient and inefficient calf RFI groups, respectively) and were intensively grazed at four stocking rates (SR) of 2.2, 2.6, 3.1 and 3.6 cows/ha on self-contained farmlets, over 3 years. Each SR treatment had equal number of cows identified as low and high calf RFI, with 24, 28, 34 and 40/11 ha farmlet. The cows divergent for calf RFI were randomly allocated to each SR. Although SR affected production, calf RFI group (low or high) did not affect milk production, reproduction, BW, BCS or changes in these parameters throughout lactation. The most efficient animals (low calf RFI) lost similar BW and BCS as the least efficient (high calf RFI) immediately post-calving, and regained similar BW and BCS before their next calving. These results indicate that selection for RFI as calves to increase efficiency of feed utilisation did not negatively affect farm productivity variables (milk production, BCS, BW and reproduction) as adults when managed under an intensive pastoral grazing system.
Sociopolitical Instability and Economic Growth Empirical Evidence from Sri Lanka

OpenAIRE

Changsheng Xu; Santhirasegaram Selvarathinam; Wen X. Li

2007-01-01

Sociopolitical instability severely affects economic growth in short and long run. This study analyzes that sociopolitical instability measured by proxy measure; annual growth rate of tourist arrivals in Sri Lanka during 1960-2005 adversely affects economic growth. Our empirical findings based on ordinary lease square econometric estimation, show that sociopolitical instability negatively and significantly affect economic growth. Reduction of economic growth rate (-0.032) due to the sociopoli...
Unemployment and endogenous growth

NARCIS (Netherlands)

van Schaik, A.B.T.M.; de Groot, H.L.F.

1995-01-01

In this paper we develop a two-sector endogenous growth model with a dual labour market, based on efficiency wages. Growth is driven by intentional R&D performed in the high-tech and high-wage sector. It is examined how a change in rivalry among firms affects simultaneously growth and unemployment.
Water availability and population origin affect the expression of the tradeoff between reproduction and growth in Plantago coronopus

DEFF Research Database (Denmark)

Hansen, C. F.; Garcia, M. B.; Ehlers, B. K.

2013-01-01

temperature and precipitation. We found that water availability affected the expression of the tradeoff (both phenotypic and genetic) between reproduction and growth, being most accentuated under dry condition. However, populations responded very differently to water treatments. Plants from annual populations...... showed a similar response to drought condition with little variation among maternal families, suggesting a history of selection favouring genotypes with high allocation to reproduction when water availability is low. Plants from annual populations also expressed the highest level of plasticity...... water availability even among geographically close populations....
High temperature combined with drought affect rainfed spring wheat and barley in South-Eastern Russia: I. Phenology and growth

Science.gov (United States)

Hossain, Akbar; Teixeira da Silva, Jaime A.; Lozovskaya, Marina Viacheslavovna; Zvolinsky, Vacheslav Petrovich

2012-01-01

Heat stress, when combined with drought, is one of the major limitations to food production worldwide, especially in areas that use rainfed agriculture. As the world population continues to grow, and water resources for the crop production decline and temperature increases, so the development of heat- and drought-tolerant cultivars is an issue of global concern. In this context, four barley and two wheat genotypes were evaluated in south-eastern Russia to identify heat- and drought-tolerant genotypes for future breeding programmes by identifying suitable sowing times for specific genotypes. High temperature stress, when combined with drought during late sowing, decreased the days to visible awns, days to heading and days to ripe harvest, finally negatively affecting the growth and development of plants and resulting in a lower plant population m−2, tillers plant−1, plant height and dry matter production m−2. On the other hand, low temperature in combination with early sowing increased the number of days to germination, reduced seedling stand establishment and tillering capacity, finally affecting the growth and development of the crops. Compared to overall performance and optimum sowing date, barley genotypes ‘Zernograd.770’ and ‘Nutans’, and wheat genotype ‘Line4’ performed best in both late (high temperature with drought) and early (low temperature) stress conditions. PMID:23961209
The effect of Penicillium bilaii on wheat growth and phosphorus uptake as affected by soil pH, soil P and application of sewage sludge

DEFF Research Database (Denmark)

Sánchez-Esteva, S.; Gomez Muñoz, Beatriz; Jensen, Lars Stoumann

2016-01-01

Penicillium bilaii may enhance P availability to plants, since it has been shown to increase plant growth and P uptake. There is currently increasing interest in using microorganisms to promote P mobilisation from organic P sources. An investigation was conducted to determine the effects of P. bi....... bilaii on P uptake and growth of wheat in the presence and absence of sewage sludge. Two soils differing in P contents and pH were used, as it was hypothesised that these affect the efficiency of P mobilisation....
CENPA overexpression promotes genome instability in pRb-depleted human cells

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Lentini Laura

2009-12-01

Full Text Available Abstract Background Aneuploidy is a hallmark of most human cancers that arises as a consequence of chromosomal instability and it is frequently associated with centrosome amplification. Functional inactivation of the Retinoblastoma protein (pRb has been indicated as a cause promoting chromosomal instability as well centrosome amplification. However, the underlying molecular mechanism still remains to be clarified. Results Here we show that pRb depletion both in wild type and p53 knockout HCT116 cells was associated with the presence of multipolar spindles, anaphase bridges, lagging chromosomes and micronuclei harbouring whole chromosomes. In addition aneuploidy caused by pRb acute loss was not affected by p53 loss. Quantitative real-time RT-PCR showed that pRB depletion altered expression of genes involved in centrosome duplication, kinetochore assembly and in the Spindle Assembly Checkpoint (SAC. However, despite MAD2 up-regulation pRb-depleted cells seemed to have a functional SAC since they arrested in mitosis after treatments with mitotic poisons. Moreover pRb-depleted HCT116 cells showed BRCA1 overexpression that seemed responsible for MAD2 up-regulation. Post-transcriptional silencing of CENPA by RNA interference, resulting in CENP-A protein levels similar to those present in control cells greatly reduced aneuploid cell numbers in pRb-depleted cells. Conclusion Altogether our findings indicate a novel aspect of pRb acute loss that promotes aneuploidy mainly by inducing CENPA overexpression that in turn might induce micronuclei by affecting the correct attachment of spindle microtubules to kinetochores.
Intrauterine growth restriction affects the preterm infant's hippocampus.

Science.gov (United States)

Lodygensky, Gregory A; Seghier, Mohammed L; Warfield, Simon K; Tolsa, Cristina Borradori; Sizonenko, Stephane; Lazeyras, François; Hüppi, Petra S

2008-04-01

The hippocampus is known to be vulnerable to hypoxia, stress, and undernutrition, all likely to be present in fetal intrauterine growth restriction (IUGR). The effect of IUGR in preterm infants on the hippocampus was studied using 3D magnetic resonance imaging at term-equivalent age Thirteen preterm infants born with IUGR after placental insufficiency were compared with 13 infants with normal intrauterine growth age matched for gestational age. The hippocampal structural differences were defined using voxel-based morphometry and manual segmentation. The specific neurobehavioral function was evaluated by the Assessment of Preterm Infants' Behavior at term and at 24 mo of corrected age by a Bayley Scales of Infant and Toddler Development. Voxel-based morphometry detected significant gray matter volume differences in the hippocampus between the two groups. This finding was confirmed by manual segmentation of the hippocampus with a reduction of hippocampal volume after IUGR. The hippocampal volume reduction was further associated with functional behavioral differences at term-equivalent age in all six subdomains of the Assessment of Preterm Infants' Behavior but not at 24 mo of corrected age. We conclude that hippocampal development in IUGR is altered and might result from a combination of maternal corticosteroid hormone exposure, hypoxemia, and micronutrient deficiency.
Plk2 regulated centriole duplication is dependent on its localization to the centrioles and a functional polo-box domain.

Science.gov (United States)

Cizmecioglu, Onur; Warnke, Silke; Arnold, Marc; Duensing, Stefan; Hoffmann, Ingrid

2008-11-15

In mammalian cells, the centrosome consists of a pair of centrioles and amorphous pericentriolar material. The centrosome duplicates once per cell cycle. Polo like kinases (Plks) perform crucial functions in cell cycle progression and during mitosis. The polo-like kinase-2, Plk2, is activated near the G(1)/S phase transition, and plays an important role in the reproduction of centrosomes. In this study, we show that the polo-box of Plk2 is required both for association to the centrosome and centriole duplication. Mutation of critical sites in the Plk2 polo-box prevents centrosomal localization and impairs centriole duplication. Plk2 is localized to centrosomes during early G(1) phase where it only associates to the mother centriole and then distributes equally to both mother and daughter centrioles at the onset of S phase. Furthermore, our results imply that Plk2 mediated centriole duplication is dependent on Plk4 function. In addition, we find that siRNA-mediated downregulation of Plk2 leads to the formation of abnormal mitotic spindles confirming that Plk2 may have a function in the reproduction of centrioles.
How Helicobacter pylori urease may affect external pH and influence growth and motility in the mucus environment: evidence from in-vitro studies.

Science.gov (United States)

Sidebotham, Ramon L; Worku, Mulugeta L; Karim, Q Najma; Dhir, Nirmal K; Baron, J Hugh

2003-04-01

Survival of Helicobacter pylori is dependent upon urease in the cytoplasm and at the bacterial surface. We have sought to clarify how alkaline ammonium salts, released from urea by this enzyme, might alter mucus pH and so affect growth and motility of the bacterium in the gastric mucus environment. Experiments were conducted in vitro to determine how the growth and motility of H. pylori are affected by changes in external pH, and how the bacterium, by hydrolysing urea, alters the pH of the bicarbonate buffer that occurs at the gastric mucosal surface. These data were fitted into experimental models that describe how pH varies within the mucus layer in the acid-secreting stomach. H. pylori was motile between pH 5 and 8, with optimal motility at pH 5. It grew between pH 6 and 8, with optimal growth at pH 6. The bacterium had urease activity between pH 2.7 and 7.4, as evidenced by pH rises in bicarbonate-buffered solutions of urea. Changes in buffer pH were dependent upon initial pH and urea concentration, with the greatest rate of pH change occurring at pH 3. Modelling experiments utilizing these data indicated that (1) in the absence of urease, H. pylori growth and motility in the mucus layer would be restricted severely by low mucus pH in the acid-secreting stomach, and (2) urease will sometimes inhibit H. pylori growth and motility in the mucus layer by elevating the pH of the mucus environment above pH 8. Urease is essential to the growth and motility of H. pylori in the mucus layer in the acid-secreting stomach, but, paradoxically, sometimes it might suppress colonization by raising the mucus pH above 8. This latter effect may protect the bacteria from the adverse consequences of overpopulation.
The Role of Microtubule End Binding (EB) Proteins in Ciliogenesis

DEFF Research Database (Denmark)

Schrøder, Jacob Morville

cellular organelles (Lansbergen and Akhmanova, 2006). EB1 also localizes to centrosomes and is required for centrosomal MT anchoring and organization of the MT network (Askham et al., 2002). Further, EB1 has been shown to localize to the flagellar tip and proximal region of the basal bodies......, are required for assembly of primary cilia in cultured human cells. The EB3 - siRNA ciliary phenotype could be rescued by GFP-EB1 expression, and GFP-EB3 over expression resulted in elongated cilia. Transmission electron microscopy (TEM) revealed that EB3-depleted cells possess stumpy cilia, a disorganized...... centrosomal MT array and abnormally long centriole-associated rootlet filaments. Cells lacking EB1 also had stumpy cilia and a disorganized centrosomal MT array, but rootlet filaments appeared normal. Further, live imaging revealed increased release frequency of MTs from the centrosome upon EB1 or EB3...

Lateral septum growth hormone secretagogue receptor affects food intake and motivation for sucrose reinforcement.

Science.gov (United States)

Terrill, Sarah J; Wall, Kaylee D; Medina, Nelson D; Maske, Calyn B; Williams, Diana L

2018-03-28

The hormone ghrelin promotes eating and is widely considered to be a hunger signal. Ghrelin receptors, growth hormone secretagogue receptors (GHSRs), are found in a number of specific regions throughout the brain, including the lateral septum (LS), an area not traditionally associated with the control of feeding. Here we investigated whether GHSRs in the LS play a role in the control of food intake. We examined the feeding effects of ghrelin and the GHSR antagonists ([D-Lys3]-GHRP-6 and JMV 2959), at doses subthreshold for effect when delivered to the lateral ventricle. Intra-LS ghrelin significantly increased chow intake during the mid-light phase, suggesting that pharmacologic activation of LS GHSRs promotes feeding. Conversely, GHSR antagonist delivered to the LS shortly before dark onset significantly reduced chow intake. These data support the hypothesis that exogenous and endogenous stimulation of GHSRs in the LS influence feeding. Ghrelin is known to affect motivation for food, and the dorsal subdivision of LS (dLS) has been shown to play a role in motivation. Thus, we investigated the role of dLS GHSRs in motivation for food reward by examining operant responding for sucrose on a progressive ratio (PR) schedule. Intra-dLS ghrelin increased PR responding for sucrose, while blockade of LS GHSRs did not affect responding in either a fed or fasted state. Together these findings for the first time substantiate the LS as a site of action for ghrelin signaling in the control of food intake.
Decentralization and public expenditure: Does special local autonomy affect regional economic growth?

Directory of Open Access Journals (Sweden)

Martapina Anggai

2018-04-01

Full Text Available This study examines the relationship between public expenditure within regional autonomy policy and economic growth in West Papua and Papua provinces. We distinguish two kinds of expenditure’s decentralization – operational and capital – and also private expenditures. We use an unbalanced panel data over the period of 2007-2010 to investigate those expenditures, whether they enhance regional economic growth or not. We find that the government’s operating and private expenditures have a positive effect on local economic growth, but there is no relationship between capital expenditure’s decentralization on economic growth. The findings did not conform to a-priori efficiency expectations, which suggest needing to reform regional autonomy and fiscal decentralization policy in both provinces.
Growth of non-Saccharomyces yeasts affects nutrient availability for Saccharomyces cerevisiae during wine fermentation.

Science.gov (United States)

Medina, Karina; Boido, Eduardo; Dellacassa, Eduardo; Carrau, Francisco

2012-07-02

Yeast produces numerous secondary metabolites during fermentation that impact final wine quality. Although it is widely recognized that growth of diverse non-Saccharomyces (NS) yeast can positively affect flavor complexity during Saccharomyces cerevisiae wine fermentation, the inability to control spontaneous or co-fermentation processes by NS yeast has restricted their use in winemaking. We selected two NS yeasts from our Uruguayan native collection to study NS-S. cerevisiae interactions during wine fermentation. The selected strains of Hanseniaspora vineae and Metschnikowia pulcherrima had different yeast assimilable nitrogen consumption profiles and had different effects on S. cerevisiae fermentation and growth kinetics. Studies in which we varied inoculum size and using either simultaneous or sequential inoculation of NS yeast and S. cerevisiae suggested that competition for nutrients had a significant effect on fermentation kinetics. Sluggish fermentations were more pronounced when S. cerevisiae was inoculated 24h after the initial stage of fermentation with a NS strain compared to co-inoculation. Monitoring strain populations using differential WL nutrient agar medium and fermentation kinetics of mixed cultures allowed for a better understanding of strain interactions and nutrient addition effects. Limitation of nutrient availability for S. cerevisiae was shown to result in stuck fermentations as well as to reduce sensory desirability of the resulting wine. Addition of diammonium phosphate (DAP) and a vitamin mix to a defined medium allowed for a comparison of nutrient competition between strains. Addition of DAP and the vitamin mix was most effective in preventing stuck fermentations. Copyright © 2012 Elsevier B.V. All rights reserved.
Abnormal Grain Growth in the Heat Affected Zone of Friction Stir Welded Joint of 32Mn-7Cr-1Mo-0.3N Steel during Post-Weld Heat Treatment

Directory of Open Access Journals (Sweden)

Yijun Li

2018-04-01

Full Text Available The abnormal grain growth in the heat affected zone of the friction stir welded joint of 32Mn-7Cr-1Mo-0.3N steel after post-weld heat treatment was confirmed by physical simulation experiments. The microstructural stability of the heat affected zone can be weakened by the welding thermal cycle. It was speculated to be due to the variation of the non-equilibrium segregation state of solute atoms at the grain boundaries. In addition, the pressure stress in the welding process can promote abnormal grain growth in the post-weld heat treatment.
Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses

International Nuclear Information System (INIS)

Wang, Zhenyu; Zhao, Xiuyang; Wang, Bing; Liu, Erlong; Chen, Ni; Zhang, Wei; Liu, Heng

2016-01-01

Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studies revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. - Highlights: • AtRNP1 is a widely expressed gene and its expression is slightly induced under abiotic stresses. • AtRNP1 protein is localized to both the nucleus and cytoplasm. • Overexpression of AtRNP1 affects plant growth. • Overexpression of AtRNP1 reduces plant tolerance to drought and salt stresses. • AtRNP1 overexpression plants show decreased proline accumulation and stress-responsive gene expressions.
Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhenyu, E-mail: wzy72609@163.com [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Zhao, Xiuyang, E-mail: xiuzh@psb.vib-ugent.be [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Wang, Bing, E-mail: wangbing@ibcas.ac.cn [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Liu, Erlong, E-mail: liuel14@lzu.edu.cn [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Chen, Ni, E-mail: 63710156@qq.com [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Zhang, Wei, E-mail: wzhang1216@yahoo.com [Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444 (China); Liu, Heng, E-mail: hengliu@lzu.edu.cn [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China)

2016-04-01

Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studies revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. - Highlights: • AtRNP1 is a widely expressed gene and its expression is slightly induced under abiotic stresses. • AtRNP1 protein is localized to both the nucleus and cytoplasm. • Overexpression of AtRNP1 affects plant growth. • Overexpression of AtRNP1 reduces plant tolerance to drought and salt stresses. • AtRNP1 overexpression plants show decreased proline accumulation and stress-responsive gene expressions.
Temperature and water stress during conditioning and incubation phase affecting Orobanche crenata seed germination and radicle growth

Directory of Open Access Journals (Sweden)

JUAN eMORAL

2015-06-01

Full Text Available Orobanche crenata is a holoparasitic plant that is potentially devastating to crop yield of legume species. Soil temperature and humidity are known to affect seed germination, however, the extent of their influence on germination and radicle growth of those of O. crenata is largely unknown. In this work, we studied the effects of temperature, water potential (Ψt and the type of water stress (matric or osmotic on O. crenata seeds during conditioning and incubation periods. We found that seeds germinated between 5 and 30ºC during both periods, with a maximum around 20ºC. Germination increased with increasing Ψt from -1.2 to 0 MPa during conditioning and incubation periods. Likewise, seed germination increased logarithmically with length of conditioning period until 40 days. The impact of the type of water stress on seed germination was similar, although the radicle growth of seeds under osmotic stress was lower than under matric stress, what could explain the lowest infestation of Orobanche spp. in regions characterized by saline soil. The data in this study will be useful to forecast infection of host roots by O. crenata.
Temperature and water stress during conditioning and incubation phase affecting Orobanche crenata seed germination and radicle growth.

Science.gov (United States)

Moral, Juan; Lozano-Baena, María Dolores; Rubiales, Diego

2015-01-01

Orobanche crenata is a holoparasitic plant that is potentially devastating to crop yield of legume species. Soil temperature and humidity are known to affect seed germination, however, the extent of their influence on germination and radicle growth of those of O. crenata is largely unknown. In this work, we studied the effects of temperature, water potential (Ψt) and the type of water stress (matric or osmotic) on O. crenata seeds during conditioning and incubation periods. We found that seeds germinated between 5 and 30°C during both periods, with a maximum around 20°C. Germination increased with increasing Ψt from -1.2 to 0 MPa during conditioning and incubation periods. Likewise, seed germination increased logarithmically with length of conditioning period until 40 days. The impact of the type of water stress on seed germination was similar, although the radicle growth of seeds under osmotic stress was lower than under matric stress, what could explain the lowest infestation of Orobanche sp. in regions characterized by saline soil. The data in this study will be useful to forecast infection of host roots by O. crenata.
growth and yield parameters of sorghum genotypes as affected

African Journals Online (AJOL)

DR. AMINU

ABSTRACT. Field trial was conducted at Bayero University, Kano research farm with the aim of determining the effect of stem injection artificial inoculation technique on the growth and yield parameters of one hundred and four sorghum genotypes against head smut. The trial was laid on a randomized complete block design ...
Grass defoliation affecting survival and growth of seedlings of ...

African Journals Online (AJOL)

Two experiments were conducted, one in the field and the other in the greenhouse, to investigate the effects of the intensity and frequency of grass defoliation on the survival and growth of Acacia karroo seedlings. In the greenhouse, seedlings growing with heavily clipped grasses had higher biomass production than those ...
Assembling the Setaria italica L. Beauv. genome into nine chromosomes and insights into regions affecting growth and drought tolerance.

Science.gov (United States)

Tsai, Kevin J; Lu, Mei-Yeh Jade; Yang, Kai-Jung; Li, Mengyun; Teng, Yuchuan; Chen, Shihmay; Ku, Maurice S B; Li, Wen-Hsiung

2016-10-13

The diploid C 4 plant foxtail millet (Setaria italica L. Beauv.) is an important crop in many parts of Africa and Asia for the vast consumption of its grain and ability to grow in harsh environments, but remains understudied in terms of complete genomic architecture. To date, there have been only two genome assembly and annotation efforts with neither assembly reaching over 86% of the estimated genome size. We have combined de novo assembly with custom reference-guided improvements on a popular cultivar of foxtail millet and have achieved a genome assembly of 477 Mbp in length, which represents over 97% of the estimated 490 Mbp. The assembly anchors over 98% of the predicted genes to the nine assembled nuclear chromosomes and contains more functional annotation gene models than previous assemblies. Our annotation has identified a large number of unique gene ontology terms related to metabolic activities, a region of chromosome 9 with several growth factor proteins, and regions syntenic with pearl millet or maize genomic regions that have been previously shown to affect growth. The new assembly and annotation for this important species can be used for detailed investigation and future innovations in growth for millet and other grains.
Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

Science.gov (United States)

Ren, Yuanyuan; Wen, Haishen; Li, Yun; Li, Jifang

2017-07-01

The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three different stocking densities (low stocking density, LSD: 5.5 kg/m3; medium stocking density, MSD: 8.0 kg/m3; and high stocking density, HSD: 11.0 kg/m3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower final body weight and specific growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2 (IGF-2), while the concentrations of serum growth hormone (GH) and insulin-like growth factor 1 (IGF-1) decreased in the HSD group. The full-length cDNAs of GH and IGF-2 genes (995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor (GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively affects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.
Detection of ATM germline variants by the p53 mitotic centrosomal localization test in BRCA1/2-negative patients with early-onset breast cancer.

Science.gov (United States)

Prodosmo, Andrea; Buffone, Amelia; Mattioni, Manlio; Barnabei, Agnese; Persichetti, Agnese; De Leo, Aurora; Appetecchia, Marialuisa; Nicolussi, Arianna; Coppa, Anna; Sciacchitano, Salvatore; Giordano, Carolina; Pinnarò, Paola; Sanguineti, Giuseppe; Strigari, Lidia; Alessandrini, Gabriele; Facciolo, Francesco; Cosimelli, Maurizio; Grazi, Gian Luca; Corrado, Giacomo; Vizza, Enrico; Giannini, Giuseppe; Soddu, Silvia

2016-09-06

Variant ATM heterozygotes have an increased risk of developing cancer, cardiovascular diseases, and diabetes. Costs and time of sequencing and ATM variant complexity make large-scale, general population screenings not cost-effective yet. Recently, we developed a straightforward, rapid, and inexpensive test based on p53 mitotic centrosomal localization (p53-MCL) in peripheral blood mononuclear cells (PBMCs) that diagnoses mutant ATM zygosity and recognizes tumor-associated ATM polymorphisms. Fresh PBMCs from 496 cancer patients were analyzed by p53-MCL: 90 cases with familial BRCA1/2-positive and -negative breast and/or ovarian cancer, 337 with sporadic cancers (ovarian, lung, colon, and post-menopausal breast cancers), and 69 with breast/thyroid cancer. Variants were confirmed by ATM sequencing. A total of seven individuals with ATM variants were identified, 5/65 (7.7 %) in breast cancer cases of familial breast and/or ovarian cancer and 2/69 (2.9 %) in breast/thyroid cancer. No variant ATM carriers were found among the other cancer cases. Excluding a single case in which both BRCA1 and ATM were mutated, no p53-MCL alterations were observed in BRCA1/2-positive cases. These data validate p53-MCL as reliable and specific test for germline ATM variants, confirm ATM as breast cancer susceptibility gene, and highlight a possible association with breast/thyroid cancers.
Markers of bone metabolism are affected by renal function and growth hormone therapy in children with chronic kidney disease.

Science.gov (United States)

Doyon, Anke; Fischer, Dagmar-Christiane; Bayazit, Aysun Karabay; Canpolat, Nur; Duzova, Ali; Sözeri, Betül; Bacchetta, Justine; Balat, Ayse; Büscher, Anja; Candan, Cengiz; Cakar, Nilgun; Donmez, Osman; Dusek, Jiri; Heckel, Martina; Klaus, Günter; Mir, Sevgi; Özcelik, Gül; Sever, Lale; Shroff, Rukshana; Vidal, Enrico; Wühl, Elke; Gondan, Matthias; Melk, Anette; Querfeld, Uwe; Haffner, Dieter; Schaefer, Franz

2015-01-01

The extent and relevance of altered bone metabolism for statural growth in children with chronic kidney disease is controversial. We analyzed the impact of renal dysfunction and recombinant growth hormone therapy on a panel of serum markers of bone metabolism in a large pediatric chronic kidney disease cohort. Bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase 5b (TRAP5b), sclerostin and C-terminal FGF-23 (cFGF23) normalized for age and sex were analyzed in 556 children aged 6-18 years with an estimated glomerular filtration rate (eGFR) of 10-60 ml/min/1.73 m2. 41 children receiving recombinant growth hormone therapy were compared to an untreated matched control group. Standardized levels of BAP, TRAP5b and cFGF-23 were increased whereas sclerostin was reduced. BAP was correlated positively and cFGF-23 inversely with eGFR. Intact serum parathormone was an independent positive predictor of BAP and TRAP5b and negatively associated with sclerostin. BAP and TRAP5B were negatively affected by increased C-reactive protein levels. In children receiving recombinant growth hormone, BAP was higher and TRAP5b lower than in untreated controls. Sclerostin levels were in the normal range and higher than in untreated controls. Serum sclerostin and cFGF-23 independently predicted height standard deviation score, and BAP and TRAP5b the prospective change in height standard deviation score. Markers of bone metabolism indicate a high-bone turnover state in children with chronic kidney disease. Growth hormone induces an osteoanabolic pattern and normalizes osteocyte activity. The osteocyte markers cFGF23 and sclerostin are associated with standardized height, and the markers of bone turnover predict height velocity.
Dissolved oxygen levels affect dimorphic growth by the entomopathogenic fungus Isaria fumosorosea

Science.gov (United States)

The entomopathogenic fungus Isaria fumosorosea is capable of dimorphic growth (hyphal or yeast-like) in submerged culture. In shake flask studies, we evaluated the impact of aeration on the mode of growth of I. fumosorosea. Using 250 mL baffled Erlenmeyer flasks, culture volumes of 50, 100, 150, a...
Resin acids as the potential growth-affecting component of pine oleoresin

Directory of Open Access Journals (Sweden)

T. J. Wodzicki

2015-01-01

Full Text Available The nonvolatile fraction of the oleoresin of Pinus sihestris L. was found to contain substances which inhibit growth of wheat ceoleoptile and oat mesocotyl sections in standard bioassays. The inhibition is mainly confined to the fraction of resin acids. Among the seven authentic resin acids tested, the effects of dehydroabietic and abietic acids were most sifgnificant. Palustric, pimaric and isopimaric acids were not effective in the wheat coleoptile section straight growth test. None of the substances, in the amounts tested, except for extremely high concentration, exerted an inhibitory effect on natural or IAA-induced elongation of pine hypocotyl sections. Neither was an inhibitory effect discovered in the microbiological test with the Aspergillus niger van Tiegh. The results obtained with pine hypocotyl sections, allow the conclusion that resin acids interfering with the results of standard bioassays are probably not effective as inhibitory factors in the regulation of pine tissue growth.
Survival and growth of Enterobacter sakazakii in infant cereal as affected by composition, reconstitution liquid, and storage temperature.

Science.gov (United States)

Lin, Li-Chun; Beuchat, Larry R

2007-06-01

Invasive infections caused by Enterobacter sakazakii have occurred predominantly in low-birth-weight neonates and infants younger than 2 months of age. However, infections have also occurred in healthy infants up to 8 months of age and in immunocompromised children up to 4 years of age. The ability of E. sakazakii to survive and grow in infant cereals as affected by composition of the cereal, composition of the reconstitution liquid, and temperature is unknown. A study was done to determine the survival and growth characteristics of E. sakazakii initially at populations of 0.005 and 0.52 CFU/ml of infant rice cereal, oatmeal cereal, or rice with mixed fruit cereal reconstituted with water, milk, or apple juice. Reconstituted cereals were stored at 4, 12, 21, and 30 degrees C, and populations were monitored for up to 72 h. Growth did not occur in reconstituted cereals stored at 4 degrees C or in cereals reconstituted with apple juice and stored at 12 degrees C. Populations (> or =1 CFU/ml) were detected in cereals reconstituted with water or milk and stored at 12, 21, and 30 degres C for 24, 8, and 4 h, respectively. The composition of infant cereals did not markedly affect the survival or growth of E. sakazakii in reconstituted cereals. Populations of E. sakazakii in reconstituted cereal decreased with increases in populations of mesophilic aerobic microflora up to 8 to 9 log CFU/ml, which was concurrent with decreases in pH. E. sakazakii, initially at 2.62 log CFU/ml of rice cereal reconstituted with apple juice (pH 4.32), survived at 40C for at least 14 days. The pathogen grew at 21 and 30 degrees C within 2 days and then decreased to undetectable levels (<1 CFU/10 ml) in cereal stored at 21 degrees C for 5 days or 30'C for 4 days. Initially, at 7.32 log CFU/ml, E. sakazakii was detected in rice cereal stored at 4 degrees C for 50 days. It is recommended that reconstituted infant cereals stored at 21 or 30 degrees C be discarded within 4 h after preparation or
Inhibition of a ubiquitously expressed pectin methyl esterase in Solanum tuberosum L. affects plant growth, leaf growth polarity, and ion partitioning.

Science.gov (United States)

Pilling, J; Willmitzer, L; Bücking, H; Fisahn, J

2004-05-01

Two pectin methyl esterases (PMEs; EC 3.1.1.11) from Solanum tuberosum were isolated and their expression characterised. One partial clone ( pest1) was expressed in leaves and fruit tissue, while pest2 was a functional full-length clone and was expressed ubiquitously, with a preference for aerial organs. Potato plants were transformed with a chimeric antisense construct that was designed to simultaneously inhibit pest1 and pest2 transcript accumulation; however, reduction of mRNA levels was confined to pest2. The decrease in pest2 transcript was accompanied by up to 50% inhibition of total PME activity, which was probably due to the reduction of only one PME isoform. PME inhibition affected plant development as reflected by smaller stem elongation rates of selected transformants when compared with control plants, leading to a reduction in height throughout the entire course of development. Expansion rates of young developing leaves were measured simultaneously by two displacement transducers in the direction of the leaf tip (proximal-distal axis) and in the perpendicular direction (medial-lateral axis). Significant differences in leaf growth patterns were detected between wild-type and transgenic plants. We suggest that these visual phenotypes could be correlated with modifications of ion accumulation and partitioning within the transgenic plants. The ion-binding capacities of cell walls from PME-inhibited plants were specifically modified as they preferentially bound more sodium, but less potassium and calcium. X-ray microanalysis also indicated an increase in the concentration of several ions within the leaf apoplast of transgenic plants. Moreover, quantification of the total content of major cations revealed differences specific for a given element between the leaves of PME-inhibited and wild-type plants. Reduced growth rates might also be due to effects of PME inhibition on pectin metabolism, predominantly illustrated by an accumulation of galacturonic acid
Cross-scale interactions affect tree growth and intrinsic water use efficiency and highlight the importance of spatial context in managing forests under global change

Science.gov (United States)

Kenneth J. Ruzicka; Klaus J. Puettmann; J. Renée Brooks

2017-01-01

Summary1. We investigated the potential of cross-scale interactions to affect the outcome of density reduction in a large-scale silvicultural experiment to better understand options for managing forests under climate change. 2. We measured tree growth and intrinsic water-use efficiency (iWUE) based on stable carbon isotopes (Î´...
Growth at adolescence. Clinical correlates.

Science.gov (United States)

Daniel, W A

1985-03-01

Several highly significant changes occur within a relatively short period of time during adolescence. Great alteration in physique, developmental progress in thinking, and psychologic gains toward attaining ego identity take place but not always synchronously. Attention is paid to physical changes because they are visible and are of intense concern to adolescents, but physicians and other professionals should remember cognitive and psychosocial growth are affected by physical growth, and vice versa. Often there is a temporary disequilibrium in the relationship of these three areas of growth, and this can affect one or another part of the developmental pattern. It is therefore necessary to remind ourselves of the diversity of adolescent growth, and of adolescents, when caring for a young patient and be cognizant of growth in areas other than physical. More and more children with congenital or acquired handicaps are living to become adolescents and perhaps adults. Handicaps can be limited to one of the three major areas of growth or involve them all in varying degrees. For example, sickle cell disease, Crohn's disease, or ulcerative colitis may postpone physical growth for a significant period; this lack of pubertal change can affect psychosocial development but usually does not impair cognitive growth. Mental retardation may have no apparent effect on physical growth but can handicap the adolescent's psychosocial development. Growth still occurs in a sequential pattern but often it seems that handicapped youngsters reach a developmental milestone by a series of "detours." Physicians must recognize these lags or differences and try to facilitate progress, promote self-esteem, and provide understanding. Much can be done with anticipatory guidance. Adolescence often provides the opportunity to overcome past damage or, in some instances, to start anew on a more optimal program for physical and psychosocial growth. Young adolescent boys and girls usually look to the

Regulation of microtubule nucleation mediated by gamma-tubulin complexes

Czech Academy of Sciences Publication Activity Database

Sulimenko, Vadym; Hájková, Zuzana; Klebanovych, Anastasiya; Dráber, Pavel

2017-01-01

Roč. 254, č. 3 (2017), s. 1187-1199 ISSN 0033-183X R&D Projects: GA MŠk(CZ) LD13015 Institutional support: RVO:68378050 Keywords : mitotic spindle formation * ring complex * fission yeast * organizing centers * protein complex * golgi-complex * cell-cycle * pole body * augmin * centrosome * Centrosomes * Microtubule nucleation * Microtubule-organizing centers * Non-centrosomal nucleation sites * Spindle pole bodies * gamma-Tubulin complexes Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Cell biology Impact factor: 2.870, year: 2016
Metabolite Depletion Affects Flux Profiling of Cell Lines

DEFF Research Database (Denmark)

Nilsson, A.; Haanstra, J. R.; Teusink, B.

2018-01-01

Quantifying the rate of consumption and release of metabolites (i.e., flux profiling) has become integral to the study of cancer. The fluxes as well as the growth of the cells may be affected by metabolite depletion during cultivation.......Quantifying the rate of consumption and release of metabolites (i.e., flux profiling) has become integral to the study of cancer. The fluxes as well as the growth of the cells may be affected by metabolite depletion during cultivation....
Timing of growth hormone treatment affects trabecular bone microarchitecture and mineralization in growth hormone deficient mice.

Science.gov (United States)

Kristensen, Erika; Hallgrímsson, Benedikt; Morck, Douglas W; Boyd, Steven K

2010-08-01

Growth hormone (GH) is essential in the development of bone mass, and a growth hormone deficiency (GHD) in childhood is frequently treated with daily injections of GH. It is not clear what effect GHD and its treatment has on bone. It was hypothesized that GHD would result in impaired microarchitecture, and an early onset of treatment would result in a better recovery than late onset. Growth hormone deficient homozygous (lit/lit) mice of both sexes were divided into two treatment groups receiving daily injections of GH, starting at an early (21 days of age) or a late time point (35 days of age, corresponding to the end of puberty). A group of heterozygous mice with normal levels of growth hormone served as controls. In vivo micro-computed tomography scans of the fourth lumbar vertebra were obtained at five time points between 21 and 60 days of age, and trabecular morphology and volumetric BMD were analyzed to determine the effects of GH on bone microarchitecture. Early GH treatment led to significant improvements in bone volume ratio (p=0.006), tissue mineral density (p=0.005), and structure model index (p=0.004) by the study endpoint (day 60), with no detected change in trabecular thickness. Trabecular number increased and trabecular separation decreased in GHD mice regardless of treatment compared to heterozygous mice. This suggests fundamental differences in the structure of trabecular bone in GHD and GH treated mice, reflected by an increased number of thinner trabeculae in these mice compared to heterozygous controls. There were no significant differences between the late treatment group and GHD mice except for connectivity density. Taken together, these results indicate that bone responds to GH treatment initiated before puberty but not to treatment commencing post-puberty, and that GH treatment does not rescue the structure of trabecular bone to that of heterozygous controls. Copyright 2010 Elsevier Inc. All rights reserved.
Earthquakes and economic growth

OpenAIRE

Fisker, Peter Simonsen

2012-01-01

This study explores the economic consequences of earthquakes. In particular, it is investigated how exposure to earthquakes affects economic growth both across and within countries. The key result of the empirical analysis is that while there are no observable effects at the country level, earthquake exposure significantly decreases 5-year economic growth at the local level. Areas at lower stages of economic development suffer harder in terms of economic growth than richer areas. In addition,...
Behavior and function of paternally inherited centrioles in brown algal zygotes.

Science.gov (United States)

Nagasato, Chikako

2005-12-01

In brown algal cells, the centrosome, consisting of a pair of centrioles and the pericentriolar material, is primarily involved in the organization of microtubules (MTs) throughout the cell cycle. In motile cells, the centrioles participate in the formation of flagellar axoneme as flagellar basal bodies, and in somatic cells they play a crucial role in many cellular activities as a part of the centrosome. With respect to the role of the centrosome as a microtubule organizing center (MTOC), brown algal cells resemble animal cells. In most animal fertilization processes, the sperm cell introduces centrioles, the core of the centrosome, into the egg cytoplasm. In this study, the behavior of centrioles from gametogenesis and fertilization to the first cell division of the zygote was examined in the three sexual reproduction patterns occurring in brown algae, i.e., oogamy, anisogamy and isogamy, by electron- and immunofluorescence-microscopy. The pair of centrioles contained in somatic cells was shown to be derived from the male gamete, irrespective of the sexual reproductive pattern. The paternally derived centrioles were duplicated before mitosis and were involved in spindle pole formation. Moreover, MTs from the centrosome play a crucial role in the process of cytokinesis, as the position of centrosomes accompanying daughter nuclei seems to determine the cytokinetic plane. A new approach to clarifying the mode of cytokinesis in brown algae is presented in this study.
Critical challenges affecting Islamic banking growth in India using Analytical Hierarchy Process (AHP)

OpenAIRE

Mosab I. Tabash

2017-01-01

The banking sector plays a vital role in growth-supporting factor for economic growth in the world’s fastest-growing economies like India. Recently, Islamic banking has become an increasingly popular method for alleviating poverty, financial inclusion and economic development around the world. Its importance is highly needed in developing and emerging countries such as India. The main purpose of the paper is to identify and prioritize the critical impeding factors for Islamic banking growth i...
Disruption of mouse Cenpj, a regulator of centriole biogenesis, phenocopies Seckel syndrome

OpenAIRE

McIntyre, Rebecca E; Lakshminarasimhan Chavali, Pavithra; Ismail, Ozama; Carragher, Damian M; Sanchez-Andrade, Gabriela; Forment, Josep V; Fu, Beiyuan; Del Castillo Velasco-Herrera, Martin; Edwards, Andrew; van der Weyden, Louise; Yang, Fengtang; Ramirez-Solis, Ramiro; Estabel, Jeanne; Gallagher, Ferdia A; Logan, Darren W

2012-01-01

Disruption of the centromere protein J gene, CENPJ (CPAP, MCPH6, SCKL4), which is a highly conserved and ubiquitiously expressed centrosomal protein, has been associated with primary microcephaly and the microcephalic primordial dwarfism disorder Seckel syndrome. The mechanism by which disruption of CENPJ causes the proportionate, primordial growth failure that is characteristic of Seckel syndrome is unknown. By generating a hypomorphic allele of Cenpj, we have developed a mouse (Cenpj(tm/tm)...
PUBLIC GOODS, CORRUPTION AND GROWTH???

OpenAIRE

Ratbek Dzhumashev

2006-01-01

In this paper, we analyse implications of corruption on growth. We extend existing growth models by incorporating ubiquitous corruption as a by-product of the public sector. Corruption affects both taxation and public good provision, and therefore causes income redistribution and inefficiencies in the public sector. These effects of corruption lead to lower growth through distortions of investment incentives and resources allocation.
How does Investors' Legal Protection affect Productivity and Growth?

OpenAIRE

Binyamin Berdugo; Sharon Hadad

2009-01-01

This paper analyzes the implications of investors' legal protection on aggregate productivity and growth. We have two main results. First, that better investors' legal protection can mitigate agency problems between investors and innovators and therefore expand the range of high-tech projects that can be financed by non-bank investors. Second, investors' legal protection shifts investment resources from less productive (medium-tech) to highly productive (high-tech) projects and therefore enha...
Do democratic institutions and foreign direct investment affect ...

African Journals Online (AJOL)

Do democratic institutions and foreign direct investment affect economic growth? Evidence from ... International Journal of Development and Management Review ... The importance of sound democratic institutional structures and foreign direct investment for enhancing economic growth is well documentedin literature.
Novel Microcephalic Primordial Dwarfism Disorder Associated with Variants in the Centrosomal Protein Ninein

DEFF Research Database (Denmark)

Dauber, Andrew; LaFranchi, Stephen H.; Maliga, Zoltan

2012-01-01

Context: Microcephalic primordial dwarfism (MPD) is a rare, severe form of human growth failure in which growth restriction is evident in utero and continues into postnatal life. Single causative gene defects have been identified in a number of patients with MPD, and all involve genes fundamental...
In utero and lactational exposure to low-dose genistein-vinclozolin mixture affects the development and growth factor mRNA expression of the submandibular salivary gland in immature female rats.

Science.gov (United States)

Kouidhi, Wided; Desmetz, Catherine; Nahdi, Afef; Bergès, Raymond; Cravedi, Jean-Pierre; Auger, Jacques; El May, Michèle; Canivenc-Lavier, Marie Chantal

2012-06-01

It has been suggested that hormonally controlled submandibular salivary gland (SSG) development and secretions may be affected by endocrine disruptor compounds. We investigated the effects of oral gestation-lactation exposure to 1 mg/kg body weight daily dose of the estrogenic soy-isoflavone genistein and/or the anti-androgenic food contaminant vinclozolin in female rats. The SSGs of female offspring were collected at postnatal day 35 to study gland morphogenesis and mRNA expression of sex-hormone receptors and endocrine growth factors as sex-dependent biomarkers. Because of high expression in neonatal SSG, mRNA expression of transforming growth factor α was also studied. Exposure to genistein, vinclozolin, or a genistein+vinclozolin mixture resulted in significantly lower numbers of striated ducts linked to an increase in their area and lower acinar proliferation (Ki-67-positive nuclei). Exposure to the mixture had the highest significant effects, which were particularly associated with repression of epidermal growth factor, nerve growth factor, and transforming growth factor α expression. In conclusion, early exposure to low doses of genistein and vinclozolin can affect glandular structure and endocrine gene mRNA expression in prepubertal SSG in female rats, and the effects are potentialized by the genistein+vinclozolin mixture. Our study provides the first evidence that SSG are targeted by both estrogenic and anti-androgenic disrupting compounds and are more sensitive to mixtures.
Growth Problems

Science.gov (United States)

... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... hypothyroidism is feeling tired or sluggish. A blood test measuring thyroid ... not affect intelligence or brain function. The cause of growth hormone ...
Knock-down of a tonoplast localized low-affinity nitrate transporter OsNPF7.2 affects rice growth under high nitrate ssupply

Directory of Open Access Journals (Sweden)

Rui Hu

2016-10-01

Full Text Available The large nitrate transporter 1/peptide transporter family (NPF has been shown to transport diverse substrates, including nitrate, amino acids, peptides, phytohormones, and glucosinolates. However, the rice (Oryza sativa root-specific expressed member OsNPF7.2 has not been characterized. Here, our data show that OsNPF7.2 is a tonoplast localized low-affinity nitrate transporter, and affects rice growth under high nitrate supply. The expression analysis showed that OsNPF7.2 was mainly expressed in the elongation and maturation zones of roots, especially in the root sclerenchyma, cortex and stele. It was also induced by high concentrations of nitrate. Subcellular localization analysis showed that OsNPF7.2 was localized on the tonoplast of large and small vacuoles. Heterogenous expression in Xenopus laevis oocytes suggested that OsNPF7.2 was a low-affinity nitrate transporter. Knock-down of OsNPF7.2 retarded rice growth under high concentrations of nitrate. Therefore, we deduce that OsNPF7.2 plays a role in intracellular allocation of nitrate in roots, and thus influences rice growth under high nitrate supply.
Tax Havens, Growth, and Welfare

OpenAIRE

Chu, Hsun; Lai, Ching-Chong; Cheng, Chu-Chuan

2013-01-01

This paper develops an endogenous growth model featuring tax havens, and uses it to examine how the existence of tax havens affects the economic growth rate and social welfare in high-tax countries. We show that the presence of tax havens generates two conflicting channels in determining the growth effect. First, the public investment effect states that tax havens may erode tax revenues and in turn decrease the government’s infrastructure expenditure, thereby reducing growth. Second, the t...
Growth curve and diet density affect eating motivation, behavior, and body composition of broiler breeders during rearing.

Science.gov (United States)

de Los Mozos, J; García-Ruiz, A I; den Hartog, L A; Villamide, M J

2017-08-01

The aim of this work has been to assess the effect of diet density [control (CON) or 15% diluted (DIL)] and growth curve [recommended by the genetic line (RBW) or 15% heavier (HBW)] and their interaction on BW uniformity, feeding motivation, behavior, and body composition of broiler breeder pullets. A total of 3,000 one-day-old female breeders Ross 308, distributed in 20 pens, was randomly assigned to each treatment. Feed allowance was weekly adjusted to reach the desired BW. Feed was provided as pelleted (zero to 3 wk) and crumble (4 to 19 wk). Time eating was measured at 7, 11, and 19 weeks. A feeding rate test was performed after 11 weeks. Behavior was observed at 9 and 15 wk, by visual scan. At 6, 13, and 19 wk of age, one bird/pen was slaughtered for weighing different organs and analyzing the composition of empty whole bodies. Treatments did not affect BW uniformity; relative weights of the ovary, oviduct, or gizzard; or protein content of empty BW. Time eating varied with the growth curve at 19 wk (P motivation. Behavior was affected by the age and by the time of the d measured, but it did not change with the treatments. Birds spent most time pecking objects (50%), feeding (28%), and drinking (17%). Pullets fed DIL had 8% lower breast yield at different ages and higher empty digestive tracts at 6 weeks. Body composition varied with age; fat content increased from 12.7 to 15.9 to 19.8% for 6, 13, and 19 wk, respectively. The lowest body fat was observed for RBW pullets fed DIL (P = 0.003) at 19 weeks. Feeding DIL diets to HBW pullets could be done to increase the time spent eating and reduce their feeling of hunger without negative effects on body composition. However, its influence on behavior and BW uniformity was not proved. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.
Availability and temporal heterogeneity of water supply affect the vertical distribution and mortality of a belowground herbivore and consequently plant growth.

Science.gov (United States)

Tsunoda, Tomonori; Kachi, Naoki; Suzuki, Jun-Ichirou

2014-01-01

We examined how the volume and temporal heterogeneity of water supply changed the vertical distribution and mortality of a belowground herbivore, and consequently affected plant biomass. Plantago lanceolata (Plantaginaceae) seedlings were grown at one per pot under different combinations of water volume (large or small volume) and heterogeneity (homogeneous water conditions, watered every day; heterogeneous conditions, watered every 4 days) in the presence or absence of a larva of the belowground herbivorous insect, Anomala cuprea (Coleoptera: Scarabaeidae). The larva was confined in different vertical distributions to top feeding zone (top treatment), middle feeding zone (middle treatment), or bottom feeding zone (bottom treatment); alternatively no larva was introduced (control treatment) or larval movement was not confined (free treatment). Three-way interaction between water volume, heterogeneity, and the herbivore significantly affected plant biomass. With a large water volume, plant biomass was lower in free treatment than in control treatment regardless of heterogeneity. Plant biomass in free treatment was as low as in top treatment. With a small water volume and in free treatment, plant biomass was low (similar to that under top treatment) under homogeneous water conditions but high under heterogeneous ones (similar to that under middle or bottom treatment). Therefore, there was little effect of belowground herbivory on plant growth under heterogeneous water conditions. In other watering regimes, herbivores would be distributed in the shallow soil and reduced root biomass. Herbivore mortality was high with homogeneous application of a large volume or heterogeneous application of a small water volume. Under the large water volume, plant biomass was high in pots in which the herbivore had died. Thus, the combinations of water volume and heterogeneity affected plant growth via the change of a belowground herbivore.
Crack growth analysis in a weld-heat-affected zone using S-version FEM

International Nuclear Information System (INIS)

Kikuchi, Masanori; Wada, Yoshitaka; Shimizu, Yuto; Li, Yulong

2012-01-01

The objective of this study is the prediction of crack propagation under thermal, residual stress fields using S-Version FEM (S-FEM). By using the S-FEM technique, only the local mesh should be re-meshed and it becomes easy to simulate crack growth. By combining with an auto-meshing technique, the local mesh is re-meshed automatically, and a curved crack path is modeled easily. Virtual crack closure integral method (VCCM) is used to evaluate energy release rate at the crack tip. For crack growth analyses, crack growth rate and growth direction are determined using criteria for mixed mode loading condition. In order to confirm the validity of this analysis, some comparisons with previously reported analyses were done, and good agreement obtained. In this study, residual stress data were provided by JAEA, Japan Atomic Energy Agency, based on their numerical simulation. Stress corrosion crack (SCC) growth analyses in a pipe are conducted in two-dimensional and three-dimensional fields. Two cases, for an axi-symmetric distribution of residual stress in the pipe wall and a non-axisymmetric one are assumed. Effects of residual stress distribution patterns on SCC cracking are evaluated and discussed.
Marine and terrestrial factors affecting Adélie penguin Pygoscelis adeliae chick growth and recruitment off the western Antarctic Peninsula

Science.gov (United States)

Chapman, Erik W.; Hofmann, Eileen E.; Patterson, Donna L.; Ribic, Christine A.; Fraser, William R.

2011-01-01

An individual-based bioenergetics model that simulates the growth of an Adélie penguin Pygoscelis adeliaechick from hatching to fledging was used to assess marine and terrestrial factors that affect chick growth and fledging mass off the western Antarctic Peninsula. Simulations considered the effects on Adélie penguin fledging mass of (1) modification of chick diet through the addition of Antarctic silverfish Pleuragramma antarcticum to an all-Antarctic krillEuphausia superba diet, (2) reduction of provisioning rate which may occur as a result of an environmental stress such as reduced prey availability, and (3) increased thermoregulatory costs due to wetting of chicks which may result from increased precipitation or snow-melt in colonies. Addition of 17% Antarctic silverfish of Age-Class 3 yr (AC3) to a penguin chick diet composed of Antarctic krill increased chick fledging mass by 5%. Environmental stress that results in >4% reduction in provisioning rate or wetting of just 10% of the chick’s surface area decreased fledging mass enough to reduce the chick’s probability of successful recruitment. The negative effects of reduced provisioning and wetting on chick growth can be compensated for by inclusion of Antarctic silverfish of AC3 and older in the chick diet. Results provide insight into climate-driven processes that influence chick growth and highlight a need for field research designed to investigate factors that determine the availability of AC3 and older Antarctic silverfish to foraging Adélie penguins and the influence of snowfall on chick wetting, thermoregulation and adult provisioning rate.
Low light availability affects leaf gas exchange, growth and survival ...

African Journals Online (AJOL)

The values of dark respiration rate (Rd) and photosynthetic compensation irradiance (Ic) were sufficiently low for a positive carbon balance. Notwithstanding, the interpretation of results of microclimate variables together with leaf gas exchange and growth variables indicated that seedlings at all sites were in a suboptimal ...

Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development.

Science.gov (United States)

Weerasekera, Manjula M; Wijesinghe, Gayan K; Jayarathna, Thilini A; Gunasekara, Chinthika P; Fernando, Neluka; Kottegoda, Nilwala; Samaranayake, Lakshman P

2016-11-01

As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabouraud dextrose broth (SDB), yeast nitrogen base (YNB), and RPMI 1640 was compared, and adhesion as well as biofilm formation were monitored using MTT and crystal violet (CV) assays and scanning electron microscopy. Planktonic cells of C. albicans, C. tropicalis and their 1:1 co-culture showed maximal growth in SDB. C. albicans/C. tropicalis adhesion was significantly facilitated in RPMI 1640 although the YNB elicited the maximum growth for C. tropicalis. Similarly, the biofilm growth was uniformly higher for both species in RPMI 1640, and C. tropicalis was the slower biofilm former in all three media. Scanning electron microscopy images tended to confirm the results of MTT and CV assay. Taken together, our data indicate that researchers should pay heed to the choice of laboratory culture media when comparing relative planktonic/biofilm growth of Candida. There is also a need for standardisation of biofilm development media so as to facilitate cross comparisons between laboratories.
Herbivory by an introduced Asian weevil negatively affects population growth of an invasive Brazilian shrub in Florida.

Science.gov (United States)

Stricker, Kerry Bohl; Stiling, Peter

2012-08-01

The enemy release hypothesis (ERH) is often cited to explain why some plants successfully invade natural communities while others do not. This hypothesis maintains that plant populations are regulated by coevolved enemies in their native range but are relieved of this pressure where their enemies have not been co-introduced. Some studies have shown that invasive plants sustain lower levels of herbivore damage when compared to native species, but how damage affects fitness and population dynamics remains unclear. We used a system of co-occurring native and invasive Eugenia congeners in south Florida (USA) to experimentally test the ERH, addressing deficiencies in our understanding of the role of natural enemies in plant invasion at the population level. Insecticide was used to experimentally exclude insect herbivores from invasive Eugenia uniflora and its native co-occurring congeners in the field for two years. Herbivore damage, plant growth, survival, and population growth rates for the three species were then compared for control and insecticide-treated plants. Our results contradict the ERH, indicating that E. uniflora sustains more herbivore damage than its native congeners and that this damage negatively impacts stem height, survival, and population growth. In addition, most damage to E. uniflora, a native of Brazil, is carried out by Myllocerus undatus, a recently introduced weevil from Sri Lanka, and M. undatus attacks a significantly greater proportion of E. uniflora leaves than those of its native congeners. This interaction is particularly interesting because M. undatus and E. uniflora share no coevolutionary history, having arisen on two separate continents and come into contact on a third. Our study is the first to document negative population-level effects for an invasive plant as a result of the introduction of a novel herbivore. Such inhibitory interactions are likely to become more prevalent as suites of previously noninteracting species continue to
Growth Phase, Oxygen, Temperature and Starvation Affect the Development of Viable but Non-Culturable State of Vibrio cholerae

Directory of Open Access Journals (Sweden)

Bin eWu

2016-03-01

Full Text Available AbstractVibrio cholerae can enter into a viable but non-culturable (VBNC state in order to survive in unfavourable environments. In this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of VBNC of V. cholerae in artificial sea water (ASW. Different strains of the organism, the growth phase, and oxygen levels affected the progress of VBNC development. It was found that the VBNC state was induced faster in V. cholerae serogroup O1 classical biotype strain O395 than in O1 El Tor biotype strains C6706 and N16961. When cells in different growth phases were used for VBNC induction, stationary-phase cells lost their culturability more quickly than exponential-phase cells, while induction of a totally non-culturable state took longer to achieve for stationary-phase cells in all three strains, suggesting that heterogeneity of cells should be considered. Aeration strongly accelerated the loss of culturability. During the development of the VBNC state, the culturable cell count under aeration conditions was almost 106-fold lower than under oxygen-limited conditions for all three strains. The other two factors, temperature and nutrients-rich environment, may prevent the induction of VBNC cells. At 22°C or 37°C in ASW, most of the cells rapidly died and the culturable cell count reduced from about 108 CFU/mL to 106–105 CFU/mL. The total cell counts showed that cells that lost viability were decomposed, and the viable cell counts were the same as culturable cell counts, indicating that the cells did not reach the VBNC state. VBNC state development was blocked when ASW was supplied with Luria-Bertani broth (LB, but it was not affected in ASW with M9, suggesting that specific nutrients in LB may prevent the development of VBNC state. These results revealed that the five factors evaluated in this study had different
Root-zone temperature and water availability affect early root growth of planted longleaf pine

Science.gov (United States)

M.A. Sword

1995-01-01

Longleaf pine seedlings from three seed sources were exposed to three root-zone temperatures and three levels of water availability for 28 days. Root growth declined as temperature and water availability decreased. Root growth differed by seed source. Results suggest that subtle changes in the regeneration environment may influence early root growth of longleaf pine...
Aspergillus niger mutants affected in conidial pigmentation do not have an increased susceptibility to water stress during growth at low water activity.

Science.gov (United States)

Segers, F J J; Wösten, H A B; Dijksterhuis, J

2018-03-01

Aspergillus niger forms conidia that contain melanin in their cell wall. This black pigment has been shown to protect fungi against UV radiation, and experimental evidence has indicated that it also protects against drought and high salt concentrations. In this study, growth of A. niger was evaluated at low water activity (a w ) and after changes in relative humidity (RH). In addition, deletion strains of A. niger affected in the melanin synthesis pathway were compared. Germination of conidia of the wild-type and deletion strains was observed at 0·81 a w and germ tubes continued growth at a w ≥ 0·83. Conidia and microcolonies of the different strains were incubated for 1 week at lowered RH (33-84%). Conidia of all strains germinated and formed colonies after exposure to RH ≥33% when transferred back to malt extract medium at a w 0·98. Conidia germinated and showed limited growth at 84% RH. Microcolonies of all strains did not survive an incubation of 1 week at RH ≤75%, but continued growth after exposure to 84% RH. Together, this is the first genetic evidence that melanin does not play a role during germination and radial extension of fungi at low water conditions. Aspergillus niger, a cosmopolitan fungus with melanized conidia, is used here as a model system for fungal growth at low water activity (a w ) and humidity dynamics. From this study it becomes clear that melanin, contrary to what has been suggested before, is not a key factor in survival and growth during situations that mimic indoor conditions. Indoor fungal growth can lead to cosmetic damage to building materials and health problems. This knowledge makes clear that novel ways to limit indoor fungal growth have to be based on interference with other cellular traits of fungi. © 2018 The Society for Applied Microbiology.
Integrated use of plant growth promoting rhizobacteria, biogas slurry and chemical nitrogen for sustainable production of maize under salt-affected conditions

International Nuclear Information System (INIS)

Ahmad, M.; Jamil, M.; Akhtar, F.U.Z.

2014-01-01

Salinity is one of the most critical constraints hampering agricultural production throughout the world, including Pakistan. Some plant growth promoting rhizobacteria (PGPR) have the ability to reduce the deleterious effect of salinity on plants due to the presence of ACC-deaminase enzyme along with some other mechanisms. The integrated use of organic, chemical and biofertilizers can reduce dependence on expensive chemical inputs. To sustain high crop yields without deterioration of soil fertility, it is important to work out optimal combination of chemical and biofertilizers, and manures in the cropping system. A pot trial was conducted to study the effect of integrated use of PGPR, chemical nitrogen, and biogas slurry for sustainable production of maize under salt-stressed conditions and for good soil health. Results showed that sole application of PGPR, chemical nitrogen and biogas slurry enhanced maize growth but their combined application was more effective. Maximum improvement in maize growth, yield, ionic concentration in leaves and nutrient concentration in grains was observed in the treatment where PGPR and biogas slurry was used in the presence of 100% recommended nitrogen as chemical fertilizer. It also improved the soil pH, ECe, and available N, P and K contents. It is concluded that integrated use of PGPR, biogas slurry and chemical nitrogen not only enhanced maize growth, yield and quality but also improved soil health. So, it may be evaluated under field conditions to get sustained yield of maize from salt-affected soils. (author)
Directed Technical Change and Economic Growth Effects of Environmental Policy

DEFF Research Database (Denmark)

Kruse-Andersen, Peter Kjær

2016-01-01

A Schumpeterian growth model is developed to investigate how environmental policy affects economic growth when environmental policy also affects the direction of technical change. In contrast to previous models, production and pollution abatement technologies are embodied in separate intermediate...... unambiguously directs research efforts toward pollution abatement technologies and away from production technologies. This directed technical change reduces economic growth and pollution emission growth. Simulation results indicate that even large environmental policy reforms have small economic growth effects....... However, these economic growth effects have relatively large welfare effects which suggest that static models and exogenous growth models leave out an important welfare effect of environmental policy....
Shaping the Development of Prejudice: Latent Growth Modeling of the Influence of Social Dominance Orientation on Outgroup Affect in Youth.

Science.gov (United States)

Bratt, Christopher; Sidanius, Jim; Sheehy-Skeffington, Jennifer

2016-12-01

Social dominance orientation (SDO) has been theorized as a stable, early-emerging trait influencing outgroup evaluations, a view supported by evidence from cross-sectional and two-wave longitudinal research. Yet, the limitations of identifying causal paths with cross-sectional and two-wave designs are increasingly being acknowledged. This article presents the first use of multi-wave data to test the over-time relationship between SDO and outgroup affect among young people. We use cross-lagged and latent growth modeling (LGM) of a three-wave data set employing Norwegian adolescents (over 2 years, N = 453) and a five-wave data set with American university students (over 4 years, N = 748). Overall, SDO exhibits high temporal rank-order stability and predicts changes in outgroup affect. This research represents the strongest test to date of SDO's role as a stable trait that influences the development of prejudice, while highlighting LGM as a valuable tool for social and political psychology. © 2016 by the Society for Personality and Social Psychology, Inc.
Tree growth and climate in the Pacific Northwest, North America: a broad-scale analysis of changing growth environments

Science.gov (United States)

Whitney L. Albright; David L. Peterson

2013-01-01

Climate change in the 21st century will affect tree growth in the Pacific Northwest region of North America, although complex climateâgrowth relationships make it difficult to identify how radial growth will respond across different species distributions. We used a novel method to examine potential growth responses to climate change at a broad geographical scale with a...
Fish intake in pregnancy and child growth

DEFF Research Database (Denmark)

Stratakis, N.; Roumeliotaki, T.; Oken, E.

2016-01-01

IMPORTANCE Maternal fish intake in pregnancy has been shown to influence fetal growth. The extent to which fish intake affects childhood growth and obesity remains unclear. OBJECTIVE To examine whether fish intake in pregnancy is associated with offspring growth and the risk of childhood overweig...
Factors affecting distribution of wood, detritus, and sediment in headwater streams draining managed young-growth red alder - Conifer forests in southeast Alaska

Science.gov (United States)

Gomi, T.; Johnson, A.C.; Deal, R.L.; Hennon, P.E.; Orlikowska, E.H.; Wipfli, M.S.

2006-01-01

Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) - conifer riparian forests (40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder-conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width (0.5-3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels. ?? 2006 NRC.
Cep63 and cep152 cooperate to ensure centriole duplication.

Directory of Open Access Journals (Sweden)

Nicola J Brown

Full Text Available Centrosomes consist of two centrioles embedded in pericentriolar material and function as the main microtubule organising centres in dividing animal cells. They ensure proper formation and orientation of the mitotic spindle and are therefore essential for the maintenance of genome stability. Centrosome function is crucial during embryonic development, highlighted by the discovery of mutations in genes encoding centrosome or spindle pole proteins that cause autosomal recessive primary microcephaly, including Cep63 and Cep152. In this study we show that Cep63 functions to ensure that centriole duplication occurs reliably in dividing mammalian cells. We show that the interaction between Cep63 and Cep152 can occur independently of centrosome localisation and that the two proteins are dependent on one another for centrosomal localisation. Further, both mouse and human Cep63 and Cep152 cooperate to ensure efficient centriole duplication by promoting the accumulation of essential centriole duplication factors upstream of SAS-6 recruitment and procentriole formation. These observations describe the requirement for Cep63 in maintaining centriole number in dividing mammalian cells and further establish the order of events in centriole formation.
Additional Common Bean in the Diet of Malawian Children Does Not Affect Linear Growth, but Reduces Intestinal Permeability.

Science.gov (United States)

Agapova, Sophia E; Stephenson, Kevin B; Divala, Oscar; Kaimila, Yankho; Maleta, Kenneth M; Thakwalakwa, Chrissie; Ordiz, M Isabel; Trehan, Indi; Manary, Mark J

2018-02-01

Chronic malnutrition, as manifested by linear growth faltering, is pervasive among rural African children. Improvements in complementary feeding may decrease the burden of environmental enteric dysfunction (EED) and thus improve growth in children during the critical first 1000 d of development. We tested the hypothesis that systematically including common bean or cowpea into complementary feeding would reduce EED and growth faltering among children in rural Malawi. This was a double-blind clinical trial in which children 12-23 mo of age were randomly assigned to receive complementary feeding with 1 of 3 foods: roasted cowpea or common bean flour, or an isoenergetic amount of corn-soy blend as a control food for 48 wk. Children aged 12-23 mo received 155 kcal/d and thereafter until 35 mo received 200 kcal/d. The primary outcomes were change in length-for-age z score (LAZ) and improvements in a biomarker of EED, the percentage of lactulose (%L) excreted as part of the lactulose:mannitol dual-sugar absorption test. Anthropometric measurements and urinary %L excretion were compared between the 2 intervention groups and the control group separately with the use of linear mixed model analyses for repeated measures. A total of 331 children completed the clinical trial. Compliance with the study interventions was excellent, with >90% of the intervention flour consumed as intended. No significant effects on LAZ, change in LAZ, or weight-for-length z score were observed due to either intervention legume, compared to the control. %L was reduced with common bean consumption (effect estimate was -0.07 percentage points of lactulose, P = 0.0007). The lactulose:mannitol test was not affected by the legume intervention. The addition of common bean to complementary feeding of rural Malawian children during the second year of life led to an improvement in a biomarker of gut health, although this did not directly translate into improved linear growth. This trial was registered at
Growth and non-renewable resources

DEFF Research Database (Denmark)

Groth, Christian; Schou, Poul

2007-01-01

, interest income taxes and investment subsidies can no longer affect the long-run growth rate, whereas resource tax instruments are decisive for growth. The results stand out both against observations in the literature from the 1970's on non-renewable resources and taxation-observations which were not based...
Rapid population growth.

Science.gov (United States)

1972-01-01

At the current rate of population growth, world population by 2000 is expected to reach 7 billion or more, with developing countries accounting for some 5.4 billion, and economically advanced nations accounting for 1.6 billion. 'Population explosion' is the result of falling mortality rates and continuing high birth rates. Many European countries, and Japan, have already completed what is termed as demographic transition, that is, birth rates have fallen to below 20 births per 1000 population, death rates to 10/1000 population, and annual growth rates are 1% or less; annual growth rates for less developed countries ranged from 2 to 3.5%. Less developed countries can be divided into 3 groups: 1) countries with both high birth and death rates; 2) countries with high birth rates and low death rates; and 3) countries with intermediate and declining birth rates and low death rates. Rapid population growth has serious economic consequences. It encourages inequities in income distribution; it limits rate of growth of gross national product by holding down level of savings and capital investments; it exerts pressure on agricultural production and land; and it creates unemployment problems. In addition, the quality of education for increasing number of chidren is adversely affected, as high proportions of children reduce the amount that can be spent for the education of each child out of the educational budget; the cost and adequacy of health and welfare services are affected in a similar way. Other serious consequences of rapid population growth are maternal death and illness, and physical and mental retardation of children of very poor families. It is very urgent that over a billion births be prevented in the next 30 years to reduce annual population growth rate from the current 2% to 1% per year.
Gastric luminal epidermal growth factor is affected by diet | Iputo ...

African Journals Online (AJOL)

Objective. Diet is an area of major interest to those investigating the causes of cancer of the oesophagus in the Transkei. This study looked at the associations between intragastric epidermal growth factor level, diet and intragastric pH. Setting and subjects. A dietary survey was co-ordinated with studies of gastric luminal ...
Fish oil supplementation from 9 to 18 months of age affects the insulin-like growth factor axis in a sex-specific manner in Danish infants

DEFF Research Database (Denmark)

Damsgaard, Camilla T.; Harsløf, Laurine B. S.; Andersen, Anders D.

2016-01-01

Several studies have investigated the effects of fish oil (FO) on infant growth, but little is known about the effects of FO and sex on insulin-like growth factor-1 (IGF-1), the main regulator of growth in childhood. We explored whether FO v. sunflower oil (SO) supplementation from 9 to 18 months...... of age affected IGF-1 and its binding protein-3 (IGFBP-3) and whether the potential effects were sex specific. Danish infants (n 115) were randomly allocated to 5 ml/d FO (1·2 g/d n-3 long-chain PUFA (n-3 LCPUFA)) or SO. We measured growth, IGF-1, IGFBP-3 and erythrocyte EPA, a biomarker of n-3 LCPUFA...... intake and status, at 9 and 18 months. Erythrocyte EPA increased strongly with FO compared with SO (PIGF-1 in the total population, but a sex×group interaction (P=0·02). Baseline-adjusted IGF-1 at 18 months was 11·1 µg/l (95 % CI 0·4, 21·8;P=0...
A Review of Plant Growth Substances

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D.A. Agboola

2014-10-01

Full Text Available Plant growth substances are compounds, either natural or synthetic that modifies or controls through physiological action, the growth and maturation of plants. If the compound is produced within the plant, it is called a plant hormone or phytohormone. In general, it is accepted that there are five major classes of plant hormones. They are Auxins (IAA, Cytokinins, Gibberellins, Ethylene and Abscisic Acid. However, there are still many plant growth substances that cannot be grouped under these classes, though they also perform similar functions, inhibiting or promoting plant growth. These substances include Brassinosteroids (Brassins, Salicylic Acid, Jasmonic Acid, Fusicoccin, Batasins, Strigolactones, Growth stimulants (e.g. Hymexazol and Pyripropanol, Defoliants (e.g. Calcium Cyanamide, Dimethipin. Researchers are still working on the biosynthetic pathways of some of these substances. Plant growth substances are very useful in agriculture in both low and high concentrations. They affect seed growth, time of flowering, the sex of flowers, senescence of leaves and fruits, leaf formation, stem growth, fruit development and ripening, plant longevity, and even plant death. Some synthetic regulators are also used as herbicides and pesticides. Therefore, attention should be paid to the production and synthesis of these substances so that they affect plants in a way that would favour yield.
Differences in extreme low salinity timing and duration differentially affect eastern oyster (Crassostrea virginica) size class growth and mortality in Breton Sound, LA

Science.gov (United States)

LaPeyre, Megan K.; Eberline, Benjamin S.; Soniat, Thomas M.; La Peyre, Jerome F.

2013-01-01

Understanding how different life history stages are impacted by extreme or stochastic environmental variation is critical for predicting and modeling organism population dynamics. This project examined recruitment, growth, and mortality of seed (25–75 mm) and market (>75 mm) sized oysters along a salinity gradient over two years in Breton Sound, LA. In April 2010, management responses to the Deepwater Horizon oil spill resulted in extreme low salinity (25 °C) significantly and negatively impacted oyster recruitment, survival and growth in 2010, while low salinity (25 °C). With increasing management of our freshwater inputs to estuaries combined with predicted climate changes, how extreme events affect different life history stages is key to understanding variation in population demographics of commercially important species and predicting future populations.
Does raking basal duff affect tree growth rates or mortality?

Science.gov (United States)

Erin Noonan-Wright; Sharon M. Hood; Danny R. Cluck

2010-01-01

Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure...

Theoretical approach of physical growth of children and adolescents

Directory of Open Access Journals (Sweden)

Rossana Gomez-Campos

2016-09-01

Full Text Available According to their genetic potential, biological characteristics and environmental factors, the study of physical growth allows us to understand the variability of this process in humans. Extrinsic and intrinsic factors could affect the normal process of physical growth, which are studied through different types of research, becoming an interesting subject for professionals in the health sciences. The aim of this study is to analyze the factors affecting physical growth and describe the types of research (transverse, longitudinal and ex post facto used in the study of physical growth. Intrinsic factors, environmental factors and the interaction between them should be studied in diverse population prioritizing the potential factors affecting physical growth of children and adolescents. This will diagnose, classify and monitor physical growth versus time (transverse and longitudinal and retrospectively (ex post facto. Consequently, the possibility for researchers and/or private and government institutions arises to promote validated anthropometric studies, helping to implement effective health policies for various purposes such as excess weight control in childhood and other disease entities related nutrition.
Does solar radiation affect the growth of tomato seeds relative to their environment?

Science.gov (United States)

Holzer, Kristi

1995-01-01

The purpose of this experiment is to sequentially study and analyze the data collected from the germination and growth of irradiated Rutgers Supreme tomato seeds to adult producing plants. This experiment will not use irradiated seeds as a control as I plan to note growth in artificial verses natural environment as the basic experiment.
The Ketogenic Diet Does Not Affect Growth of Hedgehog Pathway Medulloblastoma in Mice

Science.gov (United States)

Dang, Mai T.; Wehrli, Suzanne; Dang, Chi V.; Curran, Tom

2015-01-01

The altered metabolism of cancer cells has long been viewed as a potential target for therapeutic intervention. In particular, brain tumors often display heightened glycolysis, even in the presence of oxygen. A subset of medulloblastoma, the most prevalent malignant brain tumor in children, arises as a consequence of activating mutations in the Hedgehog (HH) pathway, which has been shown to promote aerobic glycolysis. Therefore, we hypothesized that a low carbohydrate, high fat ketogenic diet would suppress tumor growth in a genetically engineered mouse model of medulloblastoma. However, we found that the ketogenic diet did not slow the growth of spontaneous tumors or allograft flank tumors, and it did not exhibit synergy with a small molecule inhibitor of Smoothened. Serum insulin was significantly reduced in mice fed the ketogenic diet, but no alteration in PI3 kinase activity was observed. These findings indicate that while the ketogenic diet may be effective in inhibiting growth of other tumor types, it does not slow the growth of HH-medulloblastoma in mice. PMID:26192445
The Ketogenic Diet Does Not Affect Growth of Hedgehog Pathway Medulloblastoma in Mice.

Directory of Open Access Journals (Sweden)

Mai T Dang

Full Text Available The altered metabolism of cancer cells has long been viewed as a potential target for therapeutic intervention. In particular, brain tumors often display heightened glycolysis, even in the presence of oxygen. A subset of medulloblastoma, the most prevalent malignant brain tumor in children, arises as a consequence of activating mutations in the Hedgehog (HH pathway, which has been shown to promote aerobic glycolysis. Therefore, we hypothesized that a low carbohydrate, high fat ketogenic diet would suppress tumor growth in a genetically engineered mouse model of medulloblastoma. However, we found that the ketogenic diet did not slow the growth of spontaneous tumors or allograft flank tumors, and it did not exhibit synergy with a small molecule inhibitor of Smoothened. Serum insulin was significantly reduced in mice fed the ketogenic diet, but no alteration in PI3 kinase activity was observed. These findings indicate that while the ketogenic diet may be effective in inhibiting growth of other tumor types, it does not slow the growth of HH-medulloblastoma in mice.
Lichen physiological traits and growth forms affect communities of associated invertebrates.

Science.gov (United States)

Bokhorst, Stef; Asplund, Johan; Kardol, Paul; Wardle, David A

2015-09-01

While there has been much interest in the relationships between traits of primary producers and composition of associated invertebrate consumer communities, our knowledge is largely based on studies from vascular plants, while other types of functionally important producers, such as lichens, have rarely been considered. To address how physiological traits of lichens drive community composition of invertebrates, we collected thalli from 27 lichen species from southern Norway and quantified the communities of associated springtails, mites, and nematodes. For each lichen species, we measured key physiological thallus traits and determined whether invertebrate communities were correlated with these traits. We also explored whether invertebrate communities differed among lichen groups, categorized according to nitrogen-fixing ability, growth form, and substratum. Lichen traits explained up to 39% of the variation in abundances of major invertebrate groups. For many invertebrate groups, abundance was positively correlated with lichen N and P concentrations, N:P ratio, and the percentage of water content on saturation (WC), but had few relationships with concentrations of carbon-based secondary compounds. Diversity and taxonomic richness of invertebrate groups were sometimes also correlated with lichen N and N:P ratios. Nitrogen-fixing lichens showed higher abundance and diversity of some invertebrate groups than did non-N-fixing lichens. However, this emerged in part because most N-fixing lichens have a foliose growth form that benefits invertebrates, through, improving the microclimate, independently of N concentration. Furthermore, invertebrate communities associated with terricolous lichens were determined more by their close proximity to the soil invertebrate pool than by lichen traits. Overall, our results reveal that differences between lichen species have a large impact on the invertebrate communities that live among the thalli. Different invertebrate groups show
World electricity: will nuclear doubts affect growth

International Nuclear Information System (INIS)

Baum, Vladimir.

1986-01-01

The world has shown a healthy appetite for electricity even during the years of high energy prices. Between 1970 and 1985 worldwide electricity production increased by 92%, from 4,906.7 terawatt hours (TWh) to 9,421.7 TWh (1TWh = 10 9 KWh). In the same period total world energy consumption rose by 44.8% from 220.2 exajoules to 318.8 EJ (1 EJ = 23.88 million tonnes of oil equivalent). The major part of this growth occurred in the 1970s. Over the last five years, from 1980 to 1985, world energy consumption inched forward only by 7.2%, while notwithstanding widespread economic recession, electricity production advanced by 16.1%, with nuclear power responsible for an increasing share. These figures are tabulated and analysed on a worldwide regional basis. The amount of electricity produced by nuclear power plants is given, and the situation in particular countries noted. The projected future electricity demand and future nuclear electricity generating capacity are given. The effect of the Chernobyl incident is assessed. It may prove to be the beginning of the end of nuclear energy or just an unfortunate hiccough in its progress. (U.K.)
Growth of Candida boidinii on methanol and the activity of methanol-degrading enzymes as affected from formaldehyde and methylformate.

Science.gov (United States)

Aggelis, G; Margariti, N; Kralli, C; Flouri, F

2000-06-23

Formaldehyde and methylformate affect the growth of Candida boidinii on methanol and the activity of methanol-degrading enzymes. The presence of both intermediates in the feeding medium caused an increase in biomass yield and productivity and a decrease in the specific rate of methanol consumption. In the presence of formaldehyde, the activity of formaldehyde dehydrogenase and formate dehydrogenase was essentially increased, whereas the activity of methanol oxidase was decreased. On the contrary, the presence of methylformate caused an increase of the activity of methanol oxidase and a decrease of the activity of formaldehyde dehydrogenase and formate dehydrogenase. Interpretations concerning the yeast behavior in the presence of intermediate oxidation products were considered and discussed.
How protein kinases co-ordinate mitosis in animal cells.

Science.gov (United States)

Ma, Hoi Tang; Poon, Randy Y C

2011-04-01

Mitosis is associated with profound changes in cell physiology and a spectacular surge in protein phosphorylation. To accomplish these, a remarkably large portion of the kinome is involved in the process. In the present review, we will focus on classic mitotic kinases, such as cyclin-dependent kinases, Polo-like kinases and Aurora kinases, as well as more recently characterized players such as NIMA (never in mitosis in Aspergillus nidulans)-related kinases, Greatwall and Haspin. Together, these kinases co-ordinate the proper timing and fidelity of processes including centrosomal functions, spindle assembly and microtubule-kinetochore attachment, as well as sister chromatid separation and cytokinesis. A recurrent theme of the mitotic kinase network is the prevalence of elaborated feedback loops that ensure bistable conditions. Sequential phosphorylation and priming phosphorylation on substrates are also frequently employed. Another important concept is the role of scaffolds, such as centrosomes for protein kinases during mitosis. Elucidating the entire repertoire of mitotic kinases, their functions, regulation and interactions is critical for our understanding of normal cell growth and in diseases such as cancers.
Soil type affects Pinus ponderosa var. scopulorum (Pinaceae) seedling growth in simulated drought experiments 1

OpenAIRE

Lindsey, Alexander J.; Kilgore, Jason S.

2013-01-01

Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering) produced less sh...
Factors affecting growth of the spiny lobsters Panulirus gracilis and Panulirus inflatus (Decapoda: Palinuridae in Guerrero, México

Directory of Open Access Journals (Sweden)

Patricia Briones-Fourzán

2003-03-01

Full Text Available The effects of sex, injuries, season and site on the growth of the spiny lobsters Panulirus gracilis, and P. inflatus, were studied through mark-recapture techniques in two sites with different ecological characteristics on the coast of Guerrero, México. Panulirus gracilis occurred in both sites, whereas P. inflatus occurred only in one site. All recaptured individuals were adults. Both species had similar intermolt periods, but P. gracilis had significantly higher growth rates (mm carapace length week -1 than P. inflatus as a result of a larger molt increment. Growth rates of males were higher than those of females in both species owing to larger molt increments and shorter intermolt periods in males. Injuries had no effect on growth rates in either species. Individuals of P. gracilis grew faster in site 1 than in site 2. Therefore, the effect of season on growth of P. gracilis was analyzed separately in each site. In site 2, growth rates of P. gracilis were similar in summer and in winter, whereas insite 1 both species had higher growth rates in winter than in summer. This could be due to spatial differences in processes related to changes in population density and food resources, which were documented in previous works. The overall results show that P. gracilis grows faster than P. inflatus, and that growth rates of both species are highly variable and are affected by environmental factors such as site and season, which should be taken into account when attempting to produce population growth curves for each species.Se analizaron, por medio de marcado-recaptura, los efectos del sexo, heridas, estación del año y localidad sobre el crecimiento de las langostas espinosas Panulirus gracilis Streets, 1871, y Panulirus inflatus (Bouvier, 1895 en dos localidades con diferentes características ecológicas en la costa de Guerrero, México. Panulirus gracilis se presentó en ambas localidades, mientras que P. inflatus sólo se encontró en una de
Humic Fertilizer and Vermicompost Applied to the Soil Can Positively Affect Population Growth Parameters of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) on Eggs of Tuta absoluta (Lepidoptera: Gelechiidae).

Science.gov (United States)

Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M

2017-12-01

The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m ), finite rate of increase (λ), net reproductive rate (R 0 ), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m , λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.
Growth characteristics of Listeria monocytogenes as affected by a native microflora in cooked ham under refrigerated and temperature abuse conditions.

Science.gov (United States)

Hwang, Cheng-An; Sheen, Shiowshuh

2011-05-01

This study examined the growth characteristics of Listeria monocytogenes as affected by a native microflora in cooked ham at refrigerated and abuse temperatures. A five-strain mixture of L. monocytogenes and a native microflora, consisting of Brochothrix spp., isolated from cooked meat were inoculated alone (monocultured) or co-inoculated (co-cultured) onto cooked ham slices. The growth characteristics, lag phase duration (LPD, h), growth rate (GR, log(10) cfu/h), and maximum population density (MPD, log(10) cfu/g), of L. monocytogenes and the native microflora in vacuum-packed ham slices stored at 4, 6, 8, 10, and 12 °C for up to 5 weeks were determined. At 4-12 °C, the LPDs of co-cultured L. monocytogenes were not significantly different from those of monocultured L. monocytogenes in ham, indicating the LPDs of L. monocytogenes at 4-12 °C were not influenced by the presence of the native microflora. At 4-8 °C, the GRs of co-cultured L. monocytogenes (0.0114-0.0130 log(10) cfu/h) were statistically but marginally lower than those of monocultured L. monocytogenes (0.0132-0.0145 log(10) cfu/h), indicating the GRs of L. monocytogenes at 4-8 °C were reduced by the presence of the native microflora. The GRs of L. monocytogenes were reduced by 8-7% with the presence of the native microflora at 4-8 °C, whereas there was less influence of the native microflora on the GRs of L. monocytogenes at 10 and 12 °C. The MPDs of L. monocytogenes at 4-8 °C were also reduced by the presence of the native microflora. Data from this study provide additional information regarding the growth suppression of L. monocytogenes by the native microflora for assessing the survival and growth of L. monocytogenes in ready-to-eat meat products. Published by Elsevier Ltd.
Endogenous Growth, Monetary Shocks and Nominal Rigidities

OpenAIRE

Annicchiarico, Barbara; Pelloni, Alessandra; Lorenza, Rossi

2010-01-01

We introduce endogenous growth in an otherwise standard NK model with staggered prices and wages. Some results follow: (i) monetary volatility negatively affects long-run growth; (ii) the relation between nominal volatility and growth depends on the persistence of the nominal shocks and on the Taylor rule considered; (iii) a Taylor rule with smoothing increases the negative effect of nominal volatility on mean growth.
Different growing conditions affect nutrient content, fruit yield and growth in strawberry

International Nuclear Information System (INIS)

Demirsory, L.; Demirsoy, H.; Balci, G.

2011-01-01

This study aimed to determine the effects of organic and conventional growing on contents of some nutrient elements, nitrogen (N), phosphorous (P), potassium (K), iron (Fe), and manganese (Mn), yield and some growth parameters such as leaf area, petiole length, petiole diameter, crown number, crow n diameter, leaf, root dry weight in 'Sweet Charlie' and 'Camarosa' strawberry cultivars. This study consisted of two strawberry cultivars ('Camarosa' and 'Sweet Charlie'), two growing systems (organic and conventional growing) and two different mulches (black and floating sheet). There was significant difference among treatments in terms of P, K, and Mn content in root and Fe content in leaf and yield and some growth parameters. The best treatment in terms of yield and growth parameters was conventional growing with black plastic in 'Camarosa' while the best treatments were organic growing with floating sheet and black plastic in 'Sweet Charlie' in terms of P, K in root and organic growing with floating sheet in 'Sweet Charlie' in terms of Fe in leaf. (author)
2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro

Energy Technology Data Exchange (ETDEWEB)

Karman, Bethany N., E-mail: bklement@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbshivapur@gmail.com; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Flaws, Jodi A., E-mail: jflaws@illinois.edu

2012-05-15

The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1–100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 μM) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3–4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles. -- Highlights: ►TCDD disrupts sex steroid hormone levels, but not growth of antral follicles. ►Pregnenolone co-treatment by-passes TCDD-induced steroid hormone disruption. ►TCDD affects steroid hormone levels through an AHR pathway in antral follicles.
Estimation of individual growth trajectories when repeated measures are missing

DEFF Research Database (Denmark)

Brooks, Mollie Elizabeth; Clements, Christopher; Pemberton, Josephine

2017-01-01

Individuals in a population vary in their growth due to hidden and observed factors such as age, genetics, environment, disease, and carryover effects from past environments. Because size affects fitness, growth trajectories scale up to affect population dynamics. However, it can be difficult to ...
Growth plate closure: Apex view on bone scan

International Nuclear Information System (INIS)

Giles, P.H.; Trochei, M.; Yeates, K.

1984-01-01

Angular deformities of the extremities in children following premature closure of the growth plate are well known. The deformities depend on the position of an osseus bridge which forms between the epiphysis and metaphysis. Several surgical procedures including resection of the osseus bridge have been described, however, delineation of the site of fusion is difficult to define. The commonest site of growth plate arrest is the distal femoral or proximal tibial growth plate. A new technique using the bone scan has been developed which accurately defines the area and position of these osseus bridges. Two hours after injection of technetium 99m methylene diphosphonate apex views of the affected distal femoral growth plate were performed. The knee was flexed into its smallest angle. Using a pinhole collimator the gamma camera was angled to face the affected growth plate end on. The image was collected onto computer and analysed by: (I) regions of interest over segments of the growth plate to calculate the relative area of total growth plate affected: (II) generating histograms: (III) thresholding or performing isocontours to accentuate abnormal areas. The growth plate is normally uniformly increased when compared to the normal shaft of the bone. Fusion across the plate appears as an area of diminished uptake. The apex view gives a unique functional map of the growth plate such that abnormal areas are displayed, and the site, size and position of osseus fusion obtained. The technique has the potential for determining the metabolic activity of the growth plate before and after surgery. Serial studies will allow assessment of regneration of the plate and reformation of new osseus bridges
Tibial dyschondroplasia associated proteomic changes in chicken growth plate cartilage

Science.gov (United States)

Tibial dyschondroplasia (TD) is a poultry leg problem that affects the proximal growth plate of tibia preventing its transition to bone. To understand the disease-induced proteomic changes we compared the protein extracts of cartilage from normal and TD- affected growth plates. TD was induced by fe...
SOIL CHEMICAL PROPERTIES AND GROWTH OF SUNFLOWER (HELIANTHUS ANNUUS L. AS AFFECTED BY THE APPLICATION OF ORGANIC FERTILIZERS AND INOCULATION WITH ARBUSCULAR MYCORRHIZAL FUNGI

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Apolino José Nogueira da Silva

2015-02-01

Full Text Available The use of organic fertilizers and the inoculation of mycorrhizal fungi in the cultivation of oil crops is essential to reduce production costs and minimize negative impacts on natural resources. A field experiment was conducted in an Argissolo Amarelo (Ultisol with the aim of evaluating the effects of fertilizer application and inoculation of arbuscular mycorrhizal fungi on the growth attributes of sunflower (Helianthus annuus L. and on soil chemical properties. The experiment was conducted at the Federal University of Rio Grande do Norte, Brazil, using a randomized block design with three replicates in a 4 × 2 factorial arrangement consisting of four treatments in regard to application of organic fertilizer (liquid biofertilizer, cow urine, mineral fertilizer, and unfertilized control and two treatments in regard to arbuscular mycorrhizal fungi (with and without mycorrhizal fungi. The results showed that the physiological attributes of relative growth rate and leaf weight ratio were positively influenced by fertilization, compared to the control treatment, likely brought about by the supply of nutrients from the fertilizers applied. The growth and productivity attributes were positively affected by mycorrhization.
Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

Science.gov (United States)

Walz, Johanna M; Boehringer, Daniel; Deissler, Heidrun L; Faerber, Lothar; Goepfert, Jens C; Heiduschka, Peter; Kleeberger, Susannah M; Klettner, Alexa; Krohne, Tim U; Schneiderhan-Marra, Nicole; Ziemssen, Focke; Stahl, Andreas

2016-01-01

Vascular endothelial growth factor-A (VEGF-A) is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements. Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center) twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD), cannula (butterfly vs. neonatal), type of centrifuge (swing-out vs. fixed-angle), time before and after centrifugation, filling level (completely filled vs. half-filled tubes) and analyzing method (ELISA vs. multiplex bead array). Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model. The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes. VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

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Johanna M Walz

Full Text Available Vascular endothelial growth factor-A (VEGF-A is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements.Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD, cannula (butterfly vs. neonatal, type of centrifuge (swing-out vs. fixed-angle, time before and after centrifugation, filling level (completely filled vs. half-filled tubes and analyzing method (ELISA vs. multiplex bead array. Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model.The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes.VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.
Growth factor involvement in tension-induced skeletal muscle growth

Science.gov (United States)

Vandenburgh, Herman H.

1993-01-01

Long-term manned space travel will require a better understanding of skeletal muscle atrophy which results from microgravity. Astronaut strength and dexterity must be maintained for normal mission operations and for emergency situations. Although exercise in space slows the rate of muscle loss, it does not prevent it. A biochemical understanding of how gravity/tension/exercise help to maintain muscle size by altering protein synthesis and/or degradation rate should ultimately allow pharmacological intervention to prevent muscle atrophy in microgravity. The overall objective is to examine some of the basic biochemical processes involved in tension-induced muscle growth. With an experimental in vitro system, the role of exogenous and endogenous muscle growth factors in mechanically stimulated muscle growth are examined. Differentiated avian skeletal myofibers can be 'exercised' in tissue culture using a newly developed dynamic mechanical cell stimulator device which simulates different muscle activity patterns. Patterns of mechanical activity which significantly affect muscle growth and metabolic characteristics were found. Both exogenous and endogenous growth factors are essential for tension-induced muscle growth. Exogenous growth factors found in serum, such as insulin, insulin-like growth factors, and steroids, are important regulators of muscle protein turnover rates and mechanically-induced muscle growth. Endogenous growth factors are synthesized and released into the culture medium when muscle cells are mechanically stimulated. At least one family of mechanically induced endogenous factors, the prostaglandins, help to regulate the rates of protein turnover in muscle cells. Endogenously synthesized IGF-1 is another. The interaction of muscle mechanical activity and these growth factors in the regulation of muscle protein turnover rates with our in vitro model system is studied.
Exposure to altered gravity during specific developmental periods differentially affects growth, development, the cerebellum and motor functions in male and female rats

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Nguon, K.; Ladd, B.; Sajdel-Sulkowska, E. M.

2006-01-01

We previously reported that perinatal exposure to hypergravity affects cerebellar structure and motor coordination in rat neonates. In the present study, we explored the hypothesis that neonatal cerebellar structure and motor coordination may be particularly vulnerable to the effects of hypergravity during specific developmental stages. To test this hypothesis, we compared neurodevelopment, motor behavior and cerebellar structure in rat neonates exposed to 1.65 G on a 24-ft centrifuge during discrete periods of time: the 2nd week of pregnancy [gestational day (G) 8 through G15; group A], the 3rd week of pregnancy (G15 through birth on G22/G23; group B), the 1st week of nursing [birth through postnatal day (P) 6; group C], the 2nd and 3rd weeks of nursing (P6 through P21; group D), the combined 2nd and 3rd weeks of pregnancy and nursing (G8 through P21; group E) and stationary control (SC) neonates (group F). Prenatal exposure to hypergravity resulted in intrauterine growth retardation as reflected by a decrease in the number of pups in a litter and lower average mass at birth. Exposure to hypergravity immediately after birth impaired the righting response on P3, while the startle response in both males and females was most affected by exposure during the 2nd and 3rd weeks after birth. Hypergravity exposure also impaired motor functions, as evidenced by poorer performance on a rotarod; while both males and females exposed to hypergravity during the 2nd and 3rd weeks after birth performed poorly on P21, male neonates were most dramatically affected by exposure to hypergravity during the second week of gestation, when the duration of their recorded stay on the rotarod was one half that of SC males. Cerebellar mass was most reduced by later postnatal exposure. Thus, for the developing rat cerebellum, the postnatal period that overlaps the brain growth spurt is the most vulnerable to hypergravity. However, male motor behavior is also affected by midpregnancy exposure to
Assisted Reproduction Causes Reduced Fetal Growth Associated with Downregulation of Paternally Expressed Imprinted Genes That Enhance Fetal Growth in Mice.

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Li, Bo; Chen, Shuqiang; Tang, Na; Xiao, Xifeng; Huang, Jianlei; Jiang, Feng; Huang, Xiuying; Sun, Fangzhen; Wang, Xiaohong

2016-02-01

Alteration of intrauterine growth trajectory is linked to metabolic diseases in adulthood. In mammalian and, specifically, human species, pregnancies through assisted reproductive technology (ART) are associated with changes in intrauterine growth trajectory. However, it is still unclear how ART alters intrauterine growth trajectory, especially reduced fetal growth in early to midgestation. In this study, using a mouse model, it was found that ART procedures reduce fetal and placental growth at Embryonic Day 10.5. Furthermore, ART leads to decreased methylation levels at H19, KvDMR1, and Snrpn imprinting control regions in the placentae, instead of fetuses. Furthermore, in the placenta, ART downregulated a majority of parentally expressed imprinted genes, which enhance fetal growth, whereas it upregulated a majority of maternally expressed genes which repress fetal growth. Additionally, the expression of genes that regulate placental development was also affected by ART. ART also downregulated a majority of placental nutrient transporters. Disruption of genomic imprinting and abnormal expression of developmentally and functionally relevant genes in placenta may influence the placental development and function, which affect fetal growth and reprogramming. © 2016 by the Society for the Study of Reproduction, Inc.
Factors Affecting Quality and Health Promoting Compounds during Growth and Postharvest Life of Sweet Cherry (Prunus avium L.

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Sofia Correia

2017-12-01

Full Text Available Sweet cherries are attractive fruits due to their taste, color, nutritional value, and beneficial health effects. Sweet cherry is a highly perishable fruit and all quality attributes and the level of health promoting compounds are affected by growth conditions, picking, packing, transport, and storage. During production, the correct combination of scion × rootstock will produce fruits with higher firmness, weight, sugars, vitamins, and phenolic compounds that boost the fruit antioxidant activity. Orchard management, such as applying drip irrigation and summer pruning, will increase fruit sugar levels and total phenolic content, while application of growth regulators can result in improved storability, increased red coloring, increased fruit size, and reduced cracking. Salicylic acid, oxalic acid, acetylsalicylic acid, and methyl salicylate are promising growth regulators as they also increase total phenolics, anthocyanins, and induce higher activity of antioxidant enzymes. These growth regulators are now also applied as fruit coatings that improve shelf-life with higher antioxidant enzyme activities and total phenolics. Optimizing storage and transport conditions, such as hydro cooling with added CaCl2, chain temperature and relative humidity control, are crucial for slowing down decay of quality attributes and increasing the antioxidant capacity. Application of controlled atmosphere during storage is successful in delaying quality attributes, but lowers ascorbic acid levels. The combination of low temperature storage in combination with modified atmosphere packaging (MAP is successful in reducing the incidence of fruit decay, while preserving taste attributes and stem color with a higher antioxidant capacity. A new trend in MAP is the use of biodegradable films such as micro-perforated polylactic acid film that combine significant retention of quality attributes, high consumer acceptability, and a reduced environmental footprint. Another trend
Assessing Effects and interactions among key variables affecting the growth of mixotrophic microalgae: pH, inoculum volume, and growth medium composition

DEFF Research Database (Denmark)

Ale, Marcel Tutor; Pinelo, Manuel; Meyer, Anne S.

2014-01-01

of growth medium (MWC) and wastewater at different proportions (from 20 to 50% of MWC) and at different pH (from 7 to 9). Multilinear regression analysis of the biomass productivity data showed that for SA and CD the biomass productivity was independent of the proportion of medium (MWC), while the growth...... of CV and CR slowed down in mixtures with high proportions of wastewater. However, the biomass productivity of SA was dependent on pH, while the growth of the other microalgae was independent of pH (7-9). When evaluating the influence of pH and proportion of medium, CD appeared most robust among...
Tenascin-C enhances pancreatic cancer cell growth and motility and affects cell adhesion through activation of the integrin pathway.

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Igor Paron

Full Text Available BACKGROUND: Pancreatic cancer (PDAC is characterized by an abundant fibrous tissue rich in Tenascin-C (TNC, a large ECM glycoprotein mainly synthesized by pancreatic stellate cells (PSCs. In human pancreatic tissues, TNC expression increases in the progression from low-grade precursor lesions to invasive cancer. Aim of this study was the functional characterization of the effects of TNC on biologic relevant properties of pancreatic cancer cells. METHODS: Proliferation, migration and adhesion assays were performed on pancreatic cancer cell lines treated with TNC or grown on a TNC-rich matrix. Stable transfectants expressing the large TNC splice variant were generated to test the effects of endogenous TNC. TNC-dependent integrin signaling was investigated by immunoblotting, immunofluorescence and pharmacological inhibition. RESULTS: Endogenous TNC promoted pancreatic cancer cell growth and migration. A TNC-rich matrix also enhanced migration as well as the adhesion to the uncoated growth surface of poorly differentiated cell lines. In contrast, adhesion to fibronectin was significantly decreased in the presence of TNC. The effects of TNC on cell adhesion were paralleled by changes in the activation state of paxillin and Akt. CONCLUSION: TNC affects proliferation, migration and adhesion of poorly differentiated pancreatic cancer cell lines and might therefore play a role in PDAC spreading and metastasis in vivo.
Growth and ionic content of quinoa under saline irrigation

DEFF Research Database (Denmark)

Riccardi, M.; Pulvento, C.; Lavini, A.

2014-01-01

Drought and salinity are the most important abiotic stresses that affect plant's growth and productivity. The aim of the present work was to evaluate the effect of salt and water deficit on water relations, growth parameters and capacity to accumulate inorganic solutes in quinoa plants. An irriga......Drought and salinity are the most important abiotic stresses that affect plant's growth and productivity. The aim of the present work was to evaluate the effect of salt and water deficit on water relations, growth parameters and capacity to accumulate inorganic solutes in quinoa plants...... incorporated salt ions in the tissues (stems, roots, leaves) preserving seed quality. Treatment with a reduction in the irrigation water to 25 % of full irrigated treatment (Q25) caused an increase in WP and a reduced dry matter accumulation in the leaves. Quinoa plants (Q25) were initially negatively affected...... by severe drought with RGR and NAR reduction, and then, they adapted to it. Quinoa could be considered a drought tolerant crop that adapt photosynthetic rate to compensate for a reduced growth....
How maternal malnutrition affects linear growth and development in the offspring

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Maternal malnutrition is common in the developing world and has detrimental effects on both the mother and infant. Pre-pregnancy nutritional status and weight gain during pregnancy are positively related to fetal growth and development. Internationally, there is no agreement on the method of diagnos...
NaCl salinity affects lateral root development in Plantago maritima

NARCIS (Netherlands)

Rubinigg, M; Wenisch, J; Elzenga, JTM; Stulen, [No Value

2004-01-01

Root growth and morphology were assessed weekly in hydroponically-grown seedlings of the halophyte Plantago maritima L. during exposure to 0, 50, 100 and 200 mM NaCl for 21 d. Relative growth rate was reduced by 25% at 200 mM NaCl. The lower NaCl treatments did not affect relative growth rates.
Centrioles: active players or passengers during mitosis?

Science.gov (United States)

Debec, Alain; Sullivan, William; Bettencourt-Dias, Monica

2010-07-01

Centrioles are cylinders made of nine microtubule (MT) triplets present in many eukaryotes. Early studies, where centrosomes were seen at the poles of the mitotic spindle led to their coining as "the organ for cell division". However, a variety of subsequent observational and functional studies showed that centrosomes might not always be essential for mitosis. Here we review the arguments in this debate. We describe the centriole structure and its distribution in the eukaryotic tree of life and clarify its role in the organization of the centrosome and cilia, with an historical perspective. An important aspect of the debate addressed in this review is how centrioles are inherited and the role of the spindle in this process. In particular, germline inheritance of centrosomes, such as their de novo formation in parthenogenetic species, poses many interesting questions. We finish by discussing the most likely functions of centrioles and laying out new research avenues.
Asymmetric Centriole Numbers at Spindle Poles Cause Chromosome Missegregation in Cancer

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Marco R. Cosenza

2017-08-01

Full Text Available Chromosomal instability is a hallmark of cancer and correlates with the presence of extra centrosomes, which originate from centriole overduplication. Overduplicated centrioles lead to the formation of centriole rosettes, which mature into supernumerary centrosomes in the subsequent cell cycle. While extra centrosomes promote chromosome missegregation by clustering into pseudo-bipolar spindles, the contribution of centriole rosettes to chromosome missegregation is unknown. We used multi-modal imaging of cells with conditional centriole overduplication to show that mitotic rosettes in bipolar spindles frequently harbor unequal centriole numbers, leading to biased chromosome capture that favors binding to the prominent pole. This results in chromosome missegregation and aneuploidy. Rosette mitoses lead to viable offspring and significantly contribute to progeny production. We further show that centrosome abnormalities in primary human malignancies frequently consist of centriole rosettes. As asymmetric centriole rosettes generate mitotic errors that can be propagated, rosette mitoses are sufficient to cause chromosome missegregation in cancer.
Effect of smokeless tobacco products on human oral bacteria growth and viability

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Liu, Min; Jin, Jinshan; Pan, Hongmiao; Feng, Jinhui; Cerniglia, Carl E.; Yang, Maocheng; Chen, Huizhong

2017-01-01

To evaluate the toxicity of smokeless tobacco products (STPs) on oral bacteria, seven smokeless tobacco aqueous extracts (STAEs) from major brands of STPs and three tobacco-specific N-nitrosamines (TSNAs) were used in a growth and viability test against 38 oral bacterial species or subspecies. All seven STAEs showed concentration-dependent effects on the growth and viability of tested oral bacteria under anaerobic culture conditions, although there were strain-to-strain variations. In the presence of 1 mg/ml STAEs, the growth of 4 strains decreased over 0.32–2.14 log10 fold, while 14 strains demonstrated enhanced growth of 0.3–1.76 log10 fold, and the growth of 21 strains was not significantly affected. In the presence of 10 mg/ml STAEs, the growth of 17 strains was inhibited 0.3–2.11 log10 fold, 18 strains showed enhanced growth of 0.3–0.97 log10 fold, and 4 strains were not significantly affected. In the presence of 50 mg/ml STAEs, the growth of 32 strains was inhibited 0.3–2.96 log10 fold, 8 strains showed enhanced growth of 0.3–1.0 log10 fold, and 2 strains were not significantly affected. All seven STAEs could promote the growth of 4 bacterial strains, including Eubacterium nodatum, Peptostreptococcus micros, Streptococcus anginosus, and Streptococcus constellatus. Exposure to STAEs modulated the viability of some bacterial strains, with 21.1–66.5% decrease for 4 strains at 1 mg/ml, 20.3–85.7% decrease for 10 strains at 10 mg/ml, 20.0–93.3% decrease for 27 strains at 50 mg/ml, and no significant effect for 11 strains at up to 50 mg/ml. STAEs from snuffs inhibited more tested bacterial strains than those from snus indicating that the snuffs may be more toxic to the oral bacteria than snus. For TSNAs, cell growth and viability of 34 tested strains were not significantly affected at up to 100 μg/ml; while the growth of P. micros was enhanced 0.31–0.54 log10 fold; the growth of Veillonella parvula was repressed 0.33–0.36 log10 fold; and the
Nickel and ocean warming affect scleractinian coral growth.

Science.gov (United States)

Biscéré, T; Lorrain, A; Rodolfo-Metalpa, R; Gilbert, A; Wright, A; Devissi, C; Peignon, C; Farman, R; Duvieilbourg, E; Payri, C; Houlbrèque, F

2017-07-15

The sensitivity of corals and their Symbiodinium to warming has been extensively documented; however very few studies considered that anthropogenic inputs such as metal pollution have already an impact on many fringing reefs. Thus, today, nickel releases are common in coastal ecosystems. In this study, two major reef-building species Acropora muricata and Pocillopora damicornis were exposed in situ to ambient and moderate nickel concentrations on a short-term period (1h) using benthic chamber experiments. Simultaneously, we tested in laboratory conditions the combined effects of a chronic exposure (8weeks) to moderate nickel concentrations and ocean warming on A. muricata. The in situ experiment highlighted that nickel enrichment, at ambient temperature, stimulated by 27 to 47% the calcification rates of both species but not their photosynthetic performances. In contrast, an exposure to higher nickel concentration, in combination with elevated temperature simulated in aquaria, severely depressed by 30% the growth of A. muricata. Copyright © 2017 Elsevier Ltd. All rights reserved.
Electricity, growth and development in India

International Nuclear Information System (INIS)

Debeir, Jean-Claude

2014-01-01

In India, the revenue generated by rapid economic growth have been used neither to relieve the enormous social injustices affecting the oppressed, nor to develop the physical-and especially electric power-infrastructure in a determined and planned way. This growth has not reduced poverty, and it has caused huge ecological degradations
[Changes in ingestive behavior during growth affects the functional maturation of temporomandibular joint nociceptive neurons of rats].

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Hiranuma, Maya

2013-03-01

Temporomandibular joint (TMJ) loading during development promotes its growth and maintains normal structure/function. Continuous change in diet consistency is related to development and maturation of the peripheral nervous system, including the nociceptive system. However, the functional modulation of TMJ-nociceptive neurons under different ingestive behavior is unclear. We fed growing rats a liquid diet to investigate the effects of low TMJ loading on the response properties of neurons in the trigeminal spinal tract subnucleus caudalis (Sp5C). Forty 2-week-old male rats were used. They were fed chow pellets (n = 20, C group) or a liquid diet (n = 20, LD group) soon after weaning. Firing activities of single sensory units in response to TMJ pressure stimuli were recorded at 4, 5, 7 and 9 weeks. In TMJ-nociceptive neurons, the firing threshold (FT) in the LD group was significantly lower than that in the C group at each recording age. The FT in the C group remained unchanged throughout the recording period, whereas that in the LD group was the highest at 4 weeks, and gradually decreased. On the other hand, the initial firing frequency (IFF) was significantly higher in the LD group than in the C group at each recording age. The IFF in the C group remained unchanged throughout the experimental period, whereas that in the LD group was at its lowest at 4 weeks, and gradually increased. Based on these findings, ingestive behavior that results from continuous changes in the physical consistency of the diet during growth may affect the functional maturation of TMJ-nociceptive neurons.
Growth, hydrolases and ultrastructure of Fusarium oxysporum as affected by phenolic rich extracts from several xerophytic plants.

Science.gov (United States)

Mohamed, Mahmoud S M; Saleh, Ahmed M; Abdel-Farid, Ibrahim B; El-Naggar, Sabry A

2017-09-01

Fusarium oxysporum, the causal agent of rot and wilt diseases, is one of the most detrimental phytopathogens for the productivity of many economic crops. The present study was conducted to evaluate the potentiality of some xerophytic plants as eco-friendly approach for management of F. oxysporum. Phenolic rich extracts from five plants namely: Horwoodia dicksoniae, Citrullus colocynthis, Gypsophila capillaris, Pulicaria incisa and Rhanterium epapposum were examined in vitro. The different extracts showed high variability in their phenolic and flavonoid contents as well as total antioxidant capacity. A strong positive correlation existed between the antifungal activity of the tested extracts and their contents of both total phenolics and flavonoids (r values are 0.91 and 0.82, respectively). Extract of P. incisa was the most effective in reducing the mycelial growth (IC 50 =0.92mg/ml) and inhibiting the activities of CMCase, pectinase, amylase and protease by 36, 42, 58 and 55%, respectively. The high performance liquid chromatography analysis of P. incisa extract revealed the presence of eight phenolic acids along with five polyphenolic compounds. The flavonol, quercetin and its glycosides rutin and quercetrin were the most abundant followed by the phenolic acids, t-cinnamic, caffeic, ferulic and vanillic. P. incisa extract not only affects the growth and hydrolases of F. oxysporum but also induces ultrastructure changes in the mycelium, as revealed by transmission electron microscopy. To our knowledge, this is the first study to investigate the mechanisms underlying the antifungal activity of P. incisa. Copyright © 2016 Elsevier Inc. All rights reserved.
Intrauterine Cannabis Exposure Affects Fetal Growth Trajectories: The Generation R Study

Science.gov (United States)

El Marroun, Hanan; Tiemeier, Henning; Steegers, Eric A. P.; Jaddoe, Vincent W. V.; Hofman, Albert; Verhulst, Frank C.; van den Brink, Wim; Huizink, Anja C.

2009-01-01

Objective: Cannabis is the most commonly consumed illicit drug among pregnant women. Intrauterine exposure to cannabis may result in risks for the developing fetus. The importance of intrauterine growth on subsequent psychological and behavioral child development has been demonstrated. This study examined the relation between maternal cannabis use…
Does warming affect growth rate and biomass production of shrubs in the High Arctic?

DEFF Research Database (Denmark)

Campioli, Matteo; Schmidt, Niels Martin; Albert, Kristian Rost

2013-01-01

Few studies have assessed directly the impact of warming on plant growth and biomass production in the High Arctic. Here, we aimed to investigate the impact of 7 years of warming (open greenhouses) on the aboveground relative growth rate (RGR) of Cassiope tetragona and Salix arctica in North-East...
Urban sprawl, smart growth, and deliberative democracy.

Science.gov (United States)

Resnik, David B

2010-10-01

Urban sprawl is an increasingly common feature of the built environment in the United States and other industrialized nations. Although there is considerable evidence that urban sprawl has adverse affects on public health and the environment, policy frameworks designed to combat sprawl-such as smart growth-have proven to be controversial, making implementation difficult. Smart growth has generated considerable controversy because stakeholders affected by urban planning policies have conflicting interests and divergent moral and political viewpoints. In some of these situations, deliberative democracy-an approach to resolving controversial public-policy questions that emphasizes open, deliberative debate among the affected parties as an alternative to voting-would be a fair and effective way to resolve urban-planning issues.

Does religion affect economic growth and happiness? Evidence from Ramadan

OpenAIRE

Campante, Filipe; Yanagizawa-Drott, David

2015-01-01

We study the economic effects of religious practices in the context of the observance of Ramadan fasting, one of the central tenets of Islam. To establish causality, we exploit variation in the length of the fasting period due to the rotating Islamic calendar. We report two key, quantitatively meaningful results: 1) longer Ramadan fasting has a negative effect on output growth in Muslim countries, and 2) it increases subjective well-being among Muslims. We then examine labor market outcomes, ...
An Assessment of Factors Affecting Population Growth of the Mountain Plover

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Stephen J. Dinsmore

2010-06-01

Full Text Available Effective conservation measures should target the most sensitive life history attributes of a species, assuming they are responsive to potential management actions. The Mountain Plover (Charadrius montanus is a species of conservation concern with a patchy breeding distribution in western North America. Plovers prefer areas with short vegetation, bare ground, and disturbance for nesting. Current management tools, including grazing and burning, have been used to attract plovers and enhance nesting success. We used a stage-specific matrix model to study the influence of vital rates, e.g., juvenile and adult annual survival, on population growth rate in the Mountain Plover at two breeding sites in Colorado, South Park and Eastern Colorado, and one breeding site in Montana, USA. Our analysis was motivated by a need to 1 better understand the relationship between demographic rates and population growth rate, 2 assess current management tools for the plover by exploring their effect on population growth rate, and 3 identify areas of the plover's population biology where additional demographic work is needed. Stochastic population growth rate was most influenced by adult survival, especially in Montana and South Park, Colorado (elasticities > 0.60, and was least influenced by first-year reproduction (all elasticities < 0.20. The modeled relationships between lambda and each demographic rate were generally weak (r2 < 0.30 with the exception of number of eggs hatched per nest in Eastern Colorado (r2 = 0.63, chick survival in South Park (r2 = 0.40 and Montana (r2 = 0.38, and adult survival in Montana (r2 = 0.36. We examined the predicted increase in lambda that would result from increasing each demographic rate from its mean to the maximum value observed in our simulations. Chick and adult survival showed the greatest increase in lambda while eggs hatched per nest produced the smallest increase. Our results suggest that future conservation efforts should
Evaluation of environmental bacterial communities as a factor affecting the growth of duckweed Lemna minor.

Science.gov (United States)

Ishizawa, Hidehiro; Kuroda, Masashi; Morikawa, Masaaki; Ike, Michihiko

2017-01-01

Duckweed (family Lemnaceae ) has recently been recognized as an ideal biomass feedstock for biofuel production due to its rapid growth and high starch content, which inspired interest in improving their productivity. Since microbes that co-exist with plants are known to have significant effects on their growth according to the previous studies for terrestrial plants, this study has attempted to understand the plant-microbial interactions of a duckweed, Lemna minor , focusing on the growth promotion/inhibition effects so as to assess the possibility of accelerated duckweed production by modifying co-existing bacterial community. Co-cultivation of aseptic L. minor and bacterial communities collected from various aquatic environments resulted in changes in duckweed growth ranging from -24 to +14% compared to aseptic control. A number of bacterial strains were isolated from both growth-promoting and growth-inhibitory communities, and examined for their co-existing effects on duckweed growth. Irrespective of the source, each strain showed promotive, inhibitory, or neutral effects when individually co-cultured with L. minor . To further analyze the interactions among these bacterial strains in a community, binary combinations of promotive and inhibitory strains were co-cultured with aseptic L. minor , resulting in that combinations of promotive-promotive or inhibitory-inhibitory strains generally showed effects similar to those of individual strains. However, combinations of promotive-inhibitory strains tended to show inhibitory effects while only Aquitalea magnusonii H3 exerted its plant growth-promoting effect in all combinations tested. Significant change in biomass production was observed when duckweed was co-cultivated with environmental bacterial communities. Promotive, neutral, and inhibitory bacteria in the community would synergistically determine the effects. The results indicate the possibility of improving duckweed biomass production via regulation of co
Extracellular matrix organization modulates fibroblast growth and growth factor responsiveness.

Science.gov (United States)

Nakagawa, S; Pawelek, P; Grinnell, F

1989-06-01

To learn more about the relationship between extracellular matrix organization, cell shape, and cell growth control, we studied DNA synthesis by fibroblasts in collagen gels that were either attached to culture dishes or floating in culture medium during gel contraction. After 4 days of contraction, the collagen density (initially 1.5 mg/ml) reached 22 mg/ml in attached gels and 55 mg/ml in floating gels. After contraction, attached collagen gels were well organized; collagen fibrils were aligned in the plane of cell spreading; and fibroblasts had an elongated, bipolar morphology. Floating collagen gels, however, were unorganized; collagen fibrils were arranged randomly; and fibroblasts had a stellate morphology. DNA synthesis by fibroblasts in contracted collagen gels was suppressed if the gels were floating in medium but not if the gels were attached, and inhibition was independent of the extent of gel contraction. Therefore, growth of fibroblasts in contracted collagen gels could be regulated by differences in extracellular matrix organization and cell shape independently of extracellular matrix density. We also compared the responses of fibroblasts in contracted collagen gels and monolayer culture to peptide growth factors including fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta, and interleukin 1. Cells in floating collagen gels were generally unresponsive to any of the growth factors. Cells in attached collagen gels and monolayer culture were affected similarly by fibroblast growth factor but not by the others. Our results indicate that extracellular matrix organization influenced not only cell growth, but also fibroblast responsiveness to peptide growth factors.
Centriole polarisation to the immunological synapse directs secretion from cytolytic cells of both the innate and adaptive immune systems

Directory of Open Access Journals (Sweden)

Arico Maurizo

2011-06-01

Full Text Available Abstract Background Cytolytic cells of the immune system destroy pathogen-infected cells by polarised exocytosis of secretory lysosomes containing the pore-forming protein perforin. Precise delivery of this lethal hit is essential to ensuring that only the target cell is destroyed. In cytotoxic T lymphocytes (CTLs, this is accomplished by an unusual movement of the centrosome to contact the plasma membrane at the centre of the immunological synapse formed between killer and target cells. Secretory lysosomes are directed towards the centrosome along microtubules and delivered precisely to the point of target cell recognition within the immunological synapse, identified by the centrosome. We asked whether this mechanism of directing secretory lysosome release is unique to CTL or whether natural killer (NK and invariant NKT (iNKT cytolytic cells of the innate immune system use a similar mechanism to focus perforin-bearing lysosome release. Results NK cells were conjugated with B-cell targets lacking major histocompatibility complex class I 721.221 cells, and iNKT cells were conjugated with glycolipid-pulsed CD1-bearing targets, then prepared for thin-section electron microscopy. High-resolution electron micrographs of the immunological synapse formed between NK and iNKT cytolytic cells with their targets revealed that in both NK and iNKT cells, the centrioles could be found associated (or 'docked' with the plasma membrane within the immunological synapse. Secretory clefts were visible within the synapses formed by both NK and iNKT cells, and secretory lysosomes were polarised along microtubules leading towards the docked centrosome. The Golgi apparatus and recycling endosomes were also polarised towards the centrosome at the plasma membrane within the synapse. Conclusions These results reveal that, like CTLs of the adaptive immune system, the centrosomes of NK and iNKT cells (cytolytic cells of the innate immune system direct secretory lysosomes to
Centriole polarisation to the immunological synapse directs secretion from cytolytic cells of both the innate and adaptive immune systems.

Science.gov (United States)

Stinchcombe, Jane C; Salio, Mariolina; Cerundolo, Vincenzo; Pende, Daniela; Arico, Maurizo; Griffiths, Gillian M

2011-06-28

Cytolytic cells of the immune system destroy pathogen-infected cells by polarised exocytosis of secretory lysosomes containing the pore-forming protein perforin. Precise delivery of this lethal hit is essential to ensuring that only the target cell is destroyed. In cytotoxic T lymphocytes (CTLs), this is accomplished by an unusual movement of the centrosome to contact the plasma membrane at the centre of the immunological synapse formed between killer and target cells. Secretory lysosomes are directed towards the centrosome along microtubules and delivered precisely to the point of target cell recognition within the immunological synapse, identified by the centrosome. We asked whether this mechanism of directing secretory lysosome release is unique to CTL or whether natural killer (NK) and invariant NKT (iNKT) cytolytic cells of the innate immune system use a similar mechanism to focus perforin-bearing lysosome release. NK cells were conjugated with B-cell targets lacking major histocompatibility complex class I 721.221 cells, and iNKT cells were conjugated with glycolipid-pulsed CD1-bearing targets, then prepared for thin-section electron microscopy. High-resolution electron micrographs of the immunological synapse formed between NK and iNKT cytolytic cells with their targets revealed that in both NK and iNKT cells, the centrioles could be found associated (or 'docked') with the plasma membrane within the immunological synapse. Secretory clefts were visible within the synapses formed by both NK and iNKT cells, and secretory lysosomes were polarised along microtubules leading towards the docked centrosome. The Golgi apparatus and recycling endosomes were also polarised towards the centrosome at the plasma membrane within the synapse. These results reveal that, like CTLs of the adaptive immune system, the centrosomes of NK and iNKT cells (cytolytic cells of the innate immune system) direct secretory lysosomes to the immunological synapse. Morphologically, the
A putative ATP/GTP binding protein affects Leishmania mexicana growth in insect vectors and vertebrate hosts

Science.gov (United States)

Hlaváčová, Jana; Zimmer, Sara L.; Butenko, Anzhelika; Podešvová, Lucie; Leštinová, Tereza; Lukeš, Julius; Kostygov, Alexei; Votýpka, Jan; Volf, Petr

2017-01-01

Background Leishmania virulence factors responsible for the complicated epidemiology of the various leishmaniases remain mainly unidentified. This study is a characterization of a gene previously identified as upregulated in two of three overlapping datasets containing putative factors important for Leishmania’s ability to establish mammalian intracellular infection and to colonize the gut of an insect vector. Methodology/Principal findings The investigated gene encodes ATP/GTP binding motif-containing protein related to Leishmania development 1 (ALD1), a cytosolic protein that contains a cryptic ATP/GTP binding P-loop. We compared differentiation, growth rates, and infective abilities of wild-type and ALD1 null mutant cell lines of L. mexicana. Loss of ALD1 results in retarded growth kinetics but not defects in differentiation in axenic culture. Similarly, when mice and the sand fly vector were infected with the ALD1 null mutant, the primary difference in infection and colonization phenotype relative to wild type was an inability to achieve maximal host pathogenicity. While ability of the ALD1 null mutant cells to infect macrophages in vitro was not affected, replication within macrophages was clearly curtailed. Conclusions/Significance L. mexicana ALD1, encoding a protein with no assigned functional domains or motifs, was identified utilizing multiple comparative analyses with the related and often experimentally overlooked monoxenous flagellates. We found that it plays a role in Leishmania infection and colonization in vitro and in vivo. Results suggest that ALD1 functions in L. mexicana’s general metabolic network, rather than function in specific aspect of virulence as anticipated from the compared datasets. This result validates our comparative genomics approach for finding relevant factors, yet highlights the importance of quality laboratory-based analysis of genes tagged by these methods. PMID:28742133
Resolving nanoparticle growth mechanisms from size- and time-dependent growth rate analysis

Science.gov (United States)

Pichelstorfer, Lukas; Stolzenburg, Dominik; Ortega, John; Karl, Thomas; Kokkola, Harri; Laakso, Anton; Lehtinen, Kari E. J.; Smith, James N.; McMurry, Peter H.; Winkler, Paul M.

2018-01-01

Atmospheric new particle formation occurs frequently in the global atmosphere and may play a crucial role in climate by affecting cloud properties. The relevance of newly formed nanoparticles depends largely on the dynamics governing their initial formation and growth to sizes where they become important for cloud microphysics. One key to the proper understanding of nanoparticle effects on climate is therefore hidden in the growth mechanisms. In this study we have developed and successfully tested two independent methods based on the aerosol general dynamics equation, allowing detailed retrieval of time- and size-dependent nanoparticle growth rates. Both methods were used to analyze particle formation from two different biogenic precursor vapors in controlled chamber experiments. Our results suggest that growth rates below 10 nm show much more variation than is currently thought and pin down the decisive size range of growth at around 5 nm where in-depth studies of physical and chemical particle properties are needed.
Social Trust and the Growth of Schooling

DEFF Research Database (Denmark)

Bjørnskov, Christian

2009-01-01

The paper develops a simple model to examine how social trust might affect the growth of schooling through lowering transaction costs associated with employing educated individuals. In a sample of 52 countries, the paper thereafter provides empirical evidence that trust has led to faster growth...
Growth and Your Newborn

Science.gov (United States)

... drink alcohol, or use illegal drugs during pregnancy. Nutrition during pregnancy . Good nutrition is essential for a baby's growth in the uterus and beyond. A poor diet during pregnancy can affect how much a newborn weighs and ...
Pro-poor growth and gender inequality

OpenAIRE

Klasen, Stephan

2006-01-01

This paper examines to what extent gender gaps in education, health, employment, productive assets and inputs can affect pro poor growth (in the sense of increasing monetary incomes of the poor). After discussing serious methodological problems with examining gender issues in the context of an income-based pro-poor growth framework, the paper considers theory and evidence on the impact of gender inequality on pro poor growth. While there is a considerable literature suggesting negative impact...
Gender influences short-term growth hormone treatment response in children

DEFF Research Database (Denmark)

Sävendahl, Lars; Blankenstein, Oliver; Oliver, Isabelle

2012-01-01

Gender may affect growth hormone (GH) treatment outcome. This study assessed gender-related differences in change from baseline height standard deviation scores (ΔHSDS) after 2 years' GH treatment.......Gender may affect growth hormone (GH) treatment outcome. This study assessed gender-related differences in change from baseline height standard deviation scores (ΔHSDS) after 2 years' GH treatment....
Selection based on indirect genetic effects for growth, environmental enrichment and coping style affect the immune status of pigs.

Science.gov (United States)

Reimert, Inonge; Rodenburg, T Bas; Ursinus, Winanda W; Kemp, Bas; Bolhuis, J Elizabeth

2014-01-01

Pigs living in intensive husbandry systems may experience both acute and chronic stress through standard management procedures and limitations in their physical and social environment, which may have implications for their immune status. Here, the effect of a new breeding method where pigs were selected on their heritable influence on their pen mates' growth, and environmental enrichment on the immune status of pigs was investigated. Hereto, 240 pigs with a relatively positive genetic effect on the growth of their pen mates (+SBV) and 240 pigs with a relatively negative genetic effect on the growth of their pen mates (-SBV) were housed in barren or straw-enriched pens from 4 to 23 weeks of age (n = 80 pens in total). A blood sample was taken from the pigs before, three days after a 24 h regrouping test, and at week 22. In addition, effects of coping style, as assessed in a backtest, and gender were also investigated. Mainly, +SBV were found to have lower leukocyte, lymphocyte and haptoglobin concentrations than -SBV pigs. Enriched housed pigs had a lower neutrophil to lymphocyte (N:L) ratio and lower haptoglobin concentrations, but had higher antibody titers specific for Keyhole Limpet Hemocyanin (KLH) than barren housed pigs. No interactions were found between SBV class and housing. Furthermore, pigs with a proactive coping style had higher alternative complement activity and, in the enriched pens, higher antibody titers specific for KLH than pigs with a reactive coping style. Lastly, females tended to have lower leukocyte, but higher haptoglobin concentrations than castrated males. Overall, these results suggest that +SBV pigs and enriched housed pigs were less affected by stress than -SBV and barren housed pigs, respectively. Moreover, immune activation might be differently organized in individuals with different coping styles and to a lesser extent in individuals of opposite genders.
Selection based on indirect genetic effects for growth, environmental enrichment and coping style affect the immune status of pigs.

Directory of Open Access Journals (Sweden)

Inonge Reimert

Full Text Available Pigs living in intensive husbandry systems may experience both acute and chronic stress through standard management procedures and limitations in their physical and social environment, which may have implications for their immune status. Here, the effect of a new breeding method where pigs were selected on their heritable influence on their pen mates' growth, and environmental enrichment on the immune status of pigs was investigated. Hereto, 240 pigs with a relatively positive genetic effect on the growth of their pen mates (+SBV and 240 pigs with a relatively negative genetic effect on the growth of their pen mates (-SBV were housed in barren or straw-enriched pens from 4 to 23 weeks of age (n = 80 pens in total. A blood sample was taken from the pigs before, three days after a 24 h regrouping test, and at week 22. In addition, effects of coping style, as assessed in a backtest, and gender were also investigated. Mainly, +SBV were found to have lower leukocyte, lymphocyte and haptoglobin concentrations than -SBV pigs. Enriched housed pigs had a lower neutrophil to lymphocyte (N:L ratio and lower haptoglobin concentrations, but had higher antibody titers specific for Keyhole Limpet Hemocyanin (KLH than barren housed pigs. No interactions were found between SBV class and housing. Furthermore, pigs with a proactive coping style had higher alternative complement activity and, in the enriched pens, higher antibody titers specific for KLH than pigs with a reactive coping style. Lastly, females tended to have lower leukocyte, but higher haptoglobin concentrations than castrated males. Overall, these results suggest that +SBV pigs and enriched housed pigs were less affected by stress than -SBV and barren housed pigs, respectively. Moreover, immune activation might be differently organized in individuals with different coping styles and to a lesser extent in individuals of opposite genders.
ELEMENTS OF THE NEOCLASSICAL GROWTH THEORY

Directory of Open Access Journals (Sweden)

Florina Popa

2014-12-01

Full Text Available One of the relevant components of the contemporary economic science is the economic growth theory, the economic background of the time leading to new guidelines of the research. The neoclassical growth theory - the core of modern analysis - explains how the capital accumulation and technological changes affect the economy, significant for the analysis of the economic growth process being the Solow’s neoclassical growth model. The paper brief describes the elements of the economic growth model developed by Solow, both for the situation when it allows the explanation of extensive growth and that wherein the growth is of intensive nature, as a result of the intervention of exogenous technical progress – a determinant of factors productivity growth. It is highlighted the importance of the exogenous neoclassical model, proposed by Solow, who showed the determinant role of the technical progress in the economic growth phenomenon.
Social Trust and the Growth of Schooling

DEFF Research Database (Denmark)

Bjørnskov, Christian

The paper develops a simple model to exemplify how social trust might affect the growth of schooling through lowering transaction costs. In a sample of 52 countries, the paper thereafter provides empirical evidence that trust has indeed led to faster growth of schooling in the period 1960...
Influence of muscle groups' activation on proximal femoral growth tendency.

Science.gov (United States)

Yadav, Priti; Shefelbine, Sandra J; Pontén, Eva; Gutierrez-Farewik, Elena M

2017-12-01

Muscle and joint contact force influence stresses at the proximal growth plate of the femur and thus bone growth, affecting the neck shaft angle (NSA) and femoral anteversion (FA). This study aims to illustrate how different muscle groups' activation during gait affects NSA and FA development in able-bodied children. Subject-specific femur models were developed for three able-bodied children (ages 6, 7, and 11 years) using magnetic resonance images. Contributions of different muscle groups-hip flexors, hip extensors, hip adductors, hip abductors, and knee extensors-to overall hip contact force were computed. Specific growth rate for the growth plate was computed, and the growth was simulated in the principal stress direction at each element in the growth front. The predicted growth indicated decreased NSA and FA (of about [Formula: see text] over a four-month period) for able-bodied children. Hip abductors contributed the most, and hip adductors, the least, to growth rate. All muscles groups contributed to a decrease in predicted NSA ([Formula: see text]0.01[Formula: see text]-0.04[Formula: see text] and FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]), except hip extensors and hip adductors, which showed a tendency to increase the FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]). Understanding influences of different muscle groups on long bone growth tendency can help in treatment planning for growing children with affected gait.
Effects of potassium and humic acid on emergence, growth and ...

African Journals Online (AJOL)

USER

2010-08-16

Aug 16, 2010 ... okra seeds were sown in each pot having 300 cc volumes of growth media. The seedlings were ..... Dell Agnolla G (1984). Plant Growth Regulator Activitiy of ... Acid Affect Seed Germination, Growth and Nutrient Content of.
Adenylate kinase I does not affect cellular growth characteristics under normal and metabolic stress conditions.

Science.gov (United States)

de Bruin, Wieke; Oerlemans, Frank; Wieringa, Bé

2004-07-01

Adenylate kinase (AK)-catalyzed phosphotransfer is essential in the maintenance of cellular energetic economy in cells of fully differentiated tissues with highly variable energy demand, such as muscle and brain. To investigate if AK isoenzymes have a comparable function in the energy-demand management of proliferating cells, AK1 and AK1beta were expressed in mouse neuroblastoma N2a cells and in human colon carcinoma SW480 cells. Glucose deprivation, galactose feeding, and metabolic inhibitor tests revealed a differential energy dependency for these two cell lines. N2a cells showed a faster proliferation rate and strongest coupling to mitochondrial activity, SW480 proliferation was more dependent on glycolysis. Despite these differences, ectopic expression of AK1 or AK1beta did not affect their growth characteristics under normal conditions. Also, no differential effects were seen under metabolic stress upon treatment with mitochondrial and glycolytic inhibitors in in vitro culture or in solid tumors grown in vivo. Although many intimate connections have been revealed between cell death and metabolism, our results suggest that AK1- or AK1beta-mediated high-energy phosphoryl transfer is not a modulating factor in the survival of tumor cells during episodes of metabolic crisis.
Growth and Wood/Bark Properties of Abies faxoniana Seedlings as Affected by Elevated CO2

Institute of Scientific and Technical Information of China (English)

Yun-Zhou Qiao; Yuan-Bin Zhang; Kai-Yun Wang; Qian Wang; Qi-Zhuo Tian

2008-01-01

Growth and wood and bark properties of Abies faxoniana seedlings after one year's exposure to elevated CO2 concentration (ambient + 350 (=1= 25) μmol/mol) under two planting densities (28 or 84 plants/mz) were investigated in closed-top chambers. Tree height, stem diameter and cross-sectional area, and total biomass were enhanced under elevated CO2 concentration, and reduced under high planting density. Most traits of stem bark were improved under elevated CO2 concentration and reduced under high planting density. Stem wood production was significantly increased in volume under elevated CO2 concentration under both densities, and the stem wood density decreased under elevated CO2 concentration and increased under high planting density. These results suggest that the response of stem wood and bark to elevated CO2 concentration is density dependent. This may be of great importance in a future CO2 enriched world in natural forests where plant density varies considerably. The results also show that the bark/wood ratio in diameter, stem cross-sectional area and dry weight are not proportionally affected by elevated CO2 concentration under the two contrasting planting densities. This indicates that the response magnitude of stem bark and stem wood to elevated CO2 concentration are different but their response directions are the same.

Antenatal and postnatal growth and 5-year cognitive outcome in very preterm infants.

Science.gov (United States)

Leppänen, Marika; Lapinleimu, Helena; Lind, Annika; Matomäki, Jaakko; Lehtonen, Liisa; Haataja, Leena; Rautava, Päivi

2014-01-01

To study how antenatal growth affects cognitive outcome in very preterm infants and to determine whether there is an association between growth in any particular time period between birth and 5 years of age and cognitive outcome. Small for gestational age (SGA) and non-SGA infants were analyzed separately, because antenatal growth may affect postnatal growth. Very low birth weight (growth was determined as a z score change between measurement points. Cognitive development was assessed at 5 years of age with the Wechsler Preschool and Primary Scales of Intelligence-Revised. The association between growth and full-scale IQ (FSIQ) was studied. Growth in length and height was not associated with 5-year cognitive outcome. However, weight (r = 0.18, P = .04) and HC growth (r = 0.25, P = .01) between birth and 2 years of corrected age correlated to FSIQ in non-SGA children. In SGA children, HC growth (r = 0.33, P = .03) around term age correlated to FSIQ. Cognitive outcome was similar in SGA and non-SGA very preterm infants. Growth affected cognition positively in both subgroups, but the critical time period was different.
Water and nitrogen conditions affect the relationships of Delta13C and Delta18O to gas exchange and growth in durum wheat.

Science.gov (United States)

Cabrera-Bosquet, Llorenç; Molero, Gemma; Nogués, Salvador; Araus, José Luis

2009-01-01

Whereas the effects of water and nitrogen (N) on plant Delta(13)C have been reported previously, these factors have scarcely been studied for Delta(18)O. Here the combined effect of different water and N regimes on Delta(13)C, Delta(18)O, gas exchange, water-use efficiency (WUE), and growth of four genotypes of durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] cultured in pots was studied. Water and N supply significantly increased plant growth. However, a reduction in water supply did not lead to a significant decrease in gas exchange parameters, and consequently Delta(13)C was only slightly modified by water input. Conversely, N fertilizer significantly decreased Delta(13)C. On the other hand, water supply decreased Delta(18)O values, whereas N did not affect this parameter. Delta(18)O variation was mainly determined by the amount of transpired water throughout plant growth (T(cum)), whereas Delta(13)C variation was explained in part by a combination of leaf N and stomatal conductance (g(s)). Even though the four genotypes showed significant differences in cumulative transpiration rates and biomass, this was not translated into significant differences in Delta(18)O(s). However, genotypic differences in Delta(13)C were observed. Moreover, approximately 80% of the variation in biomass across growing conditions and genotypes was explained by a combination of both isotopes, with Delta(18)O alone accounting for approximately 50%. This illustrates the usefulness of combining Delta(18)O and Delta(13)C in order to assess differences in plant growth and total transpiration, and also to provide a time-integrated record of the photosynthetic and evaporative performance of the plant during the course of crop growth.
Electricity consumption and economic growth: evidence from Korea

International Nuclear Information System (INIS)

Yoo, Seung-Hoon

2005-01-01

This paper investigates the short- and long-run causality issues between electricity consumption and economic growth in Korea by using the co-integration and error-correction models. It employs annual data covering the period 1970-2002. The overall results show that there exists bi-directional causality between electricity consumption and economic growth. This means that an increase in electricity consumption directly affects economic growth and that economic growth also stimulates further electricity consumption
International Financial Integration and Economic Growth in India: An Empirical Investigation

Directory of Open Access Journals (Sweden)

Nayia MAHAJAN

2015-11-01

Full Text Available This study endeavors to estimate relationship between international financial integration and economic growth in India during 1981-2011. Apart from direct impact of international financial integration on growth, indirect impact (via financial development has also been studied empirically. Models of co-integration and Vector Error Correction Model (VECM have been applied to examine the relationships. The study observes that international financial integration affects the growth of the economy positively; and change in economic growth due to it through financial development is approximately 8.63 percent. The study also suggests that the structural reforms that took place in India in early nineties did not affect the existing relationship of global financial integration and economic growth significantly.
Problems of social and economic growth in the Kyrgyz Republic

Directory of Open Access Journals (Sweden)

Guseva Valentina Ivanovna

2016-04-01

Full Text Available In the article author explores the indirect influence of non-economic factors on the growth dynamics of the volume of GDP, including shows the effect of social problems on economic growth. It is proved that the existence of social problems have a negative impact on the pace of the economic dynamics of the country, due to the mutual dependence of key economic and non-economic factors of growth. On the one hand, the level of income of the population affects the purchasing power, which leads to the increase of the acceleration in economic growth. On the other hand, high levels of poverty and a deepening income inequality dictate political and social instability in society, which negatively affects the dynamics of economic growth. It was revealed that the feature of economic growth in the transitional economy is the negative impact of inflation and unemployment rates of economic dynamics, despite the fact that in most Western models, they are not considered as limiting growth factors.
Electricity consumption and economic growth in seven South American countries

International Nuclear Information System (INIS)

Yoo, Seung-Hoon; Kwak, So-Yoon

2010-01-01

This paper attempts to investigate the causal relationship between electricity consumption and economic growth among seven South American countries, namely Argentina, Brazil, Chile, Columbia, Ecuador, Peru, and Venezuela using widely accepted time-series techniques for the period 1975-2006. The results indicate that the causal nexus between electricity consumption and economic growth varies across countries. There is a unidirectional, short-run causality from electricity consumption to real GDP for Argentina, Brazil, Chile, Columbia, and Ecuador. This means that an increase in electricity consumption directly affects economic growth in those countries. In Venezuela, there is a bidirectional causality between electricity consumption and economic growth. This implies that an increase in electricity consumption directly affects economic growth and that economic growth also stimulates further electricity consumption in that country. However, no causal relationships exist in Peru. The documented evidence from seven South American countries can provide useful information for each government with regard to energy and growth policy.
GIT1/βPIX signaling proteins and PAK1 kinase regulate microtubule nucleation.

Science.gov (United States)

Černohorská, Markéta; Sulimenko, Vadym; Hájková, Zuzana; Sulimenko, Tetyana; Sládková, Vladimíra; Vinopal, Stanislav; Dráberová, Eduarda; Dráber, Pavel

2016-06-01

Microtubule nucleation from γ-tubulin complexes, located at the centrosome, is an essential step in the formation of the microtubule cytoskeleton. However, the signaling mechanisms that regulate microtubule nucleation in interphase cells are largely unknown. In this study, we report that γ-tubulin is in complexes containing G protein-coupled receptor kinase-interacting protein 1 (GIT1), p21-activated kinase interacting exchange factor (βPIX), and p21 protein (Cdc42/Rac)-activated kinase 1 (PAK1) in various cell lines. Immunofluorescence microscopy revealed association of GIT1, βPIX and activated PAK1 with centrosomes. Microtubule regrowth experiments showed that depletion of βPIX stimulated microtubule nucleation, while depletion of GIT1 or PAK1 resulted in decreased nucleation in the interphase cells. These data were confirmed for GIT1 and βPIX by phenotypic rescue experiments, and counting of new microtubules emanating from centrosomes during the microtubule regrowth. The importance of PAK1 for microtubule nucleation was corroborated by the inhibition of its kinase activity with IPA-3 inhibitor. GIT1 with PAK1 thus represent positive regulators, and βPIX is a negative regulator of microtubule nucleation from the interphase centrosomes. The regulatory roles of GIT1, βPIX and PAK1 in microtubule nucleation correlated with recruitment of γ-tubulin to the centrosome. Furthermore, in vitro kinase assays showed that GIT1 and βPIX, but not γ-tubulin, serve as substrates for PAK1. Finally, direct interaction of γ-tubulin with the C-terminal domain of βPIX and the N-terminal domain of GIT1, which targets this protein to the centrosome, was determined by pull-down experiments. We propose that GIT1/βPIX signaling proteins with PAK1 kinase represent a novel regulatory mechanism of microtubule nucleation in interphase cells. Copyright © 2016 Elsevier B.V. All rights reserved.
IVF culture medium affects human intrauterine growth as early as the second trimester of pregnancy.

Science.gov (United States)

Nelissen, Ewka C M; Van Montfoort, Aafke P A; Smits, Luc J M; Menheere, Paul P C A; Evers, Johannes L H; Coonen, Edith; Derhaag, Josien G; Peeters, Louis L; Coumans, Audrey B; Dumoulin, John C M

2013-08-01

When does a difference in human intrauterine growth of singletons conceived after IVF and embryo culture in two different culture media appear? Differences in fetal development after culture of embryos in one of two IVF media were apparent as early as the second trimester of pregnancy. Abnormal fetal growth patterns are a major risk factor for the development of chronic diseases in adult life. Previously, we have shown that the medium used for culturing embryos during the first few days after fertilization significantly affects the birthweight of the resulting human singletons. The exact onset of this growth difference was unknown. In this retrospective cohort study, all 294 singleton live births after fresh embryo transfer in the period July 2003 to December 2006 were included. These embryos originated from IVF treatments that were part of a previously described clinical trial. Embryos were allocated to culture in either Vitrolife or Cook commercially available sequential culture media. We analysed ultrasound examinations at 8 (n = 290), 12 (n = 83) and 20 weeks' (n = 206) gestation and used first-trimester serum markers [pregnancy-associated plasma protein-A (PAPP-A) and free β-hCG]. Differences between study groups were tested by the Student's t-test, χ(2) test or Fisher's exact test, and linear multivariable regression analysis to adjust for possible confounders (for example, parity, gestational age at the time of ultrasound and fetal gender). A total of 294 singleton pregnancies (Vitrolife group nVL = 168, Cook group: nC = 126) from 294 couples were included. At 8 weeks' gestation, there was no difference between crown-rump length-based and ovum retrieval-based gestational age (ΔGA) (nVL = 163, nC = 122, adjusted mean difference, -0.04 days, P = 0.84). A total of 83 women underwent first-trimester screening at 12 weeks' gestation (nVL = 45, nC = 38). ΔGA, nuchal translucency (multiples of median, MoM) and PAPP-A (MoM) did not differ between the study
Inequality and growth : The neglected time dimension

NARCIS (Netherlands)

Halter, D.; Oechslin, M.C.; Zweimüller, J.

Inequality affects economic performance through many mechanisms, both beneficial and harmful. Moreover, some of these mechanisms tend to set in fast while others are rather slow. The present paper (i) introduces a simple theoretical model to study how changes in inequality affect economic growth
On the growth of atmospheric nanoparticles by organic vapors

Energy Technology Data Exchange (ETDEWEB)

Yli-Juuti, T.

2013-09-01

Atmospheric aerosol particles affect the visibility, damage human health and influence the Earth's climate by scattering and absorbing radiation and acting as cloud condensation nuclei (CCN). Considerable uncertainties are associated with the estimates of aerosol climatic effects and the extent of these effects depends on the particles size, composition, concentration and location in the atmosphere. Improved knowledge on the processes affecting these properties is of great importance in predicting future climate. Significant fraction of the atmospheric aerosol particles are formed in the atmosphere from trace gases through a phase change, i.e. nucleation. The freshly nucleated secondary aerosol particles are about a nanometer in diameter, and they need to grow tens of nanometers by condensation of vapors before they affect the climate. During the growth, the nanoparticles are subject to coagulational losses, and their survival to CCN sizes is greatly dependent on their growth rate. Therefore, capturing the nanoparticle growth correctly is crucial for representing aerosol effects in climate models. A large fraction of nanoparticle growth in many environments is expected to be due to organic compounds. However a full identification of the compounds and processes involved in the growth is lacking to date. In this thesis the variability in atmospheric nanoparticle growth rates with particle size and ambient conditions was studied based on observations at two locations, a boreal forest and a Central European rural site. The importance of various organic vapor uptake mechanisms and particle phase processes was evaluated, and two nanoparticle growth models were developed to study the effect of acid-base chemistry in the uptake of organic compounds by nanoparticles. Further, the effect of inorganic solutes on the partitioning of organic aerosol constituents between gas and particle phase was studied based on laboratory experiments. Observations of the atmospheric
The use of 32P to study root growth of soybean as affected by soil compaction

International Nuclear Information System (INIS)

Sisworo, Elsje L.; Sisworo, Widjang H.; Syaukat, Sri Harti; Wemay, Johannis; Haryanto

1996-01-01

Two greenhouse and two field experiments have been conducted to study the effect of soil compaction on root and plant growth of soybean, by using 32 P in the form of carrier free KH 2 32 PO 4 solution. In the greenhouse experiment it was clearly shown that by increasing soil compaction the growth of roots and shoots was increasingly inhibited. The growth of roots was expressed in √% arcsin converted from 32 P activity (counts per minute, cpm) in the shoots and 32 P activity in the shoots (cpm) without convertion. Plant growth was expressed in plant height, number of leaves, dry weight of pods and shoots. In the field experiment, it was shown distinctively that root growth in the 15 cm soil depth was inhibited whith the increase of soil compaction. Similar with the greenhouse experiments the of plants of roots was expressed in cpm 32 P of roots, shoots, and pods, while, the growth of plants was expressed in plant height, number of pods, and dry weight of pods, seeds, and stover. (author). 19 refs, 4 tabs, 6 figs
Nubp1 is required for lung branching morphogenesis and distal progenitor cell survival in mice.

Directory of Open Access Journals (Sweden)

Carsten Schnatwinkel

Full Text Available The lung is a complex system in biology and medicine alike. Whereas there is a good understanding of the anatomy and histology of the embryonic and adult lung, less is known about the molecular details and the cellular pathways that ultimately orchestrate lung formation and affect its health. From a forward genetic approach to identify novel genes involved in lung formation, we identified a mutated Nubp1 gene, which leads to syndactyly, eye cataract and lung hypoplasia. In the lung, Nubp1 is expressed in progenitor cells of the distal epithelium. Nubp1(m1Nisw mutants show increased apoptosis accompanied by a loss of the distal progenitor markers Sftpc, Sox9 and Foxp2. In addition, Nubp1 mutation disrupts localization of the polarity protein Par3 and the mitosis relevant protein Numb. Using knock-down studies in lung epithelial cells, we also demonstrate a function of Nubp1 in regulating centrosome dynamics and microtubule organization. Together, Nubp1 represents an essential protein for lung progenitor survival by coordinating vital cellular processes including cell polarity and centrosomal dynamics.
A Conserved RhoGAP Limits M-phase Contractility and Coordinates with Microtubule Asters to Restrict Active RhoA to the Cell Equator During Cytokinesis

Science.gov (United States)

Zanin, Esther; Desai, Arshad; Poser, Ina; Toyoda, Yusuke; Andree, Cordula; Moebius, Claudia; Bickle, Marc; Conradt, Barbara; Piekny, Alisa; Oegema, Karen

2014-01-01

SUMMARY During animal cell cytokinesis, the spindle directs contractile ring assembly by activating RhoA in a narrow equatorial zone. Rapid GTPase activating protein (GAP)-mediated inactivation (RhoA flux) is proposed to limit RhoA zone dimensions. Testing the significance of RhoA flux has been hampered by the fact that the GAP targeting RhoA is not known. Here, we identify M-phase GAP (MP-GAP) as the primary GAP targeting RhoA during mitosis/cytokinesis. MP-GAP inhibition caused excessive RhoA activation in M-phase leading to the uncontrolled formation of large cortical protrusions and late cytokinesis failure. RhoA zone width was broadened by attenuation of the centrosomal asters but was not affected by MP-GAP inhibition alone. Simultaneous aster attenuation and MP-GAP inhibition led to RhoA accumulation around the entire cell periphery. These results identify the major GAP restraining RhoA during cell division and delineate the relative contributions of RhoA flux and centrosomal asters in controlling RhoA zone dimensions. PMID:24012485
Drosophila PLP assembles pericentriolar clouds that promote centriole stability, cohesion and MT nucleation

Science.gov (United States)

Pratt, Metta B.; Johnson, Errin

2018-01-01

Pericentrin is a conserved centrosomal protein whose dysfunction has been linked to several human diseases. It has been implicated in many aspects of centrosome and cilia function, but its precise role is unclear. Here, we examine Drosophila Pericentrin-like-protein (PLP) function in vivo in tissues that form both centrosomes and cilia. Plp mutant centrioles exhibit four major defects: (1) They are short and have subtle structural abnormalities; (2) They disengage prematurely, and so overduplicate; (3) They organise fewer cytoplasmic MTs during interphase; (4) When forming cilia, they fail to establish and/or maintain a proper connection to the plasma membrane—although, surprisingly, they can still form an axoneme-like structure that can recruit transition zone (TZ) proteins. We show that PLP helps assemble “pericentriolar clouds” of electron-dense material that emanate from the central cartwheel spokes and spread outward to surround the mother centriole. We propose that the partial loss of these structures may largely explain the complex centriole, centrosome and cilium defects we observe in Plp mutant cells. PMID:29425198
Drosophila PLP assembles pericentriolar clouds that promote centriole stability, cohesion and MT nucleation.

Directory of Open Access Journals (Sweden)

Helio Roque

2018-02-01

Full Text Available Pericentrin is a conserved centrosomal protein whose dysfunction has been linked to several human diseases. It has been implicated in many aspects of centrosome and cilia function, but its precise role is unclear. Here, we examine Drosophila Pericentrin-like-protein (PLP function in vivo in tissues that form both centrosomes and cilia. Plp mutant centrioles exhibit four major defects: (1 They are short and have subtle structural abnormalities; (2 They disengage prematurely, and so overduplicate; (3 They organise fewer cytoplasmic MTs during interphase; (4 When forming cilia, they fail to establish and/or maintain a proper connection to the plasma membrane-although, surprisingly, they can still form an axoneme-like structure that can recruit transition zone (TZ proteins. We show that PLP helps assemble "pericentriolar clouds" of electron-dense material that emanate from the central cartwheel spokes and spread outward to surround the mother centriole. We propose that the partial loss of these structures may largely explain the complex centriole, centrosome and cilium defects we observe in Plp mutant cells.
Tourism in Austria: biodiversity, environmental sustainability, and growth issues.

Science.gov (United States)

Malik, Muhammad Asad Saleem; Shah, Syed Asim; Zaman, Khalid

2016-12-01

This study examined the long-run and causal relationships between international tourism, biodiversity loss, environmental sustainability, and specific growth factors under the premises of sustainable tourism in Austria, by using a consistent time series data from 1975 to 2015. The results reveal that inbound tourism, per capita income, and population density affected the potential habitat area while population density largely affected the food production in a country. Inbound tourism and population density both deteriorate the environmental quality in a form of increasing carbon dioxide (CO 2 ) emissions and fossil fuel energy consumption while per capita income reduces the fossil fuel energy consumption. Food exports increase per capita income, while food imports and population density both decrease economic growth. Inbound tourism and economic growth advance population density while forest area and food exports decrease the population density. The study supports growth-led tourism and growth-led food production in a country.
Two-sector disequilibrium growth

NARCIS (Netherlands)

J.G.M. van Marrewijk (Charles); J.B.L.M. Verbeek (Jos)

1994-01-01

textabstractWe investigate the effects of (i) profit distribution to either laborers or capital-owners, (ii) sector-specific or efficient rationing schemes, and (iii) government consumption in a two-sector disequilibrium growth model with sluggish real wage rate adjustment (which affects capital
8-Nitro-cGMP promotes bone growth through expansion of growth plate cartilage.

Science.gov (United States)

Hoshino, Marie; Kaneko, Kotaro; Miyamoto, Yoichi; Yoshimura, Kentaro; Suzuki, Dai; Akaike, Takaaki; Sawa, Tomohiro; Ida, Tomoaki; Fujii, Shigemoto; Ihara, Hideshi; Tanaka, Junichi; Tsukuura, Risa; Chikazu, Daichi; Mishima, Kenji; Baba, Kazuyoshi; Kamijo, Ryutaro

2017-09-01

In endochondral ossification, growth of bones occurs at their growth plate cartilage. While it is known that nitric oxide (NO) synthases are required for proliferation of chondrocytes in growth plate cartilage and growth of bones, the precise mechanism by which NO facilitates these process has not been clarified yet. C-type natriuretic peptide (CNP) also positively regulate elongation of bones through expansion of the growth plate cartilage. Both NO and CNP are known to use cGMP as the second messenger. Recently, 8-nitro-cGMP was identified as a signaling molecule produced in the presence of NO in various types of cells. Here, we found that 8-nitro-cGMP is produced in proliferating chondrocytes in the growth plates, which was enhanced by CNP, in bones cultured ex vivo. In addition, 8-nitro-cGMP promoted bone growth with expansion of the proliferating zone as well as increase in the number of proliferating cells in the growth plates. 8-Nitro-cGMP also promoted the proliferation of chondrocytes in vitro. On the other hand, 8-bromo-cGMP enhanced the growth of bones with expansion of hypertrophic zone of the growth plates without affecting either the width of proliferating zone or proliferation of chondrocytes. These results indicate that 8-nitro-cGMP formed in growth plate cartilage accelerates chondrocyte proliferation and bone growth as a downstream molecule of NO. Copyright © 2017. Published by Elsevier Inc.
AtLSG1-2 Regulates Leaf Growth by Affecting Cell Proliferation and the Onset of Endoreduplication and Synergistically Interacts with AtNMD3 during Cell Proliferation Process

KAUST Repository

Zhao, Huayan

2017-03-10

AtLSG1-2 is a circularly permuted GTPase required for ribosome biogenesis and recently shown to be involved in early leaf development, although it was unclear how AtLSG1-2 affects leaf growth. Here, we found that atlsg1-2 mutants had reduced leaf size as a result of decreased cell size and cell number. Leaf kinematic analysis and CYCB1;1
AtLSG1-2 Regulates Leaf Growth by Affecting Cell Proliferation and the Onset of Endoreduplication and Synergistically Interacts with AtNMD3 during Cell Proliferation Process

KAUST Repository

Zhao, Huayan; Lü , Shiyou; Xiong, Liming

2017-01-01

AtLSG1-2 is a circularly permuted GTPase required for ribosome biogenesis and recently shown to be involved in early leaf development, although it was unclear how AtLSG1-2 affects leaf growth. Here, we found that atlsg1-2 mutants had reduced leaf size as a result of decreased cell size and cell number. Leaf kinematic analysis and CYCB1;1

Cotyledon persistence and seedling growth in fluted Pumpkin ...

African Journals Online (AJOL)

Photosynthetic activity of exposed cotyledons of Telfairia occidentalis during seed germination and the growth of seedlings with removed or attached cotyledons were investigated. The experiment investigated how early cotyledon removal affects seedling growth. Seedlings from seeds germinated in light and those ...
EVERREST prospective study: a 6-year prospective study to define the clinical and biological characteristics of pregnancies affected by severe early onset fetal growth restriction.

Science.gov (United States)

Spencer, Rebecca; Ambler, Gareth; Brodszki, Jana; Diemert, Anke; Figueras, Francesc; Gratacós, Eduard; Hansson, Stefan R; Hecher, Kurt; Huertas-Ceballos, Angela; Marlow, Neil; Marsál, Karel; Morsing, Eva; Peebles, Donald; Rossi, Carlo; Sebire, Neil J; Timms, John F; David, Anna L

2017-01-23

Fetal growth restriction (FGR) is a serious obstetric condition for which there is currently no treatment. The EVERREST Prospective Study has been designed to characterise the natural history of pregnancies affected by severe early onset FGR and establish a well phenotyped bio-bank. The findings will provide up-to-date information for clinicians and patients and inform the design and conduct of the EVERREST Clinical Trial: a phase I/IIa trial to assess the safety and efficacy of maternal vascular endothelial growth factor (VEGF) gene therapy in severe early onset FGR. Data and samples from the EVERREST Prospective Study will be used to identify ultrasound and/or biochemical markers of prognosis in pregnancies with an estimated fetal weight (EFW) economic impact; psychological impact; neonatal condition, progress and complications; and infant growth and neurodevelopment to 2 years of corrected age in surviving infants. Standardised longitudinal ultrasound measurements are performed, including: fetal biometry; uterine artery, umbilical artery, middle cerebral artery, and ductus venosus Doppler velocimetry; and uterine artery and umbilical vein volume blood flow. Samples of maternal blood and urine, amniotic fluid (if amniocentesis performed), placenta, umbilical cord blood, and placental bed (if caesarean delivery performed) are collected for bio-banking. An initial analysis of maternal blood samples at enrolment is planned to identify biochemical markers that are predictors for fetal or neonatal death. The findings of the EVERREST Prospective Study will support the development of a novel therapy for severe early onset FGR by describing in detail the natural history of the disease and by identifying women whose pregnancies have the poorest outcomes, in whom a therapy might be most advantageous. The findings will also enable better counselling of couples with affected pregnancies, and provide a valuable resource for future research into the causes of FGR. NCT02097667
The Impact of Regional Disparities on Economic Growth

Directory of Open Access Journals (Sweden)

Henryk Gurgul

2011-01-01

Full Text Available The authors investigated how economic growth affects the disparity in the distribution of regional income in Poland and vice versa. The research was based on annual data covering the period 2000-2009. In general, the research was divided into two main parts. First, the authors examined the evolution of the level of spatial inequalities in income in Poland over the last decade using the concepts of sigma and beta convergence. Next the nature of causal dependences was investigated between this inequality and economic growth. It was found that Polish regions did not converge with respect to the distribution of income as total GDP grew. The second part of the research provided evidence to claim that this inequality caused growth. Moreover, the evidence was also found that growth affected regional inequality. Finally, the authors noticed that the effects of both these factors were positive. The results suggest that as a consequence of rapid economic growth, some regions in Poland seized new opportunities, while less developed regions were unable to keep up with the challenging requirements of a decade of fast economic growth. (original abstract
Temperature influences on growth of aquatic organisms

International Nuclear Information System (INIS)

Coutant, C.C.; Suffern, J.S.

1977-01-01

Temperature profoundly affects the growth rates of aquatic organisms, and its control is essential for effective aquaculture. Characteristically, both low and high temperatures produce slow growth rates and inefficient food conversion, while intermediate temperature ranges provide rapid growth and efficient food conversion. Distinct, species-specific optimum temperatures and upper and lower temperatures of zero growth can often be defined. Thermal effects can be greatly modified by amounts and quality of food. These data not only provide the basis for criteria which maintain growth of wild organisms but also for effectively using waste heat to create optimal conditions of temperature and food ration for growing aquatic organisms commercially
The Dynamic Relationship between Crime and Economic Growth in Nigeria

Directory of Open Access Journals (Sweden)

Adekoya Adenuga Fabian

2017-03-01

Full Text Available Crime is a major impediment to economic growth and development in Nigeria despite measures taken to reduce it. There is, however, currently no major statistical analysis of how crime affects economic growth in that country. This study examines the link between crime and growth based on the theory of rational choice and empirical data. Exogenous and endogenous growth models are employed, and include deterrence variables. The period examined is 1970–2013 and estimation is done using the autoregressive distributed lag model. The results of our study show that crime affects economic growth at a 1% and 10% level of significance. In other words, crime imposes the costs of prosecution and punishment on the citizens and country, which influences the growth of the economy. Given our results, we suggest that police and the system of justice should be strengthened. Indeed, this may be necessary if the development target stated in Nigeria vision 20: 2020 is to be reached.
THE CONCEPT OF SUSTAINABLE DEVELOPMENT THROUGH ECONOMIC GROWTH AND DIVERSIFICATION OF THE LABOUR MARKET IN THE INDUSTRIAL AREAS AFFECTED BY RESTRUCTURING

Directory of Open Access Journals (Sweden)

Marius Eremia VLAICU POPA

2013-06-01

Full Text Available In the context of what is implemented through dualism "ecosystem-efficient", sustainable development involves the care of the human potential of the present situation and the future of its natural resources, energy, materials and information. As an effect of responsibility for future generations, the efficient use of resources requires, at the same time, the operation of a sustainable economy, by diversification and development of the labour market in order to meet present and future demands of human society. At local and regional level, through the closing of mines and large enterprises, with an effect in restructuring the economic sector and employment, development strategies and rehabilitation of the affected industrial areas as a common principle approach, analyzing the problems, defining the objectives and policies, identifying actions to attack problems and provide for mechanisms that will enable the progress control. In this paper it is presented the concept of sustainable development as imperative for economic growth, diversification and development of the labour market, being dealt the representative criteria and principles of sustainable development strategy of any company. Are defined the components and objectives of a strategy for local and regional development of industrial areas affected by the restructuring.
Weaknesses of 'wage-led growth'

OpenAIRE

Skott, Peter

2016-01-01

The emphasis in post-Keynesian macroeconomics on wage- versus profit- led growth may not have been helpful. The profit share is not an exogenous variable, and the correlations between the pro.t share and economic growth can be positive for some exogenous shocks but negative for others. The terminology, second, suggests a unidirectional causality from distribution to aggregate demand while in fact distribution can itself be directly affected by shifts in aggregate demand. The reduced form corr...
Essential fats: how do they affect growth and development of infants and young children in developing countries? A literature review.

Science.gov (United States)

Huffman, Sandra L; Harika, Rajwinder K; Eilander, Ans; Osendarp, Saskia J M

2011-10-01

Omega-3 and omega-6 fatty acids, particularly docosahexaenoic acid (DHA), are known to play an essential role in the development of the brain and retina. Intakes in pregnancy and early life affect growth and cognitive performance later in childhood. However, total fat intake, alpha-linolenic acid (ALA) and DHA intakes are often low among pregnant and lactating women, infants and young children in developing countries. As breast milk is one of the best sources of ALA and DHA, breastfed infants are less likely to be at risk of insufficient intakes than those not breastfed. Enhancing intake of ALA through plant food products (soy beans and oil, canola oil, and foods containing these products such as lipid-based nutrient supplements) has been shown to be feasible. However, because of the low conversion rates of ALA to DHA, it may be more efficient to increase DHA status through increasing fish consumption or DHA fortification, but these approaches may be more costly. In addition, breastfeeding up to 2 years and beyond is recommended to ensure an adequate essential fat intake in early life. Data from developing countries have shown that a higher omega-3 fatty acid intake or supplementation during pregnancy may result in small improvements in birthweight, length and gestational age based on two randomized controlled trials and one cross-sectional study. More rigorous randomized controlled trials are needed to confirm this effect. Limited data from developing countries suggest that ALA or DHA supplementation during lactation and in infants may be beneficial for growth and development of young children 6-24 months of age in these settings. These benefits are more pronounced in undernourished children. However, there is no evidence for improvements in growth following omega-3 fatty acid supplementation in children >2 years of age. © 2011 Blackwell Publishing Ltd.
[Metabolic and hemodynamic effects of the growth hormone system - insulin-like growth factor].

Science.gov (United States)

Manhylova, T A; Gafarova, N H

2015-01-01

Significant congenital deficiency of growth factor (GF) results in pituitary nanism (dwarfism) and its substantial excess is accompanied by the development of gigantism or acromegaly. Its impact on the growth of the whole body or its individual parts is impossible without affecting metabolic processes and hemodynamic parameters. A number of investigations have proven that GF has a direct lipolytic effect: adequate replacement therapy for pituitary nanism gives rise to a reduction in fat depots. Since the concentration of GF is lower in obesity, Whether it may be used to treat this abnormality is considered.
The Effect of Zirconia in Hydroxyapatite on Staphylococcus epidermidis Growth

Directory of Open Access Journals (Sweden)

Widowati Siswomihardjo

2012-01-01

. Conclusion. The addition of zirconia into hydroxyapatite affected the growth of S. epidermidis. Hydroxyapatite with 20% zirconia proved to be an effective concentration to inhibit the growth of S. epidermidis colony.
Reserve growth during financial volatility in a technologically challenging world

Science.gov (United States)

Klett, Timothy R.; Gautier, Donald L.

2010-01-01

Reserve growth (growth-to-known) is the addition of oil and gas quantities to reported proved or proved-plus-probable reserves in discovered fields. The amount of reserve growth fluctuates through time with prevailing economic and technological conditions. Most reserve additions are the result of investment in field operations and in development technology. These investments can be justified by higher prices of oil and gas, the desire to maintain cash flow, and by greater recovery efficiency in well established fields. The price/cost ratio affects decisions for field abandonment and (or) implementation of improved recovery methods. Although small- to medium-size fields might show higher percentages of reserve growth, a relatively few giant fields contribute most volumetric reserve growth, indicating that companies may prefer to invest in existing fields with low geologic and production risk and an established infrastructure in order to increase their price/cost relationship. Whereas many previous estimates of reserve growth were based on past trends of reported reserves, future reserve growth is expected to be greatly affected by financial volatility and fluctuating economic and technological conditions.
Effects of graphene on seed germination and seedling growth

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ming; Gao, Bin, E-mail: bg55@ufl.edu [University of Florida, Department of Agricultural and Biological Engineering (United States); Chen, Jianjun [University of Florida, Department of Environmental Horticulture and Mid-Florida Research & Education Center (United States); Li, Yuncong [University of Florida, Soil and Water Science Department Tropical Research & Education Center (United States)

2015-02-15

The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.
Light affects Varronia curassavica essential oil yield by increasing trichomes frequency

Directory of Open Access Journals (Sweden)

Emily V.R. da S. Feijó

Full Text Available Light can act on essential oil yield directly on synthesis of secondary metabolites, or indirectly on plant growth. Varronia curassavica Jacq., Boraginaceae, is a native medicinal species from Brazil known as “erva-baleeira”, with anti-inflammatory activity related to its essential oil. Despite pharmacological evidences of this species and its economic importance for herbal medicine production, little is known about the effect of light on growth and essential oil production. This study aimed to analyze the influence of different irradiances on growth, frequency of trichomes, essential oil yield and composition of V. curassavica. The irradiance affected plant growth, but no significant alteration on leaf biomass was detected. The increase in essential oil content under higher irradiance reflected on essential oil yield, and is associated with higher frequency of glandular, globular trichomes. The essential oil composition, rich in caryophyllene derivatives was affected by irradiance, but α-humulene, the constituent of pharmaceutical interest, remained unchanged.
Fibroblast growth factor receptors in breast cancer.

Science.gov (United States)

Wang, Shuwei; Ding, Zhongyang

2017-05-01

Fibroblast growth factor receptors are growth factor receptor tyrosine kinases, exerting their roles in embryogenesis, tissue homeostasis, and development of breast cancer. Recent genetic studies have identified some subtypes of fibroblast growth factor receptors as strong genetic loci associated with breast cancer. In this article, we review the recent epidemiological findings and experiment results of fibroblast growth factor receptors in breast cancer. First, we summarized the structure and physiological function of fibroblast growth factor receptors in humans. Then, we discussed the common genetic variations in fibroblast growth factor receptors that affect breast cancer risk. In addition, we also introduced the potential roles of each fibroblast growth factor receptors isoform in breast cancer. Finally, we explored the potential therapeutics targeting fibroblast growth factor receptors for breast cancer. Based on the biological mechanisms of fibroblast growth factor receptors leading to the pathogenesis in breast cancer, targeting fibroblast growth factor receptors may provide new opportunities for breast cancer therapeutic strategies.
Does pollen limitation affect population growth of the endangered Dracocephalum austriacum L.?

Czech Academy of Sciences Publication Activity Database

Castro, Sílvia; Dostálek, Tomáš; van der Meer, S.; Oostermeijer, G.; Münzbergová, Zuzana

2015-01-01

Roč. 57, č. 1 (2015), s. 105-116 ISSN 1438-3896 R&D Projects: GA ČR GP13-10850P; GA ČR GAP505/10/0593 Institutional support: RVO:67985939 Keywords : Dracocephalum austriacum * pollination ecology * population growth rate Subject RIV: EF - Botanics Impact factor: 1.698, year: 2015
Parameters of Economic Growth in Kosovo

Directory of Open Access Journals (Sweden)

Shkumbin Misini

2016-01-01

Full Text Available This paper analysis the macroeconomic components that influenced macroeconomic growth in a country, more concretely, the focus will be on the measurement of components that affected economic growth under nominal GDP, in Kosovo. We intend to found out which component of nominal GDP has the biggest and the lowest influence on economic growth. Thus, in order to measure it, GDP components must be analysed: consumption measurement, investments measurement, government expenditures measurement and export measurement. These parameters will be measured by analysing their importance in relation to one another, and the major influence on the growth of nominal GDP. The paper includes a graphic analysis of nominal GDP in relation to consumption, investments, governmental expenses and export.
Nuclear energy consumption and economic growth in nine developed countries

International Nuclear Information System (INIS)

Wolde-Rufael, Yemane; Menyah, Kojo

2010-01-01

This article attempts to test the causal relationship between nuclear energy consumption and real GDP for nine developed countries for the period 1971-2005 by including capital and labour as additional variables. Using a modified version of the Granger causality test developed by Toda and Yamamoto (1995), we found a unidirectional causality running from nuclear energy consumption to economic growth in Japan, Netherlands and Switzerland; the opposite uni-directional causality running from economic growth to nuclear energy consumption in Canada and Sweden; and a bi-directional causality running between economic growth and nuclear energy consumption in France, Spain, the United Kingdom and the United States. In Spain, the United Kingdom and the USA, increases in nuclear energy consumption caused increases in economic growth implying that conservation measures taken that reduce nuclear energy consumption may negatively affect economic growth. In France, Japan, Netherlands and Switzerland increases in nuclear energy consumption caused decreases in economic growth, suggesting that energy conservation measure taken that reduce nuclear energy consumption may help to mitigate the adverse effects of nuclear energy consumption on economic growth. In Canada and Sweden energy conservation measures affecting nuclear energy consumption may not harm economic growth.
Effect of feeding frequency and feeding rate on growth of ...

African Journals Online (AJOL)

Effect of feeding frequency and feeding rate on growth of Oreochromis mossambicus (Teleostei: Cichlidae) fry. ... Weight gain, specific growth rate and gross food conversion ratio were significantly affected by ... AJOL African Journals Online.
Population growth, accessibility spillovers and persistent borders: Historical growth in West-European municipalities.

Science.gov (United States)

Jacobs-Crisioni, Chris; Koomen, Eric

2017-06-01

Lack of cross-border transport supply has repeatedly been blamed for the fact that national borders limit spatial interaction and, consequently, the growth of border regions. This study applies an accessibility approach to investigate for most municipalities in ten countries in mainland West Europe if foreign transport supply is lagging behind, and if population growth in these municipalities has been affected by the limits that national borders have imposed on market access. To do so, data describing historical population changes and road networks between 1961 and 2011 have been used. The results show that in the study area, cross-border transport accessibility was not at a disadvantage in 1961 and has since then grown even more than domestic accessibility. However, municipal population growth has depended almost exclusively on domestic market access. Processes of economic international integration in the study area are found to coincide with the growth of cross-border accessibility, but do not have a clear coincidence with the effects of cross-border accessibility on population growth.
Growth, unemployment and wage inertia

OpenAIRE

Raurich, Xavier; Sorolla, Valeri

2014-01-01

We introduce wage setting via efficiency wages in the neoclassical one-sector growth model to study the growth effects of wage inertia. We compare the dynamic equilibrium of an economy with wage inertia with the equilibrium of an economy without wage inertia. We show that wage inertia affects the long run employment rate and that the transitional dynamics of the main economic variables will be different because wages are a state variable when wage inertia is introduced. In particular, we show...

Corruption, Growth, and Public Finances

OpenAIRE

Vito Tanzi; Hamid R Davoodi

2000-01-01

The paper discusses some channels through which corruption affects growth such as the impact of corruption on enterprises, on the allocation of talent, and on investment. It also discusses the impact of corruption on some aspects of public finance.
Traffic fatalities and economic growth

Science.gov (United States)

2003-04-01

As countries develop death rates usually fall, especially for diseases that affect the young and result in substantial life-years lost. Deaths due to traffic accidents are a notable exception: the growth in motor vehicles that accompanies economic gr...
Intrauterine growth restriction: screening, diagnosis, and management.

Science.gov (United States)

Lausman, Andrea; Kingdom, John

2013-08-01

Intrauterine growth restriction (IUGR) is an obstetrical complication, which by definition would screen in 10% of fetuses in the general population. The challenge is to identify the subset of pregnancies affected with pathological growth restriction in order to allow intervention that would decrease morbidity and mortality. The purpose of this guideline is to provide summary statements and recommendations and to establish a framework for screening, diagnosis, and management of pregnancies affected with IUGR. Affected pregnancies are compared with pregnancies in which the fetus is at an appropriate weight for its gestational age. History, physical examination, and laboratory investigations including biochemical markers and ultrasound characteristics of IUGR are reviewed, and a management strategy is suggested. Published literature in English was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library in January 2013 using appropriate controlled vocabulary via MeSH terms (fetal growth restriction and small for gestational age) and key words (fetal growth, restriction, growth retardation, IUGR, low birth weight, small for gestational age). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table). Implementation of the recommendations in this guideline should increase clinician recognition of IUGR and guide intervention where appropriate. Optimal long-term follow-up of neonates diagnosed as IUGR may improve their long-term health.
Collaborative Project: Understanding the Chemical Processes tat Affect Growth rates of Freshly Nucleated Particles

Energy Technology Data Exchange (ETDEWEB)

McMurry, Peter [Univ. of Minnesota, Minneapolis, MN (United States); Smuth, James [University Corporation for Atmospheric Research, Irvine, CA (United States)

2015-11-12

This final technical report describes our research activities that have, as the ultimate goal, the development of a model that explains growth rates of freshly nucleated particles. The research activities, which combine field observations with laboratory experiments, explore the relationship between concentrations of gas-phase species that contribute to growth and the rates at which those species are taken up. We also describe measurements of the chemical composition of freshly nucleated particles in a variety of locales, as well as properties (especially hygroscopicity) that influence their effects on climate.
Anisotropic Growth of Otavite on Calcite: Implications for Heteroepitaxial Growth Mechanisms

Energy Technology Data Exchange (ETDEWEB)

Riechers, Shawn L.; Kerisit, Sebastien N.

2017-12-18

Elucidating how cation intermixing can affect the mechanisms of heteroepitaxial growth in aqueous media has remained a challenging endeavor. Toward this goal, in situ atomic force microscopy was employed to image the heteroepitaxial growth of otavite (CdCO3) at the (10-14) surface of calcite (CaCO3) single crystals in static aqueous conditions. Heteroepitaxial growth proceeded via spreading of three-dimensional (3D) islands and two-dimensional (2D) atomic layers at low and high initial saturation levels, respectively. Experiments were carried out as a function of applied force and imaging mode thus enabling determination of growth mechanisms unaltered by imaging artifacts. This approach revealed the significant anisotropic nature of heteroepitaxial growth on calcite in both growth modes and its dependence on supersaturation, intermixing, and substrate topography. The 3D islands not only grew preferentially along the [42-1] direction relative to the [010] direction, resulting in rod-like surface precipitates, but also showed clear preference for growth from the island end rich in obtuse/obtuse kink sites. Pinning to step edges was observed to often reverse this tendency. In the 2D growth mode, the relative velocities of acute and obtuse steps were observed to switch between the first and second atomic layers. This phenomenon stemmed from the significant Cd-Ca intermixing in the first layer, despite bulk thermodynamics predicting the formation of almost pure otavite. Composition effects were also responsible for the inability of 3D islands to grow on 2D layers in cases where both modes were observed to occur simultaneously. Overall, the AFM images highlighted the effects of intermixing on heteroepitaxial growth, particularly how it can induce thickness-dependent growth mechanisms at the nanoscale.
Growth and yield of the sweet cherry ( Prunus avium L.) as affected ...

African Journals Online (AJOL)

Three different training systems (Spanish bush, Spindle bush and "V") were compared. The smaller vegetative growth, expressed as trunk crosssectional area (TCSA) was recorded in Spanish bush (34.68 cm2) when compared to Spindle bush (40.11 cm2) and "V" (40.82 cm2). The largest cumulative yield per hectare was ...
Analysis of Factors Affecting Growth of Pension Mutual Funds in Turkey

OpenAIRE

Ersin Acikgoz; Hasan Uygurturk; Turhan Korkmaz

2015-01-01

In this study, the level of relationship between the real growth rate of the stock pension mutual funds that have been involved in the individual pension system and the variables such as the number of fund participants, the real fund returns, fund operating expenses and share of fund assets to the total assets of the funds are analyzed with panel data methodology. The results have reported that apart from the fund operating expenses, the selected independent variables are statistically signif...
Experimental intrauterine growth retardation.

Science.gov (United States)

van Marthens, E; Harel, S; Zamenshof, S

1975-01-01

The effects of experimental intrauterine growth retardation on subsequent fetal development, especially with respect to brain development, were studied in a new animal model. The rabbit was chosen since it has a perinatal pattern of brain development similar to that of the human. Experimental ischemia was induced during the last trimester by ligation of spiral arterioles and the differential effects on fetal development at term (30th gestational day) are reported. Specific brain regions were examined for wet weight, total cell number (DNA) and total protein content. Highly significant decreases in all these parameters were found in both the cortex and cerebellum following experimental intrauterine growth retardation; these two organs were differentially affected. The prospects and advantages of using this animal model for the study of the postnatal "catch-up growth" are discussed.
Population growth, poverty and health.

Science.gov (United States)

Kibirige, J S

1997-07-01

One of the most popular explanations for the many problems that face Africa is population growth. Africa's population has doubled since 1960. Africa has the highest fertility rate in the world and the rate of population growth is higher than in any other region. At the same time, Africa faces a social and economic situation that is viewed by many as alarming. Among the problems that devastate Africa is that of persistent poor health. Africa has lower life expectancy, higher mortality rates and is affected by more disease and illness conditions than any other region. Focusing on sub-Saharan Africa, this paper examines the relationship between population growth, poverty and poor health. While most analyses have focused on population growth as an original cause of poverty and underdevelopment, this paper argues that while both population growth and poor health play a significant role in exacerbating the problem of poverty, they are themselves primary consequences of poverty rather than its cause.
The effect of size and competition on tree growth rate in old-growth coniferous forests

Science.gov (United States)

Das, Adrian

2012-01-01

Tree growth and competition play central roles in forest dynamics. Yet models of competition often neglect important variation in species-specific responses. Furthermore, functions used to model changes in growth rate with size do not always allow for potential complexity. Using a large data set from old-growth forests in California, models were parameterized relating growth rate to tree size and competition for four common species. Several functions relating growth rate to size were tested. Competition models included parameters for tree size, competitor size, and competitor distance. Competitive strength was allowed to vary by species. The best ranked models (using Akaike’s information criterion) explained between 18% and 40% of the variance in growth rate, with each species showing a strong response to competition. Models indicated that relationships between competition and growth varied substantially among species. The results also suggested that the relationship between growth rate and tree size can be complex and that how we model it can affect not only our ability to detect that complexity but also whether we obtain misleading results. In this case, for three of four species, the best model captured an apparent and unexpected decline in potential growth rate for the smallest trees in the data set.
Rearing Mozambique tilapia in tidally-changing salinities: Effects on growth and the growth hormone/insulin-like growth factor I axis.

Science.gov (United States)

Moorman, Benjamin P; Yamaguchi, Yoko; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

2016-08-01

The growth hormone (GH)/insulin-like growth factor (IGF) axis plays a central role in the regulation of growth in teleosts and has been shown to be affected by acclimation salinity. This study was aimed at characterizing the effects of rearing tilapia, Oreochromis mossambicus, in a tidally-changing salinity on the GH/IGF axis and growth. Tilapia were raised in fresh water (FW), seawater (SW), or in a tidally-changing environment, in which salinity is switched between FW (TF) and SW (TS) every 6h, for 4months. Growth was measured over all time points recorded and fish reared in a tidally-changing environment grew significantly faster than other groups. The levels of circulating growth hormone (GH), insulin-like growth factor I (IGF-I), pituitary GH mRNA, gene expression of IGF-I, IGF-II, and growth hormone receptor 2 (GHR) in the muscle and liver were also determined. Plasma IGF-I was higher in FW and TS than in SW and TF tilapia. Pituitary GH mRNA was higher in TF and TS than in FW and SW tilapia. Gene expression of IGF-I in the liver and of GHR in both the muscle and liver changed between TF and TS fish. Fish growth was positively correlated with GH mRNA expression in the pituitary, and GHR mRNA expression in muscle and liver tissues. Our study indicates that rearing fish under tidally-changing salinities elicits a distinct pattern of endocrine regulation from that observed in fish reared in steady-state conditions, and may provide a new approach to increase tilapia growth rate and study the regulation of growth in euryhaline fish. Copyright © 2016 Elsevier Inc. All rights reserved.
Dietary supplementation of probiotics affects growth, immune response and disease resistance of Cyprinus carpio fry.

Science.gov (United States)

Gupta, Akhil; Gupta, Paromita; Dhawan, Asha

2014-12-01

The effects of dietary Bacillus coagulans (MTCC 9872), Bacillus licheniformis (MTCC 6824) and Paenibacillus polymyxa (MTCC 122) supplementation on growth performance, non-specific immunity and protection against Aeromonas hydrophila infection were evaluated in common carp, Cyprinus carpio fry. Laboratory maintained B. coagulans, B. licheniformis and P. polymyxa were used to study antagonistic activity against fish pathogenic bacteria by agar well diffusion assay. Healthy fish fry were challenged by this bacterium for determination of its safety. Fish were fed for 80 days with control basal diet (B0) and experimental diets containing B. coagulans (B1), B. licheniformis (B2) and P. polymyxa (B3) at 10(9) CFU/g diet. Fish fry (mean weight 0.329 ± 0.01 g) were fed these diets and growth performance, various non-specific immune parameters and disease resistance study were conducted at 80 days post-feeding. The antagonism study showed inhibition zone against A. hydrophila and Vibrio harveyi. All the probiotic bacterial strains were harmless to fish fry as neither mortality nor morbidities were observed of the challenge. The growth-promoting influences of probiotic supplemented dietary treatments were observed with fish fry and the optimum survival, growth and feed utilization were obtained with P. polymyxa (B3) supplemented diet. Study of different non-specific innate immunological parameters viz. lysozyme activity, respiratory burst assay and myeloperoxidase content showed significant (p growth, feed utilization, non-specific immune responses and disease resistance of fry common carp, C. carpio. Copyright © 2014. Published by Elsevier Ltd.
Human activities affecting trace gases and climate

International Nuclear Information System (INIS)

Braatz, B.; Ebert, C.

1990-01-01

The Earth's climate has been in a constant state of change throughout geologic time due to natural perturbations in the global geobiosphere. However, various human activities have the potential to cause future global warming over a relatively short amount of time. These activities, which affect the Earth's climate by altering the concentrations of trace gases in the atmosphere, include energy consumption, particularly fossil-fuel consumption; industrial processes (production and use of chlorofluorocarbons, halons, and chlorocarbons, landfilling of wastes, and cement manufacture); changes in land use patterns, particularly deforestation and biomass burning; and agricultural practices (waste burning, fertilizer usage, rice production, and animal husbandry). Population growth is an important underlying factor affecting the level of growth in each activity. This paper describes how the human activities listed above contribute to atmospheric change, the current pattern of each activity, and how levels of each activity have changed since the early part of this century
Characterization of ubiquitination dependent dynamics in growth factor receptor signaling by quantitative proteomics

DEFF Research Database (Denmark)

Akimov, Vyacheslav; Rigbolt, Kristoffer T G; Nielsen, Mogens M

2011-01-01

Protein ubiquitination is a dynamic reversible post-translational modification that plays a key role in the regulation of numerous cellular processes including signal transduction, endocytosis, cell cycle control, DNA repair and gene transcription. The conjugation of the small protein ubiquitin...... investigating ubiquitination on a proteomic scale, mainly due to the inherited complexity and heterogeneity of ubiquitination. We describe here a quantitative proteomics strategy based on the specificity of ubiquitin binding domains (UBDs) and Stable Isotope Labeling by Amino acids in Cell culture (SILAC...... as ubiquitination-dependent events in signaling pathways. In addition to a detailed seven time-point profile of EGFR ubiquitination over 30 minutes of ligand stimulation, our data determined prominent involvement of Lysine-63 ubiquitin branching in EGF signaling. Furthermore, we found two centrosomal proteins, PCM1...
Three-dimensional culture conditions differentially affect astrocyte modulation of brain endothelial barrier function in response to transforming growth factor β1.

Science.gov (United States)

Hawkins, Brian T; Grego, Sonia; Sellgren, Katelyn L

2015-05-22

Blood-brain barrier (BBB) function is regulated by dynamic interactions among cell types within the neurovascular unit, including astrocytes and endothelial cells. Co-culture models of the BBB typically involve astrocytes seeded on two-dimensional (2D) surfaces, which recent studies indicate cause astrocytes to express a phenotype similar to that of reactive astrocytes in situ. We hypothesized that the culture conditions of astrocytes would differentially affect their ability to modulate BBB function in vitro. Brain endothelial cells were grown alone or in co-culture with astrocytes. Astrocytes were grown either as conventional (2D) monolayers, or in a collagen-based gel which allows them to grow in a three-dimensional (3D) construct. Astrocytes were viable in 3D conditions, and displayed a marked reduction in their expression of glial fibrillary acidic protein (GFAP), suggesting reduced activation. Stimulation of astrocytes with transforming growth factor (TGF)β1 decreased transendothelial electrical resistance (TEER) and reduced expression of claudin-5 in co-cultures, whereas treatment of endothelial cells in the absence of astrocytes was without effect. The effect of TGFβ1 on TEER was significantly more pronounced in endothelial cells cultured with 3D astrocytes compared to 2D astrocytes. These results demonstrate that astrocyte culture conditions differentially affect their ability to modulate brain endothelial barrier function, and suggest a direct relationship between reactive gliosis and BBB permeability. Moreover, these studies demonstrate the potential importance of physiologically relevant culture conditions to in vitro modeling of disease processes that affect the neurovascular unit. Copyright © 2015 Elsevier B.V. All rights reserved.
Nutrient availability affects pigment production but not growth in lichens of biological soil crusts

Science.gov (United States)

Bowker, M.A.; Koch, G.W.; Belnap, J.; Johnson, N.C.

2008-01-01

Recent research suggests that micronutrients such as Mn may limit growth of slow-growing biological soil crusts (BSCs) in some of the drylands of the world. These soil surface communities contribute strongly to arid ecosystem function and are easily degraded, creating a need for new restoration tools. The possibility that Mn fertilization could be used as a restoration tool for BSCs has not been tested previously. We used microcosms in a controlled greenhouse setting to investigate the hypothesis that Mn may limit photosynthesis and consequently growth in Collema tenax, a dominant N-fixing lichen found in BSCs worldwide. We found no evidence to support our hypothesis; furthermore, addition of other nutrients (primarily P, K, and Zn) had a suppressive effect on gross photosynthesis (P = 0.05). We also monitored the growth and physiological status of our microcosms and found that other nutrients increased the production of scytonemin, an important sunscreen pigment, but only when not added with Mn (P = 0.01). A structural equation model indicated that this effect was independent of any photosynthesis-related variable. We propose two alternative hypotheses to account for this pattern: (1) Mn suppresses processes needed to produce scytonemin; and (2) Mn is required to suppress scytonemin production at low light, when it is an unnecessary photosynthate sink. Although Mn fertilization does not appear likely to increase photosynthesis or growth of Collema, it could have a role in survivorship during environmentally stressful periods due to modification of scytonemin production. Thus, Mn enrichment should be studied further for its potential to facilitate BSC rehabilitation. ?? 2008 Elsevier Ltd.
Economic Growth, Economic Freedom, and Governance

OpenAIRE

Cebula, Richard; Ekstrom, Marcus

2008-01-01

This exploratory study examines the impact of various forms of economic freedom and various dimensions of governance, as well as a number of economic factors, on economic growth among OECD nations. Empirical estimation finds that the natural log of per capita purchasing-power-parity adjusted real GDP in OECD nations is positively impacted by business freedom, monetary freedom, trade freedom, and property rights security. Economic growth is found to be negatively affected by perceived governme...
FINANCIAL INTERMEDIATION, ENTREPRENEURSHIP AND ECONOMIC GROWTH

OpenAIRE

Wenli Cheng

2007-01-01

This paper presents a simple general equilibrium model of financial intermediation, entrepreneurship and economic growth. In this model, the role of financial intermediation is to pool savings and to lend the pooled funds to an entrepreneur, who in turn invests the funds in a new production technology. The adoption of the new production technology improves individual real income. Thus financial intermediation promotes economic growth through affecting individualsâ€™ saving behaviour and enabl...
Shocks in economic growth=shocking effects for food security?

NARCIS (Netherlands)

Kavallari, A.; Fellmann, T.; Hubertus Gay, H.

2014-01-01

The recent economic and financial turmoil raises the question on how global economic growth affects agricultural commodity markets and, hence, food security. To address this question, this paper assesses the potential impacts of faster economic growth in developed and emerging economies on the one
Douglas-fir displays a range of growth responses to ...

Science.gov (United States)

Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC using time series intervention analysis of intra-annual tree-ring width data collected at nine forest stands in western Oregon, USA. The effects of temperature and SNC were similar in importance on tree growth at all sites. Previous-year DPD during the annual drought period was a key factor limiting growth regionally. Winter temperature was more important at high elevation cool sites, whereas summer temperature was more important at warm and dry sites. Growth rate increased with summer temperature to an optimum (Topt) then decreased at higher temperatures. At drier sites, temperature and water affected growth interactively such that Topt decreased with decreasing summer soil moisture. With climate change, growth rates increased at high elevation sites and declined at mid-elevation inland sites since ~1990. Growth response to climate is masked by SNC regionally. We conclude that as temperature rises and precipitation patterns shift towards wetter winters and drier summers, Douglas-fir will experience greater temperature and water stress and an increase in severity of SNC. By the end of the 21st century, climate models predict hotter, drier summers and warmer, wetter winters in the Pac

Growth in pediatric renal transplant recipients.

Science.gov (United States)

Vasudevan, A; Phadke, K

2007-04-01

One of the fundamental challenges in managing pediatric renal transplant recipient is to ensure normal growth and development. The goal of renal transplant is not just to prolong life but to optimize quality of life. Short stature during childhood may be associated with academic underachievement and development of comorbidities such as attention deficit hyperactivity disorder, learning disability, and mood disorders. The most important factors affecting growth are use of corticosteroids, allograft function, and age and height deficit at the time of transplant. Aggressive conservative management of chronic renal failure and early use of growth hormone therapy will help in optimizing height at time of transplant. Early transplant, steroid minimization or withdrawal, and growth hormone therapy will help in achieving normal adult height in a majority of renal post transplant population. Steroid avoidance to achieve good growth still needs to be validated.
Centriolar satellites

DEFF Research Database (Denmark)

Tollenaere, Maxim A X; Mailand, Niels; Bekker-Jensen, Simon

2015-01-01

Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking...... highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases....
Phenology and growth in four annual species grown in ambient and elevated CO2

Energy Technology Data Exchange (ETDEWEB)

Reekie, E.G. (Acadia Univ., Wolfville, NS (Canada)); Bazzaz, F.A. (Harvard Univ., Cambridge, MA (USA))

1991-01-01

The objectives of this study were to test the hypothesis that changes in phenology with CO{sub 2} are a function of the effect of CO{sub 2} upon growth and to determine if CO{sub 2}-induced changes in phenology can influence competitive outcome. The effect of 350, 525, and 700{mu}l/l CO{sub 2} on Guara brachycarpa, Gailardia pulchella, Oenothera laciniata, and Lupinus texenis was examined. Plants were grown as individuals in 150-, 500-, or 1000-ml pots and in competition in 1000-ml pots. Growth and development were monitored at twice-weekly intervals by recording the number of leaves and noting the presence or absence of stem elongation, branching, flower buds, and open flowers. Elevated CO{sub 2} affected both growth and phenology, but the direction and magnitude of effects varied with species and soil volume. Elevated CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} on growth were generally different from those treatments in which CO{sub 2} affected phenology. Rather than affecting phenology by changing plant size, CO{sub 2} appeared to affect phenology by modifying the size at which plants switched from one stage to the next. The level of CO{sub 2} changed competitive outcome; the importance of Lupinus increased whereas that of Oenothera decreased with increased CO{sub 2}. These changes were more closely related to the effect of CO{sub 2} on growth than its effect on phenology. 19 refs., 2 figs., 4 tabs.
Nutritive values of brassica campestris L. oil as affected by growth regulator treatments

International Nuclear Information System (INIS)

Bano, A.; Khan, N.

2009-01-01

The effects of plant growth regulators, viz. Indole acetic acid (IAA), Gibberellic acid (GA) and Abscisic acid (ABA) were studied on fatty acid compositions, glucosinolate content and protein content of Brassica campestris L subsp. Oleifera (common name yellow sarson). Growth regulators were applied in seed soaking solution as well as foliar spray during vegetative phase and at flowering stage. There were reductions in the amount of long chain fatty acids viz erucic acid, eicosenoic acid and increase in the amount of unsaturated fatty acid viz. linoleic acid by lAA applications. The stimulating effect of lAA which reduced amount of unsaturated fatty acid was more pronounced when applied as foliar spray at vegetative stage. But, foliar spray of ABA during flowering increased the concentration of linoleic acid and reduced the eicosenoic acid and erucic acid. The glucosinolate content was greater in seeds soaked in 10/sup -5/ M lAA than that of control but less in 10/sup -5/ M GA treated seeds than that of control. The ABA treatment (10/sup -5/M) increased the concentration of glucosinolates in the seeds IAA treatments (10/sup -5/M) increased the protein percentage in the seeds. Foliar application of GA (10/sup -5/M) during vegetative growth and ABA (10/sup -5/M) as seed soaking prior to sowing as well as foliar spry during flowering decreased the protein content of seeds. (author)
The Relationship Among Poverty, Economic Growth, and Inequality Revisited

OpenAIRE

Lonnie K. Stevans; David N. Sessions

2008-01-01

It has been shown in prior research that increased economic growth reduces poverty. Authors have also found that the effect of growth in Gross Domestic Product (GDP) on poverty growth has either diminished or remained unchanged over time, and economic expansion in the 1980s in the United States had no affect on poverty. Using a formal error-correction model, we find that increases in economic growth are significantly related to reductions in the poverty rate for all families. Specifically, GD...
Manipulating Rayleigh-Taylor Growth Using Adjoints

Science.gov (United States)

Kord, Ali; Capecelatro, Jesse

2017-11-01

It has been observed that initial interfacial perturbations affect the growth of Rayleigh-Taylor (RT) instabilities. However, it remains to be seen to what extent the perturbations alter the RT growth rate. Direct numerical simulations (DNS) provide a powerful means for studying the effects of initial conditions (IC) on the growth rate. However, a brute-force approach for identifying optimal initial perturbations is not practical via DNS. In addition, identifying sensitivity of the RT growth to the large number of parameters used in defining the IC is computationally expensive. A discrete adjoint is formulated to measure sensitivities of multi-mode RT growth to ICs in a high-order finite difference framework. The sensitivity is used as a search direction for adjusting the initial perturbations to both maximize and suppress the RT growth rate during its non-linear regime. The modes that contribute the greatest sensitivity are identified, and optimized perturbation energy spectrum are reported. PhD Student, Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI.
Regional growth and energy supply: Is there an energy security issue?

Energy Technology Data Exchange (ETDEWEB)

Roop, J.M.; Freund, K.A.; Godoy-Kain, P.; Gu, A.Y.; Johnson, A.K.; Paananen, O.H.; Woodruff, M.G.

1996-12-01

This study examines how the growth of the developing world might affect energy markets in the future. Based on recent growth trends, world energy demand could reasonably be expected to grow from about 350 Exajoules (EJ: 1.0E18=0.95 Quad) to nearly 1025 EJ by the year 2020, nearly 3x current consumption estimates. Introduction of more energy-efficient technologies could reduce this growth by about 17% to 830 EJ. But one cannot rely exclusively on current trends to forecast future energy demand. The growth of the developing world will interact with supply to affect prices, which in turn will mitigate the growth of demand, and growth rates of energy use will be much more modes. Under the Business as Usual scenario, energy demand will grow to 835 EJ by 2020, and this could be reduced a further 15% to 714 EJ through the adoption of more energy efficient technologies. Fuel prices based on model results are analyzed. Energy security implications of rapid growth in the developing world are considered and found to be of likely little significance.
Diameter Growth of Loblolly Pine Trees as Affected by Soil-Moisture Availibility

Science.gov (United States)

John R. Bassett

1964-01-01

In a 30-year-old even-aged stand of loblolly pine on a site 90 loessial soil in southeast Arkansas during foul growing seasons, most trees on plots thinned to 125 square feet of basal area per acre increased in basal area continuously when, under the crown canopy, available water in the surface foot remained above 65 percent. Measurable diameter growth ceased when...
Historical Evidence on the Finance-Trade-Growth Nexus

OpenAIRE

Michael D. Bordo; Peter L. Rousseau

2011-01-01

We study linkages between financial development, international trade, and long-run growth using data since 1880 for seventeen now-developed "Atlantic" economies and a set of cross-country and dynamic panel data models. We find that finance and trade reinforced each other before 1930, but that these effects did not persist after the Second World War. Financial development has positive effects on growth throughout the sample period, while trade affects growth strongly and independently after 19...
The South African tax mix and economic growth

OpenAIRE

AH de Wet; NJ Schoeman; SF Koch

2014-01-01

The research reported in this paper suggests that government fiscal policy can influence economic growth through alterations in the tax mix and the overall size of government spending. The authors estimate the impact on economic growth of changes in fiscal policy via government expenditure, direct taxation and indirect taxation. The results show that economic growth is negatively affected by increases in the size of government, as reflected in its expenditures and direct tax revenues, alth...
MoMuLV-ts-1: A Unique Mouse Model of Retrovirus-Induced Lymphoma Transmitted by Breast Milk

Directory of Open Access Journals (Sweden)

J. Chakraborty

2011-01-01

Full Text Available Our laboratory has developed a murine model of lymphoma via breast milk transmission of MoMuLV-ts-1 (Moloney murine leukemia virus-temperature sensitive mutant-1. Uninfected offspring suckled from infected surrogate mothers become infected and develop lymphoma. Multiple gene integration sites of ts-1 into the infected mouse genome including tacc3, aurka, ndel1, tpx2, p53, and rhamm were identified, and mRNA expressions were quantitated. These genes produce centrosomal proteins, which may be involved in abnormal chromosomal segregation leading to aneuploidy or multiploidy, thus causing lymphoma. Since there is no report to date on this retroviral model leading to centrosomal abnormality, and causing lymphoma development, this is a valuable and unique model to study the centrosomal involvement in lymphomagenesis.
Mutations in ORC1, encoding the largest subunit of the origin recognition complex, cause microcephalic primordial dwarfism resembling Meier-Gorlin syndrome.

Science.gov (United States)

Bicknell, Louise S; Walker, Sarah; Klingseisen, Anna; Stiff, Tom; Leitch, Andrea; Kerzendorfer, Claudia; Martin, Carol-Anne; Yeyati, Patricia; Al Sanna, Nouriya; Bober, Michael; Johnson, Diana; Wise, Carol; Jackson, Andrew P; O'Driscoll, Mark; Jeggo, Penny A

2011-02-27

Studies into disorders of extreme growth failure (for example, Seckel syndrome and Majewski osteodysplastic primordial dwarfism type II) have implicated fundamental cellular processes of DNA damage response signaling and centrosome function in the regulation of human growth. Here we report that mutations in ORC1, encoding a subunit of the origin recognition complex, cause microcephalic primordial dwarfism resembling Meier-Gorlin syndrome. We establish that these mutations disrupt known ORC1 functions including pre-replicative complex formation and origin activation. ORC1 deficiency perturbs S-phase entry and S-phase progression. Additionally, we show that Orc1 depletion in zebrafish is sufficient to markedly reduce body size during rapid embryonic growth. Our data suggest a model in which ORC1 mutations impair replication licensing, slowing cell cycle progression and consequently impeding growth during development, particularly at times of rapid proliferation. These findings establish a novel mechanism for the pathogenesis of microcephalic dwarfism and show a surprising but important developmental impact of impaired origin licensing.
Growth and yield of mixed polyclonal stands of Populus in short-rotation coppice

Energy Technology Data Exchange (ETDEWEB)

Benbrahim, Mohammed; Gavaland, Andre [INRA centre de Toulouse (France). Unite Agroforesterie et foret Paysanne; Gauvin, Jean [INRA centre d' Orleans (France). Unite d' Amelioration des arbres forestiers

2000-07-01

Eight clones of poplar were used to compare the growth and productivity of monoclonal and polyclonal mixed plantations in short-rotation coppice. At the end of the eight growing season, the diameter at breast height (DBH) and height of trees were measured and dry weight and yield were estimated. Polyclonal mixtures did not affect mortality. Few differences in growth were observed between clones in monoclonal plots. Polyclonal mixture slightly affected the growth and tree size of the clones compared with monoclonal plots. No increase in stand heterogeneity in relation to clone deployment was observed. A neighbourhood index was calculated for each tree and was significantly affected by polyclonal mixture. However, the relationship between the neighbourhood index and the DBH indicated that this effect did not cause a great change in DBH. Consequently, dry weight and yield productivity were not affected by clone deployment.
Overexpression of the kiwifruit SVP3 gene affects reproductive development and suppresses anthocyanin biosynthesis in petals, but has no effect on vegetative growth, dormancy, or flowering time.

Science.gov (United States)

Wu, Rongmei; Wang, Tianchi; McGie, Tony; Voogd, Charlotte; Allan, Andrew C; Hellens, Roger P; Varkonyi-Gasic, Erika

2014-09-01

SVP-like MADS domain transcription factors have been shown to regulate flowering time and both inflorescence and flower development in annual plants, while having effects on growth cessation and terminal bud formation in perennial species. Previously, four SVP genes were described in woody perennial vine kiwifruit (Actinidia spp.), with possible distinct roles in bud dormancy and flowering. Kiwifruit SVP3 transcript was confined to vegetative tissues and acted as a repressor of flowering as it was able to rescue the Arabidopsis svp41 mutant. To characterize kiwifruit SVP3 further, ectopic expression in kiwifruit species was performed. Ectopic expression of SVP3 in A. deliciosa did not affect general plant growth or the duration of endodormancy. Ectopic expression of SVP3 in A. eriantha also resulted in plants with normal vegetative growth, bud break, and flowering time. However, significantly prolonged and abnormal flower, fruit, and seed development were observed, arising from SVP3 interactions with kiwifruit floral homeotic MADS-domain proteins. Petal pigmentation was reduced as a result of SVP3-mediated interference with transcription of the kiwifruit flower tissue-specific R2R3 MYB regulator, MYB110a, and the gene encoding the key anthocyanin biosynthetic step, F3GT1. Constitutive expression of SVP3 had a similar impact on reproductive development in transgenic tobacco. The flowering time was not affected in day-neutral and photoperiod-responsive Nicotiana tabacum cultivars, but anthesis and seed germination were significantly delayed. The accumulation of anthocyanin in petals was reduced and the same underlying mechanism of R2R3 MYB NtAN2 transcript reduction was demonstrated. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Somatic growth dynamics of West Atlantic hawksbill sea turtles: a spatio-temporal perspective

Science.gov (United States)

Bjorndal, Karen A.; Chaloupka, Milani; Saba, Vincent S.; Diez, Carlos E.; van Dam, Robert P.; Krueger, Barry H.; Horrocks, Julia A.; Santos, Armando J.B.; Bellini, Cláudio; Marcovaldi, Maria A.G.; Nava, Mabel; Willis, Sue; Godley, Brendan J.; Gore, Shannon; Hawkes, Lucy A.; McGowan, Andrew; Witt, Matthew J.; Stringell, Thomas B.; Sanghera, Amdeep; Richardson, Peter B.; Broderick, Annette C.; Phillips, Quinton; Calosso, Marta C.; Claydon, John A.B.; Blumenthal, Janice; Moncada, Felix; Nodarse, Gonzalo; Medina, Yosvani; Dunbar, Stephen G.; Wood, Lawrence D.; Lagueux, Cynthia J.; Campbell, Cathi L.; Meylan, Anne B.; Meylan, Peter A.; Burns Perez, Virginia R.; Coleman, Robin A.; Strindberg, Samantha; Guzmán-H, Vicente; Hart, Kristen M.; Cherkiss, Michael S.; Hillis-Starr, Zandy; Lundgren, Ian; Boulon, Ralf H.; Connett, Stephen; Outerbridge, Mark E.; Bolten, Alan B.

2016-01-01

Somatic growth dynamics are an integrated response to environmental conditions. Hawksbill sea turtles (Eretmochelys imbricata) are long-lived, major consumers in coral reef habitats that move over broad geographic areas (hundreds to thousands of kilometers). We evaluated spatio-temporal effects on hawksbill growth dynamics over a 33-yr period and 24 study sites throughout the West Atlantic and explored relationships between growth dynamics and climate indices. We compiled the largest ever data set on somatic growth rates for hawksbills – 3541 growth increments from 1980 to 2013. Using generalized additive mixed model analyses, we evaluated 10 covariates, including spatial and temporal variation, that could affect growth rates. Growth rates throughout the region responded similarly over space and time. The lack of a spatial effect or spatio-temporal interaction and the very strong temporal effect reveal that growth rates in West Atlantic hawksbills are likely driven by region-wide forces. Between 1997 and 2013, mean growth rates declined significantly and steadily by 18%. Regional climate indices have significant relationships with annual growth rates with 0- or 1-yr lags: positive with the Multivariate El Niño Southern Oscillation Index (correlation = 0.99) and negative with Caribbean sea surface temperature (correlation = −0.85). Declines in growth rates between 1997 and 2013 throughout the West Atlantic most likely resulted from warming waters through indirect negative effects on foraging resources of hawksbills. These climatic influences are complex. With increasing temperatures, trajectories of decline of coral cover and availability in reef habitats of major prey species of hawksbills are not parallel. Knowledge of how choice of foraging habitats, prey selection, and prey abundance are affected by warming water temperatures is needed to understand how climate change will affect productivity of consumers that live in association with coral reefs. Main
Soil acidification by atmospheric pollution and forest growth

Science.gov (United States)

Bengt Jonsson

1976-01-01

In recent years concern has been expressed about the danger of harmful pollution deposits which affect areas at great distances from the emission sources. The investigation was so designed that a possible reaction in growth resulting from a supposed acidification could be observed as far as possible. A poorer growth development was observed in regions, which are...
Warming affects growth rates and microcystin production in tropical bloom-forming microcystis strains

NARCIS (Netherlands)

Bui, Trung; Dao, Thanh Son; Vo, Truong Giang; Lürling, Miquel

2018-01-01

Warming climate is predicted to promote cyanobacterial blooms but the toxicity of cyanobacteria under global warming is less well studied. We tested the hypothesis that raising temperature may lead to increased growth rates but to decreased microcystin (MC) production in tropical Microcystis
The little women of Loja--growth hormone-receptor deficiency in an inbred population of southern Ecuador.

Science.gov (United States)

Rosenbloom, A L; Guevara Aguirre, J; Rosenfeld, R G; Fielder, P J

1990-11-15

Laron-type dwarfism, which is characterized by the clinical appearance of isolated growth hormone deficiency with elevated serum levels of growth hormone and decreased serum levels of insulin-like growth factor I (IGF-I), has been described in approximately 50 patients. This condition is caused by a deficiency of the cellular receptor for growth hormone, and it is transmitted as an autosomal recessive trait, as indicated by an equal sex distribution and a high rate of consanguinity in affected families. We studied 20 patients (19 females and 1 male, 2 to 49 years of age), from an inbred Spanish population in southern Ecuador, who had the clinical features of Laron-type dwarfism. Seventeen patients were members of two large pedigrees. Among the 13 affected sibships, there were 19 affected and 24 unaffected female siblings and 1 affected and 21 unaffected male siblings. The patients' heights ranged from 10.0 to 6.7 SD below the normal mean height for age in the United States. In addition to the previously described features, 15 patients had limited elbow extensibility, all had blue scleras, affected adults had relatively short extremities, and all four affected women over 30 years of age had hip degeneration. Basal serum concentrations of growth hormone were elevated in all affected children (30 to 160 micrograms per liter) and normal to moderately elevated in the adults. The serum level of growth hormone-binding protein ranged from 1 to 30 percent of normal; IGF-I concentrations were low--less than or equal to 7 micrograms per liter in the children and less than or equal to 66 micrograms per liter in the adults (normal for Ecuadorean women, 98 to 238). Serum levels of IGF-II and growth hormone-dependent IGF-binding protein-3 were also low. We describe an inbred population with a high incidence of growth hormone-receptor deficiency resulting in a clinical picture resembling Laron-type dwarfism but differing principally in showing a marked predominance of affected
Estimating the optimal growth-maximising public debt threshold for ...

African Journals Online (AJOL)

This paper attempts to estimate an optimal growth-maximising public debt threshold for Zimbabwe. The public debt threshold is estimated by assessing the relationship between public debt and economic growth. The analysis is undertaken to determine the tipping point beyond which increases in public debt adversely affect ...
Seed Burial Depth and Soil Water Content Affect Seedling Emergence and Growth of Ulmus pumila var. sabulosa in the Horqin Sandy Land

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Jiao Tang

2016-01-01

Full Text Available We investigated the effects of seed burial depth and soil water content on seedling emergence and growth of Ulmus pumila var. sabulosa (sandy elm, an important native tree species distributed over the European-Asian steppe. Experimental sand burial depths in the soil were 0.5, 1.0, 1.5, 2.0 and 2.5 cm, and soil water contents were 4%, 8%, 12% and 16% of field capacity. All two-way ANOVA (five sand burial depths and four soil water contents results showed that seed burial depths, soil water content and their interactions significantly affected all the studied plant variables. Most of the times, seedling emergence conditions were greater at the lower sand burial depths (less than 1.0 cm than at the higher (more than 1.0 cm seed burial depths, and at the lower water content (less than 12% than at the higher soil water content. However, high seed burial depths (more than 1.5 cm or low soil water content (less than 12% reduced seedling growth or change in the root/shoot biomass ratios. In conclusion, the most suitable range of sand burial was from 0.5 to 1.0 cm soil depth and soil water content was about 12%, respectively, for the processes of seedling emergence and growth. These findings indicate that seeds of the sandy elm should be kept at rather shallow soil depths, and water should be added up to 12% of soil capacity when conducting elm planting and management. Our findings could help to create a more appropriate sandy elm cultivation and understand sparse elm woodland recruitment failures in arid and semi-arid regions.

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