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Sample records for placental mammal phylogeny

  1. Nomenclature and placental mammal phylogeny

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    Helgen Kristofer M

    2010-04-01

    Full Text Available Abstract An issue arising from recent progress in establishing the placental mammal Tree of Life concerns the nomenclature of high-level clades. Fortunately, there are now several well-supported clades among extant mammals that require unambiguous, stable names. Although the International Code of Zoological Nomenclature does not apply above the Linnean rank of family, and while consensus on the adoption of competing systems of nomenclature does not yet exist, there is a clear, historical basis upon which to arbitrate among competing names for high-level mammalian clades. Here, we recommend application of the principles of priority and stability, as laid down by G.G. Simpson in 1945, to discriminate among proposed names for high-level taxa. We apply these principles to specific cases among placental mammals with broad relevance for taxonomy, and close with particular emphasis on the Afrotherian family Tenrecidae. We conclude that no matter how reconstructions of the Tree of Life change in years to come, systematists should apply new names reluctantly, deferring to those already published and maximizing consistency with existing nomenclature.

  2. Mitochondrial data are not suitable for resolving placental mammal phylogeny.

    Science.gov (United States)

    Morgan, Claire C; Creevey, Christopher J; O'Connell, Mary J

    2014-12-01

    Mitochondrial data have traditionally been used in reconstructing a variety of species phylogenies. The low rates of recombination and thorough characterization of mitochondrial data across vertebrate species make it a particularly attractive phylogenetic marker. The relatively low number of fully sequenced mammal genomes and the lack of extensive sampling within Superorders have posed a serious problem for reaching agreement on the placement mammal species. The use of mitochondrial data sequences from large numbers of mammals could serve to circumvent the taxon-sampling deficit. Here we assess the suitability of mitochondrial data as a phylogenetic marker in mammal phylogenetics. MtDNA datasets of mammal origin have been filtered as follows: (i) we have sampled sparsely across the phylogenetic tree, (ii) we have constrained our sampling to genes with high taxon coverage, (iii) we have categorised rates across sites in a phylogeny independent manner and have removed fast evolving sites, and (iv), we have sampled from very shallow divergence times to reduce phylogenetic conflict. However, topologies obtained using these filters are not consistent with previous studies and are discordant across different genes. Individual mitochondrial genes, and indeed all mitochondrial genes analysed as a supermatrix, resulted in poor resolution of the species phylogeny. Overall, our study highlights the limitations of mitochondrial data, not only for resolving deep divergences and but also for shallow divergences in the mammal phylogeny.

  3. Heterogeneous models place the root of the placental mammal phylogeny.

    Science.gov (United States)

    Morgan, Claire C; Foster, Peter G; Webb, Andrew E; Pisani, Davide; McInerney, James O; O'Connell, Mary J

    2013-09-01

    Heterogeneity among life traits in mammals has resulted in considerable phylogenetic conflict, particularly concerning the position of the placental root. Layered upon this are gene- and lineage-specific variation in amino acid substitution rates and compositional biases. Life trait variations that may impact upon mutational rates are longevity, metabolic rate, body size, and germ line generation time. Over the past 12 years, three main conflicting hypotheses have emerged for the placement of the placental root. These hypotheses place the Atlantogenata (common ancestor of Xenarthra plus Afrotheria), the Afrotheria, or the Xenarthra as the sister group to all other placental mammals. Model adequacy is critical for accurate tree reconstruction and by failing to account for these compositional and character exchange heterogeneities across the tree and data set, previous studies have not provided a strongly supported hypothesis for the placental root. For the first time, models that accommodate both tree and data set heterogeneity have been applied to mammal data. Here, we show the impact of accurate model assignment and the importance of data sets in accommodating model parameters while maintaining the power to reject competing hypotheses. Through these sophisticated methods, we demonstrate the importance of model adequacy, data set power and provide strong support for the Atlantogenata over other competing hypotheses for the position of the placental root.

  4. Ultraconserved elements are novel phylogenomic markers that resolve placental mammal phylogeny when combined with species-tree analysis

    Science.gov (United States)

    McCormack, John E.; Faircloth, Brant C.; Crawford, Nicholas G.; Gowaty, Patricia Adair; Brumfield, Robb T.; Glenn, Travis C.

    2012-01-01

    Phylogenomics offers the potential to fully resolve the Tree of Life, but increasing genomic coverage also reveals conflicting evolutionary histories among genes, demanding new analytical strategies for elucidating a single history of life. Here, we outline a phylogenomic approach using a novel class of phylogenetic markers derived from ultraconserved elements and flanking DNA. Using species-tree analysis that accounts for discord among hundreds of independent loci, we show that this class of marker is useful for recovering deep-level phylogeny in placental mammals. In broad outline, our phylogeny agrees with recent phylogenomic studies of mammals, including several formerly controversial relationships. Our results also inform two outstanding questions in placental mammal phylogeny involving rapid speciation, where species-tree methods are particularly needed. Contrary to most phylogenomic studies, our study supports a first-diverging placental mammal lineage that includes elephants and tenrecs (Afrotheria). The level of conflict among gene histories is consistent with this basal divergence occurring in or near a phylogenetic “anomaly zone” where a failure to account for coalescent stochasticity will mislead phylogenetic inference. Addressing a long-standing phylogenetic mystery, we find some support from a high genomic coverage data set for a traditional placement of bats (Chiroptera) sister to a clade containing Perissodactyla, Cetartiodactyla, and Carnivora, and not nested within the latter clade, as has been suggested recently, although other results were conflicting. One of the most remarkable findings of our study is that ultraconserved elements and their flanking DNA are a rich source of phylogenetic information with strong potential for application across Amniotes. PMID:22207614

  5. Ultraconserved elements are novel phylogenomic markers that resolve placental mammal phylogeny when combined with species-tree analysis.

    Science.gov (United States)

    McCormack, John E; Faircloth, Brant C; Crawford, Nicholas G; Gowaty, Patricia Adair; Brumfield, Robb T; Glenn, Travis C

    2012-04-01

    Phylogenomics offers the potential to fully resolve the Tree of Life, but increasing genomic coverage also reveals conflicting evolutionary histories among genes, demanding new analytical strategies for elucidating a single history of life. Here, we outline a phylogenomic approach using a novel class of phylogenetic markers derived from ultraconserved elements and flanking DNA. Using species-tree analysis that accounts for discord among hundreds of independent loci, we show that this class of marker is useful for recovering deep-level phylogeny in placental mammals. In broad outline, our phylogeny agrees with recent phylogenomic studies of mammals, including several formerly controversial relationships. Our results also inform two outstanding questions in placental mammal phylogeny involving rapid speciation, where species-tree methods are particularly needed. Contrary to most phylogenomic studies, our study supports a first-diverging placental mammal lineage that includes elephants and tenrecs (Afrotheria). The level of conflict among gene histories is consistent with this basal divergence occurring in or near a phylogenetic "anomaly zone" where a failure to account for coalescent stochasticity will mislead phylogenetic inference. Addressing a long-standing phylogenetic mystery, we find some support from a high genomic coverage data set for a traditional placement of bats (Chiroptera) sister to a clade containing Perissodactyla, Cetartiodactyla, and Carnivora, and not nested within the latter clade, as has been suggested recently, although other results were conflicting. One of the most remarkable findings of our study is that ultraconserved elements and their flanking DNA are a rich source of phylogenetic information with strong potential for application across Amniotes.

  6. Placentation in mammals

    DEFF Research Database (Denmark)

    Carter, A M; Enders, A C

    2016-01-01

    chorioallantois, has known functions in ruminants and carnivores and is found in several other orders of mammal where its function has yet to be explored. In human gestation, the chorion (avascular chorioallantois) is important for hormone synthesis. The true chorion of squirrels and hedgehogs is avascular...

  7. Placentation in mammals once grouped as insectivores.

    Science.gov (United States)

    Carter, Anthony M; Enders, Allen C

    2010-01-01

    Interest in insectivoran grade mammals has been reawakened by taxonomic changes that place tenrecs and golden moles in a new order and separate hedgehogs from moles, shrews and solenodons. This survey of their placentation shows there is great variation even within families. As an example three subfamilies of tenrec have been examined. The interhemal region is cellular hemomonochorial in Echinops and Microgale but endotheliochorial in Micropotamogale. Golden moles, which are placed in the same order, have hemodichorial placentation. Many insectivores have complex arrangements for histotrophic nutrition involving columnar trophoblast cells. These range from areolae in moles through complexly folded hemophagous regions in tenrecs to the trophoblastic annulus in shrews. Of these placental characters, few offer support to current phylogenies. However, the case for placing hedgehogs and gymnures in a separate order (Erinaceomorpha) is bolstered by the presence of interstitial implantation, amniogenesis by cavitation, a hemochorial barrier and a prominent spongy zone; these features do not occur in shrews, moles or solenodons (Soricomorpha). Three insectivoran grade mammals deserve close attention as they have been selected for genome sequencing. One of these, the European hedgehog (Erinaceus europaeus), has not been studied with current methodology and renewed investigation of this or the closely related genus Atelerix should be a priority.

  8. Molecules consolidate the placental mammal tree

    NARCIS (Netherlands)

    Springer, M.S.; Stanhope, M.J.; Madsen, O.; Jong, W.W.W. de

    2004-01-01

    Deciphering relationships among the orders of placental mammals remains an important problem in evolutionary biology and has implications for understanding patterns of morphological character evolution, reconstructing the ancestral placental genome, and evaluating the role of plate tectonics and dis

  9. Molecules consolidate the placental mammal tree

    NARCIS (Netherlands)

    Springer, M.S.; Stanhope, M.J.; Madsen, O.; Jong, W.W.W. de

    2004-01-01

    Deciphering relationships among the orders of placental mammals remains an important problem in evolutionary biology and has implications for understanding patterns of morphological character evolution, reconstructing the ancestral placental genome, and evaluating the role of plate tectonics and

  10. A higher-level MRP supertree of placental mammals

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    Bininda-Emonds Olaf RP

    2006-11-01

    Full Text Available Abstract Background The higher-level phylogeny of placental mammals has long been a phylogenetic Gordian knot, with disagreement about both the precise contents of, and relationships between, the extant orders. A recent MRP supertree that favoured 'outdated' hypotheses (notably, monophyly of both Artiodactyla and Lipotyphla has been heavily criticised for including low-quality and redundant data. We apply a stringent data selection protocol designed to minimise these problems to a much-expanded data set of morphological, molecular and combined source trees, to produce a supertree that includes every family of extant placental mammals. Results The supertree is well-resolved and supports both polyphyly of Lipotyphla and paraphyly of Artiodactyla with respect to Cetacea. The existence of four 'superorders' – Afrotheria, Xenarthra, Laurasiatheria and Euarchontoglires – is also supported. The topology is highly congruent with recent (molecular phylogenetic analyses of placental mammals, but is considerably more comprehensive, being the first phylogeny to include all 113 extant families without making a priori assumptions of suprafamilial monophyly. Subsidiary analyses reveal that the data selection protocol played a key role in the major changes relative to a previously published higher-level supertree of placentals. Conclusion The supertree should provide a useful framework for hypothesis testing in phylogenetic comparative biology, and supports the idea that biogeography has played a crucial role in the evolution of placental mammals. Our results demonstrate the importance of minimising poor and redundant data when constructing supertrees.

  11. Microparasites and Placental Invasiveness in Eutherian Mammals.

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    Isabella Capellini

    Full Text Available Placental invasiveness-the number of maternal tissue layers separating fetal tissues from maternal blood-is variable across mammalian species. Although this diversity is likely to be functionally important, variation in placental invasiveness remains unexplained. Here we test the hypothesis that increased risk of transplacental transmission of pathogens from the mother to the fetus promotes the evolution of non-invasive placentation, the most likely derived condition in eutherian mammals. Specifically, we predict that non-invasive placentation is associated with increased microparasite species richness relative to more invasive placental types, based on the assumption that higher numbers of microparasites in a population reflects greater risk of transplacental transmission to fetuses. As predicted, higher bacteria species richness is associated with non-invasive placentation. Protozoa species richness, however, shows the opposite pattern. Because invasive placentae facilitate the transfer of maternal antibodies to the fetus, we propose that the ancestral condition of invasive placentation is retained under selection for protection of newborns from higher risk of postnatal protozoan infection. Hence, our findings suggest that a tradeoff exists between protection against bacterial infection prenatally and protozoan infection postnatally. Future studies are needed to investigate how maternal prevalence of infection and the relative pre- versus postnatal risk of fetal infection by different microparasite groups vary among mammalian hosts in relation to placental invasiveness.

  12. Placentation in mammals once grouped as insectivores

    DEFF Research Database (Denmark)

    Carter, Anthony; Enders, Allen

    2009-01-01

    Interest in insectivoran grade mammals has been reawakened by taxonomic changes that place tenrecs and golden moles in a new order and separate hedgehogs from moles, shrews and solenodons. This survey of their placentation shows there is great variation even within families. As an example three...... in a separate order (Erinaceomorpha) is bolstered by the presence of interstitial implantation, amniogenesis by cavitation, a hemochorial barrier and a prominent spongy zone; these features do not occur in shrews, moles or solenodons (Soricomorpha). Three insectivoran grade mammals deserve close attention...

  13. A web-database of mammalian morphology and a reanalysis of placental phylogeny

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    Asher Robert J

    2007-07-01

    Full Text Available Abstract Background Recent publications concerning the interordinal phylogeny of placental mammals have converged on a common signal, consisting of four major radiations with some ambiguity regarding the placental root. The DNA data with which these relationships have been reconstructed are easily accessible from public databases; access to morphological characters is much more difficult. Here, I present a graphical web-database of morphological characters focusing on placental mammals, in tandem with a combined-data phylogenetic analysis of placental mammal phylogeny. Results The results reinforce the growing consensus regarding the extant placental mammal clades of Afrotheria, Xenarthra, Euarchontoglires, and Laurasiatheria. Unweighted parsimony applied to all DNA sequences and insertion-deletion (indel characters of extant taxa alone support a placental root at murid rodents; combined with morphology this shifts to Afrotheria. Bayesian analyses of morphology, indels, and DNA support both a basal position for Afrotheria and the position of Cretaceous eutherians outside of crown Placentalia. Depending on treatment of third codon positions, the affinity of several fossils (Leptictis,Paleoparadoxia, Plesiorycteropus and Zalambdalestes vary, highlighting the potential effect of sequence data on fossils for which such data are missing. Conclusion The combined dataset supports the location of the placental mammal root at Afrotheria or Xenarthra, not at Erinaceus or rodents. Even a small morphological dataset can have a marked influence on the location of the root in a combined-data analysis. Additional morphological data are desirable to better reconstruct the position of several fossil taxa; and the graphic-rich, web-based morphology data matrix presented here will make it easier to incorporate more taxa into a larger data matrix.

  14. Extensive intron gain in the ancestor of placental mammals

    Science.gov (United States)

    2011-01-01

    Background Genome-wide studies of intron dynamics in mammalian orthologous genes have found convincing evidence for loss of introns but very little for intron turnover. Similarly, large-scale analysis of intron dynamics in a few vertebrate genomes has identified only intron losses and no gains, indicating that intron gain is an extremely rare event in vertebrate evolution. These studies suggest that the intron-rich genomes of vertebrates do not allow intron gain. The aim of this study was to search for evidence of de novo intron gain in domesticated genes from an analysis of their exon/intron structures. Results A phylogenomic approach has been used to analyse all domesticated genes in mammals and chordates that originated from the coding parts of transposable elements. Gain of introns in domesticated genes has been reconstructed on well established mammalian, vertebrate and chordate phylogenies, and examined as to where and when the gain events occurred. The locations, sizes and amounts of de novo introns gained in the domesticated genes during the evolution of mammals and chordates has been analyzed. A significant amount of intron gain was found only in domesticated genes of placental mammals, where more than 70 cases were identified. De novo gained introns show clear positional bias, since they are distributed mainly in 5' UTR and coding regions, while 3' UTR introns are very rare. In the coding regions of some domesticated genes up to 8 de novo gained introns have been found. Intron densities in Eutheria-specific domesticated genes and in older domesticated genes that originated early in vertebrates are lower than those for normal mammalian and vertebrate genes. Surprisingly, the majority of intron gains have occurred in the ancestor of placentals. Conclusions This study provides the first evidence for numerous intron gains in the ancestor of placental mammals and demonstrates that adequate taxon sampling is crucial for reconstructing intron evolution. The

  15. Extensive intron gain in the ancestor of placental mammals

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    Kordiš Dušan

    2011-11-01

    Full Text Available Abstract Background Genome-wide studies of intron dynamics in mammalian orthologous genes have found convincing evidence for loss of introns but very little for intron turnover. Similarly, large-scale analysis of intron dynamics in a few vertebrate genomes has identified only intron losses and no gains, indicating that intron gain is an extremely rare event in vertebrate evolution. These studies suggest that the intron-rich genomes of vertebrates do not allow intron gain. The aim of this study was to search for evidence of de novo intron gain in domesticated genes from an analysis of their exon/intron structures. Results A phylogenomic approach has been used to analyse all domesticated genes in mammals and chordates that originated from the coding parts of transposable elements. Gain of introns in domesticated genes has been reconstructed on well established mammalian, vertebrate and chordate phylogenies, and examined as to where and when the gain events occurred. The locations, sizes and amounts of de novo introns gained in the domesticated genes during the evolution of mammals and chordates has been analyzed. A significant amount of intron gain was found only in domesticated genes of placental mammals, where more than 70 cases were identified. De novo gained introns show clear positional bias, since they are distributed mainly in 5' UTR and coding regions, while 3' UTR introns are very rare. In the coding regions of some domesticated genes up to 8 de novo gained introns have been found. Intron densities in Eutheria-specific domesticated genes and in older domesticated genes that originated early in vertebrates are lower than those for normal mammalian and vertebrate genes. Surprisingly, the majority of intron gains have occurred in the ancestor of placentals. Conclusions This study provides the first evidence for numerous intron gains in the ancestor of placental mammals and demonstrates that adequate taxon sampling is crucial for

  16. The new framework for understanding placental mammal evolution.

    Science.gov (United States)

    Asher, Robert J; Bennett, Nigel; Lehmann, Thomas

    2009-08-01

    An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of dermopterans within euarchontoglires. A variety of names for sub-clades within the new placental mammal tree have been proposed, not all of which follow conventions regarding priority and stability. More importantly, the new phylogenetic framework enables the formulation of new hypotheses and testing thereof, for example regarding the possible developmental dichotomy that seems to distinguish members of the newly identified southern and northern radiations of living placental mammals.

  17. Differential Loss of Embryonic Globin Genes during the Radiation of Placental Mammals

    National Research Council Canada - National Science Library

    Juan C. Opazo; Federico G. Hoffmann; Jay F. Storz

    2008-01-01

    ...-globin gene family of placental mammals. By analyzing genomic sequence data from representatives of each of the main superordinal clades of placental mammals, we were able to reconstruct pathways of gene family evolution during the basal...

  18. The placental mammal ancestor and the post-K-Pg radiation of placentals.

    Science.gov (United States)

    O'Leary, Maureen A; Bloch, Jonathan I; Flynn, John J; Gaudin, Timothy J; Giallombardo, Andres; Giannini, Norberto P; Goldberg, Suzann L; Kraatz, Brian P; Luo, Zhe-Xi; Meng, Jin; Ni, Xijun; Novacek, Michael J; Perini, Fernando A; Randall, Zachary S; Rougier, Guillermo W; Sargis, Eric J; Silcox, Mary T; Simmons, Nancy B; Spaulding, Michelle; Velazco, Paúl M; Weksler, Marcelo; Wible, John R; Cirranello, Andrea L

    2013-02-01

    To discover interordinal relationships of living and fossil placental mammals and the time of origin of placentals relative to the Cretaceous-Paleogene (K-Pg) boundary, we scored 4541 phenomic characters de novo for 86 fossil and living species. Combining these data with molecular sequences, we obtained a phylogenetic tree that, when calibrated with fossils, shows that crown clade Placentalia and placental orders originated after the K-Pg boundary. Many nodes discovered using molecular data are upheld, but phenomic signals overturn molecular signals to show Sundatheria (Dermoptera + Scandentia) as the sister taxon of Primates, a close link between Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of echolocating Chiroptera (bats). Our tree suggests that Placentalia first split into Xenarthra and Epitheria; extinct New World species are the oldest members of Afrotheria.

  19. RUNX2 tandem repeats and the evolution of facial length in placental mammals

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    Pointer Marie A

    2012-06-01

    Full Text Available Abstract Background When simple sequence repeats are integrated into functional genes, they can potentially act as evolutionary ‘tuning knobs’, supplying abundant genetic variation with minimal risk of pleiotropic deleterious effects. The genetic basis of variation in facial shape and length represents a possible example of this phenomenon. Runt-related transcription factor 2 (RUNX2, which is involved in osteoblast differentiation, contains a functionally-important tandem repeat of glutamine and alanine amino acids. The ratio of glutamines to alanines (the QA ratio in this protein seemingly influences the regulation of bone development. Notably, in domestic breeds of dog, and in carnivorans in general, the ratio of glutamines to alanines is strongly correlated with facial length. Results In this study we examine whether this correlation holds true across placental mammals, particularly those mammals for which facial length is highly variable and related to adaptive behavior and lifestyle (e.g., primates, afrotherians, xenarthrans. We obtained relative facial length measurements and RUNX2 sequences for 41 mammalian species representing 12 orders. Using both a phylogenetic generalized least squares model and a recently-developed Bayesian comparative method, we tested for a correlation between genetic and morphometric data while controlling for phylogeny, evolutionary rates, and divergence times. Non-carnivoran taxa generally had substantially lower glutamine-alanine ratios than carnivorans (primates and xenarthrans with means of 1.34 and 1.25, respectively, compared to a mean of 3.1 for carnivorans, and we found no correlation between RUNX2 sequence and face length across placental mammals. Conclusions Results of our diverse comparative phylogenetic analyses indicate that QA ratio does not consistently correlate with face length across the 41 mammalian taxa considered. Thus, although RUNX2 might function as a ‘tuning knob’ modifying face

  20. RUNX2 tandem repeats and the evolution of facial length in placental mammals.

    Science.gov (United States)

    Pointer, Marie A; Kamilar, Jason M; Warmuth, Vera; Chester, Stephen G B; Delsuc, Frédéric; Mundy, Nicholas I; Asher, Robert J; Bradley, Brenda J

    2012-06-28

    When simple sequence repeats are integrated into functional genes, they can potentially act as evolutionary 'tuning knobs', supplying abundant genetic variation with minimal risk of pleiotropic deleterious effects. The genetic basis of variation in facial shape and length represents a possible example of this phenomenon. Runt-related transcription factor 2 (RUNX2), which is involved in osteoblast differentiation, contains a functionally-important tandem repeat of glutamine and alanine amino acids. The ratio of glutamines to alanines (the QA ratio) in this protein seemingly influences the regulation of bone development. Notably, in domestic breeds of dog, and in carnivorans in general, the ratio of glutamines to alanines is strongly correlated with facial length. In this study we examine whether this correlation holds true across placental mammals, particularly those mammals for which facial length is highly variable and related to adaptive behavior and lifestyle (e.g., primates, afrotherians, xenarthrans). We obtained relative facial length measurements and RUNX2 sequences for 41 mammalian species representing 12 orders. Using both a phylogenetic generalized least squares model and a recently-developed Bayesian comparative method, we tested for a correlation between genetic and morphometric data while controlling for phylogeny, evolutionary rates, and divergence times. Non-carnivoran taxa generally had substantially lower glutamine-alanine ratios than carnivorans (primates and xenarthrans with means of 1.34 and 1.25, respectively, compared to a mean of 3.1 for carnivorans), and we found no correlation between RUNX2 sequence and face length across placental mammals. Results of our diverse comparative phylogenetic analyses indicate that QA ratio does not consistently correlate with face length across the 41 mammalian taxa considered. Thus, although RUNX2 might function as a 'tuning knob' modifying face length in carnivorans, this relationship is not conserved across

  1. A dating success story: genomes and fossils converge on placental mammal origins

    OpenAIRE

    Goswami Anjali

    2012-01-01

    Abstract The timing of the placental mammal radiation has been a source of contention for decades. The fossil record of mammals extends over 200 million years, but no confirmed placental mammal fossils are known prior to 64 million years ago, which is approximately 1.5 million years after the Cretaceous-Paleogene (K-Pg) mass extinction that saw the end of non-avian dinosaurs. Thus, it came as a great surprise when the first published molecular clock studies suggested that placental mammals or...

  2. Evolution of the placenta during the early radiation of placental mammals

    DEFF Research Database (Denmark)

    Mess, Andrea; Carter, Anthony M

    2007-01-01

    . This interhaemal barrier occurs in three principal variants. The focus of this review is on determining how the barrier evolved in placental mammals. The analysis was based on current knowledge of placental structure, as far as possible using ultrastructural data, and on current views about the evolution...... of placental mammals, derived from molecular phylogenetics. We show that epitheliochorial placentation, the least invasive type, is a derived state and discuss factors that may have determined its evolution with reference to conflict theory, as applied to the allocation of resources between mother and fetus...

  3. A dating success story: genomes and fossils converge on placental mammal origins

    Directory of Open Access Journals (Sweden)

    Goswami Anjali

    2012-08-01

    Full Text Available Abstract The timing of the placental mammal radiation has been a source of contention for decades. The fossil record of mammals extends over 200 million years, but no confirmed placental mammal fossils are known prior to 64 million years ago, which is approximately 1.5 million years after the Cretaceous-Paleogene (K-Pg mass extinction that saw the end of non-avian dinosaurs. Thus, it came as a great surprise when the first published molecular clock studies suggested that placental mammals originated instead far back in the Cretaceous, in some cases doubling divergence estimates based on fossils. In the last few decades, more than a hundred new genera of Mesozoic mammals have been discovered, and molecular divergence studies have grown from simple clock-like models applied to a few genes to sophisticated analyses of entire genomes. Yet, molecular and fossil-based divergence estimates for placental mammal origins have remained remote, with knock-on effects for macro-scale reconstructions of mammal evolution. A few recent molecular studies have begun to converge with fossil-based estimates, and a new phylogenomic study in particular shows that the palaeontological record was mostly correct; most placental mammal orders diversified after the K-Pg mass extinction. While a small gap still remains for Late Cretaceous supraordinal divergences, this study has significantly improved the congruence between molecular and palaeontological data and heralds a broader integration of these fields of evolutionary science.

  4. Cholinergic urethral brush cells are widespread throughout placental mammals.

    Science.gov (United States)

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago.

  5. Phylogeny, niche conservatism and the latitudinal diversity gradient in mammals

    Science.gov (United States)

    Buckley, Lauren B.; Davies, T. Jonathan; Ackerly, David D.; Kraft, Nathan J. B.; Harrison, Susan P.; Anacker, Brian L.; Cornell, Howard V.; Damschen, Ellen I.; Grytnes, John-Avid; Hawkins, Bradford A.; McCain, Christy M.; Stephens, Patrick R.; Wiens, John J.

    2010-01-01

    Biologists have long searched for mechanisms responsible for the increase in species richness with decreasing latitude. The strong correlation between species richness and climate is frequently interpreted as reflecting a causal link via processes linked to energy or evolutionary rates. Here, we investigate how the aggregation of clades, as dictated by phylogeny, can give rise to significant climate–richness gradients without gradients in diversification or environmental carrying capacity. The relationship between climate and species richness varies considerably between clades, regions and time periods in a global-scale phylogenetically informed analysis of all terrestrial mammal species. Many young clades show negative richness–temperature slopes (more species at cooler temperatures), with the ages of these clades coinciding with the expansion of temperate climate zones in the late Eocene. In carnivores, we find steeply positive richness–temperature slopes in clades with restricted distributions and tropical origins (e.g. cat clade), whereas widespread, temperate clades exhibit shallow, negative slopes (e.g. dog–bear clade). We show that the slope of the global climate–richness gradient in mammals is driven by aggregating Chiroptera (bats) with their Eutherian sister group. Our findings indicate that the evolutionary history should be accounted for as part of any search for causal links between environment and species richness. PMID:20335205

  6. Evolution of the placenta during the early radiation of placental mammals.

    Science.gov (United States)

    Mess, Andrea; Carter, Anthony M

    2007-12-01

    The chorioallantoic placenta is an organ of gaseous exchange that exhibits a high degree of structural diversity. One factor determining oxygen transfer across the placenta, the diffusion distance, is in part dependent on the number of cell layers separating maternal from fetal blood. This interhaemal barrier occurs in three principal variants. The focus of this review is on determining how the barrier evolved in placental mammals. The analysis was based on current knowledge of placental structure, as far as possible using ultrastructural data, and on current views about the evolution of placental mammals, derived from molecular phylogenetics. We show that epitheliochorial placentation, the least invasive type, is a derived state and discuss factors that may have determined its evolution with reference to conflict theory, as applied to the allocation of resources between mother and fetus. It is not yet possible to determine which of the two more invasive types of placentation occurred in the last common ancestor of crown placentals. Depending on tree topology and taxon sampling, the result achieved is either endotheliochorial, haemochorial or unresolved. Finally we discuss other factors important to placental gas exchange and point to physiological variables that might become amenable to phylogenetic analysis.

  7. Ancient dates or accelerated rates? Morphological clocks and the antiquity of placental mammals.

    Science.gov (United States)

    Beck, Robin M D; Lee, Michael S Y

    2014-10-22

    Analyses of a comprehensive morphological character matrix of mammals using 'relaxed' clock models (which simultaneously estimate topology, divergence dates and evolutionary rates), either alone or in combination with an 8.5 kb nuclear sequence dataset, retrieve implausibly ancient, Late Jurassic-Early Cretaceous estimates for the initial diversification of Placentalia (crown-group Eutheria). These dates are much older than all recent molecular and palaeontological estimates. They are recovered using two very different clock models, and regardless of whether the tree topology is freely estimated or constrained using scaffolds to match the current consensus placental phylogeny. This raises the possibility that divergence dates have been overestimated in previous analyses that have applied such clock models to morphological and total evidence datasets. Enforcing additional age constraints on selected internal divergences results in only a slight reduction of the age of Placentalia. Constraining Placentalia to less than 93.8 Ma, congruent with recent molecular estimates, does not require major changes in morphological or molecular evolutionary rates. Even constraining Placentalia to less than 66 Ma to match the 'explosive' palaeontological model results in only a 10- to 20-fold increase in maximum evolutionary rate for morphology, and fivefold for molecules. The large discrepancies between clock- and fossil-based estimates for divergence dates might therefore be attributable to relatively small changes in evolutionary rates through time, although other explanations (such as overly simplistic models of morphological evolution) need to be investigated. Conversely, dates inferred using relaxed clock models (especially with discrete morphological data and MrBayes) should be treated cautiously, as relatively minor deviations in rate patterns can generate large effects on estimated divergence dates.

  8. Differential loss of embryonic globin genes during the radiation of placental mammals.

    Science.gov (United States)

    Opazo, Juan C; Hoffmann, Federico G; Storz, Jay F

    2008-09-02

    The differential gain and loss of genes from homologous gene families represents an important source of functional variation among the genomes of different species. Differences in gene content between species are primarily attributable to lineage-specific gene gains via duplication and lineage-specific losses via deletion or inactivation. Here, we use a comparative genomic approach to investigate this process of gene turnover in the beta-globin gene family of placental mammals. By analyzing genomic sequence data from representatives of each of the main superordinal clades of placental mammals, we were able to reconstruct pathways of gene family evolution during the basal radiation of this physiologically and morphologically diverse vertebrate group. Our analysis revealed that an initial expansion of the nonadult portion of the beta-globin gene cluster in the ancestor of placental mammals was followed by the differential loss and retention of ancestral gene lineages, thereby generating variation in the complement of embryonic globin genes among contemporary species. The sorting of epsilon-, gamma-, and eta-globin gene lineages among the basal clades of placental mammals has produced species differences in the functional types of hemoglobin isoforms that can be synthesized during the course of embryonic development.

  9. Conservation of placentation during the tertiary radiation of mammals in South America

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, Andrea Maria

    2013-01-01

    and may have been present in the founder generation on arrival in South America. In conclusion, there is a dichotomy within Xenarthra but otherwise the ancient South American mammals do not show much variation in principal placental characters. Thus, the successful radiation of these three groups...

  10. Motilin and ghrelin gene experienced episodic evolution during primitive placental mammal evolution

    Institute of Scientific and Technical Information of China (English)

    IRWIN; M.; David

    2010-01-01

    Motilin and ghrelin,members of a structure-function-related hormone family,play important roles in gastrointestinal function,regulation of energy homeostasis and growth hormone secretion.We observed episodic evolution in both of their prehormone gene sequences during primitive placental mammal evolution,during which most of the nonsynonymous changes result in radical substitution.Of note,a functional obestatin hormone might have only originated after this episodic evolution event.Early in placental mammal evolution,a series of biology complexities evolved.At the same time the motilin and ghrelin prehormone genes,which play important roles in several of these processes,experienced episodic evolution with dramatic changes in their coding sequences.These observations suggest that some of the lineage-specific physiological adaptations are due to episodic evolution of the motilin and ghrelin genes.

  11. Motilin and ghrelin gene experienced episodic evolution during primitive placental mammal evolution.

    Science.gov (United States)

    He, Jing; Irwin, M David; Zhang, YaPing

    2010-06-01

    Motilin and ghrelin, members of a structure-function-related hormone family, play important roles in gastrointestinal function, regulation of energy homeostasis and growth hormone secretion. We observed episodic evolution in both of their prehormone gene sequences during primitive placental mammal evolution, during which most of the nonsynonymous changes result in radical substitution. Of note, a functional obestatin hormone might have only originated after this episodic evolution event. Early in placental mammal evolution, a series of biology complexities evolved. At the same time the motilin and ghrelin prehormone genes, which play important roles in several of these processes, experienced episodic evolution with dramatic changes in their coding sequences. These observations suggest that some of the lineage-specific physiological adaptations are due to episodic evolution of the motilin and ghrelin genes.

  12. Extreme expansion of the olfactory receptor gene repertoire in African elephants and evolutionary dynamics of orthologous gene groups in 13 placental mammals.

    Science.gov (United States)

    Niimura, Yoshihito; Matsui, Atsushi; Touhara, Kazushige

    2014-09-01

    Olfactory receptors (ORs) detect odors in the environment, and OR genes constitute the largest multigene family in mammals. Numbers of OR genes vary greatly among species--reflecting the respective species' lifestyles--and this variation is caused by frequent gene gains and losses during evolution. However, whether the extent of gene gains/losses varies among individual gene lineages and what might generate such variation is unknown. To answer these questions, we used a newly developed phylogeny-based method to classify >10,000 intact OR genes from 13 placental mammal species into 781 orthologous gene groups (OGGs); we then compared the OGGs. Interestingly, African elephants had a surprisingly large repertoire (∼ 2000) of functional OR genes encoded in enlarged gene clusters. Additionally, OR gene lineages that experienced more gene duplication had weaker purifying selection, and Class II OR genes have evolved more dynamically than those in Class I. Some OGGs were highly expanded in a lineage-specific manner, while only three OGGs showed complete one-to-one orthology among the 13 species without any gene gains/losses. These three OGGs also exhibited highly conserved amino acid sequences; therefore, ORs in these OGGs may have physiologically important functions common to every placental mammal. This study provides a basis for inferring OR functions from evolutionary trajectory. © 2014 Niimura et al.; Published by Cold Spring Harbor Laboratory Press.

  13. Comparative Anatomy of the Bony Labyrinth (Inner Ear of Placental Mammals.

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    Eric G Ekdale

    Full Text Available Variation is a naturally occurring phenomenon that is observable at all levels of morphology, from anatomical variations of DNA molecules to gross variations between whole organisms. The structure of the otic region is no exception. The present paper documents the broad morphological diversity exhibited by the inner ear region of placental mammals using digital endocasts constructed from high-resolution X-ray computed tomography (CT. Descriptions cover the major placental clades, and linear, angular, and volumetric dimensions are reported.The size of the labyrinth is correlated to the overall body mass of individuals, such that large bodied mammals have absolutely larger labyrinths. The ratio between the average arc radius of curvature of the three semicircular canals and body mass of aquatic species is substantially lower than the ratios of related terrestrial taxa, and the volume percentage of the vestibular apparatus of aquatic mammals tends to be less than that calculated for terrestrial species. Aspects of the bony labyrinth are phylogenetically informative, including vestibular reduction in Cetacea, a tall cochlear spiral in caviomorph rodents, a low position of the plane of the lateral semicircular canal compared to the posterior canal in Cetacea and Carnivora, and a low cochlear aspect ratio in Primatomorpha.The morphological descriptions that are presented add a broad baseline of anatomy of the inner ear across many placental mammal clades, for many of which the structure of the bony labyrinth is largely unknown. The data included here complement the growing body of literature on the physiological and phylogenetic significance of bony labyrinth structures in mammals, and they serve as a source of data for future studies on the evolution and function of the vertebrate ear.

  14. Inactivation of C4orf26 in toothless placental mammals.

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    Springer, Mark S; Starrett, James; Morin, Phillip A; Lanzetti, Agnese; Hayashi, Cheryl; Gatesy, John

    2016-02-01

    Previous studies have reported inactivated copies of six enamel-related genes (AMBN, AMEL, AMTN, ENAM, KLK4, MMP20) and one dentin-related gene (DSPP) in one or more toothless vertebrates and/or vertebrates with enamelless teeth, thereby providing evidence that these genes are enamel or tooth-specific with respect to their critical functions that are maintained by natural selection. Here, we employ available genome sequences for edentulous and enamelless mammals to evaluate the enamel specificity of four genes (WDR72, SLC24A4, FAM83H, C4orf26) that have been implicated in amelogenesis imperfecta, a condition in which proper enamel formation is abrogated during tooth development. Coding sequences for WDR72, SCL24A4, and FAM83H are intact in four edentulous taxa (Chinese pangolin, three baleen whales) and three taxa (aardvark, nine-banded armadillo, Hoffmann's two-toed sloth) with enamelless teeth, suggesting that these genes have critical functions beyond their involvement in tooth development. By contrast, genomic data for C4orf26 reveal inactivating mutations in pangolin and bowhead whale as well as evidence for deletion of this gene in two minke whale species. Hybridization capture of exonic regions and PCR screens provide evidence for inactivation of C4orf26 in eight additional baleen whale species. However, C4orf26 is intact in all three species with enamelless teeth that were surveyed, as well as in 95 additional mammalian species with enamel-capped teeth. Estimates of selection intensity suggest that dN/dS ratios on branches leading to taxa with enamelless teeth are similar to the dN/dS ratio on branches leading to taxa with enamel-capped teeth. Based on these results, we conclude that C4orf26 is tooth-specific, but not enamel-specific, with respect to its essential functions that are maintained by natural selection. A caveat is that an alternative splice site variant, which translates exon 3 in a different reading frame, is putatively functional in

  15. Evolutionary history of LINE-1 in the major clades of placental mammals.

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    Paul D Waters

    Full Text Available BACKGROUND: LINE-1 constitutes an important component of mammalian genomes. It has a dynamic evolutionary history characterized by the rise, fall and replacement of subfamilies. Most data concerning LINE-1 biology and evolution are derived from the human and mouse genomes and are often assumed to hold for all placentals. METHODOLOGY: To examine LINE-1 relationships, sequences from the 3' region of the reverse transcriptase from 21 species (representing 13 orders across Afrotheria, Xenarthra, Supraprimates and Laurasiatheria were obtained from whole genome sequence assemblies, or by PCR with degenerate primers. These sequences were aligned and analysed. PRINCIPAL FINDINGS: Our analysis reflects accepted placental relationships suggesting mostly lineage-specific LINE-1 families. The data provide clear support for several clades including Glires, Supraprimates, Laurasiatheria, Boreoeutheria, Xenarthra and Afrotheria. Within the afrotherian LINE-1 (AfroLINE clade, our tree supports Paenungulata, Afroinsectivora and Afroinsectiphillia. Xenarthran LINE-1 (XenaLINE falls sister to AfroLINE, providing some support for the Atlantogenata (Xenarthra+Afrotheria hypothesis. SIGNIFICANCE: LINEs and SINEs make up approximately half of all placental genomes, so understanding their dynamics is an essential aspect of comparative genomics. Importantly, a tree of LINE-1 offers a different view of the root, as long edges (branches such as that to marsupials are shortened and/or broken up. Additionally, a robust phylogeny of diverse LINE-1 is essential in testing that site-specific LINE-1 insertions, often regarded as homoplasy-free phylogenetic markers, are indeed unique and not convergent.

  16. Oxytocin and arginine vasopressin receptor evolution: implications for adaptive novelties in placental mammals

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    Pamela Paré

    Full Text Available Abstract Oxytocin receptor (OXTR and arginine vasopressin receptors (AVPR1a, AVPR1b, and AVPR2 are paralogous genes that emerged through duplication events; along the evolutionary timeline, owing to speciation, numerous orthologues emerged as well. In order to elucidate the evolutionary forces that shaped these four genes in placental mammals and to reveal specific aspects of their protein structures, 35 species were selected. Specifically, we investigated their molecular evolutionary history and intrinsic protein disorder content, and identified the presence of short linear interaction motifs. OXTR seems to be under evolutionary constraint in placental mammals, whereas AVPR1a, AVPR1b, and AVPR2 exhibit higher evolutionary rates, suggesting that they have been under relaxed or experienced positive selection. In addition, we describe here, for the first time, that the OXTR, AVPR1a, AVPR1b, and AVPR2 mammalian orthologues preserve their disorder content, while this condition varies among the paralogues. Finally, our results reveal the presence of short linear interaction motifs, indicating possible functional adaptations related to physiological and/or behavioral taxa-specific traits.

  17. Oxytocin and arginine vasopressin receptor evolution: implications for adaptive novelties in placental mammals

    Science.gov (United States)

    Paré, Pamela; Paixão-Côrtes, Vanessa R.; Tovo-Rodrigues, Luciana; Vargas-Pinilla, Pedro; Viscardi, Lucas Henriques; Salzano, Francisco Mauro; Henkes, Luiz E.; Bortolini, Maria Catira

    2016-01-01

    Abstract Oxytocin receptor (OXTR) and arginine vasopressin receptors (AVPR1a, AVPR1b, and AVPR2) are paralogous genes that emerged through duplication events; along the evolutionary timeline, owing to speciation, numerous orthologues emerged as well. In order to elucidate the evolutionary forces that shaped these four genes in placental mammals and to reveal specific aspects of their protein structures, 35 species were selected. Specifically, we investigated their molecular evolutionary history and intrinsic protein disorder content, and identified the presence of short linear interaction motifs. OXTR seems to be under evolutionary constraint in placental mammals, whereas AVPR1a, AVPR1b, and AVPR2 exhibit higher evolutionary rates, suggesting that they have been under relaxed or experienced positive selection. In addition, we describe here, for the first time, that the OXTR, AVPR1a, AVPR1b, and AVPR2 mammalian orthologues preserve their disorder content, while this condition varies among the paralogues. Finally, our results reveal the presence of short linear interaction motifs, indicating possible functional adaptations related to physiological and/or behavioral taxa-specific traits. PMID:27505307

  18. Mammals from ‘down under’: a multi-gene species-level phylogeny of marsupial mammals (Mammalia, Metatheria)

    Science.gov (United States)

    Kilpatrick, C. William; Agnarsson, Ingi

    2015-01-01

    Marsupials or metatherians are a group of mammals that are distinct in giving birth to young at early stages of development and in having a prolonged investment in lactation. The group consists of nearly 350 extant species, including kangaroos, koala, possums, and their relatives. Marsupials are an old lineage thought to have diverged from early therian mammals some 160 million years ago in the Jurassic, and have a remarkable evolutionary and biogeographical history, with extant species restricted to the Americas, mostly South America, and to Australasia. Although the group has been the subject of decades of phylogenetic research, the marsupial tree of life remains controversial, with most studies focusing on only a fraction of the species diversity within the infraclass. Here we present the first Methaterian species-level phylogeny to include 80% of the extant marsupial species and five nuclear and five mitochondrial markers obtained from Genbank and a recently published retroposon matrix. Our primary goal is to provide a summary phylogeny that will serve as a tool for comparative research. We evaluate the extent to which the phylogeny recovers current phylogenetic knowledge based on the recovery of “benchmark clades” from prior studies—unambiguously supported key clades and undisputed traditional taxonomic groups. The Bayesian phylogenetic analyses recovered nearly all benchmark clades but failed to find support for the suborder Phalagiformes. The most significant difference with previous published topologies is the support for Australidelphia as a group containing Microbiotheriidae, nested within American marsupials. However, a likelihood ratio test shows that alternative topologies with monophyletic Australidelphia and Ameridelphia are not significantly different than the preferred tree. Although further data are needed to solidify understanding of Methateria phylogeny, the new phylogenetic hypothesis provided here offers a well resolved and detailed tool

  19. Robust time estimation reconciles views of the antiquity of placental mammals.

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    Yasuhiro Kitazoe

    Full Text Available BACKGROUND: Molecular studies have reported divergence times of modern placental orders long before the Cretaceous-Tertiary boundary and far older than paleontological data. However, this discrepancy may not be real, but rather appear because of the violation of implicit assumptions in the estimation procedures, such as non-gradual change of evolutionary rate and failure to correct for convergent evolution. METHODOLOGY/PRINCIPAL FINDINGS: New procedures for divergence-time estimation robust to abrupt changes in the rate of molecular evolution are described. We used a variant of the multidimensional vector space (MVS procedure to take account of possible convergent evolution. Numerical simulations of abrupt rate change and convergent evolution showed good performance of the new procedures in contrast to current methods. Application to complete mitochondrial genomes identified marked rate accelerations and decelerations, which are not obtained with current methods. The root of placental mammals is estimated to be approximately 18 million years more recent than when assuming a log Brownian motion model. Correcting the pairwise distances for convergent evolution using MVS lowers the age of the root about another 20 million years compared to using standard maximum likelihood tree branch lengths. These two procedures combined revise the root time of placental mammals from around 122 million years ago to close to 84 million years ago. As a result, the estimated distribution of molecular divergence times is broadly consistent with quantitative analysis of the North American fossil record and traditional morphological views. CONCLUSIONS/SIGNIFICANCE: By including the dual effects of abrupt rate change and directly accounting for convergent evolution at the molecular level, these estimates provide congruence between the molecular results, paleontological analyses and morphological expectations. The programs developed here are provided along with sample

  20. Waking the undead: Implications of a soft explosive model for the timing of placental mammal diversification.

    Science.gov (United States)

    Springer, Mark S; Emerling, Christopher A; Meredith, Robert W; Janečka, Jan E; Eizirik, Eduardo; Murphy, William J

    2017-01-01

    The explosive, long fuse, and short fuse models represent competing hypotheses for the timing of placental mammal diversification. Support for the explosive model, which posits both interordinal and intraordinal diversification after the KPg mass extinction, derives from morphological cladistic studies that place Cretaceous eutherians outside of crown Placentalia. By contrast, most molecular studies favor the long fuse model wherein interordinal cladogenesis occurred in the Cretaceous followed by intraordinal cladogenesis after the KPg boundary. Phillips (2016) proposed a soft explosive model that allows for the emergence of a few lineages (Xenarthra, Afrotheria, Euarchontoglires, Laurasiatheria) in the Cretaceous, but otherwise agrees with the explosive model in positing the majority of interordinal diversification after the KPg mass extinction. Phillips (2016) argues that rate transference errors associated with large body size and long lifespan have inflated previous estimates of interordinal divergence times, and further suggests that most interordinal divergences are positioned after the KPg boundary when rate transference errors are avoided through the elimination of calibrations in large-bodied and/or long lifespan clades. Here, we show that rate transference errors can also occur in the opposite direction and drag forward estimated divergence dates when calibrations in large-bodied/long lifespan clades are omitted. This dragging forward effect results in the occurrence of more than half a billion years of 'zombie lineages' on Phillips' preferred timetree. By contrast with ghost lineages, which are a logical byproduct of an incomplete fossil record, zombie lineages occur when estimated divergence dates are younger than the minimum age of the oldest crown fossils. We also present the results of new timetree analyses that address the rate transference problem highlighted by Phillips (2016) by deleting taxa that exceed thresholds for body size and lifespan

  1. Genetic recapitulation of human pre-eclampsia risk during convergent evolution of reduced placental invasiveness in eutherian mammals.

    Science.gov (United States)

    Elliot, Michael G; Crespi, Bernard J

    2015-03-05

    The relationship between phenotypic variation arising through individual development and phenotypic variation arising through diversification of species has long been a central question in evolutionary biology. Among humans, reduced placental invasion into endometrial tissues is associated with diseases of pregnancy, especially pre-eclampsia, and reduced placental invasiveness has also evolved, convergently, in at least 10 lineages of eutherian mammals. We tested the hypothesis that a common genetic basis underlies both reduced placental invasion arising through a developmental process in human placental disease and reduced placental invasion found as a derived trait in the diversification of Euarchontoglires (rodents, lagomorphs, tree shrews, colugos and primates). Based on whole-genome analyses across 18 taxa, we identified 1254 genes as having evolved adaptively across all three lineages exhibiting independent evolutionary transitions towards reduced placental invasion. These genes showed strong evidence of enrichment for associations with pre-eclampsia, based on genetic-association studies, gene-expression analyses and gene ontology. We further used in silico prediction to identify a subset of 199 genes that are likely targets of natural selection during transitions in placental invasiveness and which are predicted to also underlie human placental disorders. Our results indicate that abnormal ontogenies can recapitulate major phylogenetic shifts in mammalian evolution, identify new candidate genes for involvement in pre-eclampsia, imply that study of species with less-invasive placentation will provide useful insights into the regulation of placental invasion and pre-eclampsia, and recommend a novel comparative functional-evolutionary approach to the study of genetically based human disease and mammalian diversification. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  2. Co-evolution of MHC class I and variable NK cell receptors in placental mammals.

    Science.gov (United States)

    Guethlein, Lisbeth A; Norman, Paul J; Hilton, Hugo G; Parham, Peter

    2015-09-01

    Shaping natural killer (NK) cell functions in human immunity and reproduction are diverse killer cell immunoglobulin-like receptors (KIRs) that recognize polymorphic MHC class I determinants. A survey of placental mammals suggests that KIRs serve as variable NK cell receptors only in certain primates and artiodactyls. Divergence of the functional and variable KIRs in primates and artiodactyls predates placental reproduction. Among artiodactyls, cattle but not pigs have diverse KIRs. Catarrhine (humans, apes, and Old World monkeys) and platyrrhine (New World monkeys) primates, but not prosimians, have diverse KIRs. Platyrrhine and catarrhine systems of KIR and MHC class I are highly diverged, but within the catarrhines, a stepwise co-evolution of MHC class I and KIR is discerned. In Old World monkeys, diversification focuses on MHC-A and MHC-B and their cognate lineage II KIR. With evolution of C1-bearing MHC-C from MHC-B, as informed by orangutan, the focus changes to MHC-C and its cognate lineage III KIR. Evolution of C2 from C1 and fixation of MHC-C drove further elaboration of MHC-C-specific KIR, as exemplified by chimpanzee. In humans, the evolutionary trajectory changes again. Emerging from reorganization of the KIR locus and selective attenuation of KIR avidity for MHC class I are the functionally distinctive KIR A and KIR B haplotypes.

  3. How body mass and lifestyle affect juvenile biomass production in placental mammals.

    Science.gov (United States)

    Sibly, Richard M; Grady, John M; Venditti, Chris; Brown, James H

    2014-02-22

    In mammals, the mass-specific rate of biomass production during gestation and lactation, here called maternal productivity, has been shown to vary with body size and lifestyle. Metabolic theory predicts that post-weaning growth of offspring, here termed juvenile productivity, should be higher than maternal productivity, and juveniles of smaller species should be more productive than those of larger species. Furthermore because juveniles generally have similar lifestyles to their mothers, across species juvenile and maternal productivities should be correlated. We evaluated these predictions with data from 270 species of placental mammals in 14 taxonomic/lifestyle groups. All three predictions were supported. Lagomorphs, perissodactyls and artiodactyls were very productive both as juveniles and as mothers as expected from the abundance and reliability of their foods. Primates and bats were unproductive as juveniles and as mothers, as expected as an indirect consequence of their low predation risk and consequent low mortality. Our results point the way to a mechanistic explanation for the suite of correlated life-history traits that has been called the slow-fast continuum.

  4. Shape, variance and integration during craniogenesis: contrasting marsupial and placental mammals.

    Science.gov (United States)

    Goswami, A; Polly, P D; Mock, O B; Sánchez-Villagra, M R

    2012-05-01

    Studies of morphological integration can provide insight into developmental patterns, even in extinct taxa known only from skeletal remains, thus making them an important tool for studies of evolutionary development. However, interpreting patterns of integration and assessing their significance for organismal evolution requires detailed understanding of the developmental interactions that shape integration and how those interactions change through ontogeny. Thus far, relatively little comparative data have been produced for this important topic, and the data that do exist are overwhelmingly from humans and their close relatives or from laboratory models such as mice. Here, we compare data on shape, variance and integration through postnatal ontogeny for a placental mammal, the least shrew, Cryptotis parva, and a marsupial mammal, the gray short-tailed opossum, Monodelphis domestica. Cranial variance decreased dramatically from early to late ontogeny in Cryptotis, but remained stable through ontogeny in Monodelphis, potentially reflecting functional constraints related to the short gestation and early ossification of oral bones in marsupials. Both Cryptotis and Monodelphis showed significant changes in cranial integration through ontogeny, with a mixture of increased, decreased and stable levels of integration in different cranial regions. Of particular note is that Monodelphis showed an unambiguous decrease in integration of the oral region through ontogeny, potentially relating to their early ossification. Selection at different stages of development may have markedly different effects if patterns of integration change substantially through ontogeny. Our results suggest that high integration of the oral region combined with functional constraints for suckling during early postnatal ontogeny may drive the stagnant variance observed in Monodelphis and potentially other marsupials. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For

  5. Expressed sequence tags as a tool for phylogenetic analysis of placental mammal evolution.

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    Morgan Kullberg

    Full Text Available BACKGROUND: We investigate the usefulness of expressed sequence tags, ESTs, for establishing divergences within the tree of placental mammals. This is done on the example of the established relationships among primates (human, lagomorphs (rabbit, rodents (rat and mouse, artiodactyls (cow, carnivorans (dog and proboscideans (elephant. METHODOLOGY/PRINCIPAL FINDINGS: We have produced 2000 ESTs (1.2 mega bases from a marsupial mouse and characterized the data for their use in phylogenetic analysis. The sequences were used to identify putative orthologous sequences from whole genome projects. Although most ESTs stem from single sequence reads, the frequency of potential sequencing errors was found to be lower than allelic variation. Most of the sequences represented slowly evolving housekeeping-type genes, with an average amino acid distance of 6.6% between human and mouse. Positive Darwinian selection was identified at only a few single sites. Phylogenetic analyses of the EST data yielded trees that were consistent with those established from whole genome projects. CONCLUSIONS: The general quality of EST sequences and the general absence of positive selection in these sequences make ESTs an attractive tool for phylogenetic analysis. The EST approach allows, at reasonable costs, a fast extension of data sampling from species outside the genome projects.

  6. Resolution among major placental mammal interordinal relationships with genome data imply that speciation influenced their earliest radiations

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    Janke Axel

    2008-05-01

    Full Text Available Abstract Background A number of the deeper divergences in the placental mammal tree are still inconclusively resolved despite extensive phylogenomic analyses. A recent analysis of 200 kbp of protein coding sequences yielded only limited support for the relationships among Laurasiatheria (cow, dog, bat and shrew, probably because the divergences occurred only within a few million years from each other. It is generally expected that increasing the amount of data and improving the taxon sampling enhance the resolution of narrow divergences. Therefore these and other difficult splits were examined by phylogenomic analysis of the hitherto largest sequence alignment. The increasingly complete genome data of placental mammals also allowed developing a novel and stringent data search method. Results The rigorous data handling, recursive BLAST, successfully removed the sequences from gene families, including those from well-known families hemoglobin, olfactory, myosin and HOX genes, thus avoiding alignment of possibly paralogous sequences. The current phylogenomic analysis of 3,012 genes (2,844,615 nucleotides from a total of 22 species yielded statistically significant support for most relationships. While some major clades were confirmed using genomic sequence data, the placement of the treeshrew, bat and the relationship between Boreoeutheria, Xenarthra and Afrotheria remained problematic to resolve despite the size of the alignment. Phylogenomic analysis of divergence times dated the basal placental mammal splits at 95–100 million years ago. Many of the following divergences occurred only a few (2–4 million years later. Relationships with narrow divergence time intervals received unexpectedly limited support even from the phylogenomic analyses. Conclusion The narrow temporal window within which some placental divergences took place suggests that inconsistencies and limited resolution of the mammalian tree may have their natural explanation in

  7. Phylogenomic Resolution of the Phylogeny of Laurasiatherian Mammals: Exploring Phylogenetic Signals within Coding and Noncoding Sequences.

    Science.gov (United States)

    Chen, Meng-Yun; Liang, Dan; Zhang, Peng

    2017-08-01

    The interordinal relationships of Laurasiatherian mammals are currently one of the most controversial questions in mammalian phylogenetics. Previous studies mainly relied on coding sequences (CDS) and seldom used noncoding sequences. Here, by data mining public genome data, we compiled an intron data set of 3,638 genes (all introns from a protein-coding gene are considered as a gene) (19,055,073 bp) and a CDS data set of 10,259 genes (20,994,285 bp), covering all major lineages of Laurasiatheria (except Pholidota). We found that the intron data contained stronger and more congruent phylogenetic signals than the CDS data. In agreement with this observation, concatenation and species-tree analyses of the intron data set yielded well-resolved and identical phylogenies, whereas the CDS data set produced weakly supported and incongruent results. Further analyses showed that the phylogeny inferred from the intron data is highly robust to data subsampling and change in outgroup, but the CDS data produced unstable results under the same conditions. Interestingly, gene tree statistical results showed that the most frequently observed gene tree topologies for the CDS and intron data are identical, suggesting that the major phylogenetic signal within the CDS data is actually congruent with that within the intron data. Our final result of Laurasiatheria phylogeny is (Eulipotyphla,((Chiroptera, Perissodactyla),(Carnivora, Cetartiodactyla))), favoring a close relationship between Chiroptera and Perissodactyla. Our study 1) provides a well-supported phylogenetic framework for Laurasiatheria, representing a step towards ending the long-standing "hard" polytomy and 2) argues that intron within genome data is a promising data resource for resolving rapid radiation events across the tree of life. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. Origin, evolution, and biological role of miRNA cluster in DLK-DIO3 genomic region in placental mammals.

    Science.gov (United States)

    Glazov, Evgeny A; McWilliam, Sean; Barris, Wesley C; Dalrymple, Brian P

    2008-05-01

    MicroRNAs (miRNAs) are a rapidly growing family of small regulatory RNAs modulating gene expression in plants and animals. In animals, most of the miRNAs discovered in early studies were found to be evolutionarily conserved across the whole kingdom. More recent studies, however, have identified many miRNAs that are specific to a particular group of organisms or even a single species. These present a question about evolution of the individual miRNAs and their role in establishing and maintaining lineage-specific functions and characteristics. In this study, we describe a detailed analysis of the miRNA cluster (hereafter mir-379/mir-656 cluster) located within the imprinted DLK-DIO3 region on human chromosome 14. We show that orthologous miRNA clusters are present in all sequenced genomes of the placental (eutherian) mammals but not in the marsupial (metatherian), monotreme (prototherian), or any other vertebrate genomes. We provide evidence that the locus encompassing this cluster emerged in an early eutherian ancestor prior to the radiation of modern placental mammals by tandem duplication of the ancient precursor sequence. The original amplified cluster may have contained in excess of 250 miRNA precursor sequences, most of which now appear to be inactive. Examination of the eutherian genomes showed that the cluster has been maintained in evolution for approximately 100 Myr. Analysis of genes that contain predicted evolutionarily conserved targets for miRNAs from this cluster revealed significant overrepresentation of the Gene Ontology terms associated with biological processes such as neurogenesis, embryonic development, transcriptional regulation, and RNA metabolism. Consistent with these findings, a survey of the miRNA expression data within the cluster demonstrates a strong bias toward brain and placenta samples from adult organisms and some embryonic tissues. Our results suggest that emergence of the mir-379/mir-656 miRNA cluster was one of the factors that

  9. Similar associations of tooth microwear and morphology indicate similar diet across marsupial and placental mammals

    National Research Council Canada - National Science Library

    Christensen, Hilary B

    2014-01-01

    ... indistinguishable, indicating that microwear can be used to infer diet across the mammals. Microwear data were compared to body size and molar shearing crest length in order to develop a system to distinguish the diet of mammals...

  10. Aerobic characteristics of red kangaroo skeletal muscles: is a high aerobic capacity matched by muscle mitochondrial and capillary morphology as in placental mammals?

    Science.gov (United States)

    Dawson, Terence J; Mifsud, Brock; Raad, Matthew C; Webster, Koa N

    2004-07-01

    Marsupials and placentals together comprise the Theria, the advanced mammals, but they have had long independent evolutionary histories, with the last common ancestor occurring more than 125 million years ago. Although in the past the marsupials were considered to be metabolically 'primitive', the red kangaroo Macropus rufus has been reported to have an aerobic capacity (VO2max) comparable to that of the most 'athletic' of placentals such as dogs. However, kangaroos travel at moderate speeds with lower relative cost than quadrupedal placentals. Given the long independent evolution of the two therian groups, and their unusual locomotor energetics, do kangaroos achieve their high aerobic capacity using the same structural and functional mechanisms used by (athletic) placentals? Red kangaroo skeletal muscle morphometry matched closely the general aerobic characteristics of placental mammals. The relationship between total mitochondrial volume in skeletal muscle and VO2max during exercise was identical to that in quadrupedal placentals, and differed from that in bipedal humans. As for placentals generally, red kangaroo mitochondrial oxygen consumption at VO2max was 4.7 ml O2 min(-1) ml(-1) of mitochondria. Also, the inner mitochondrial membrane densities were 35.8 +/- 0.7 m2 ml(-1) of mitochondria, which is the same as for placental mammals, and the same pattern of similarity was seen for capillary densities and volumes. The overall data for kangaroos was equivalent to that seen in athletic placentals such as dogs and pronghorns. Total skeletal muscle mass was high, being around 50% of body mass, and was concentrated around the pelvis and lower back. The majority of the muscles sampled had relatively high mitochondrial volume densities, in the range 8.8-10.6% in the major locomotor muscles. Again, capillary densities and capillary blood volumes followed the pattern seen for mitochondria. Our results indicate that the red kangaroo, despite its locomotion and extreme

  11. Molecular phylogeny and taxonomy of Lagenidium-like oomycetes pathogenic to mammals.

    Science.gov (United States)

    Spies, Christoffel F J; Grooters, Amy M; Lévesque, C André; Rintoul, Tara L; Redhead, Scott A; Glockling, Sally L; Chen, Chi-Yu; de Cock, Arthur W A M

    2016-08-01

    Over the past twenty years, infections caused by previously unrecognised oomycete pathogens with morphological and molecular similarities to known Lagenidium species have been observed with increasing frequency, primarily in dogs but also in cats and humans. Three of these pathogens were formally described as Lagenidium giganteum forma caninum, Lagenidium deciduum, and Paralagenidium karlingii in advance of published phylogenetic verification. Due to the complex nature of Lagenidium taxonomy alongside recent reports of mammalian pathogenic species, these taxa needed to be verified with due consideration of the available data for Lagenidium and its allied genera. This study does so through morphologic characterisation of the mammalian pathogenic species, and phylogenetic analyses. The six-gene phylogeny generally supports the most recent comprehensive classification of Lagenidium with a well-supported Lagenidium clade that includes the mammalian pathogens L. giganteum f. caninum and L. deciduum, and well-supported clades for which the names Myzocytiopsis and Salilagenidium can be applied. The genus Paralagenidium is phylogenetically unrelated to any of the main clades within the class Peronosporomycetes. Close relationships between pathogens of mammals and those of insects or nematodes were revealed. Further characterisation of Lagenidium-like taxa is needed to establish the risk of mammalian infection by pathogens of insects and nematodes. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  12. Summary of Laurasiatheria (Mammalia) Phylogeny

    Institute of Scientific and Technical Information of China (English)

    Jingyang HU; Yaping ZHANG; Li YU

    2012-01-01

    Laurasiatheria is one of the richest and most diverse superorders of placental mammals.Because this group had a rapid evolutionary radiation,the phylogenetic relationships among the six orders of Laurasiatheria remain a subject of heated debate and several issues related to its phylogeny remain open.Reconstructing the true phylogenetic relationships of Laurasiatheria is a significant case study in evolutionary biology due to the diversity of this suborder and such research will have significant implications for biodiversity conservation.We review the higher-level (inter-ordinal) phylogenies of Laurasiatheria based on previous cytogenetic,morphological and molecular data,and discuss the controversies of its phylogenetic relationship.This review aims to outline future researches on Laurasiatheria phylogeny and adaptive evolution.

  13. Postnatal long bone growth in terrestrial placental mammals: allometry, life history, and organismal traits.

    Science.gov (United States)

    Kilbourne, Brandon M; Makovicky, Peter J

    2012-10-01

    The ontogenetic allometry of long bone proportions is poorly understood in Mammalia. It has previously been suggested that during mammalian ontogeny long bone proportions grow more slender (positive allometry; length ∝ circumference(>1.0) ), although this conclusion was based upon data from a few small-bodied taxa. It remains unknown how ontogenetic long bone allometry varies across Mammalia in terms of both taxonomy and body size. We collected long bone length and circumference data for ontogenetic samples of 22 species of mammals spanning six major clades and three orders of magnitude in body mass. Using reduced major axis bivariate regressions to compare bone length to circumference, we found that isometry and positive allometry are the most widespread patterns of growth across mammals. Negative allometry (i.e., bones growing more robust during ontogeny) occurs in mammals but is largely restricted to cetartiodactyls. Using regression slope as a proxy for long bone allometry, we compared long bone allometry to life history and organismal traits. Neonatal body mass, adult body mass, and growth rate have a negative relationship with long bone allometry. At an adult mass of roughly 15-20 kg, long bone growth shifts from positive allometry to mainly isometry and negative allometry. There were no significant relationships between ontogenetic long bone allometry and either cursoriality or basal metabolic rate. Copyright © 2012 Wiley Periodicals, Inc.

  14. Endogenous viral sequences from the Cape golden mole (Chrysochloris asiatica reveal the presence of foamy viruses in all major placental mammal clades.

    Directory of Open Access Journals (Sweden)

    Guan-Zhu Han

    Full Text Available Endogenous retroviruses provide important insights into the deep history of this viral lineage. Endogenous foamy viruses are thought to be very rare and only a few cases have been identified to date. Here we report a novel endogenous foamy virus (CaEFV within the genome of the Cape golden mole (Chrysochloris asiatica. The identification of CaEFV reveals the presence of foamy virus in the placental mammal superorder Afrotheria. Phylogenetic analyses place CaEFV basal to other foamy viruses of Eutherian origin, suggesting an ancient codivergence between foamy virus and placental mammals. These findings have implications for understanding the long-term evolution, diversity, and biology of retroviruses.

  15. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    Directory of Open Access Journals (Sweden)

    Charles C. Frasier

    2015-09-01

    Full Text Available The Mass, Metabolism and Length Explanation (MMLE was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymassb. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or

  16. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    Science.gov (United States)

    2015-01-01

    The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymass)b. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or not MMLE can

  17. A species-level phylogeny of all extant and late Quaternary extinct mammals using a novel heuristic-hierarchical Bayesian approach.

    Science.gov (United States)

    Faurby, Søren; Svenning, Jens-Christian

    2015-03-01

    Across large clades, two problems are generally encountered in the estimation of species-level phylogenies: (a) the number of taxa involved is generally so high that computation-intensive approaches cannot readily be utilized and (b) even for clades that have received intense study (e.g., mammals), attention has been centered on relatively few selected species, and most taxa must therefore be positioned on the basis of very limited genetic data. Here, we describe a new heuristic-hierarchical Bayesian approach and use it to construct a species-level phylogeny for all extant and late Quaternary extinct mammals. In this approach, species with large quantities of genetic data are placed nearly freely in the mammalian phylogeny according to these data, whereas the placement of species with lower quantities of data is performed with steadily stricter restrictions for decreasing data quantities. The advantages of the proposed method include (a) an improved ability to incorporate phylogenetic uncertainty in downstream analyses based on the resulting phylogeny, (b) a reduced potential for long-branch attraction or other types of errors that place low-data taxa far from their true position, while maintaining minimal restrictions for better-studied taxa, and (c) likely improved placement of low-data taxa due to the use of closer outgroups. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Similar Associations of Tooth Microwear and Morphology Indicate Similar Diet across Marsupial and Placental Mammals: e102789

    National Research Council Canada - National Science Library

    Hilary B Christensen

    2014-01-01

    ... indistinguishable, indicating that microwear can be used to infer diet across the mammals. Microwear data were compared to body size and molar shearing crest length in order to develop a system to distinguish the diet of mammals...

  19. Mammalian Placentation

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, A. M.

    2014-01-01

    This guide to animal models of human placentation assesses the strengths and weaknesses of species in common use. We argue that structural differences from human placenta, though important in some contexts, are less of a drawback than differences in reproductive strategy. Many laboratory rodents...... to consider animal models with longer gestations and well-developed neonates. Placentation in different orders of mammal is surveyed and their proximity to humans described in an evolutionary context. Animal models are then compared with the human in terms of the functional anatomy, physiology, and immunology...... have brief gestations resulting in the birth of poorly developed young. They can provide useful insights on placental development and function relevant to early human pregnancy. However, to model the events of a 9-month gestation, which imposes added requirements on the placenta, it is necessary...

  20. New specimens of the multituberculate mammal Sphenopsalis from China: Implications for phylogeny and biology of taeniolabidoids

    Directory of Open Access Journals (Sweden)

    Fang-Yuan Mao

    2016-06-01

    Full Text Available Multituberculates are the most diverse and best known group of Mesozoic mammals; they also persisted into the Paleogene and became extinct in the Eocene, possibly outcompeted by rodents that have similar morphological and presumably ecological adaptations. Among the Paleogene multituberculates, those that have the largest body sizes belong to taeniolabidoids, which contain several derived species from North America and Asia and some species with uncertain taxonomic positions. Of the known taeniolabidoids, the poorest known taxon is Sphenopsalis nobilis from Mongolia and Inner Mongolia, China, represented previously by a few isolated teeth. Its relationship with other multituberculates thus has remained unclear. Here we report new specimens of Sphenopsalis nobilis collected from the upper Paleocene of the Erlian Basin, Inner Mongolia, China, during a multi-year field effort beginning in 2000. These new specimens document substantial parts of the dental, partial cranial and postcranial morphologies of Sphenopsalis, including the upper and lower incisors, partial premolars, complete upper and lower molars, a partial rostrum, fragments of the skull roof, middle ear cavity, a partial scapula, and partial limb bones. With the new specimens we are able to present a detailed description of Sphenopsalis, comparisons among relevant taeniolabidoids, and brief phylogenetic analyses based on a dataset consisting of 43 taxa and 102 characters. In light of the new evidence, we assess the phylogenetic position of Sphenopsalis and re-establish the family Lambdopsalidae. The monophyly of Taeniolabidoidea is supported in all our phylogenetic analyses. Within Taeniolabidoidea the Asian lambdopsalids and the North American taeniolabidids represent two significantly different trends of adaptations, one characterized by shearing (lambdopsalids and the other by crushing and grinding (taeniolabidids in mastication, which supports their wider systematic separation, as

  1. Phylogeny, diet, and cranial integration in australodelphian marsupials.

    Directory of Open Access Journals (Sweden)

    Anjali Goswami

    Full Text Available Studies of morphological integration provide valuable information on the correlated evolution of traits and its relationship to long-term patterns of morphological evolution. Thus far, studies of morphological integration in mammals have focused on placentals and have demonstrated that similarity in integration is broadly correlated with phylogenetic distance and dietary similarity. Detailed studies have also demonstrated a significant correlation between developmental relationships among structures and adult morphological integration. However, these studies have not yet been applied to marsupial taxa, which differ greatly from placentals in reproductive strategy and cranial development and could provide the diversity necessary to assess the relationships among phylogeny, ecology, development, and cranial integration. This study presents analyses of morphological integration in 20 species of australodelphian marsupials, and shows that phylogeny is significantly correlated with similarity of morphological integration in most clades. Size-related correlations have a significant affect on results, particularly in Peramelia, which shows a striking decrease in similarity of integration among species when size is removed. Diet is not significantly correlated with similarity of integration in any marsupial clade. These results show that marsupials differ markedly from placental mammals in the relationships of cranial integration, phylogeny, and diet, which may be related to the accelerated development of the masticatory apparatus in marsupials.

  2. Mammalian Placentation

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, A. M.

    2014-01-01

    This guide to animal models of human placentation assesses the strengths and weaknesses of species in common use. We argue that structural differences from human placenta, though important in some contexts, are less of a drawback than differences in reproductive strategy. Many laboratory rodents...... to consider animal models with longer gestations and well-developed neonates. Placentation in different orders of mammal is surveyed and their proximity to humans described in an evolutionary context. Animal models are then compared with the human in terms of the functional anatomy, physiology, and immunology...... of the placenta. This information is collated both to assess common animal models such as mouse, sheep, and primates and to introduce some alternatives that we consider worthy of attention....

  3. Evolution of species-specific major seminal fluid proteins in placental mammals by gene death and positive selection

    NARCIS (Netherlands)

    Meslin, C.; Laurin, M.; Callebaut, I.; Druart, X.; Monget, P.

    2015-01-01

    The seminal fluid is a complex substance composed of a variety of secreted proteins and has been shown to play an important role in the fertilisation process in mammals and also in Drosophila. Several genes under positive selection have been documented in some rodents and primates. Our study documen

  4. Did sex chromosome turnover promote divergence of the major mammal groups?: De novo sex chromosomes and drastic rearrangements may have posed reproductive barriers between monotremes, marsupials and placental mammals.

    Science.gov (United States)

    Graves, Jennifer A M

    2016-08-01

    Comparative mapping and sequencing show that turnover of sex determining genes and chromosomes, and sex chromosome rearrangements, accompany speciation in many vertebrates. Here I review the evidence and propose that the evolution of therian mammals was precipitated by evolution of the male-determining SRY gene, defining a novel XY sex chromosome pair, and interposing a reproductive barrier with the ancestral population of synapsid reptiles 190 million years ago (MYA). Divergence was reinforced by multiple translocations in monotreme sex chromosomes, the first of which supplied a novel sex determining gene. A sex chromosome-autosome fusion may have separated eutherians (placental mammals) from marsupials 160 MYA. Another burst of sex chromosome change and speciation is occurring in rodents, precipitated by the degradation of the Y. And although primates have a more stable Y chromosome, it may be just a matter of time before the same fate overtakes our own lineage. Also watch the video abstract. © 2016 The Authors. BioEssays Published by WILEY Periodicals, Inc.

  5. A new phylogeny for basal Trechnotheria and Cladotheria and affinities of South American endemic Late Cretaceous mammals

    Science.gov (United States)

    Averianov, Alexander O.; Martin, Thomas; Lopatin, Alexey V.

    2013-04-01

    The endemic South American mammals Meridiolestida, considered previously as dryolestoid cladotherians, are found to be non-cladotherian trechnotherians related to spalacotheriid symmetrodontans based on a parsimony analysis of 137 morphological characters among 44 taxa. Spalacotheriidae is the sister taxon to Meridiolestida, and the latter clade is derived from a primitive spalacolestine that migrated to South America from North America at the beginning of the Late Cretaceous. Meridiolestida survived until the early Paleocene ( Peligrotherium) and early Miocene ( Necrolestes) in South America, and their extinction is probably linked to the increasing competition with metatherian and eutherian tribosphenic mammals. The clade Meridiolestida plus Spalacotheriidae is the sister taxon to Cladotheria and forms a new clade Alethinotheria. Alethinotheria and its sister taxon Zhangheotheria, new clade (Zhangheotheriidae plus basal taxa), comprise Trechnotheria. Cladotheria is divided into Zatheria (plus stem taxa, including Amphitherium) and Dryolestida, including Dryolestidae and a paraphyletic array of basal dryolestidans (formerly classified as "Paurodontidae"). The South American Vincelestes and Groebertherium are basal dryolestidans.

  6. The artiodactyl APOBEC3 innate immune repertoire shows evidence for a multi-functional domain organization that existed in the ancestor of placental mammals

    Directory of Open Access Journals (Sweden)

    Andrésdóttir Valgerdur

    2008-11-01

    Full Text Available Abstract Background APOBEC3 (A3 proteins deaminate DNA cytosines and block the replication of retroviruses and retrotransposons. Each A3 gene encodes a protein with one or two conserved zinc-coordinating motifs (Z1, Z2 or Z3. The presence of one A3 gene in mice (Z2–Z3 and seven in humans, A3A-H (Z1a, Z2a-Z1b, Z2b, Z2c-Z2d, Z2e-Z2f, Z2g-Z1c, Z3, suggests extraordinary evolutionary flexibility. To gain insights into the mechanism and timing of A3 gene expansion and into the functional modularity of these genes, we analyzed the genomic sequences, expressed cDNAs and activities of the full A3 repertoire of three artiodactyl lineages: sheep, cattle and pigs. Results Sheep and cattle have three A3 genes, A3Z1, A3Z2 and A3Z3, whereas pigs only have two, A3Z2 and A3Z3. A comparison between domestic and wild pigs indicated that A3Z1 was deleted in the pig lineage. In all three species, read-through transcription and alternative splicing also produced a catalytically active double domain A3Z2-Z3 protein that had a distinct cytoplasmic localization. Thus, the three A3 genes of sheep and cattle encode four conserved and active proteins. These data, together with phylogenetic analyses, indicated that a similar, functionally modular A3 repertoire existed in the common ancestor of artiodactyls and primates (i.e., the ancestor of placental mammals. This mammalian ancestor therefore possessed the minimal A3 gene set, Z1-Z2-Z3, required to evolve through a remarkable series of eight recombination events into the present day eleven Z domain human repertoire. Conclusion The dynamic recombination-filled history of the mammalian A3 genes is consistent with the modular nature of the locus and a model in which most of these events (especially the expansions were selected by ancient pathogenic retrovirus infections.

  7. Mammal madness: is the mammal tree of life not yet resolved?

    Science.gov (United States)

    Foley, Nicole M; Springer, Mark S; Teeling, Emma C

    2016-07-19

    Most molecular phylogenetic studies place all placental mammals into four superordinal groups, Laurasiatheria (e.g. dogs, bats, whales), Euarchontoglires (e.g. humans, rodents, colugos), Xenarthra (e.g. armadillos, anteaters) and Afrotheria (e.g. elephants, sea cows, tenrecs), and estimate that these clades last shared a common ancestor 90-110 million years ago. This phylogeny has provided a framework for numerous functional and comparative studies. Despite the high level of congruence among most molecular studies, questions still remain regarding the position and divergence time of the root of placental mammals, and certain 'hard nodes' such as the Laurasiatheria polytomy and Paenungulata that seem impossible to resolve. Here, we explore recent consensus and conflict among mammalian phylogenetic studies and explore the reasons for the remaining conflicts. The question of whether the mammal tree of life is or can be ever resolved is also addressed.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. © 2016 The Author(s).

  8. Glycosylation at the fetomaternal interface in hemomonochorial placentae from five widely separated species of mammal

    DEFF Research Database (Denmark)

    Jones, Carolyn J. P.; Carter, Anthony M.; Aplin, John D.

    2007-01-01

    Hemomonochorial placentation occurs in diverse species. We have examined placental glycosylation in five widely separated mammals with this type of placentation--lesser hedgehog tenrec (Echinops telfairi), spotted hyena (Crocuta crocuta), nine-banded armadillo (Dasypus novemcinctus), human (Homo...

  9. Placental economies

    DEFF Research Database (Denmark)

    Lee, Jieun

    2016-01-01

    and sustained through the relations and practices of care that animate the placenta in different forms. On the basis of an ethnographic fieldwork conducted in Korea, this article focuses on two different forms of care (lab workers’ care of cells, and pregnant women’s care of fetuses) that enable the (re......Thinking with the vital materiality of placentas as it is evinced in a placental stem cell research lab in Korea, this article explores the relations and practices of care that are essential to the circulation of biological matters as infrastructure of tissue economies. I attend to the flows...... of care that sustain tissue economies with the notion of ‘placental economies’. Shifting attention from donor subjects and tissue objects to practices and relations of care as an infrastructure for the circulation of tissues, I explore how the vitality of biological matters is an achievement made...

  10. The evolutionary host switches of Polychromophilus: a multi-gene phylogeny of the bat malaria genus suggests a second invasion of mammals by a haemosporidian parasite

    Directory of Open Access Journals (Sweden)

    Witsenburg Fardo

    2012-02-01

    Full Text Available Abstract Background The majority of Haemosporida species infect birds or reptiles, but many important genera, including Plasmodium, infect mammals. Dipteran vectors shared by avian, reptilian and mammalian Haemosporida, suggest multiple invasions of Mammalia during haemosporidian evolution; yet, phylogenetic analyses have detected only a single invasion event. Until now, several important mammal-infecting genera have been absent in these analyses. This study focuses on the evolutionary origin of Polychromophilus, a unique malaria genus that only infects bats (Microchiroptera and is transmitted by bat flies (Nycteribiidae. Methods Two species of Polychromophilus were obtained from wild bats caught in Switzerland. These were molecularly characterized using four genes (asl, clpc, coI, cytb from the three different genomes (nucleus, apicoplast, mitochondrion. These data were then combined with data of 60 taxa of Haemosporida available in GenBank. Bayesian inference, maximum likelihood and a range of rooting methods were used to test specific hypotheses concerning the phylogenetic relationships between Polychromophilus and the other haemosporidian genera. Results The Polychromophilus melanipherus and Polychromophilus murinus samples show genetically distinct patterns and group according to species. The Bayesian tree topology suggests that the monophyletic clade of Polychromophilus falls within the avian/saurian clade of Plasmodium and directed hypothesis testing confirms the Plasmodium origin. Conclusion Polychromophilus' ancestor was most likely a bird- or reptile-infecting Plasmodium before it switched to bats. The invasion of mammals as hosts has, therefore, not been a unique event in the evolutionary history of Haemosporida, despite the suspected costs of adapting to a new host. This was, moreover, accompanied by a switch in dipteran host.

  11. New specimens of the rare taeniodont Wortmania (Mammalia: Eutheria from the San Juan Basin of New Mexico and comments on the phylogeny and functional morphology of "archaic" mammals.

    Directory of Open Access Journals (Sweden)

    Thomas E Williamson

    Full Text Available BACKGROUND: Taeniodonta is a clade of Late Cretaceous-Paleogene mammals remarkable for their relatively extreme cranial, dental, and postcranial adaptations and notable for being among the first mammals to achieve relatively large size following the Cretaceous-Paleogene mass extinction. Previous workers have hypothesized that taeniodonts can be divided into two clades: Conoryctidae, a group of small-bodied taeniodonts with supposedly "generalized" postcranial skeletons, and Stylinodontidae, a group of large-bodied, robust animals with massive forelimbs and claws adapted for scratch-digging. However, many taeniodont taxa are poorly known and few are represented by postcranial material, leaving many details about their anatomy, biology, and evolution ambiguous. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we describe three new specimens of the rare taxon Wortmania otariidens from the early Paleocene (Puercan of New Mexico. Among these specimens is one that includes remarkably complete cranial and dental material, including associated upper and lower teeth, and another that consists of partial forelimbs. These specimens allow for an updated anatomical description of this unusual taxon, supply new data for phylogenetic analyses, and enable a more constrained discussion of taeniodont biology and functional morphology. CONCLUSIONS/SIGNIFICANCE: The new specimen of Wortmania that includes associated upper and lower teeth indicates that previous interpretations of the upper dentition of this taxon were not accurate and the taxon Robertschochia sullivani is a junior synonym of W. otariidens. New specimens that include partial forelimbs indicate that Wortmania is very similar to later, large-bodied taeniodonts, with marked and distinctive adaptations for scratch-digging. Comparisons with other taeniodont taxa that include postcranial material suggest that all taeniodonts may have had scratch-digging adaptations. A phylogenetic analysis shows that

  12. Evolution of placental function in mammals

    DEFF Research Database (Denmark)

    Carter, Anthony Michael

    2012-01-01

    Placenta has a wide range of functions. Some are supported by novel genes that have evolved following gene duplication events while others require acquisition of gene expression by the trophoblast. Although not expressed in the placenta, high-affinity fetal hemoglobins play a key role in placenta...

  13. Dipalmitoylphosphatidylcholine is not the major surfactant phospholipid species in all mammals.

    Science.gov (United States)

    Lang, Carol J; Postle, Anthony D; Orgeig, Sandra; Possmayer, Fred; Bernhard, Wolfgang; Panda, Amiya K; Jürgens, Klaus D; Milsom, William K; Nag, Kaushik; Daniels, Christopher B

    2005-11-01

    Pulmonary surfactant, a complex mixture of lipids and proteins, lowers the surface tension in terminal air spaces and is crucial for lung function. Within an animal species, surfactant composition can be influenced by development, disease, respiratory rate, and/or body temperature. Here, we analyzed the composition of surfactant in three heterothermic mammals (dunnart, bat, squirrel), displaying different torpor patterns, to determine: 1) whether increases in surfactant cholesterol (Chol) and phospholipid (PL) saturation occur during long-term torpor in squirrels, as in bats and dunnarts; 2) whether surfactant proteins change during torpor; and 3) whether PL molecular species (molsp) composition is altered. In addition, we analyzed the molsp composition of a further nine mammals (including placental/marsupial and hetero-/homeothermic contrasts) to determine whether phylogeny or thermal behavior determines molsp composition in mammals. We discovered that like bats and dunnarts, surfactant Chol increases during torpor in squirrels. However, changes in PL saturation during torpor may not be universal. Torpor was accompanied by a decrease in surfactant protein A in dunnarts and squirrels, but not in bats, whereas surfactant protein B did not change in any species. Phosphatidylcholine (PC)16:0/16:0 is highly variable between mammals and is not the major PL in the wombat, dunnart, shrew, or Tasmanian devil. An inverse relationship exists between PC16:0/16:0 and two of the major fluidizing components, PC16:0/16:1 and PC16:0/14:0. The PL molsp profile of an animal species is not determined by phylogeny or thermal behavior. We conclude that there is no single PL molsp composition that functions optimally in all mammals; rather, surfactant from each animal is unique and tailored to the biology of that animal.

  14. Pregnancy Complications: Placental Abruption

    Science.gov (United States)

    ... wall of the uterus (womb) and supplies the baby with food and oxygen through the umbilical cord. Placental abruption ... wall of the uterus (womb) and supplies the baby with food and oxygen through the umbilical cord. Placental abruption ...

  15. Comparative aspects of trophoblast development and placentation

    Directory of Open Access Journals (Sweden)

    Enders Allen C

    2004-07-01

    Full Text Available Abstract Based on the number of tissues separating maternal from fetal blood, placentas are classified as epitheliochorial, endotheliochorial or hemochorial. We review the occurrence of these placental types in the various orders of eutherian mammals within the framework of the four superorders identified by the techniques of molecular phylogenetics. The superorder Afrotheria diversified in ancient Africa and its living representatives include elephants, sea cows, hyraxes, aardvark, elephant shrews and tenrecs. Xenarthra, comprising armadillos, anteaters and sloths, diversified in South America. All placentas examined from members of these two oldest superorders are either endotheliochorial or hemochorial. The superorder Euarchontoglires includes two sister groups, Glires and Euarchonta. The former comprises rodents and lagomorphs, which typically have hemochorial placentas. The most primitive members of Euarchonta, the tree shrews, have endotheliochorial placentation. Flying lemurs and all higher primates have hemochorial placentas. However, the lemurs and lorises are exceptional among primates in having epitheliochorial placentation. Laurasiatheria, the last superorder to arise, includes several orders with epitheliochorial placentation. These comprise whales, camels, pigs, ruminants, horses and pangolins. In contrast, nearly all carnivores have endotheliochorial placentation, whilst bats have endotheliochorial or hemochorial placentas. Also included in Laurasiatheria are a number of insectivores that have many conserved morphological characters; none of these has epitheliochorial placentation. Consideration of placental type in relation to the findings of molecular phylogenetics suggests that the likely path of evolution in Afrotheria was from endotheliochorial to hemochorial placentation. This is also a likely scenario for Xenarthra and the bats. We argue that a definitive epitheliochorial placenta is a secondary specialization and that it

  16. Brain size, life history, and metabolism at the marsupial/placental dichotomy.

    Science.gov (United States)

    Weisbecker, Vera; Goswami, Anjali

    2010-09-14

    The evolution of mammalian brain size is directly linked with the evolution of the brain's unique structure and performance. Both maternal life history investment traits and basal metabolic rate (BMR) correlate with relative brain size, but current hypotheses regarding the details of these relationships are based largely on placental mammals. Using encephalization quotients, partial correlation analyses, and bivariate regressions relating brain size to maternal investment times and BMR, we provide a direct quantitative comparison of brain size evolution in marsupials and placentals, whose reproduction and metabolism differ extensively. Our results show that the misconception that marsupials are systematically smaller-brained than placentals is driven by the inclusion of one large-brained placental clade, Primates. Marsupial and placental brain size partial correlations differ in that marsupials lack a partial correlation of BMR with brain size. This contradicts hypotheses stating that the maintenance of relatively larger brains requires higher BMRs. We suggest that a positive BMR-brain size correlation is a placental trait related to the intimate physiological contact between mother and offspring during gestation. Marsupials instead achieve brain sizes comparable to placentals through extended lactation. Comparison with avian brain evolution suggests that placental brain size should be constrained due to placentals' relative precociality, as has been hypothesized for precocial bird hatchlings. We propose that placentals circumvent this constraint because of their focus on gestation, as opposed to the marsupial emphasis on lactation. Marsupials represent a less constrained condition, demonstrating that hypotheses regarding placental brain size evolution cannot be generalized to all mammals.

  17. Rodent phylogeny revised: analysis of six nuclear genes from all major rodent clades

    Directory of Open Access Journals (Sweden)

    Pupko Tal

    2009-04-01

    Full Text Available Abstract Background Rodentia is the most diverse order of placental mammals, with extant rodent species representing about half of all placental diversity. In spite of many morphological and molecular studies, the family-level relationships among rodents and the location of the rodent root are still debated. Although various datasets have already been analyzed to solve rodent phylogeny at the family level, these are difficult to combine because they involve different taxa and genes. Results We present here the largest protein-coding dataset used to study rodent relationships. It comprises six nuclear genes, 41 rodent species, and eight outgroups. Our phylogenetic reconstructions strongly support the division of Rodentia into three clades: (1 a "squirrel-related clade", (2 a "mouse-related clade", and (3 Ctenohystrica. Almost all evolutionary relationships within these clades are also highly supported. The primary remaining uncertainty is the position of the root. The application of various models and techniques aimed to remove non-phylogenetic signal was unable to solve the basal rodent trifurcation. Conclusion Sequencing and analyzing a large sequence dataset enabled us to resolve most of the evolutionary relationships among Rodentia. Our findings suggest that the uncertainty regarding the position of the rodent root reflects the rapid rodent radiation that occurred in the Paleocene rather than the presence of conflicting phylogenetic and non-phylogenetic signals in the dataset.

  18. Molecular phylogeny, biogeography, and habitat preference evolution of marsupials.

    Science.gov (United States)

    Mitchell, Kieren J; Pratt, Renae C; Watson, Laura N; Gibb, Gillian C; Llamas, Bastien; Kasper, Marta; Edson, Janette; Hopwood, Blair; Male, Dean; Armstrong, Kyle N; Meyer, Matthias; Hofreiter, Michael; Austin, Jeremy; Donnellan, Stephen C; Lee, Michael S Y; Phillips, Matthew J; Cooper, Alan

    2014-09-01

    Marsupials exhibit great diversity in ecology and morphology. However, compared with their sister group, the placental mammals, our understanding of many aspects of marsupial evolution remains limited. We use 101 mitochondrial genomes and data from 26 nuclear loci to reconstruct a dated phylogeny including 97% of extant genera and 58% of modern marsupial species. This tree allows us to analyze the evolution of habitat preference and geographic distributions of marsupial species through time. We found a pattern of mesic-adapted lineages evolving to use more arid and open habitats, which is broadly consistent with regional climate and environmental change. However, contrary to the general trend, several lineages subsequently appear to have reverted from drier to more mesic habitats. Biogeographic reconstructions suggest that current views on the connectivity between Australia and New Guinea/Wallacea during the Miocene and Pliocene need to be revised. The antiquity of several endemic New Guinean clades strongly suggests a substantially older period of connection stretching back to the Middle Miocene and implies that New Guinea was colonized by multiple clades almost immediately after its principal formation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Placental transfusion: a review

    Science.gov (United States)

    Katheria, A C; Lakshminrusimha, S; Rabe, H; McAdams, R; Mercer, J S

    2017-01-01

    Recently there have been a number of studies and presentations on the importance of providing a placental transfusion to the newborn. Early cord clamping is an avoidable, unphysiologic intervention that prevents the natural process of placental transfusion. However, placental transfusion, although simple in concept, is affected by multiple factors, is not always straightforward to implement, and can be performed using different methods, making this basic procedure important to discuss. Here, we review three placental transfusion techniques: delayed cord clamping, intact umbilical cord milking and cut-umbilical cord milking, and the evidence in term and preterm newborns supporting this practice. We will also review several factors that influence placental transfusion, and discuss perceived risks versus benefits of this procedure. Finally, we will provide key straightforward concepts and implementation strategies to ensure that placental-to-newborn transfusion can become routine practice at any institution. PMID:27654493

  20. Rapid action in the Palaeogene, the relationship between phenotypic and taxonomic diversification in Coenozoic mammals.

    Science.gov (United States)

    Raia, P; Carotenuto, F; Passaro, F; Piras, P; Fulgione, D; Werdelin, L; Saarinen, J; Fortelius, M

    2013-01-01

    A classic question in evolutionary biology concerns the tempo and mode of lineage evolution. Considered variously in relation to resource utilization, intrinsic constraints or hierarchic level, the question of how evolutionary change occurs in general has continued to draw the attention of the field for over a century and a half. Here we use the largest species-level phylogeny of Coenozoic fossil mammals (1031 species) ever assembled and their body size estimates, to show that body size and taxonomic diversification rates declined from the origin of placentals towards the present, and very probably correlate to each other. These findings suggest that morphological and taxic diversifications of mammals occurred hierarchically, with major shifts in body size coinciding with the birth of large clades, followed by taxonomic diversification within these newly formed clades. As the clades expanded, rates of taxonomic diversification proceeded independently of phenotypic evolution. Such a dynamic is consistent with the idea, central to the Modern Synthesis, that mammals radiated adaptively, with the filling of adaptive zones following the radiation.

  1. Mammals(1)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ What is a mammal? Mammals are warm-blooded animals that have a backbone.Mammals are the only animals that feed their babies with mother's milk.All mammals are warm-blllded.That means they keep the same body temperature all the time.

  2. The evolution of epitheliochorial placentation.

    Science.gov (United States)

    Carter, Anthony M; Enders, Allen C

    2013-01-01

    Epitheliochorial placentation is a derived condition and has evolved separately in strepsirrhine primates and laurasiatherians (pangolins, whales, and hoofed mammals). Usually it is associated with a long gestation period, small litters, and precocial young. Oxygen transfer is facilitated by indenting of the uterine and trophoblast epithelia by maternal and fetal capillaries, respectively. Histotrophic nutrition is important, and adaptations include areolas and hemophagous regions. In pigs and horses, for example, iron is transported as uteroferrin secreted from the uterine glands and taken up by areolas. In the horse, invasive trophoblast cells form cups within the endometrium that are the source of equine chorionic gonadotropin. In ruminants, binucleate trophoblast cells fuse with uterine epithelial cells to form trinucleate cells or plaques that secrete pregnancy hormones. There is evidence of immunosuppression in connection with these more invasive types of trophoblasts. The epitheliochorial condition may be advantageous for long pregnancies in large animals.

  3. Placental gene therapy

    OpenAIRE

    David, A. L.; Ashcroft, R

    2009-01-01

    Gene therapy uses genetic material as a drug delivery vehicle to express therapeutic proteins. Placental gene therapy may be useful for correction of two important obstetric conditions, foetal growth restriction and pre-eclampsia in which there is a failure of the physiological trophoblast remodelling of the uterine spiral arteries in early pregnancy. The patient in this scenario is the foetus. Placental gene therapy might be justifiable when: there is reasonable certainty that the foetus wil...

  4. Placental Protein 13 (PP13 – a placental immunoregulatory galectin protecting pregnancy

    Directory of Open Access Journals (Sweden)

    Nandor Gabor Than

    2014-08-01

    Full Text Available Galectins are glycan-binding proteins that regulate innate and adaptive immune responses, and some confer maternal-fetal immune tolerance in eutherian mammals. A chromosome 19 cluster of galectins has emerged in anthropoid primates, species with deep placentation and long gestation. Three of the five human cluster galectins are solely expressed in the placenta, where they may confer additional immunoregulatory functions to enable deep placentation. One of these is galectin-13, also known as Placental Protein 13 (PP13. It has a jelly-roll fold, carbohydrate-recognition domain and sugar-binding preference resembling to other mammalian galectins. PP13 is predominantly expressed by the syncytiotrophoblast and released from the placenta into the maternal circulation. Its ability to induce apoptosis of activated T cells in vitro, and to divert and kill T cells as well as macrophages in the maternal decidua in situ suggests important immune functions. Indeed, mutations in the promoter and an exon of LGALS13 presumably leading to altered or non-functional protein expression are associated with a higher frequency of preeclampsia and other obstetrical syndromes, which involve immune dysregulation. Moreover, decreased placental expression of PP13 and its low first trimester maternal serum concentrations are associated with elevated risk of preeclampsia. Indeed, PP13 turned to be a good early biomarker to assess maternal risk for the subsequent development of pregnancy complications caused by impaired placentation. Due to the ischemic placental stress in preterm preeclampsia, there is an increased trophoblastic shedding of PP13 immunopositive microvesicles starting in the second trimester, which leads to high maternal blood PP13 concentrations. Our meta-analysis suggests that this phenomenon may enable the potential use of PP13 in directing patient management near to or at the time of delivery. Recent findings on the beneficial effects of PP13 on decreasing

  5. Developmental genes during placentation: insights from mouse mutants

    Institute of Scientific and Technical Information of China (English)

    Jinhu a LU; Qiang WANG; Bingyan WANG; Fengchao WANG; Haibin WANG

    2011-01-01

    Placenta,a temporary organ first formed during the development of a new life is essential for the survival and growth of the fetus in eutherian mammals.It serves as an interface for the exchange of nutrients,gases and wastes between the maternal and fetal compartments.During the past decades,studies employing gene-engineered mouse mutants have revealed a wide range of signaling molecules governing the trophoblast development and function during placentation under various pathophysiological conditions.Here,we summarize the recent progress with particular respect to the involvement of developmental genes during placentation.

  6. The relaxin family peptide receptors and their ligands: new developments and paradigms in the evolution from jawless fish to mammals.

    Science.gov (United States)

    Yegorov, Sergey; Bogerd, Jan; Good, Sara V

    2014-12-01

    Relaxin family peptide receptors (Rxfps) and their ligands, relaxin (Rln) and insulin-like (Insl) peptides, are broadly implicated in the regulation of reproductive and neuroendocrine processes in mammals. Most placental mammals harbour genes for four receptors, namely rxfp1, rxfp2, rxfp3 and rxfp4. The number and identity of rxfps in other vertebrates are immensely variable, which is probably attributable to intraspecific variation in reproductive and neuroendocrine regulation. Here, we highlight several interesting, but greatly overlooked, aspects of the rln/insl-rxfp evolutionary history: the ancient origin, recruitment of novel receptors, diverse roles of selection, differential retention and lineage-specific loss of genes over evolutionary time. The tremendous diversity of rln/insl and rxfp genes appears to have arisen from two divergent receptors and one ligand that were duplicated by whole genome duplications (WGD) in early vertebrate evolution, although several genes, notably relaxin in mammals, were also duplicated via small scale duplications. Duplication and loss of genes have varied across lineages: teleosts retained more WGD-derived genes, dominated by those thought to be involved in neuroendocrine regulation (rln3, insl5 and rxfp 3/4 genes), while eutherian mammals witnessed the diversification and rapid evolution of genes involved in reproduction (rln/insl3). Several genes that arose early in evolutionary history were lost in most mammals, but retained in teleosts and, to a lesser extent, in early diverging tetrapods. To elaborate on their evolutionary history, we provide updated phylogenies of the Rxfp1/2 and Rxfp3/4 receptors and their ligands, including new sequences from early diverging vertebrate taxa such as coelacanth, skate, spotted gar, and lamprey. We also summarize the recent progress made towards understanding the functional biology of Rxfps in non-mammalian taxa, providing a new conceptual framework for research on Rxfp signaling across

  7. Risk factors of placental abruption

    OpenAIRE

    2013-01-01

    Background: Placental abruption is one of the most common causes of bleeding during pregnancy. Multiple factors are known to be associated with increase of risk of placental abruption such as alcohol, cocaine use and cigarette smoking. The objective of this study was to identify risk factors for placental abruption in an Iranian women population. Materials and Methods: In a retrospective case - control study birth records included 78 cases with placental abruption and 780 randomly selected co...

  8. [Evolution of parasitism in mammal-associated mites of the group Psoroptidia (Acari:Astigmata)].

    Science.gov (United States)

    Bochkov, A V

    2011-01-01

    Host-parasite relationships of mammals and astigmatan mites (Acariformes: Astigmata) belonging to the parvorder Psoroptidia are analyzed. The absolute majority of mammal-associated psoroptidians belongs to the paraphyletic superfamily Sarcoptoidea. Mites of the family complex Psoroptidae (Lobalgidae, Psoroptidae, and Paracoroptinae) shifted from birds to placental mammals independently from each other. Mites of the family complex Sarcoptidae, including all other sarcoptoid families, derived from the common stalk of Psoroptidia independently from the Psoroptid complex. Mites of the sarcoptid complex shifted from nidicoly in mammalian nests to the permanent parasitism on these hosts. They are widely represented on both marsupial and placental mammals and are absent on Monotremata.

  9. Convergence of Afrotherian and Laurasiatherian Ungulate-Like Mammals: First Morphological Evidence from the Paleocene of Morocco.

    Directory of Open Access Journals (Sweden)

    Emmanuel Gheerbrant

    Full Text Available Molecular-based analyses showed that extant "ungulate" mammals are polyphyletic and belong to the two main clades Afrotheria (Paenungulata and Laurasiatheria (Euungulata: Cetartiodactyla-Perissodactyla. However, paleontological and neontological studies hitherto failed to demonstrate the morphological convergence of African and Laurasian "ungulate" orders. They support an "Altungulata" group including the Laurasian order Perissodactyla and the African superorder Paenungulata and characterized especially by quadritubercular and bilophodont molars adapted for a folivorous diet. We report new critical fossils of one of the few known African condylarth-like mammal, the enigmatic Abdounodus from the middle Paleocene of Morocco. They show that Abdounodus and Ocepeia display key intermediate morphologies refuting the homology of the fourth main cusp of upper molars in Paenungulata and Perissodactyla: Paenungulates unexpectedly have a metaconule-derived pseudohypocone, instead of a cingular hypocone. Comparative and functional dental anatomy of Abdounodus demonstrates indeed the convergence of the quadritubercular and bilophodont pattern in "ungulates". Consistently with our reconstruction of the structural evolution of paenungulate bilophodonty, the phylogenetic analysis relates Abdounodus and Ocepeia to Paenungulata as stem taxa of the more inclusive new clade Paenungulatomorpha which is distinct from the Perissodactyla and Anthracobunidae. Abdounodus and Ocepeia help to identify the first convincing synapomorphy within the Afrotheria-i.e., the pseudohypocone-that demonstrates the morphological convergence of African and Laurasian ungulate-like placentals, in agreement with molecular phylogeny. Abdounodus and Ocepeia are the only known representatives of the early African ungulate radiation predating the divergence of extant paenungulate orders. Paenungulatomorpha evolved in Africa since the early Tertiary independently from laurasiatherian

  10. Convergence of Afrotherian and Laurasiatherian Ungulate-Like Mammals: First Morphological Evidence from the Paleocene of Morocco

    Science.gov (United States)

    Gheerbrant, Emmanuel; Filippo, Andrea; Schmitt, Arnaud

    2016-01-01

    Molecular-based analyses showed that extant “ungulate” mammals are polyphyletic and belong to the two main clades Afrotheria (Paenungulata) and Laurasiatheria (Euungulata: Cetartiodactyla-Perissodactyla). However, paleontological and neontological studies hitherto failed to demonstrate the morphological convergence of African and Laurasian “ungulate” orders. They support an “Altungulata” group including the Laurasian order Perissodactyla and the African superorder Paenungulata and characterized especially by quadritubercular and bilophodont molars adapted for a folivorous diet. We report new critical fossils of one of the few known African condylarth-like mammal, the enigmatic Abdounodus from the middle Paleocene of Morocco. They show that Abdounodus and Ocepeia display key intermediate morphologies refuting the homology of the fourth main cusp of upper molars in Paenungulata and Perissodactyla: Paenungulates unexpectedly have a metaconule-derived pseudohypocone, instead of a cingular hypocone. Comparative and functional dental anatomy of Abdounodus demonstrates indeed the convergence of the quadritubercular and bilophodont pattern in “ungulates”. Consistently with our reconstruction of the structural evolution of paenungulate bilophodonty, the phylogenetic analysis relates Abdounodus and Ocepeia to Paenungulata as stem taxa of the more inclusive new clade Paenungulatomorpha which is distinct from the Perissodactyla and Anthracobunidae. Abdounodus and Ocepeia help to identify the first convincing synapomorphy within the Afrotheria–i.e., the pseudohypocone–that demonstrates the morphological convergence of African and Laurasian ungulate-like placentals, in agreement with molecular phylogeny. Abdounodus and Ocepeia are the only known representatives of the early African ungulate radiation predating the divergence of extant paenungulate orders. Paenungulatomorpha evolved in Africa since the early Tertiary independently from laurasiatherian

  11. Placental apoptosis in recurrent miscarriage

    Directory of Open Access Journals (Sweden)

    Tarek A. Atia

    2017-09-01

    Full Text Available Apoptosis is an interactive and dynamic biological process involved in all phases of embryogenesis. We aimed to study the effect of placental apoptosis on recurrent miscarriage (RM. Placental tissue samples were collected from 40 women with RM (study group and 30 women with sporadic spontaneous abortion (control group. Samples were prepared and stained immunohistochemically with markers for both the apoptotic protein (p53 and anti-apoptotic Bcl-2 antibodies. Our results showed that expression of the apoptotic (p53 protein was significantly increased in the placental tissues of the RM group (p = 0.003. By contrast, the expression of anti-apoptotic (Bcl-2 antibodies was significantly increased in the placental tissues of the control group (p = 0.025. We concluded that placental apoptosis plays a crucial role in pregnancy continuation. However, increased p53 expression in placental tissue in early pregnancy could negatively affect pregnancy continuation.

  12. The nocturnal bottleneck and the evolution of activity patterns in mammals

    NARCIS (Netherlands)

    Gerkema, Menno P.; Davies, Wayne I. L.; Foster, Russell G.; Menaker, Michael; Hut, Roelof A.

    2013-01-01

    In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals

  13. The nocturnal bottleneck and the evolution of activity patterns in mammals

    NARCIS (Netherlands)

    Gerkema, Menno P.; Davies, Wayne I. L.; Foster, Russell G.; Menaker, Michael; Hut, Roelof A.

    2013-01-01

    In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals

  14. Mammal Reproductive Strategies Driven by Offspring Mortality-Size Relationships

    DEFF Research Database (Denmark)

    Sibly, Richard M.; Brown, James H.

    2009-01-01

    and lifestyle. Results suggest that preweaning vulnerability to predation has been the major factor determining how female placental mammals allocate production between a few large and many small offspring within a litter and between a few large litters and many small ones within a reproductive season...

  15. Evolution of organogenesis and the origin of altriciality in mammals.

    Science.gov (United States)

    Werneburg, Ingmar; Laurin, Michel; Koyabu, Daisuke; Sánchez-Villagra, Marcelo R

    2016-07-01

    Mammals feature not only great phenotypic disparity, but also diverse growth and life history patterns, especially in maturity level at birth, ranging from altriciality to precocity. Gestation length, morphology at birth, and other markers of life history are fundamental to our understanding of mammalian evolution. Based on the first synthesis of embryological data and the study of new ontogenetic series, we reconstructed estimates of the ancestral chronology of organogenesis and life-history modes in placental mammals. We found that the ancestor of marsupial and placental mammals was placental-like at birth but had a long, marsupial-like infancy. We hypothesize that mammalian viviparity might have evolved in association with the extension of growth after birth, enabled through lactation, and that mammalian altriciality is inherited from the earliest amniotes. The precocial lifestyle of extant sauropsids and that of many placental mammals were acquired secondarily. We base our conclusions on the best estimates and provide a comprehensive discussion on the methods used and the limitations of our dataset. We provide the most comprehensive embryological dataset ever published, "rescue" old literature sources, and apply available methods and illustrate thus an approach on how to investigate comparatively organogenesis in macroevolution. © 2016 Wiley Periodicals, Inc.

  16. Placental Aromatase Is Deficient in Placental Ischemia and Preeclampsia.

    Directory of Open Access Journals (Sweden)

    Alejandra Perez-Sepulveda

    Full Text Available Preeclampsia is a maternal hypertensive disorder with uncertain etiology and a leading cause of maternal and fetal mortality worldwide, causing nearly 40% of premature births delivered before 35 weeks of gestation. The first stage of preeclampsia is characterized by reduction of utero-placental blood flow which is reflected in high blood pressure and proteinuria during the second half of pregnancy. In human placenta androgens derived from the maternal and fetal adrenal glands are converted into estrogens by the enzymatic action of placental aromatase. This implies that alterations in placental steroidogenesis and, subsequently, in the functionality or bioavailability of placental aromatase may be mechanistically involved in the pathophysiology of PE.Serum samples were collected at 32-36 weeks of gestation and placenta biopsies were collected at time of delivery from PE patients (n = 16 and pregnant controls (n = 32. The effect of oxygen tension on placental cells was assessed by incubation JEG-3 cells under 1% and 8% O2 for different time periods, Timed-mated, pregnant New Zealand white rabbits (n = 6 were used to establish an in vivo model of placental ischemia (achieved by ligature of uteroplacental vessels. Aromatase content and estrogens and androgens concentrations were measured.The protein and mRNA content of placental aromatase significantly diminished in placentae obtained from preeclamptic patients compared to controls. Similarly, the circulating concentrations of 17-β-estradiol/testosterone and estrone/androstenedione were reduced in preeclamptic patients vs. controls. These data are consistent with a concomitant decrease in aromatase activity. Aromatase content was reduced in response to low oxygen tension in the choriocarcinoma JEG-3 cell line and in rabbit placentae in response to partial ligation of uterine spiral arteries, suggesting that reduced placental aromatase activity in preeclamptic patients may be associated with chronic

  17. Audubon Mammal Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Mammals," a leaders' guide, a large wall chart picturing 39 North American mammals, and a separate booklet describing the mammals on the wall chart. The student reader presents these main topics: What Is a Mammal?; How Mammals Differ From Each Other; Where, When, and How To Find Mammals;…

  18. Audubon Mammal Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Mammals," a leaders' guide, a large wall chart picturing 39 North American mammals, and a separate booklet describing the mammals on the wall chart. The student reader presents these main topics: What Is a Mammal?; How Mammals Differ From Each Other; Where, When, and How To Find Mammals;…

  19. Evolution of invasive placentation with special reference to non-human primates

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Pijnenborg, Robert

    2011-01-01

    It is now possible to view human placentation in an evolutionary context because advances in molecular phylogenetics provide a reliable scenario for the evolution of mammals. Perhaps the most striking finding is the uniqueness of human placenta. The lower primates have non-invasive placentae...

  20. Risk factors of placental abruption

    Directory of Open Access Journals (Sweden)

    Hooria Seyedhosseini Ghaheh

    2013-01-01

    Full Text Available Background: Placental abruption is one of the most common causes of bleeding during pregnancy. Multiple factors are known to be associated with increase of risk of placental abruption such as alcohol, cocaine use and cigarette smoking. The objective of this study was to identify risk factors for placental abruption in an Iranian women population. Materials and Methods: In a retrospective case - control study birth records included 78 cases with placental abruption and 780 randomly selected controls were investigated. Statistical analysis for comparing the studied risk factors between groups was performed using Pearson ′ s Chi-square test along with presenting relevant odds ratio (OR. Results: From 7301 deliveries included in the study, 78 (1% was complicated placental abruption. Women aged 35 or more likely for experiencing (OR = 3.650, 95% confidence interval [CL] = 1.57-6.83 and those who had a previous cesarean section (OR = 2.65, 95% CL = 3.91- 33.41 were in higher risk for placental abruption ([50 cases] 64% vs. [28 cases] 36% P < 0.01. Conclusion: The results indicate that among the placental abruption is one of the most common causes of bleeding during the pregnancy and one of the major obstetrical emergency.

  1. Risk factors of placental abruption

    Science.gov (United States)

    Ghaheh, Hooria Seyedhosseini; Feizi, Awat; Mousavi, Maryam; Sohrabi, Davood; Mesghari, Leila; Hosseini, Zahra

    2013-01-01

    Background: Placental abruption is one of the most common causes of bleeding during pregnancy. Multiple factors are known to be associated with increase of risk of placental abruption such as alcohol, cocaine use and cigarette smoking. The objective of this study was to identify risk factors for placental abruption in an Iranian women population. Materials and Methods: In a retrospective case – control study birth records included 78 cases with placental abruption and 780 randomly selected controls were investigated. Statistical analysis for comparing the studied risk factors between groups was performed using Pearson's Chi-square test along with presenting relevant odds ratio (OR). Results: From 7301 deliveries included in the study, 78 (1%) was complicated placental abruption. Women aged 35 or more likely for experiencing (OR = 3.650, 95% confidence interval [CL] = 1.57-6.83) and those who had a previous cesarean section (OR = 2.65, 95% CL = 3.91- 33.41) were in higher risk for placental abruption ([50 cases] 64% vs. [28 cases] 36% P < 0.01). Conclusion: The results indicate that among the placental abruption is one of the most common causes of bleeding during the pregnancy and one of the major obstetrical emergency. PMID:24174950

  2. Plate tectonics, seaways and climate in the historical biogeography of mammals

    Directory of Open Access Journals (Sweden)

    C Barry Cox

    2000-08-01

    Full Text Available The marsupial and placental mammals originated at a time when the pattern of geographical barriers (oceans, shallow seas and mountains was very different from that of today, and climates were warmer. The sequence of changes in these barriers, and their effects on the dispersal of the mammal families and on the faunas of mammals in the different continents, are reviewed. The mammal fauna of South America changed greatly in the Pliocene/Pleistocene, when the newly-complete Panama Isthmus allowed the North American fauna to enter the continent and replace most of the former South American mammal families. Marsupial, but not placental, mammals reached Australia via Antarctica before Australia became isolated, while rats and bats are the only placentals that dispersed naturally from Asia to Australia in the late Cenozoic. Little is known of the early history of the mammal fauna of India. A few mammal families reached Madagascar from Africa in the early Cenozoic over a chain of islands. Africa was isolated for much of the early Cenozoic, though some groups did succeed in entering from Europe. Before the climate cooled in the mid-Cenozoic, the mammal faunas of the Northern Hemisphere were much richer than those of today.

  3. Plate tectonics, seaways and climate in the historical biogeography of mammals.

    Science.gov (United States)

    Cox, C B

    2000-01-01

    The marsupial and placental mammals originated at a time when the pattern of geographical barriers (oceans, shallow seas and mountains) was very different from that of today, and climates were warmer. The sequence of changes in these barriers, and their effects on the dispersal of the mammal families and on the faunas of mammals in the different continents, are reviewed. The mammal fauna of South America changed greatly in the Pliocene/Pleistocene, when the newly-complete Panama Isthmus allowed the North American fauna to enter the continent and replace most of the former South American mammal families. Marsupial, but not placental, mammals reached Australia via Antarctica before Australia became isolated, while rats and bats are the only placentals that dispersed naturally from Asia to Australia in the late Cenozoic. Little is known of the early history of the mammal fauna of India. A few mammal families reached Madagascar from Africa in the early Cenozoic over a chain of islands. Africa was isolated for much of the early Cenozoic, though some groups did succeed in entering from Europe. Before the climate cooled in the mid-Cenozoic, the mammal faunas of the Northern Hemisphere were much richer than those of today.

  4. Placental perfusion - a human alternative

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E

    2006-01-01

    Foetal exposures to environmental and medicinal products have impact on the growth of the foetus (e.g. cigarette smoke) and development of organs (e.g. methylmercury and Thalidomide). Perfusion studies of the human term placenta enable investigation of placental transport of chemical substances...... between the mother and foetus. Dual perfusion of a single cotyledon in the human placenta can contribute to a better understanding of the placental barrier, transport rate and mechanisms of different substances and placental metabolism. The perfusion system has recently been established in Copenhagen...

  5. Extant mammal body masses suggest punctuated equilibrium

    Science.gov (United States)

    Mattila, Tiina M; Bokma, Folmer

    2008-01-01

    Is gradual microevolutionary change within species simultaneously the source of macroevolutionary differentiation between species? Since its first publication, Darwin's original idea that phenotypic differences between species develop gradually over time, as the accumulation of small selection-induced changes in successive generations has been challenged by palaeontologists claiming that, instead, new species quickly acquire their phenotypes to remain virtually unchanged until going extinct again. This controversy, widely known as the ‘punctuated equilibrium’ debate, remained unresolved, largely owing to the difficulty of distinguishing biological species from fossil remains. We analysed body masses of 2143 existing mammal species on a phylogeny comprising 4510 (i.e. nearly all) extant species to estimate rates of gradual (anagenetic) and speciational (cladogenetic) evolution. Our Bayesian estimates from mammals as well as separate sub-clades such as primates and carnivores suggest that gradual evolution is responsible for only a small part of body size variation between mammal species. PMID:18595835

  6. Placental Transmogrification of the lung

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Woo; Park, Il Hwan; Kwon, Woo Cheol; Eom, Min Seob; Kim, Young Ju; Hwan, Joong Hwan [Yonsei University Wonju College of Medicine, Wonju (Korea, Republic of)

    2013-12-15

    Placental transmogrification is a very rare lung disease, where the alveoli resemble the chorionic villi of placenta, and this change is a characteristic finding. A 31-year-old female patient presented with cough and dyspnea that had begun 2 weeks prior to admission. Along with giant bulla found in the left upper lung field, subsegmental consolidation was also identified in the lingular segment on plain chest radiograph and CT scan. Wedge resection was performed to remove the bulla. Pathologic examination of the resected bulla revealed destruction of the normal structures and characteristic villous and papillary changes. These changes led to a diagnosis of placental transmogrification. We made an encounter of an unusual placental transmogrification which had different image findings from other reported transmogrification cases. Thus, we report an atypical placental transmogrification case where both consolidation and giant bulla coexist.

  7. Placental abruption: a persisting killer

    Directory of Open Access Journals (Sweden)

    Shakuntala Amirchand Chhabra

    2014-06-01

    Full Text Available Background: Placental abruption, common disorder in obstetric practice, enigma too, is uniquely fraught with dangers to mother baby. Objectives of study were to study trends of placental abruption, risk factors, management strategies to learn more for reduction in morbidity-mortality of mother-baby, even with low resources, also get insight for future research. Methods: Records of cases of placental abruption managed over 27 years (between 1985 to 2011 were divided into three yearly blocks, A to I and analysed. Details including operative procedures like dilatation-curettage, Caesarean Section (CS or Ante-Partum Haemorrhage (APH in past, disorders like chronic hypertension, threatened abortion, pregnancy specific hypertension, diabetes, anaemia in index pregnancy, management done maternal-neonatal outcome were analysed using stata 6 software. Results: There were 66,459 births during analysis period with 667 cases of placental abruption, 1% births, increasing trends from, 0.73% between 1985-1987 to, 1.11% in 2009-2011. In these 667 cases of placental abruption, 211 (32.5% perinatal deaths occurred. Ratio of perinatal deaths due to placental abruption to overall perinatal deaths increased from 2.12% (8 cases between 1985-1987 (Block A to 5.12% (37 cases between 2009-2011 (Block I. Case fatality in cases of placental abruption has been fluctuating between 3 to 5% till 2004, contributing to around 12-15%, maternal mortality, with no fatality in last 7 years. Conclusions: Cases of placental abruption have been increasing with no obvious reason. In recent past maternal deaths could be prevented but perinatal deaths, have been persisting actually more in last decade. [Int J Reprod Contracept Obstet Gynecol 2014; 3(3.000: 604-609

  8. Evolution of UCP1 Transcriptional Regulatory Elements Across the Mammalian Phylogeny

    Directory of Open Access Journals (Sweden)

    Michael J. Gaudry

    2017-09-01

    Full Text Available Uncoupling protein 1 (UCP1 permits non-shivering thermogenesis (NST when highly expressed in brown adipose tissue (BAT mitochondria. Exclusive to placental mammals, BAT has commonly been regarded to be advantageous for thermoregulation in hibernators, small-bodied species, and the neonates of larger species. While numerous regulatory control motifs associated with UCP1 transcription have been proposed for murid rodents, it remains unclear whether these are conserved across the eutherian mammal phylogeny and hence essential for UCP1 expression. To address this shortcoming, we conducted a broad comparative survey of putative UCP1 transcriptional regulatory elements in 139 mammals (135 eutherians. We find no evidence for presence of a UCP1 enhancer in monotremes and marsupials, supporting the hypothesis that this control region evolved in a stem eutherian ancestor. We additionally reveal that several putative promoter elements (e.g., CRE-4, CCAAT identified in murid rodents are not conserved among BAT-expressing eutherians, and together with the putative regulatory region (PRR and CpG island do not appear to be crucial for UCP1 expression. The specificity and importance of the upTRE, dnTRE, URE1, CRE-2, RARE-2, NBRE, BRE-1, and BRE-2 enhancer elements first described from rats and mice are moreover uncertain as these motifs differ substantially—but generally remain highly conserved—in other BAT-expressing eutherians. Other UCP1 enhancer motifs (CRE-3, PPRE, and RARE-3 as well as the TATA box are also highly conserved in nearly all eutherian lineages with an intact UCP1. While these transcriptional regulatory motifs are generally also maintained in species where this gene is pseudogenized, the loss or degeneration of key basal promoter (e.g., TATA box and enhancer elements in other UCP1-lacking lineages make it unlikely that the enhancer region is pleiotropic (i.e., co-regulates additional genes. Importantly, differential losses of (or mutations

  9. A New Symmetrodont Mammal with Fur Impressions from the Mesozoic of China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Western Liaoning of northeastern China is world-renowned for the Mesozoic Jehol biota, especially for yielding many feathered dinosaurs, primitive birds, mammals and fossil angiosperm. This paper describes a complete specimen of a symmetrodont mammal with well-preserved hairs and soft tissue from the basal part of the Yixian Formation in the Sihetun area, Beipiao, western Liaoning. It is significant for understanding the morphology, osteology, phylogeny and life habits of Mesozoic symmetrodont mammals.

  10. Placental Growth Factor Administration Abolishes Placental Ischemia-Induced Hypertension.

    Science.gov (United States)

    Spradley, Frank T; Tan, Adelene Y; Joo, Woo S; Daniels, Garrett; Kussie, Paul; Karumanchi, S Ananth; Granger, Joey P

    2016-04-01

    Preeclampsia is a pregnancy-specific disorder of new-onset hypertension. Unfortunately, the most effective treatment is early delivery of the fetus and placenta. Placental ischemia appears central to the pathogenesis of preeclampsia because placental ischemia/hypoxia induced in animals by reduced uterine perfusion pressure (RUPP) or in humans stimulates release of hypertensive placental factors into the maternal circulation. The anti-angiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1), which antagonizes and reduces bioavailable vascular endothelial growth factor and placental growth factor (PlGF), is elevated in RUPP rats and preeclampsia. Although PlGF and vascular endothelial growth factor are both natural ligands for sFlt-1, vascular endothelial growth factor also has high affinity to VEGFR2 (Flk-1) causing side effects like edema. PlGF is specific for sFlt-1. We tested the hypothesis that PlGF treatment reduces placental ischemia-induced hypertension by antagonizing sFlt-1 without adverse consequences to the mother or fetus. On gestational day 14, rats were randomized to 4 groups: normal pregnant or RUPP±infusion of recombinant human PlGF (180 μg/kg per day; AG31, a purified, recombinant human form of PlGF) for 5 days via intraperitoneal osmotic minipumps. On day 19, mean arterial blood pressure and plasma sFlt-1 were higher and glomerular filtration rate lower in RUPP than normal pregnant rats. Infusion of recombinant human PlGF abolished these changes seen with RUPP along with reducing oxidative stress. These data indicate that the increased sFlt-1 and reduced PlGF resulting from placental ischemia contribute to maternal hypertension. Our novel finding that recombinant human PlGF abolishes placental ischemia-induced hypertension, without major adverse consequences, suggests a strong therapeutic potential for this growth factor in preeclampsia.

  11. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  12. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  13. Three new Jurassic euharamiyidan species reinforce early divergence of mammals.

    Science.gov (United States)

    Bi, Shundong; Wang, Yuanqing; Guan, Jian; Sheng, Xia; Meng, Jin

    2014-10-30

    The phylogeny of Allotheria, including Multituberculata and Haramiyida, remains unsolved and has generated contentious views on the origin and earliest evolution of mammals. Here we report three new species of a new clade, Euharamiyida, based on six well-preserved fossils from the Jurassic period of China. These fossils reveal many craniodental and postcranial features of euharamiyidans and clarify several ambiguous structures that are currently the topic of debate. Our phylogenetic analyses recognize Euharamiyida as the sister group of Multituberculata, and place Allotheria within the Mammalia. The phylogeny suggests that allotherian mammals evolved from a Late Triassic (approximately 208 million years ago) Haramiyavia-like ancestor and diversified into euharamiyidans and multituberculates with a cosmopolitan distribution, implying homologous acquisition of many craniodental and postcranial features in the two groups. Our findings also favour a Late Triassic origin of mammals in Laurasia and two independent detachment events of the middle ear bones during mammalian evolution.

  14. Divergence time estimates of mammals from molecular clocks and fossils: Relevance of new fossil finds from India

    Indian Academy of Sciences (India)

    G V R Prasad

    2009-11-01

    This paper presents a brief review of recent advances in the classification of mammals at higher levels using fossils and molecular clocks. It also discusses latest fossil discoveries from the Cretaceous – Eocene (66–55 m.y.) rocks of India and their relevance to our current understanding of placental mammal origins and diversifications.

  15. The relaxin family peptide receptors and their ligands : new developments and paradigms in the evolution from jawless fish to mammals

    NARCIS (Netherlands)

    Yegorov, Sergey; Bogerd, Jan; Good, Sara V

    2014-01-01

    Relaxin family peptide receptors (Rxfps) and their ligands, relaxin (Rln) and insulin-like (Insl) peptides, are broadly implicated in the regulation of reproductive and neuroendocrine processes in mammals. Most placental mammals harbour genes for four receptors, namely rxfp1, rxfp2, rxfp3 and rxfp4.

  16. Whole-genome prokaryotic phylogeny

    National Research Council Canada - National Science Library

    Henz, Stefan R; Huson, Daniel H; Auch, Alexander F; Nieselt-Struwe, Kay; Schuster, Stephan C

    2005-01-01

    .... We introduce a new strategy, GBDP, 'genome blast distance phylogeny', and show that different variants of this approach robustly produce phylogenies that are biologically sound, when applied to 91 prokaryotic genomes...

  17. Low frequency of paleoviral infiltration across the avian phylogeny

    DEFF Research Database (Denmark)

    Cui, Jie; Zhao, Wei; Huang, Zhiyong

    2014-01-01

    of endogenous viral element evolution.Results: Through a systematic screening of the genomes of 48 species sampled across the avian phylogeny we reveal that birds harbor a limited number of endogenous viral elements compared to mammals, with only five viral families observed: Retroviridae, Hepadnaviridae...... and host genome size, such that the occurrence of endogenous viral elements in bird genomes is 6¿13 fold less frequent than in mammals.Conclusions: These results reveal that avian genomes harbor relatively small numbers of endogenous viruses, particularly those derived from RNA viruses, and hence...

  18. Imaging and assessment of placental function.

    LENUS (Irish Health Repository)

    Moran, Mary

    2011-09-01

    The placenta is the vital support organ for the developing fetus. This article reviews current ultrasound (US) methods of assessing placental function. The ability of ultrasound to detect placental pathology is discussed. Doppler technology to investigate the fetal, placental, and maternal circulations in both high-risk and uncomplicated pregnancies is discussed and the current literature on the value of three-dimensional power Doppler studies to assess placental volume and vascularization is also evaluated. The article highlights the need for further research into three-dimensional ultrasound and alternative methods of placental evaluation if progress is to be made in optimizing placental function assessment.

  19. What Makes a Mammal a Mammal?

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Describes the distinctive characteristics of mammals and compares modern mammals with their prehistoric relatives as well as with other animal groups. Includes activities and ready-to-copy games, illustrations, and diagrams of wolves, vertebrates, and past and present mammals. (ML)

  20. Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans

    Directory of Open Access Journals (Sweden)

    Vizcaíno Sergio F

    2004-04-01

    Full Text Available Abstract Background Comparative genomic data among organisms allow the reconstruction of their phylogenies and evolutionary time scales. Molecular timings have been recently used to suggest that environmental global change have shaped the evolutionary history of diverse terrestrial organisms. Living xenarthrans (armadillos, anteaters and sloths constitute an ideal model for studying the influence of past environmental changes on species diversification. Indeed, extant xenarthran species are relicts from an evolutionary radiation enhanced by their isolation in South America during the Tertiary era, a period for which major climate variations and tectonic events are relatively well documented. Results We applied a Bayesian approach to three nuclear genes in order to relax the molecular clock assumption while accounting for differences in evolutionary dynamics among genes and incorporating paleontological uncertainties. We obtained a molecular time scale for the evolution of extant xenarthrans and other placental mammals. Divergence time estimates provide substantial evidence for contemporaneous diversification events among independent xenarthran lineages. This correlated pattern of diversification might possibly relate to major environmental changes that occurred in South America during the Cenozoic. Conclusions The observed synchronicity between planetary and biological events suggests that global change played a crucial role in shaping the evolutionary history of extant xenarthrans. Our findings open ways to test this hypothesis further in other South American mammalian endemics like hystricognath rodents, platyrrhine primates, and didelphid marsupials.

  1. Placental lactogen levels in diabetic pregnancy.

    Science.gov (United States)

    Ursell, W; Brudenell, M; Chard, T

    1973-04-14

    A prospective study has been carried out of placental lactogen levels in pregnancy complicated by diabetes mellitus. The levels were higher than those in normal pregnant subjects; the higher levels were related to increased placental and fetal weight but more closely to the former; and lower levels were found when there was clinical evidence of placental dysfunction. Those patients requiring the largest insulin increment for the control of their diabetes in the pregnancy have placental lactogen levels in the higher range.

  2. Triazole fungicide tebuconazole disrupts human placental trophoblast cell functions.

    Science.gov (United States)

    Zhou, Jinghua; Zhang, Jianyun; Li, Feixue; Liu, Jing

    2016-05-05

    Triazole fungicides are one of the top ten classes of current-use pesticides. Although exposure to triazole fungicides is associated with reproductive toxicity in mammals, limited information is available regarding the effects of triazole fungicides on human placental trophoblast function. Tebuconazole (TEB) is a common triazole fungicide that has been extensively used for fungi control. In this work, we showed that TEB could reduce cell viability, disturb normal cell cycle distribution and induce apoptosis of human placental trophoblast cell line HTR-8/SVneo (HTR-8). Bcl-2 protein expression decreased and the level of Bax protein increased after TEB treatment in HTR-8 cells. The results demonstrated that this fungicide induced apoptosis of trophoblast cells via mitochondrial pathway. Importantly, we found that the invasive and migratory capacities of HTR-8 cells decreased significantly after TEB administration. TEB altered the expression of key regulatory genes involved in the modulation of trophoblast functions. Taken together, TEB suppressed human trophoblast invasion and migration through affecting the expression of protease, hormones, angiogenic factors, growth factors and cytokines. As the invasive and migratory abilities of trophoblast are essential for successful placentation and fetus development, our findings suggest a potential risk of triazole fungicides to human pregnancy.

  3. Intrapritoneal Hemorrhage after Placental Abruption

    Directory of Open Access Journals (Sweden)

    Nahid Sakhavar

    2012-06-01

    Full Text Available A placental abruption or abruptio placentae (where in the placental lining has separated from the uterus of the mother is one of the complications caused by trauma during pregnancy. It lets the blood flow to infiltrate in the uterine lining and to develop Couvelaire uterus (also known as uteroplacental apoplexy and uterine atony (a condition in which a woman's uterine muscles lose the ability to contract after childbirth; however, it rarely develops considerable hemoperitoneum which needs hysterectomy. In this report, a unique case of placental abruption caused by trauma in a 28-year-old Afghan woman is introduced in which severity and duration of trauma because of delay in reaching health equipped center led to developing massive hemoperitoneum (infiltration of great amount of blood into the abdominal cavity and its complications.

  4. Fossils and decapod phylogeny

    NARCIS (Netherlands)

    Schram, Frederick R.; Dixon, Christopher

    2003-01-01

    An expanded series of morphological characters developed for a cladistic analysis of extant decapods has yielded a new hypothesis for the phylogeny of the group. Application of this database to selected fossil genera produces some interesting results and demonstrates the feasibility of treating foss

  5. The phylogeny of Arthrotardigrada

    DEFF Research Database (Denmark)

    Hansen, Jesper Guldberg

    2011-01-01

    The order Arthrotardigrada, or water bears, constitutes a small group of 160 species of marine, microscopical invertebrates, within the phylum Tardigrada. Although the position of tardigrades in the Animal Kingdom has received much attention focusing on the metazoan phylogeny, the phylogenetic...

  6. Building a Twig Phylogeny

    Science.gov (United States)

    Flinn, Kathryn M.

    2015-01-01

    In this classroom activity, students build a phylogeny for woody plant species based on the morphology of their twigs. Using any available twigs, students can practice the process of cladistics to test evolutionary hypotheses for real organisms. They identify homologous characters, determine polarity through outgroup comparison, and construct a…

  7. Building a Twig Phylogeny

    Science.gov (United States)

    Flinn, Kathryn M.

    2015-01-01

    In this classroom activity, students build a phylogeny for woody plant species based on the morphology of their twigs. Using any available twigs, students can practice the process of cladistics to test evolutionary hypotheses for real organisms. They identify homologous characters, determine polarity through outgroup comparison, and construct a…

  8. Plasma placental lactogen in pregnancy.

    Science.gov (United States)

    Raghuramulu, N

    1978-01-01

    Plasma placental lactogen (HPL) and urinary oestrogen levels were investigated in pregnant women belonging to low and high socio-economic groups. Plasma HPL levels increased progressively with increasing gestation in women of both the socio-economic groups. The mean values in the two groups were not statistically different at any period of gestation. No correlation was observed between the birth weight of the infant and the maternal plasma placental lactogen levels at term. A positive correlation was observed between urinary oestrogen excretion and plasma HPL concentration.

  9. Lithuanian mammal fauna review

    Directory of Open Access Journals (Sweden)

    Linas Balciauskas

    1996-12-01

    Full Text Available Abstract Data on Lithuania mammal fauna are presented. From 78 mammal species recorded in Lithuania, 7 were seen only in the 17-18th centuries, two species are extinct. Recent Lithuanian mammal fauna contains 68 species. Five of them are observed occasionally. 63 mammal species are permant inhabitants, 18 included in the Red Data Book, mostly bats and dormice. 8 mammal species were introduced or reintroduced. Population tendencies of game animals are also considered.

  10. Mega-phylogeny approach for comparative biology: an alternative to supertree and supermatrix approaches

    Directory of Open Access Journals (Sweden)

    Beaulieu Jeremy M

    2009-02-01

    Full Text Available Abstract Background Biology has increasingly recognized the necessity to build and utilize larger phylogenies to address broad evolutionary questions. Large phylogenies have facilitated the discovery of differential rates of molecular evolution between trees and herbs. They have helped us understand the diversification patterns of mammals as well as the patterns of seed evolution. In addition to these broad evolutionary questions there is increasing awareness of the importance of large phylogenies for addressing conservation issues such as biodiversity hotspots and response to global change. Two major classes of methods have been employed to accomplish the large tree-building task: supertrees and supermatrices. Although these methods are continually being developed, they have yet to be made fully accessible to comparative biologists making extremely large trees rare. Results Here we describe and demonstrate a modified supermatrix method termed mega-phylogeny that uses databased sequences as well as taxonomic hierarchies to make extremely large trees with denser matrices than supermatrices. The two major challenges facing large-scale supermatrix phylogenetics are assembling large data matrices from databases and reconstructing trees from those datasets. The mega-phylogeny approach addresses the former as the latter is accomplished by employing recently developed methods that have greatly reduced the run time of large phylogeny construction. We present an algorithm that requires relatively little human intervention. The implemented algorithm is demonstrated with a dataset and phylogeny for Asterales (within Campanulidae containing 4954 species and 12,033 sites and an rbcL matrix for green plants (Viridiplantae with 13,533 species and 1,401 sites. Conclusion By examining much larger phylogenies, patterns emerge that were otherwise unseen. The phylogeny of Viridiplantae successfully reconstructs major relationships of vascular plants that previously

  11. Evolutionary perspectives into placental biology and disease

    Directory of Open Access Journals (Sweden)

    Edward B. Chuong

    2013-12-01

    Full Text Available In all mammals including humans, development takes place within the protective environment of the maternal womb. Throughout gestation, nutrients and waste products are continuously exchanged between mother and fetus through the placenta. Despite the clear importance of the placenta to successful pregnancy and the health of both mother and offspring, relatively little is understood about the biology of the placenta and its role in pregnancy-related diseases. Given that pre- and peri-natal diseases involving the placenta affect millions of women and their newborns worldwide, there is an urgent need to understand placenta biology and development. Here, we suggest that the placenta is an organ under unique selective pressures that have driven its rapid diversification throughout mammalian evolution. The high divergence of the placenta complicates the use of non-human animal models and necessitates an evolutionary perspective when studying its biology and role in disease. We suggest that diversifying evolution of the placenta is primarily driven by intraspecies evolutionary conflict between mother and fetus, and that many pregnancy diseases are a consequence of this evolutionary force. Understanding how maternal–fetal conflict shapes both basic placental and reproductive biology – in all species – will provide key insights into diseases of pregnancy.

  12. Triazole fungicide tebuconazole disrupts human placental trophoblast cell functions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jinghua [Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058 (China); Zhang, Jianyun [Research Center for Air Pollution and Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Li, Feixue [Zhejiang Key Laboratory of Organ Development and Regeneration, Institute of Developmental and Regenerative Biology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); Liu, Jing, E-mail: jliue@zju.edu.cn [Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058 (China); Research Center for Air Pollution and Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2016-05-05

    Highlights: • Tebuconazole (TEB) inhibited the proliferation of human placental trophoblasts. • TEB changed cell cycle distribution of G1 and G2 phases of trophoblasts. • TEB induced apoptosis of trophoblasts via mitochondrial pathway. • TEB decreased the invasive and migratory capacities of trophoblasts. • TEB altered the mRNA levels of key regulatory genes in trophoblasts - Abstract: Triazole fungicides are one of the top ten classes of current-use pesticides. Although exposure to triazole fungicides is associated with reproductive toxicity in mammals, limited information is available regarding the effects of triazole fungicides on human placental trophoblast function. Tebuconazole (TEB) is a common triazole fungicide that has been extensively used for fungi control. In this work, we showed that TEB could reduce cell viability, disturb normal cell cycle distribution and induce apoptosis of human placental trophoblast cell line HTR-8/SVneo (HTR-8). Bcl-2 protein expression decreased and the level of Bax protein increased after TEB treatment in HTR-8 cells. The results demonstrated that this fungicide induced apoptosis of trophoblast cells via mitochondrial pathway. Importantly, we found that the invasive and migratory capacities of HTR-8 cells decreased significantly after TEB administration. TEB altered the expression of key regulatory genes involved in the modulation of trophoblast functions. Taken together, TEB suppressed human trophoblast invasion and migration through affecting the expression of protease, hormones, angiogenic factors, growth factors and cytokines. As the invasive and migratory abilities of trophoblast are essential for successful placentation and fetus development, our findings suggest a potential risk of triazole fungicides to human pregnancy.

  13. Dental eruption in afrotherian mammals

    Directory of Open Access Journals (Sweden)

    Lehmann Thomas

    2008-03-01

    Full Text Available Abstract Background Afrotheria comprises a newly recognized clade of mammals with strong molecular evidence for its monophyly. In contrast, morphological data uniting its diverse constituents, including elephants, sea cows, hyraxes, aardvarks, sengis, tenrecs and golden moles, have been difficult to identify. Here, we suggest relatively late eruption of the permanent dentition as a shared characteristic of afrotherian mammals. This characteristic and other features (such as vertebral anomalies and testicondy recall the phenotype of a human genetic pathology (cleidocranial dysplasia, correlations with which have not been explored previously in the context of character evolution within the recently established phylogeny of living mammalian clades. Results Although data on the absolute timing of eruption in sengis, golden moles and tenrecs are still unknown, craniometric comparisons for ontogenetic series of these taxa show that considerable skull growth takes place prior to the complete eruption of the permanent cheek teeth. Specimens showing less than half (sengis, golden moles or two-thirds (tenrecs, hyraxes of their permanent cheek teeth reach or exceed the median jaw length of conspecifics with a complete dentition. With few exceptions, afrotherians are closer to median adult jaw length with fewer erupted, permanent cheek teeth than comparable stages of non-afrotherians. Manatees (but not dugongs, elephants and hyraxes with known age data show eruption of permanent teeth late in ontogeny relative to other mammals. While the occurrence of delayed eruption, vertebral anomalies and other potential afrotherian synapomorphies resemble some symptoms of a human genetic pathology, these characteristics do not appear to covary significantly among mammalian clades. Conclusion Morphological characteristics shared by such physically disparate animals such as elephants and golden moles are not easy to recognize, but are now known to include late eruption

  14. Feto- and utero-placental vascular adaptations to chronic maternal hypoxia in the mouse.

    Science.gov (United States)

    Cahill, Lindsay S; Rennie, Monique Y; Hoggarth, Johnathan; Yu, Lisa X; Rahman, Anum; Kingdom, John C; Seed, Mike; Macgowan, Christopher K; Sled, John G

    2017-09-01

    Chronic fetal hypoxia is one of the most common complications of pregnancy and is known to cause fetal growth restriction. The structural adaptations of the placental vasculature responsible for growth restriction with chronic hypoxia are not well elucidated. Using a mouse model of chronic maternal hypoxia in combination with micro-computed tomography and scanning electron microscopy, we found several placental adaptations that were beneficial to fetal growth including capillary expansion, thinning of the interhaemal membrane and increased radial artery diameters, resulting in a large drop in total utero-placental vascular resistance. One of the mechanisms used to achieve the rapid increase in capillaries was intussusceptive angiogenesis, a strategy used in human placental development to form terminal gas-exchanging villi. These results contribute to our understanding of the structural mechanisms of the placental vasculature responsible for fetal growth restriction and provide a baseline for understanding adaptive physiological responses of the placenta to chronic hypoxia. The fetus and the placenta in eutherian mammals have a unique set of compensatory mechanisms to respond to several pregnancy complications including chronic maternal hypoxia. This study examined the structural adaptations of the feto- and utero-placental vasculature in an experimental mouse model of chronic maternal hypoxia (11% O2 from embryonic day (E) 14.5-E17.5). While placental weights were unaffected by exposure to chronic hypoxia, using micro-computed tomography, we found a 44% decrease in the absolute feto-placental arterial vascular volume and a 30% decrease in total vessel segments in the chronic hypoxia group compared to control group. Scanning electron microscopy imaging showed significant expansion of the capillary network; consequently, the interhaemal membrane was 11% thinner to facilitate maternal-fetal exchange in the chronic hypoxia placentas. One of the mechanisms for the rapid

  15. Placental diversity in malagasy tenrecs

    DEFF Research Database (Denmark)

    Enders, A C; Blankenship, T N; Goodman, S M;

    2007-01-01

    Placentation in tenrecs of the subfamily Oryzorictinae, family Tenrecidae, has not been described previously. The structure of the placenta of this group and especially of the genus Microgale was investigated to determine its similarity or dissimilarity to previously described placentas of the te...

  16. PLACENTAL SIZE AND PERINATAL OUTCOMES

    Directory of Open Access Journals (Sweden)

    Nagamani

    2015-03-01

    Full Text Available BACKGROUND : The human placenta, a transient organ or pregnancy provides information about fetal well - being and pregnancy outcome . AIMS: To study the placental ultrasound characters in relation to perinatal outcomes . SETTINGS: Tertiary care hospital in southern India . METHODS AND MATERIAL S: The study sample comprised 500 consecutive women who presented to the Depart ment of Obstetrics and Gynecology at the King George Hospital who met the inclusion criteria. Ultrasonographic study was performed using a transabdominal 3.5 MHz volume transducer. Post natally the weight of the baby and of the placenta was recorded. Perina tal outcome was assessed by birth weight, APGAR score and the need for admission in neonatal intensive care unit. STATISTICAL ANALYSIS : Pearson’s correlation analysis and Chi square test was used. Statistical significance was considered at a p value <0.05 . RESULTS: The mean placental thickness was 3.10 cm; 76% (n:380 had normal thickness. Mean placental diameter was 21.306 cm, and its weight varied from 310 women 62% (n:310. Correlation of placental thickness (normal and abnormal, with birth weight, the difference was significant ( <0.001. CONCLUSION: Ultrasound forms a readily available, fairly safe, effective non - invasive method to identify and prevent fetal malnutrition in a cost - effective way.

  17. Some Histories of Molecular Evolution: Amniote Phylogeny, Vertebrate Eye Lens Evolution, and the Prion Gene

    NARCIS (Netherlands)

    Rheede, T. van

    2004-01-01

    In this thesis, the principles of molecular evolution and phylogeny are introduced in Chapter 1, while the subsequent chapters deal with the three topics mentioned in the title. Part I: Birds, reptiles and mammals are Amniota, organisms that have an amnion during their embryonal development. Even th

  18. Some Histories of Molecular Evolution: Amniote Phylogeny, Vertebrate Eye Lens Evolution, and the Prion Gene

    NARCIS (Netherlands)

    Rheede, T. van

    2004-01-01

    In this thesis, the principles of molecular evolution and phylogeny are introduced in Chapter 1, while the subsequent chapters deal with the three topics mentioned in the title. Part I: Birds, reptiles and mammals are Amniota, organisms that have an amnion during their embryonal development. Even

  19. Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase

    OpenAIRE

    Richard, Sophie; Moslemi, Safa; Sipahutar, Herbert; Benachour, Nora; Seralini, Gilles-Eric

    2005-01-01

    Roundup is a glyphosate-based herbicide used worldwide, including on most genetically modified plants that have been designed to tolerate it. Its residues may thus enter the food chain, and glyphosate is found as a contaminant in rivers. Some agricultural workers using glyphosate have pregnancy problems, but its mechanism of action in mammals is questioned. Here we show that glyphosate is toxic to human placental JEG3 cells within 18 hr with concentrations lower than those found with agricult...

  20. Inferring phylogenies from RAD sequence data.

    Directory of Open Access Journals (Sweden)

    Benjamin E R Rubin

    Full Text Available Reduced-representation genome sequencing represents a new source of data for systematics, and its potential utility in interspecific phylogeny reconstruction has not yet been explored. One approach that seems especially promising is the use of inexpensive short-read technologies (e.g., Illumina, SOLiD to sequence restriction-site associated DNA (RAD--the regions of the genome that flank the recognition sites of restriction enzymes. In this study, we simulated the collection of RAD sequences from sequenced genomes of different taxa (Drosophila, mammals, and yeasts and developed a proof-of-concept workflow to test whether informative data could be extracted and used to accurately reconstruct "known" phylogenies of species within each group. The workflow consists of three basic steps: first, sequences are clustered by similarity to estimate orthology; second, clusters are filtered by taxonomic coverage; and third, they are aligned and concatenated for "total evidence" phylogenetic analysis. We evaluated the performance of clustering and filtering parameters by comparing the resulting topologies with well-supported reference trees and we were able to identify conditions under which the reference tree was inferred with high support. For Drosophila, whole genome alignments allowed us to directly evaluate which parameters most consistently recovered orthologous sequences. For the parameter ranges explored, we recovered the best results at the low ends of sequence similarity and taxonomic representation of loci; these generated the largest supermatrices with the highest proportion of missing data. Applications of the method to mammals and yeasts were less successful, which we suggest may be due partly to their much deeper evolutionary divergence times compared to Drosophila (crown ages of approximately 100 and 300 versus 60 Mya, respectively. RAD sequences thus appear to hold promise for reconstructing phylogenetic relationships in younger clades in

  1. Inferring phylogenies from RAD sequence data.

    Science.gov (United States)

    Rubin, Benjamin E R; Ree, Richard H; Moreau, Corrie S

    2012-01-01

    Reduced-representation genome sequencing represents a new source of data for systematics, and its potential utility in interspecific phylogeny reconstruction has not yet been explored. One approach that seems especially promising is the use of inexpensive short-read technologies (e.g., Illumina, SOLiD) to sequence restriction-site associated DNA (RAD)--the regions of the genome that flank the recognition sites of restriction enzymes. In this study, we simulated the collection of RAD sequences from sequenced genomes of different taxa (Drosophila, mammals, and yeasts) and developed a proof-of-concept workflow to test whether informative data could be extracted and used to accurately reconstruct "known" phylogenies of species within each group. The workflow consists of three basic steps: first, sequences are clustered by similarity to estimate orthology; second, clusters are filtered by taxonomic coverage; and third, they are aligned and concatenated for "total evidence" phylogenetic analysis. We evaluated the performance of clustering and filtering parameters by comparing the resulting topologies with well-supported reference trees and we were able to identify conditions under which the reference tree was inferred with high support. For Drosophila, whole genome alignments allowed us to directly evaluate which parameters most consistently recovered orthologous sequences. For the parameter ranges explored, we recovered the best results at the low ends of sequence similarity and taxonomic representation of loci; these generated the largest supermatrices with the highest proportion of missing data. Applications of the method to mammals and yeasts were less successful, which we suggest may be due partly to their much deeper evolutionary divergence times compared to Drosophila (crown ages of approximately 100 and 300 versus 60 Mya, respectively). RAD sequences thus appear to hold promise for reconstructing phylogenetic relationships in younger clades in which sufficient

  2. [Jaws of primitive mammals].

    Science.gov (United States)

    Tsubamoto, Takehisa

    2005-06-01

    Some of main osteological differences between mammals and reptiles are seen in the number of bones that constitute lower jaw and in jaw articulation. A lower jaw of mammals consists of only one bone, while in reptiles it consists of several bones (e.g., four to six in lizards and five in crocodiles). The jaw articulation in mammals is performed by squamosal of the skull and the mandible ( = dentary), while in reptiles it is done by quadrate of the skull and articular of the lower jaw. When mammals first appeared about 200 million years ago in the Mesozoic Era, the jaws of primitive mammals were morphologically intermediate between those of reptiles and typical mammals. Here, I briefly introduce the evolution of lower jaw morphology from the reptilian one to the mammalian one, showing lower jaw features of some mammal-like reptiles and primitive mammals.

  3. The placentation of eulipotyphla-reconstructing a morphotype of the Mammalian placenta.

    Science.gov (United States)

    Ferner, Kirsten; Siniza, Swetlana; Zeller, Ulrich

    2014-10-01

    Placentation determines the developmental status of the neonate, which can be considered as the most vulnerable stage in the mammalian life cycle. In this respect, the different evolutionary and ecological adaptations of marsupial and placental mammals have most likely been associated with the different reproductive strategies of the two therian clades. The morphotypes of marsupial and placental neonates, as well as the placental stem species pattern of Marsupialia, have already been reconstructed. To contribute to a better understanding of the evolution of Placentalia, a histological and ultrastructural investigation of the placenta in three representatives of Eulipotyphla, that is, core insectivores, has been carried out in this study. We studied the Musk shrew (Suncus murinus), the four-toed hedgehog (Atelerix albiventris), and the Iberian mole (Talpa occidentalis). As a result, a eulipotyphlan placental morphotype consisting of a compact and invasive placenta was reconstructed. This supports the widely accepted hypothesis that the stem lineage of Placentalia is characterized by an invasive, either endothelio- or hemochorial placenta. Evolutionary transformations toward a diffuse, noninvasive placenta occurred in the stem lineages of lower primates and cetartiodactyles and were associated with prolonged gestation and the production of few and highly precocial neonates. Compared to the choriovitelline placenta of Marsupialia, the chorioallantoic placenta of Placentalia allows for a more intimate contact and is associated with more advanced neonates.

  4. The key elements of a comprehensive global mammal conservation strategy.

    Science.gov (United States)

    Rondinini, Carlo; Rodrigues, Ana S L; Boitani, Luigi

    2011-09-27

    A global strategy is necessary to achieve the level of coordination, synergy and therefore optimization of resources to achieve the broad goal of conserving mammals worldwide. Key elements for the development of such a strategy include: an institutional subject that owns the strategy; broad conservation goals, quantitative targets derived from them and appropriate indicators; data on the distribution of species, their threats, the cost-effectiveness of conservation actions; and a set of methods for the identification of conservation priorities. Previous global mammal research investigated phylogeny, extinction risk, and the species and areas that should be regarded as global conservation priorities. This theme issue presents new key elements: an updated Red List Index, a new list of evolutionarily distinct and globally endangered species, new high-resolution mammal distribution models, a global connectivity analysis and scenarios of future mammal distribution based on climate and land-cover change. Area prioritization schemes account for mammalian phylogeny, governance and cost-benefit of measures to abate habitat loss. Three discussion papers lay the foundations for the development of a global unifying mammal conservation strategy, which should not be further deterred by the knowledge gaps still existing.

  5. Adaptive evolution toward larger size in mammals.

    Science.gov (United States)

    Baker, Joanna; Meade, Andrew; Pagel, Mark; Venditti, Chris

    2015-04-21

    The notion that large body size confers some intrinsic advantage to biological species has been debated for centuries. Using a phylogenetic statistical approach that allows the rate of body size evolution to vary across a phylogeny, we find a long-term directional bias toward increasing size in the mammals. This pattern holds separately in 10 of 11 orders for which sufficient data are available and arises from a tendency for accelerated rates of evolution to produce increases, but not decreases, in size. On a branch-by-branch basis, increases in body size have been more than twice as likely as decreases, yielding what amounts to millions and millions of years of rapid and repeated increases in size away from the small ancestral mammal. These results are the first evidence, to our knowledge, from extant species that are compatible with Cope's rule: the pattern of body size increase through time observed in the mammalian fossil record. We show that this pattern is unlikely to be explained by several nonadaptive mechanisms for increasing size and most likely represents repeated responses to new selective circumstances. By demonstrating that it is possible to uncover ancient evolutionary trends from a combination of a phylogeny and appropriate statistical models, we illustrate how data from extant species can complement paleontological accounts of evolutionary history, opening up new avenues of investigation for both.

  6. Characterization of placental cholesterol transport

    DEFF Research Database (Denmark)

    Lindegaard, Marie L; Wassif, Christopher A; Vaisman, Boris

    2008-01-01

    Patients with Smith-Lemli-Opitz syndrome (SLOS) are born with multiple congenital abnormalities. Postnatal cholesterol supplementation is provided; however, it cannot correct developmental malformations due to in utero cholesterol deficit. Increased transport of cholesterol from maternal to fetal...... circulation might attenuate congenital malformations. The cholesterol transporters Abca1, Abcg1, and Sr-b1 are present in placenta; however, their potential role in placental transport remains undetermined. In mice, expression analyses showed that Abca1 and Abcg1 transcripts increased 2-3-fold between...... embryonic days 13.5 and 18.5 in placental tissue; whereas, Sr-b1 expression decreased. To examine the functional role of Abca1, Abcg1 and Sr-b1 we measured the maternal-fetal transfer of (14)C-cholesterol in corresponding mutant embryos. Disruption of either Abca1 or Sr-b1 decreased cholesterol transfer...

  7. Placental chimerism in early human pregnancy

    Directory of Open Access Journals (Sweden)

    Ashutosh Halder

    2005-01-01

    Full Text Available Background0 : Human chimerism is rare and usually uncovered through investigations of ambiguous genitalia or blood grouping or prenatal diagnosis. Most of the publications on placental chimerism are mainly case reports. There is no systematic search with sensitive techniques for placental chimerism in human. Aim0 : This study was aimed to asses placental chimerism through two sensitive molecular techniques i.e., interphase fluorescent in situ hybridization and quantitative fluorescent PCR. Material and methods0 : Placental chimerism was analyzed using X & Y dual color fluorescent in-situ hybridization onto 154 placentae from natural conceptions, obtained at termination of pregnancy between 7 to 16 weeks of gestation. Results0 : Three cases of placental sex chromosome chimerism were observed (1.95%. Exclusion of maternal contamination and diagnosis was confirmed later by quantitative fluorescent PCR. Conclusion0 : This finding indicates that placental chimerism in early human pregnancy is not rare.

  8. Altered fetal growth, placental abnormalities, and stillbirth.

    Science.gov (United States)

    Bukowski, Radek; Hansen, Nellie I; Pinar, Halit; Willinger, Marian; Reddy, Uma M; Parker, Corette B; Silver, Robert M; Dudley, Donald J; Stoll, Barbara J; Saade, George R; Koch, Matthew A; Hogue, Carol; Varner, Michael W; Conway, Deborah L; Coustan, Donald; Goldenberg, Robert L

    2017-01-01

    Worldwide, stillbirth is one of the leading causes of death. Altered fetal growth and placental abnormalities are the strongest and most prevalent known risk factors for stillbirth. The aim of this study was to identify patterns of association between placental abnormalities, fetal growth, and stillbirth. Population-based case-control study of all stillbirths and a representative sample of live births in 59 hospitals in 5 geographic areas in the U.S. Fetal growth abnormalities were categorized as small (90th percentile) for gestational age at death (stillbirth) or delivery (live birth) using a published algorithm. Placental examination by perinatal pathologists was performed using a standardized protocol. Data were weighted to account for the sampling design. Among 319 singleton stillbirths and 1119 singleton live births at ≥24 weeks at death or delivery respectively, 25 placental findings were investigated. Fifteen findings were significantly associated with stillbirth. Ten of the 15 were also associated with fetal growth abnormalities (single umbilical artery; velamentous insertion; terminal villous immaturity; retroplacental hematoma; parenchymal infarction; intraparenchymal thrombus; avascular villi; placental edema; placental weight; ratio birth weight/placental weight) while 5 of the 15 associated with stillbirth were not associated with fetal growth abnormalities (acute chorioamnionitis of placental membranes; acute chorioamionitis of chorionic plate; chorionic plate vascular degenerative changes; perivillous, intervillous fibrin, fibrinoid deposition; fetal vascular thrombi in the chorionic plate). Five patterns were observed: placental findings associated with (1) stillbirth but not fetal growth abnormalities; (2) fetal growth abnormalities in stillbirths only; (3) fetal growth abnormalities in live births only; (4) fetal growth abnormalities in stillbirths and live births in a similar manner; (5) a different pattern of fetal growth abnormalities in

  9. Placental oxygen transport estimated by the hyperoxic placental BOLD MRI response

    DEFF Research Database (Denmark)

    Sørensen, Anne Nødgaard; Sinding, Marianne; Peters, David A;

    2015-01-01

    cases of severe early onset FGR, placental BOLD MRI was performed in a 1.5 Tesla MRI system (TR:8000 msec, TE:50 msec, Flip angle:90). Placental histological examination was performed in the FGR cases. In normal pregnancies, the average hyperoxic placental BOLD response was 12.6 ± 5.4% (mean ± SD...

  10. Animal Models of Human Placentation - A Review

    DEFF Research Database (Denmark)

    Carter, Anthony Michael

    2007-01-01

    This review examines the strengths and weaknesses of animal models of human placentation and pays particular attention to the mouse and non-human primates. Analogies can be drawn between mouse and human in placental cell types and genes controlling placental development. There are, however...... and endometrium is similar in macaques and baboons, as is the subsequent lacunar stage. The absence of interstitial trophoblast cells in the monkey is an important difference from human placentation. However, there is a strong resemblance in the way spiral arteries are invaded and transformed in the macaque...

  11. Emotion and phylogeny.

    Science.gov (United States)

    Cabanac, M

    1999-02-01

    Gentle handling of mammals (rats, mice) and lizards (Iguana), but not of frogs (Rana) and fish (Carassius), elevated the set-point for body temperature (i.e., produced an emotional fever) achieved only behaviorally in lizards. Heart rate, another detector of emotion in mammals, was also accelerated by gentle handling, from ca. 70 beats/min to ca. 110 beats/min in lizards. This tachycardia faded in about 10 min. The same handling did not significantly modify the frogs' heart rates. The absence of emotional tachycardia in frogs and its presence in lizards (as well as in mammals), together with the emotional fever exhibited by mammals and reptiles, but not by frogs or fish, would suggest that emotion emerged in the evolutionary lineage between amphibians and reptiles. Such a conclusion would imply that reptiles possess consciousness with its characteristic affective dimension, pleasure. The role of sensory pleasure in decision making was therefore verified in iguanas placed in a motivational conflict. To be able to reach a bait (lettuce), the iguanas had to leave a warm refuge, provided with standard food, and venture into a cold environment. The results showed that lettuce was not necessary to the iguanas and that they traded off the palatability of the bait against the disadvantage of the cold. Thus, the behavior of the iguanas was likely to be produced, as it is in humans, through the maximization of sensory pleasure. Altogether, these results may indicate that the first elements of mental experience emerged between amphibians and reptiles.

  12. A phylogenetic approach to total evaporative water loss in mammals.

    Science.gov (United States)

    Van Sant, Matthew J; Oufiero, Christopher E; Muñoz-Garcia, Agustí; Hammond, Kimberly A; Williams, Joseph B

    2012-01-01

    Maintaining appropriate water balance is a constant challenge for terrestrial mammals, and this problem can be exacerbated in desiccating environments. It has been proposed that natural selection has provided desert-dwelling mammals physiological mechanisms to reduce rates of total evaporative water loss. In this study, we evaluated the relationship between total evaporative water loss and body mass in mammals by using a recent phylogenetic hypothesis. We compared total evaporative water loss in 80 species of arid-zone mammals to that in 56 species that inhabit mesic regions, ranging in size from 4 g to 3,500 kg, to test the hypothesis that mammals from arid environments have lower rates of total evaporative water loss than mammals from mesic environments once phylogeny is taken into account. We found that arid species had lower rates of total evaporative water loss than mesic species when using a dichotomous variable to describe habitat (arid or mesic). We also found that total evaporative water loss was negatively correlated with the average maximum and minimum environmental temperature as well as the maximum vapor pressure deficit of the environment. Annual precipitation and the variable Q (a measure of habitat aridity) were positively correlated with total evaporative water loss. These results support the hypothesis that desert-dwelling mammals have lower rates of total evaporative water loss than mesic species after controlling for body mass and evolutionary relatedness regardless of whether categorical or continuous variables are used to describe habitat.

  13. The evolution of the mammal placenta — a computational approach to the identification and analysis of placenta-specific genes and microRNAs.

    OpenAIRE

    Walsh, Thomas A.

    2013-01-01

    The presence of a placenta is an important synapomorphy that defines the mammal clade. From the fossil record we know that the first placental mammal lived approximately 125 million years ago, with the chorioallantoic placenta evolving not long after. In this thesis a set of 22 complete genomes from Eutherian, non-Eutherian and outgroup species are compared, the aim being to identify protein-coding and regulatory alterations that are likely to be implicated in the emergence of mammal placenta...

  14. Endocrine activity of extraembryonic membranes extends beyond placental amniotes.

    Directory of Open Access Journals (Sweden)

    Lori C Albergotti

    Full Text Available BACKGROUND: During development, all amniotes (mammals, reptiles, and birds form extraembryonic membranes, which regulate gas and water exchange, remove metabolic wastes, provide shock absorption, and transfer maternally derived nutrients. In viviparous (live-bearing amniotes, both extraembryonic membranes and maternal uterine tissues contribute to the placenta, an endocrine organ that synthesizes, transports, and metabolizes hormones essential for development. Historically, endocrine properties of the placenta have been viewed as an innovation of placental amniotes. However, an endocrine role of extraembryonic membranes has not been investigated in oviparous (egg-laying amniotes despite similarities in their basic structure, function, and shared evolutionary ancestry. In this study, we ask whether the oviparous chorioallantoic membrane (CAM of chicken (Gallus gallus has the capability to synthesize and receive signaling of progesterone, a major placental steroid hormone. METHODOLOGY/PRINCIPAL FINDINGS: We quantified mRNA expression of key steroidogenic enzymes involved in progesterone synthesis and found that 3beta-hydroxysteroid dehydrogenase, which converts pregnenolone to progesterone exhibited a 464 fold increase in the CAM from day 8 to day 18 of embryonic development (F(5, 68 = 89.282, p<0.0001. To further investigate progesterone synthesis, we performed explant culture and found that the CAM synthesizes progesterone in vitro in the presence of a steroid precursor. Finally, we quantified mRNA expression and performed protein immunolocalization of the progesterone receptor in the CAM. CONCLUSIONS/SIGNIFICANCE: Collectively, our data indicate that the chick CAM is steroidogenic and has the capability to both synthesize progesterone and receive progesterone signaling. These findings represent a paradigm shift in evolutionary reproductive biology by suggesting that endocrine activity of extraembryonic membranes is not a novel characteristic of

  15. Nearly complete rRNA genes assembled from across the metazoan animals: effects of more taxa, a structure-based alignment, and paired-sites evolutionary models on phylogeny reconstruction.

    Science.gov (United States)

    Mallatt, Jon; Craig, Catherine Waggoner; Yoder, Matthew J

    2010-04-01

    This study (1) uses nearly complete rRNA-gene sequences from across Metazoa (197 taxa) to reconstruct animal phylogeny; (2) presents a highly annotated, manual alignment of these sequences with special reference to rRNA features including paired sites (http://purl.oclc.org/NET/rRNA/Metazoan_alignment) and (3) tests, after eliminating as few disruptive, rogue sequences as possible, if a likelihood framework can recover the main metazoan clades. We found that systematic elimination of approximately 6% of the sequences, including the divergent or unstably placed sequences of cephalopods, arrowworm, symphylan and pauropod myriapods, and of myzostomid and nemertodermatid worms, led to a tree that supported Ecdysozoa, Lophotrochozoa, Protostomia, and Bilateria. Deuterostomia, however, was never recovered, because the rRNA of urochordates goes (nonsignificantly) near the base of the Bilateria. Counterintuitively, when we modeled the evolution of the paired sites, phylogenetic resolution was not increased over traditional tree-building models that assume all sites in rRNA evolve independently. The rRNA genes of non-bilaterians contain a higher % AT than do those of most bilaterians. The rRNA genes of Acoela and Myzostomida were found to be secondarily shortened, AT-enriched, and highly modified, throwing some doubt on the location of these worms at the base of Bilateria in the rRNA tree--especially myzostomids, which other evidence suggests are annelids instead. Other findings are marsupial-with-placental mammals, arrowworms in Ecdysozoa (well supported here but contradicted by morphology), and Placozoa as sister to Cnidaria. Finally, despite the difficulties, the rRNA-gene trees are in strong concordance with trees derived from multiple protein-coding genes in supporting the new animal phylogeny.

  16. Maternal Outcomes According to Placental Position in Placental Previa

    Directory of Open Access Journals (Sweden)

    Dong Gyu Jang, Ji Sun We, Jae Un Shin, Yun Jin Choi, Hyun Sun Ko, In Yang Park, Jong Chul Shin

    2011-01-01

    Full Text Available Purpose: The purpose of this retrospective cohort study was to elucidate whether the location of placenta below uterine incision in cesarean section is important in the development of maternal complications in placenta previa patients.Methods: The study was conducted on 409 patients 414 parturition at 3 hospitals in affiliation with the Catholic Medical Center, Seoul, Korea from May 1999 to December 2009. The subjects were divided to two groups: the group whose placenta was located in the anterior portion of the uterus (anterior group and the group whose placenta was located in the posterior portion of the uterus (posterior group. And then they are compared to each other. Logistic regression was used to control for confounding factors.Results: In the anterior group, regardless of confounding factors, the incidence of excessive blood loss (OR 2.97; 95% CI: 1.64-5.37, massive transfusion (OR 3.31; 95% CI: 1.33-8.26, placental accreta (OR 2.60, 95% CI: 1.40-4.83, and hysterectomy (OR 3.47, 95% CI: 1.39-8.68 was higher.Conclusion: Sonographic determination of the placental position where its location beneath the uterine incision is very important to predict maternal outcomes in placenta previa patients, and such cases, close attention should be paid for massive hemorrhage.

  17. Placental urocortins and CRF in late gestation.

    NARCIS (Netherlands)

    Pepels, P.P.L.M.; Spaanderman, M.E.A.; Bulten, J.; Smits, P.; Hermus, A.R.M.M.; Lotgering, F.K.; Sweep, C.G.J.

    2009-01-01

    Placental corticotropin-releasing factor (CRF) are thought to induce labor via activation of CRF receptor type 1 (CRF-R1) leading to several feed forward mechanisms in the placental, fetal and maternal compartments. Recently, receptor type 2 (CRF-R2) selective ligands called urocortin 2 and 3 (Ucn

  18. Placental iron uptake and its regulation

    NARCIS (Netherlands)

    M. Bierings (Marc)

    1989-01-01

    textabstractIron transport in pregnancy is an active one-way process, from mother to fetus. Early in gestation fetal iron needs are low, and so is trans-placental transport, but as erythropoiesis develops, rising fetal iron needs are met by trans-placental iron transport. Apparently, the fetus is pr

  19. Regional Diversity and Diversification in Mammals.

    Science.gov (United States)

    Machac, Antonin; Graham, Catherine H

    2017-01-01

    The effects of regional diversity on diversification remain controversial. The classic hypothesis that diversification decelerates as regional diversity increases has been recently revived. Yet, there is little geographic evidence for slower diversification across regions of high diversity, and diversity is often thought to promote diversification through its effects on ecological divergence and speciation. Here, we use the newest phylogeny for mammals (4,990 species) and two different methods to test the effects of regional diversity on diversification. We find that regions of high diversity are dominated by expanding clades that are far from their estimated carrying capacities. Regions of low diversity host clades that are small and mostly saturated. These results were supported across mammals and their six largest orders. They were corroborated by the two methods when controlling for clade relatedness, clade nestedness, and clade size. Together, these results reject the hypothesis that high geographic concentration of mammals effectively suppresses their further diversification. Instead, highly diverse regions (especially the tropics) seem to act as the engine of mammalian richness.

  20. Cell fusions in mammals

    DEFF Research Database (Denmark)

    Larsson, Lars-Inge; Bjerregaard, Bolette; Talts, Jan Fredrik

    2008-01-01

    Cell fusions are important to fertilization, placentation, development of skeletal muscle and bone, calcium homeostasis and the immune defense system. Additionally, cell fusions participate in tissue repair and may be important to cancer development and progression. A large number of factors appe...

  1. Mapping Mutations on Phylogenies

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2005-01-01

    This chapter provides a short review of recent methodologies developed for mapping mutations on phylogenies. Mapping of mutations, or character changes in general, using the maximum parsimony principle has been one of the most powerful tools in phylogenetics, and it has been used in a variety...... of different applications, for example, in the detection of correlated evolution and to identify selection acting on DNA sequences. However, many uses of parsimony mappings have been criticized because they focus on only one of many possible mappings and/or because they do not incorporate statistical...... uncertainty in the mapping. Recently developed probabilistic methods can incorporate statistical uncertainty in the character mappings. In these methods, focus is on a probability distribution of mutational mappings instead of a single estimate of the mutational mapping....

  2. Reassessing the relationship between brain size, life history, and metabolism at the marsupial/placental dichotomy.

    Science.gov (United States)

    Weisbecker, Vera; Goswami, Anjali

    2014-09-01

    A vigorous discussion surrounds the question as to what enables some mammals--including primates and cetaceans--to evolve large brains. We recently published a study suggesting that the radiation of marsupial mammals is highly relevant to this question because of the unique reproductive and metabolic traits within this clade. In particular, we controversially suggested that marsupial brain sizes are not systematically smaller than those of placentals, and that elevated basal metabolic rates (BMR) are not linked to larger marsupial brains. As our dataset was found to contain some erroneous body size data, derived from a published source, we here use an updated and corrected dataset and employ standard as well as phylogenetically corrected analyses to re-assess and elaborate on our original conclusions. Our proposal that marsupials are not systematically smaller-brained than placentals remains supported, particularly when the unusually large-brained placental clade, Primates, is excluded. Use of the new dataset not only confirms that high metabolic rates are not associated with larger brain size in marsupials, but we additionally find some support for a striking negative correlation between BMR and brain size. The best supported correlates of large brain size remain the reproductive traits of weaning age and litter size. These results support our suggestion that mammalian brain sizes (including, by inference, those of monotremes) are predominantly constrained by the ability of females to fuel the growth of their offspring's large brains, rather than by the maintenance requirements of the adult brain.

  3. Brucella placentitis and seroprevalence in northern fur seals (Callorhinus ursinus) of the Pribilof Islands, Alaska.

    Science.gov (United States)

    Duncan, Colleen G; Tiller, Rebekah; Mathis, Demetrius; Stoddard, Robyn; Kersh, Gilbert J; Dickerson, Bobette; Gelatt, Tom

    2014-05-01

    Brucella species infect a wide range of hosts with a broad spectrum of clinical manifestations. In mammals, one of the most significant consequences of Brucella infection is reproductive failure. There is evidence of Brucella exposure in many species of marine mammals, but the outcome of infection is often challenging to determine. The eastern Pacific stock of northern fur seals (NFSs, Callorhinus ursinus) has declined significantly, spawning research into potential causes for this trend, including investigation into reproductive health. The objective of the current study was to determine if NFSs on St. Paul Island, Alaska have evidence of Brucella exposure or infection. Archived DNA extracted from placentas (n = 119) and serum (n = 40) samples were available for testing by insertion sequence (IS) 711 polymerase chain reaction (PCR) and the Brucella microagglutination test (BMAT), respectively. As well, placental tissue was available for histologic examination. Six (5%) placentas were positive by PCR, and a single animal had severe placentitis. Multilocus variable number tandem repeat analysis profiles were highly clustered and closely related to other Brucella pinnipedialis isolates. A single animal was positive on BMAT, and 12 animals had titers within the borderline range; 1 borderline animal was positive by PCR on serum. The findings suggest that NFSs on the Pribilof Islands are exposed to Brucella and that the organism has the ability to cause severe placental disease. Given the population trend of the NFS, and the zoonotic nature of this pathogen, further investigation into the epidemiology of this disease is recommended.

  4. Recent Advances in Studies on Mesozoic and Paleogene Mammals in China

    Institute of Scientific and Technical Information of China (English)

    WANG Yuanqing; NI Xijun

    2010-01-01

    @@ Like in other fields of paleontology,research in paleomammalogy mainly falls into two aspects.One is related to the biological nature of fossil mammals,such as their systematics,origin,evolution,phylogenetic relationships,transformation of key features and paleobiogeography,and the other is related to the geological context,involving biostratigraphy,biochronology,faunal turnover and its relations to the global and regional environmental changes.In the last decade,a number of well-preserved mammalian specimens were collected from different localities around the country.Such discoveries have provided significant information for understanding the early evolution of mammals and reconstructing the phylogeny of early mammals.

  5. Marine Mammal Protection Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Mammal Protection Act (MMPA or Act) prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas,...

  6. Protection of Marine Mammals

    NARCIS (Netherlands)

    Knoll, M.; Ciaccia, E.; Dekeling, R.P.A.; Kvadsheim, P.H.; Liddell, K.; Gunnarsson, S.L.; Ludwig, S.; Nissen, I.; Lorenzen, D.; Kreimeyer, R.; Pavan, G.; Meneghetti, N.; Nordlund, N.; Benders, F.P.A.; Zwan, T. van der; Zon, A.T. van; Fraser, L.; Johansson, T.; Garmelius, M.

    2016-01-01

    Within the European Defense Agency (EDA), the Protection of Marine Mammals (PoMM) project, a comprehensive common marine mammal database essential for risk mitigation tools, was established. The database, built on an extensive dataset collection with the focus on areas of operational interest for

  7. The mammalian PYHIN gene family: Phylogeny, evolution and expression

    Directory of Open Access Journals (Sweden)

    Cridland Jasmyn A

    2012-08-01

    Full Text Available Abstract Background Proteins of the mammalian PYHIN (IFI200/HIN-200 family are involved in defence against infection through recognition of foreign DNA. The family member absent in melanoma 2 (AIM2 binds cytosolic DNA via its HIN domain and initiates inflammasome formation via its pyrin domain. AIM2 lies within a cluster of related genes, many of which are uncharacterised in mouse. To better understand the evolution, orthology and function of these genes, we have documented the range of PYHIN genes present in representative mammalian species, and undertaken phylogenetic and expression analyses. Results No PYHIN genes are evident in non-mammals or monotremes, with a single member found in each of three marsupial genomes. Placental mammals show variable family expansions, from one gene in cow to four in human and 14 in mouse. A single HIN domain appears to have evolved in the common ancestor of marsupials and placental mammals, and duplicated to give rise to three distinct forms (HIN-A, -B and -C in the placental mammal ancestor. Phylogenetic analyses showed that AIM2 HIN-C and pyrin domains clearly diverge from the rest of the family, and it is the only PYHIN protein with orthology across many species. Interestingly, although AIM2 is important in defence against some bacteria and viruses in mice, AIM2 is a pseudogene in cow, sheep, llama, dolphin, dog and elephant. The other 13 mouse genes have arisen by duplication and rearrangement within the lineage, which has allowed some diversification in expression patterns. Conclusions The role of AIM2 in forming the inflammasome is relatively well understood, but molecular interactions of other PYHIN proteins involved in defence against foreign DNA remain to be defined. The non-AIM2 PYHIN protein sequences are very distinct from AIM2, suggesting they vary in effector mechanism in response to foreign DNA, and may bind different DNA structures. The PYHIN family has highly varied gene composition between

  8. A stochastic model for early placental development.

    KAUST Repository

    Cotter, Simon L

    2014-08-01

    In the human, placental structure is closely related to placental function and consequent pregnancy outcome. Studies have noted abnormal placental shape in small-for-gestational-age infants which extends to increased lifetime risk of cardiovascular disease. The origins and determinants of placental shape are incompletely understood and are difficult to study in vivo. In this paper, we model the early development of the human placenta, based on the hypothesis that this is driven by a chemoattractant effect emanating from proximal spiral arteries in the decidua. We derive and explore a two-dimensional stochastic model, and investigate the effects of loss of spiral arteries in regions near to the cord insertion on the shape of the placenta. This model demonstrates that disruption of spiral arteries can exert profound effects on placental shape, particularly if this is close to the cord insertion. Thus, placental shape reflects the underlying maternal vascular bed. Abnormal placental shape may reflect an abnormal uterine environment, predisposing to pregnancy complications. Through statistical analysis of model placentas, we are able to characterize the probability that a given placenta grew in a disrupted environment, and even able to distinguish between different disruptions.

  9. The placental gateway of maternal transgenerational epigenetic inheritance

    Indian Academy of Sciences (India)

    S. PURNIMA SAILASREE; SURABHI SRIVASTAVA; RAKESH K. MISHRA

    2017-07-01

    While much of our understanding of genetic inheritance is based on the genome of the organism, it is becoming clear that there is an ample amount of epigenetic inheritance, which though reversible, escapes erasing process during gametogenesis and goes on to the next generation. Several examples of transgenerational inheritance of epigenetic features with potential impact onembryonic development and subsequent adult life have come to light. In placental mammals, the placenta is an additional route for epigenetic information flow. This information does not go through any meiotic reprogramming and is, therefore, likely to have a more profound influence on the organism. This also has the implication of providing epigenetic instructions for several months, which isclearly a maternal advantage. Although less well-known, there is also an impact of the embryo in emitting genetic information to the maternal system that remains well beyond the completion of the pregnancy. In this review, we discuss several factors in the context of the evolution of this mammal-specific phenomenon, including genomic imprinting, micromosaicism, and assisted reproduction.Wealso highlight how this kind of inheritancemight require attention in the modern lifestyle within the larger context of the evolutionary process.

  10. ULTRASONOGRAPHIC CORRELATION OF PLACENTAL THICKNESS WITH FETAL GESTATIONAL AGE AND GRADING OF PLACENTAL MATURIT

    Directory of Open Access Journals (Sweden)

    Nagesh

    2016-03-01

    Full Text Available AIMS AND OBJECTIVES Comparative correlation of placental thickness with foetal gestational age, and evaluation of placental maturity by ultrasonography. MATERIALS AND METHODS The study includes 100 normal singleton gestations between 10 to 40 weeks of gestation referred to our centre for routine antenatal ultrasound examination. All the women were evaluated by transabdominal ultrasonography. Foetal gestational age in weeks was determined by crown rump length, biparietal diameter, head circumference, abdominal circumference and femoral length. Placental thickness was measured in millimeters. All the placentae were graded using ultrasonographic grading system. RESULTS Our observations revealed that the placental thickness gradually increased from 11.8 mm at 12 weeks to 38.5 mm at 39 weeks. Placental thickness almost corresponds to advancing gestational age exhibiting a linear and direct growth. Progressive maturity changes were noted in placenta with advancing gestational age. CONCLUSION Placental thickness measured at cord insertion site can be used as one of the parameter for estimating foetal gestational age. Placental thickness measurement can also be used to differentiate certain abnormal conditions related to thick and thin placenta. Ultrasonographic placental grading helps to rule out certain conditions associated with premature or delayed placental maturation

  11. Hyperemesis gravidarum and placental dysfunction disorders

    NARCIS (Netherlands)

    Koudijs, Heleen M; Savitri, Ary I; Browne, Joyce L; Amelia, Dwirani; Baharuddin, Mohammad; Grobbee, Diederick E; Uiterwaal, Cuno S P M

    2016-01-01

    BACKGROUND: Evidence about the consequence of hyperemesis gravidarum (HG) on pregnancy outcomes is still inconclusive. In this study, we evaluated if occurrence of hyperemesis gravidarum is associated with placental dysfunction disorders and neonatal outcomes. METHODS: A prospective cohort study was

  12. Postpartum deaths: piglet, placental, and umbilical characteristics.

    Science.gov (United States)

    Rootwelt, V; Reksen, O; Farstad, W; Framstad, T

    2013-06-01

    The fetal growth of the piglet is highly dependent on its placenta, and the newborn piglet birth weight is highly associated with postpartum death. However, there is little information available in the literature on the assessment of the placenta in relation to postpartum death in piglets. The aim of this study was to evaluate the impact of the placental area and placental weight, status of the umbilical cord, and piglet birth characteristics, such as blood parameters, vitality score, and birth weight on postpartum death. All live born piglets in litters from 26 Landrace-Yorkshire sows were monitored during farrowing and the status of each was recorded, including placental area and placental weight and blood variables obtained from the piglets and umbilical veins. Out of the 386 live-born piglets, 16.8% died before weaning at 5 wk. Among these, 78.5% died within the first 3 d of life. Mean blood concentration of lactate was increased in piglets that did not survive to weaning (P = 0.003). Concentrations of hemoglobin and hematocrit were decreased (P Piglets born with a broken umbilical cord had a reduced vitality score vs. piglets born with an intact umbilical cord (P = 0.021), and they had an increased probability of dying before weaning (P = 0.050). Mean birth weight, body mass index, placental area (P piglets that died before weaning vs. those that survived. Birth weight and placental area were furthermore negatively associated with live litter size. Blood concentrations of IgG and albumin recorded at d 1 were decreased in piglets that died before weaning (P < 0.01), and blood concentration of albumin was positively associated with placental area (P < 0.001). We conclude that placental area and placental weight, status of the umbilical cord, birth weight, body mass index, blood concentrations of lactate, hemoglobin, and hematocrit recorded at birth, and blood concentrations of IgG and albumin recorded at d 1 were associated with postpartum death in this study

  13. Small Mammal Trapping 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Small mammal traps were placed in the Baring division and in the Edmunds division of Moosehom National Wildlife Refuge. There were a total of 98 traps set for up to...

  14. Impact on Small Mammals

    African Journals Online (AJOL)

    abundance and diversity of the small mammal community on burnt and unbumt habitats of the area using .... Captured animals were shaken gently ..... Wetlands Management Project: Environ- ... ofrodents, SwedishNatural Science Research.

  15. Prediction of fetal acidemia in placental abruption

    OpenAIRE

    MATSUDA, Yoshio; OGAWA, Masaki; KONNO, Jun; MITANI, Minoru; MATSUI, Hideo

    2013-01-01

    Background To determine the major predictive factors for fetal acidemia in placental abruption. Methods A retrospective review of pregnancies with placental abruption was performed using a logistic regression model. Fetal acidemia was defined as a pH of less than 7.0 in umbilical artery. The severe abruption score, which was derived from a linear discriminant function, was calculated to determine the probability of fetal acidemia. Results Fetal acidemia was seen in 43 survivors (43/222, 19%)....

  16. Exotic Mammal Laparoscopy.

    Science.gov (United States)

    Sladakovic, Izidora; Divers, Stephen J

    2016-01-01

    Laparoscopy is an evolving field in veterinary medicine, and there is an increased interest in using laparoscopic techniques in nondomestic mammals, including zoo animals, wildlife, and exotic pets. The aim of this article is to summarize the approach to laparoscopic procedures, including instrumentation, patient selection and preparation, and surgical approaches, and to review the current literature on laparoscopy in exotic mammals. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. The distinct proteome of placental malaria parasites.

    Energy Technology Data Exchange (ETDEWEB)

    Fried, Michal; Hixson, Kim K.; Anderson, Lori; Ogata, Yuko; Mutabingwa, Theonest K.; Duffy, Patrick E.

    2007-09-01

    Malaria proteins expressed on the surface of Plasmodium falciparum infected erythrocytes (IE) mediate adhesion and are targeted by protective immune responses. During pregnancy, IE sequester in the placenta. Placental IE bind to the molecule chondroitin sulfate A (CSA) and preferentially transcribe the gene that encodes VAR2CSA, a member of the PfEMP1 variant surface antigen family. Over successive pregnancies women develop specific immunity to CSA-binding IE and antibodies to VAR2CSA. We used tandem mass spectrometry together with accurate mass and time tag technology to study IE membrane fractions of placental parasites. VAR2CSA peptides were detected in placental IE and in IE from children, but the MC variant of VAR2CSA was specifically associated with placental IE. We identified six conserved hypothetical proteins with putative TM or signal peptides that were exclusively expressed by the placental IE, and 11 such proteins that were significantly more abundant in placental IE. One of these hypothetical proteins, PFI1785w, is a 42kDa molecule detected by Western blot in parasites infecting pregnant women but not those infecting children.

  18. Detecting shifts in diversity limits from molecular phylogenies: what can we know?

    Science.gov (United States)

    McInnes, Lynsey; Orme, C David L; Purvis, A

    2011-11-01

    Large complete species-level molecular phylogenies can provide the most direct information about the macroevolutionary history of clades having poor fossil records. However, extinction will ultimately erode evidence of pulses of rapid speciation in the deep past. Assessment of how well, and for how long, phylogenies retain the signature of such pulses has hitherto been based on a--probably untenable--model of ongoing diversity-independent diversification. Here, we develop two new tests for changes in diversification 'rules' and evaluate their power to detect sudden increases in equilibrium diversity in clades simulated with diversity-dependent speciation and extinction rates. Pulses of diversification are only detected easily if they occurred recently and if the rate of species turnover at equilibrium is low; rates reported for fossil mammals suggest that the power to detect a doubling of species diversity falls to 50 per cent after less than 50 Myr even with a perfect phylogeny of extant species. Extinction does eventually draw a veil over past dynamics, suggesting that some questions are beyond the limits of inference, but sudden clade-wide pulses of speciation can be detected after many millions of years, even when overall diversity is constrained. Applying our methods to existing phylogenies of mammals and angiosperms identifies intervals of elevated diversification in each.

  19. A mitogenomic phylogeny of living primates.

    Science.gov (United States)

    Finstermeier, Knut; Zinner, Dietmar; Brameier, Markus; Meyer, Matthias; Kreuz, Eva; Hofreiter, Michael; Roos, Christian

    2013-01-01

    Primates, the mammalian order including our own species, comprise 480 species in 78 genera. Thus, they represent the third largest of the 18 orders of eutherian mammals. Although recent phylogenetic studies on primates are increasingly built on molecular datasets, most of these studies have focused on taxonomic subgroups within the order. Complete mitochondrial (mt) genomes have proven to be extremely useful in deciphering within-order relationships even up to deep nodes. Using 454 sequencing, we sequenced 32 new complete mt genomes adding 20 previously not represented genera to the phylogenetic reconstruction of the primate tree. With 13 new sequences, the number of complete mt genomes within the parvorder Platyrrhini was widely extended, resulting in a largely resolved branching pattern among New World monkey families. We added 10 new Strepsirrhini mt genomes to the 15 previously available ones, thus almost doubling the number of mt genomes within this clade. Our data allow precise date estimates of all nodes and offer new insights into primate evolution. One major result is a relatively young date for the most recent common ancestor of all living primates which was estimated to 66-69 million years ago, suggesting that the divergence of extant primates started close to the K/T-boundary. Although some relationships remain unclear, the large number of mt genomes used allowed us to reconstruct a robust primate phylogeny which is largely in agreement with previous publications. Finally, we show that mt genomes are a useful tool for resolving primate phylogenetic relationships on various taxonomic levels.

  20. Visual acuity in mammals: effects of eye size and ecology.

    Science.gov (United States)

    Veilleux, Carrie C; Kirk, E Christopher

    2014-01-01

    Previous comparative research has attributed interspecific variation in eye size among mammals to selection related to visual acuity. Mammalian species have also been hypothesized to differ in visual acuity partly as a result of differences in ecology. While a number of prior studies have explored ecological and phylogenetic effects on eye shape, a broad comparative analysis of the relationships between visual acuity, eye size and ecology in mammals is currently lacking. Here we use phylogenetic comparative methods to explore these relationships in a taxonomically and ecologically diverse sample of 91 mammal species. These data confirm that axial eye length and visual acuity are significantly positively correlated in mammals. This relationship conforms to expectations based on theoretical optics and prior analyses of smaller comparative samples. Our data also demonstrate that higher visual acuity in mammals is associated with: (1) diurnality and (2) predatory habits once the effects of eye size and phylogeny have been statistically controlled. These results suggest that interspecific variation in mammalian visual acuity is the result of a complex interplay between phylogenetic history, visual anatomy and ecology.

  1. Phylogeny and Evolution of Lepidoptera.

    Science.gov (United States)

    Mitter, Charles; Davis, Donald R; Cummings, Michael P

    2017-01-31

    Until recently, deep-level phylogeny in Lepidoptera, the largest single radiation of plant-feeding insects, was very poorly understood. Over the past two decades, building on a preceding era of morphological cladistic studies, molecular data have yielded robust initial estimates of relationships both within and among the ∼43 superfamilies, with unsolved problems now yielding to much larger data sets from high-throughput sequencing. Here we summarize progress on lepidopteran phylogeny since 1975, emphasizing the superfamily level, and discuss some resulting advances in our understanding of lepidopteran evolution.

  2. The placental exposome: Placental determinants of fetal adiposity and postnatal body composition

    NARCIS (Netherlands)

    R.M. Lewis (R.); H. Demmelmair (Hans); R. Gaillard (Romy); N. Godfrey; S. Hauguel-De Mouzon (S.); B. Huppertz (B.); E. Larque (E.); R. Saffery (R.); M.E. Symonds (M.); G. Desoye (G.)

    2013-01-01

    textabstractOffspring of obese and diabetic mothers are at increased risk of being born with excess adiposity as a consequence of their intrauterine environment. Excessive fetal fat accretion reflects additional placental nutrient transfer, suggesting an effect of the maternal environment on placent

  3. The placental exposome: Placental determinants of fetal adiposity and postnatal body composition

    NARCIS (Netherlands)

    R.M. Lewis (R.); H. Demmelmair (Hans); R. Gaillard (Romy); N. Godfrey; S. Hauguel-De Mouzon (S.); B. Huppertz (B.); E. Larque (E.); R. Saffery (R.); M.E. Symonds (M.); G. Desoye (G.)

    2013-01-01

    textabstractOffspring of obese and diabetic mothers are at increased risk of being born with excess adiposity as a consequence of their intrauterine environment. Excessive fetal fat accretion reflects additional placental nutrient transfer, suggesting an effect of the maternal environment on placent

  4. The Miocene mammal Necrolestes demonstrates the survival of a Mesozoic nontherian lineage into the late Cenozoic of South America.

    Science.gov (United States)

    Rougier, Guillermo W; Wible, John R; Beck, Robin M D; Apesteguía, Sebastian

    2012-12-04

    The early Miocene mammal Necrolestes patagonensis from Patagonia, Argentina, was described in 1891 as the only known extinct placental "insectivore" from South America (SA). Since then, and despite the discovery of additional well-preserved material, the systematic status of Necrolestes has remained in flux, with earlier studies leaning toward placental affinities and more recent ones endorsing either therian or specifically metatherian relationships. We have further prepared the best-preserved specimens of Necrolestes and compared them with newly discovered nontribosphenic Mesozoic mammals from Argentina; based on this, we conclude that Necrolestes is related neither to marsupials nor placentals but is a late-surviving member of the recently recognized nontherian clade Meridiolestida, which is currently known only from SA. This conclusion is supported by a morphological phylogenetic analysis that includes a broad sampling of therian and nontherian taxa and that places Necrolestes within Meridiolestida. Thus, Necrolestes is a remnant of the highly endemic Mesozoic fauna of nontribosphenic mammals in SA and extends the known record of meridiolestidans by almost 45 million years. Together with other likely relictual mammals from earlier in the Cenozoic of SA and Antarctica, Necrolestes demonstrates the ecological diversity of mammals and the mosaic pattern of fauna replacement in SA during the Cenozoic. In contrast to northern continents, the Cenozoic faunal history of SA was characterized by a long period of interaction between endemic mammalian lineages of Mesozoic origin and metatherian and eutherian lineages that probably dispersed to SA during the latest Cretaceous or earliest Paleocene.

  5. The placental RCAS1 expression during stillbirth

    Directory of Open Access Journals (Sweden)

    Tetlak Tomasz

    2005-06-01

    Full Text Available Abstract Background Independently of the fetal death cause the beginning and course of stillbirth is closely related with the growing cytotoxic activity at the maternal-fetal interface. RCAS1 participates in the inhibition of maternal immune response during pregnancy. The alterations of RCAS1 protein expression in placental cells seem to determine the beginning of the labor and participate in the placental abruption. The aim of the present study was to investigate RCAS1 expression in placentas obtained following stillbirths or normal term births. Methods: RCAS1 expression was evaluated by Western blot method with the use of monoclonal anti-RCAS1 antibody in 67 placental tissue samples. Pregnant women were divided into four groups according to the mode of labor onset – spontaneous or induced, and the type of labor, stillbirth or labor at term. Placental beta-Actin expression was chosen as a control protein. Relative amounts of placental RCAS1 were compared with the use of Student's t-test, whereas beta-Actin control data were compared with the use of Mann-Whitney U test. Results: The average relative amount of RCAS1 was significantly lower in women with induced stillbirths than in women with induced labor at term. Similarly, significantly lower RCAS1 placental levels were observed in patients with spontaneous stillbirths than in women with spontaneous labor at term. Significant differences in RCAS1 expression were also observed with the respect to the beginning of the stillbirth: spontaneous and induced. Lowest RCAS1 placental levels were observed in women with spontaneous stillbirth. Conclusions: These preliminary results indicate that the alterations of RCAS1 expression in the human placenta may be involved in the changes of maternal immune system that take place during stillbirth.

  6. Ecotoxicology of Wild Mammals

    Science.gov (United States)

    2001-01-01

    An international group of 32 scientists has critically reviewed the scientific literature on exposure and effects of environmental contaminants in wild mammals. The underlying theme of this text is encompassed by the following four questions: What exactly do we know about environmental contaminants in mammals? What are the commonalities and differences between mammal orders/species in the effects that contaminants have? How and to what degree of accuracy can we predict the adverse effects of environmental contaminants on mammalian wildlife? How significant are contaminant insults compared with other density-independent and -dependent factors such as habitat loss, climatic factors and disease? The book is organized three topical sections including introductory chapters that provide a background on environmental contaminants and the mammalian orders, eight taxonomic chapters discussing all aspects of the exposure to and effects of contaminants in mammalian orders, and four thematic chapters that review and discuss generic issues including biomarkers, prediction and extrapolation of exposure and effects, hazard and risk assessment, and the relative significance of contaminants on mammals compared with other commonly encountered stressors. A final a summary chapter identifies phylogenetic trends, critical data gaps, and overarching research needs. Although the absolute number of toxicological studies in domesticated and wild mammals eclipses that wildlife species, a detailed examination of our knowledge base reveals that information for 'wild' birds is actually greater than that for 'wild' mammals. Of the various mammalian taxa, ecotoxicological data is most noticeably lacking for marsupials and monotremes. In contrast, rodents (comprising 43% of all mammal species) have been studied extensively, despite evidence of their tolerance to some organochlorine compounds, rodenticides, and even radionuclides. Mammalian species at greatest risk of exposure include those that

  7. Sex determination in mammals--before and after the evolution of SRY.

    Science.gov (United States)

    Wallis, M C; Waters, P D; Graves, J A M

    2008-10-01

    Therian mammals (marsupials and placentals) have an XX female: XY male sex chromosome system, which is homologous to autosomes in other vertebrates. The testis-determining gene, SRY, is conserved on the Y throughout therians, but is absent in other vertebrates, suggesting that the mammal system evolved about 310 million years ago (MYA). However, recent work on the basal monotreme mammals has completely changed our conception of how and when this change occurred. Platypus and echidna lack SRY, and the therian X and Y are represented by autosomes, implying that SRY evolved in therians after their divergence from monotremes only 166 MYA. Clues to the ancestral mechanism usurped by SRY in therians are provided by the monotremes, whose sex chromosomes are homologous to the ZW of birds. This suggests that the therian X and Y, and the SRY gene, evolved from an ancient bird-like sex chromosome system which predates the divergence of mammals and reptiles 310 MYA.

  8. The shape of mammalian phylogeny

    DEFF Research Database (Denmark)

    Purvis, Andy; Fritz, Susanne A; Rodríguez, Jesús

    2011-01-01

    Mammalian phylogeny is far too asymmetric for all contemporaneous lineages to have had equal chances of diversifying. We consider this asymmetry or imbalance from four perspectives. First, we infer a minimal set of 'regime changes'-points at which net diversification rate has changed-identifying ...

  9. Prenatal Brain-Body Allometry in Mammals.

    Science.gov (United States)

    Halley, Andrew C

    2016-01-01

    Variation in relative brain size among adult mammals is produced by different patterns of brain and body growth across ontogeny. Fetal development plays a central role in generating this diversity, and aspects of prenatal physiology such as maternal relative metabolic rate, altriciality, and placental morphology have been proposed to explain allometric differences in neonates and adults. Primates are also uniquely encephalized across fetal development, but it remains unclear when this pattern emerges during development and whether it is common to all primate radiations. To reexamine these questions across a wider range of mammalian radiations, data on the primarily fetal rapid growth phase (RGP) of ontogenetic brain-body allometry was compiled for diverse primate (np = 12) and nonprimate (nnp = 16) mammalian species, and was complemented by later ontogenetic data in 16 additional species (np = 9; nnp = 7) as well as neonatal proportions in a much larger sample (np = 38; nnp = 83). Relative BMR, litter size, altriciality, and placental morphology fail to predict RGP slopes as would be expected if physiological and life history variables constrained fetal brain growth, but are associated with differences in birth timing along allometric trajectories. Prenatal encephalization is shared by all primate radiations, is unique to the primate Order, and is characterized by: (1) a robust change in early embryonic brain/body proportions, and (2) higher average RGP allometric slopes due to slower fetal body growth. While high slopes are observed in several nonprimate species, primates alone exhibit an intercept shift at 1 g body size. This suggests that primate prenatal encephalization is a consequence of early changes to embryonic neural and somatic tissue growth in primates that remain poorly understood.

  10. Osmoregulation in marine mammals

    Science.gov (United States)

    Ortiz, R. M.

    2001-01-01

    Osmoregulation in marine mammals has been investigated for over a century; however, a review of recent advances in our understanding of water and electrolyte balance and of renal function in marine mammals is warranted. The following topics are discussed: (i) kidney structure and urine concentrating ability, (ii) sources of water, (iii) the effects of feeding, fasting and diving, (iv) the renal responses to infusions of varying salinity and (v) hormonal regulation. The kidneys of pinnipeds and cetaceans are reniculate in structure, unlike those of terrestrial mammals (except bears), but this difference does not confer any greater concentrating ability. Pinnipeds, cetaceans, manatees and sea otters can concentrate their urine above the concentration of sea water, but only pinnipeds and otters have been shown to produce urine concentrations of Na+ and Cl- that are similar to those in sea water. This could afford them the capacity to drink sea water and not lose fresh water. However, with few exceptions, drinking is not a common behavior in pinnipeds and cetaceans. Water balance is maintained in these animals via metabolic and dietary water, while incidental ingestion and dietary salt may help maintain electrolyte homeostasis. Unlike most other aquatic mammals, sea otters commonly drink sea water and manatees frequently drink fresh water. Among the various taxonomic groups of marine mammals, the sensitivity of the renin-angiotensin-aldosterone system appears to be influenced by the availability of Na+. The antidiuretic role of vasopressin remains inconclusive in marine mammals, while the natriuretic function of atrial natriuretic peptide has yet to be examined. Ideas on the direction of future studies are presented.

  11. Relation between utero-placental and feto-placental circulations: a longitudinal study.

    Science.gov (United States)

    Flo, Kari; Wilsgaard, Tom; Acharya, Ganesh

    2010-10-01

    To explore the relation between total utero-placental (TQ(uta)) and feto-placental (Q(uv)) blood flows and establish longitudinal reference ranges for the TQ(uta)/Q(uv) ratio and the mean uterine artery and umbilical artery pulsatility (UtaPI/UAPI) and resistance index (UtaRI/UARI) ratios. Prospective longitudinal observational study. University hospital in Norway. Fifty-three low-risk pregnant women. Uterine artery and umbilical vein blood flow was measured using Doppler ultrasonography at 4-weekly intervals from 22(+0) to 39(+6) weeks of gestation. Ratios between utero-placental and feto-placental volume blood flows and between indices of uterine and umbilical artery impedance. The TQ(uta)/Q(uv) ratio had a significant association with the gestational age (p feto-placental circulations do not appear to be affected by each other under physiological conditions. We have established longitudinal reference ranges for the utero-placental and feto-placental blood flow and impedance ratios during the second half of pregnancy.

  12. PPAR Signaling in Placental Development and Function.

    Science.gov (United States)

    Barak, Yaacov; Sadovsky, Yoel; Shalom-Barak, Tali

    2008-01-01

    With the major attention to the pivotal roles of PPARs in diverse aspects of energy metabolism, the essential functions of PPARgamma and PPARbeta/delta in placental development came as a surprise and were often considered a nuisance en route to their genetic analysis. However, these findings provided an opportune entrée into placental biology. Genetic and pharmacological studies, primarily of knockout animal models and cell culture, uncovered networks of PPARgamma and PPARdelta, their heterodimeric RXR partners, associated transcriptional coactivators, and target genes, that regulate various aspects of placental development and function. These studies furnish both specific information about trophoblasts and the placenta and potential hints about the functions of PPARs in other tissues and cell types. They reveal that the remarkable versatility of PPARs extends beyond the orchestration of metabolism to the regulation of cellular differentiation, tissue development, and trophoblast-specific functions. This information and its implications are the subject of this review.

  13. Louisiana ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for terrestrial mammals in Louisiana. Vector polygons in this data set represent terrestrial mammal...

  14. Confined placental mosaicism in short term culture

    Directory of Open Access Journals (Sweden)

    Petrović Bojana

    2016-01-01

    Full Text Available Finding of fetal chromosomal mosaicism complicates genetic counseling, as well as pregnancy management. The aim of this study was to determine the risk of confined placental mosaicism in short term culture of chorionic villous samples. We conducted a retrospective review of karyotype analysis results obtained after chorionic villous sampling (CVS in two years period. A 420 samples of chorionic villi were taken transabdominally and obtained by a semidirect method (overnight incubating culture. All fetuses with CVS mosaicism were under the intensive perinatal care. In all cases of chromosome mosaicism the additional karyotyping was performed from fetal blood samples after 22nd gestational week in order to exclude true fetal mosaicism. After delivery newborns were examined by experienced pediatrician. From 420 analyzed samples in 11 (2,6% cases we found placental mosaicism. No anomalies were seen in genetic sonogram of this fetuses and mosaicism was confirmed only in one case. Confined placental mosaicism (CPM was found in 2,1% (9/420 of all analyzed cases, and it made 90% of all placental mosaicism. In 60% (6/10 of placental mosaicism cases we found mosaicism with single aberrant cell. Trisomy 21 mosaicism was the most frequent aberration found in 30% of cases. Finding of mosaicism in chorionic villi sample is at special importance for genetic counseling, because every case has to be reveled individually regarding the type and level of mosaicism. Anyway, in every case of placental mosaicism intensive antenatal monitoring is necessary, with additional chromosome analysis from different tissue in consideration of previous findings.

  15. Placental ontogeny in Tasmanian snow skinks (genus Niveoscincus) (Lacertilia: Scincidae).

    Science.gov (United States)

    Stewart, James R; Thompson, Michael B

    2009-04-01

    Lizards of the viviparous genus Niveoscincus contributed importantly to a classic model for the evolution of placentation of squamate reptiles. This model predicts that: (1) placental function is correlated with placental structural complexity and (2) the type of chorioallantoic placenta attributed to three species of Niveoscincus (N. metallicus, N. ocellatus, N. pretiosus) is intermediate in complexity to a highly placentotrophic type of placenta. Recent studies of two of these species (N. metallicus, N. ocellatus) revealed additional variation in placental structure, as well as variation in the level of placentotrophy; N. metallicus is predominantly lecithotrophic, while N. ocellatus is highly placentotrophic. We used light microscopy to study placental ontogeny in two biennially reproducing species of Niveoscincus (N. greeni, N. microlepidotus) and placental morphology in late stage embryos of N. pretiosus. These data, in combination with prior studies, provide descriptions of placental structure for six of the eight species assigned to this lineage. The genus Niveoscincus has greater variation in placental structure than any other squamate lineage. We recognize four distinct groupings among these six species based on placental structure. The most highly placentotrophic species, N. ocellatus, has a complex placental morphology, yet shares these structures with a predominantly lecithotrophic species, N. microlepidotus. Thus, among species of Niveoscincus, placental structural complexity is not an infallible predictor of overall placental function.

  16. Quality assessment of a placental perfusion protocol

    DEFF Research Database (Denmark)

    Mathiesen, Line; Mose, Tina; Mørck, Thit Juul;

    2010-01-01

    the placental perfusion model in Copenhagen including control substances. The positive control substance antipyrine shows no difference in transport regardless of perfusion media used or of terms of delivery (n=59, pmarked dextran correspond with leakage criteria (...mlh(-1) from the fetal reservoir) when adding 2 (n=7) and 20mg (n=9) FITC-dextran/100ml fetal perfusion media. Success rate of the Copenhagen placental perfusions is provided in this study, including considerations and quality control parameters. Three checkpoints suggested to determine success rate...

  17. The gut bacterial community of mammals from marine and terrestrial habitats.

    Directory of Open Access Journals (Sweden)

    Tiffanie M Nelson

    Full Text Available After birth, mammals acquire a community of bacteria in their gastro-intestinal tract, which harvests energy and provides nutrients for the host. Comparative studies of numerous terrestrial mammal hosts have identified host phylogeny, diet and gut morphology as primary drivers of the gut bacterial community composition. To date, marine mammals have been excluded from these comparative studies, yet they represent distinct examples of evolutionary history, diet and lifestyle traits. To provide an updated understanding of the gut bacterial community of mammals, we compared bacterial 16S rRNA gene sequence data generated from faecal material of 151 marine and terrestrial mammal hosts. This included 42 hosts from a marine habitat. When compared to terrestrial mammals, marine mammals clustered separately and displayed a significantly greater average relative abundance of the phylum Fusobacteria. The marine carnivores (Antarctic and Arctic seals and the marine herbivore (dugong possessed significantly richer gut bacterial community than terrestrial carnivores and terrestrial herbivores, respectively. This suggests that evolutionary history and dietary items specific to the marine environment may have resulted in a gut bacterial community distinct to that identified in terrestrial mammals. Finally we hypothesize that reduced marine trophic webs, whereby marine carnivores (and herbivores feed directly on lower trophic levels, may expose this group to high levels of secondary metabolites and influence gut microbial community richness.

  18. The gut bacterial community of mammals from marine and terrestrial habitats.

    Science.gov (United States)

    Nelson, Tiffanie M; Rogers, Tracey L; Brown, Mark V

    2013-01-01

    After birth, mammals acquire a community of bacteria in their gastro-intestinal tract, which harvests energy and provides nutrients for the host. Comparative studies of numerous terrestrial mammal hosts have identified host phylogeny, diet and gut morphology as primary drivers of the gut bacterial community composition. To date, marine mammals have been excluded from these comparative studies, yet they represent distinct examples of evolutionary history, diet and lifestyle traits. To provide an updated understanding of the gut bacterial community of mammals, we compared bacterial 16S rRNA gene sequence data generated from faecal material of 151 marine and terrestrial mammal hosts. This included 42 hosts from a marine habitat. When compared to terrestrial mammals, marine mammals clustered separately and displayed a significantly greater average relative abundance of the phylum Fusobacteria. The marine carnivores (Antarctic and Arctic seals) and the marine herbivore (dugong) possessed significantly richer gut bacterial community than terrestrial carnivores and terrestrial herbivores, respectively. This suggests that evolutionary history and dietary items specific to the marine environment may have resulted in a gut bacterial community distinct to that identified in terrestrial mammals. Finally we hypothesize that reduced marine trophic webs, whereby marine carnivores (and herbivores) feed directly on lower trophic levels, may expose this group to high levels of secondary metabolites and influence gut microbial community richness.

  19. Selective Amplification of the Genome Surrounding Key Placental Genes in Trophoblast Giant Cells.

    Science.gov (United States)

    Hannibal, Roberta L; Baker, Julie C

    2016-01-25

    While most cells maintain a diploid state, polyploid cells exist in many organisms and are particularly prevalent within the mammalian placenta [1], where they can generate more than 900 copies of the genome [2]. Polyploidy is thought to be an efficient method of increasing the content of the genome by avoiding the costly and slow process of cytokinesis [1, 3, 4]. Polyploidy can also affect gene regulation by amplifying a subset of genomic regions required for specific cellular function [1, 3, 4]. This mechanism is found in the fruit fly Drosophila melanogaster, where polyploid ovarian follicle cells amplify genomic regions containing chorion genes, which facilitate secretion of eggshell proteins [5]. Here, we report that genomic amplification also occurs in mammals at selective regions of the genome in parietal trophoblast giant cells (p-TGCs) of the mouse placenta. Using whole-genome sequencing (WGS) and digital droplet PCR (ddPCR) of mouse p-TGCs, we identified five amplified regions, each containing a gene family known to be involved in mammalian placentation: the prolactins (two clusters), serpins, cathepsins, and the natural killer (NK)/C-type lectin (CLEC) complex [6-12]. We report here the first description of amplification at selective genomic regions in mammals and present evidence that this is an important mode of genome regulation in placental TGCs.

  20. Placental lesions and outcome in preterm born children : the relation between placental lesions, neonatal morbidity and neurological development

    NARCIS (Netherlands)

    Roescher, Annemiek

    2014-01-01

    The placenta is the link between the mother and her fetus during pregnancy and plays a crucial role in fetal growth and development. A less than optimal placental function as a result of placental lesions, may lead to maternal and or fetal problems. It is known that placental lesions are an importan

  1. Eye size and visual acuity influence vestibular anatomy in mammals.

    Science.gov (United States)

    Kemp, Addison D; Christopher Kirk, E

    2014-04-01

    The semicircular canals of the inner ear detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity require precise gaze stabilization mechanisms because they experience diminished visual functionality at low thresholds of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here, we examine the relationship between mean semicircular canal radius of curvature, eye size, and visual acuity in a large sample of mammals. Our results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that variation in mean semicircular canal radius of curvature among mammals is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. Our results also provide a possible functional explanation for the small semicircular canal radii of fossorial mammals and plesiadapiforms. Copyright © 2014 Wiley Periodicals, Inc.

  2. 77 FR 2512 - Marine Mammals

    Science.gov (United States)

    2012-01-18

    ... National Oceanic and Atmospheric Administration RIN 0648-XA905 Marine Mammals AGENCY: National Marine...; receipt of application. SUMMARY: Notice is hereby given that Dorian Houser, Ph.D., National Marine Mammal... under the authority of the Marine Mammal Protection Act of 1972, as amended (MMPA; 16 U.S.C. 1361 et seq...

  3. 77 FR 9627 - Marine Mammals

    Science.gov (United States)

    2012-02-17

    ... National Oceanic and Atmospheric Administration RIN 0648-XB005 Marine Mammals AGENCY: National Marine.../2\\ W. 4th Avenue, Olympia, WA 98501, has applied in due form for a permit to take marine mammals in... subject permit is requested under the authority of the Marine Mammal Protection Act of 1972, as amended...

  4. 75 FR 68605 - Marine Mammals

    Science.gov (United States)

    2010-11-08

    ... National Oceanic and Atmospheric Administration RIN 0648-XX23 Marine Mammals AGENCY: National Marine... Marine Science Center, Newport, OR has been issued a permit to conduct research on marine mammals... authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations...

  5. 76 FR 75524 - Marine Mammals

    Science.gov (United States)

    2011-12-02

    ... National Oceanic and Atmospheric Administration RIN 0648-XO45 Marine Mammals AGENCY: National Marine... conduct research on marine mammals. ADDRESSES: The application and related documents are available for... under the authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq...

  6. 76 FR 72680 - Marine Mammals

    Science.gov (United States)

    2011-11-25

    ... National Oceanic and Atmospheric Administration RIN 0648-XA078 Marine Mammals AGENCY: National Marine.... Environmental Research and Services, Fairbanks, AK, to conduct research on marine mammals in Alaska. ADDRESSES... authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations...

  7. Physiological Monitoring in Diving Mammals

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Physiological Monitoring in Diving Mammals Andreas...825-2025 email: andreas.fahlman@tamucc.edu Peter L. Tyack School of Biology Sea Mammal Research Unit Scottish Oceans Institute...OBJECTIVES This project is separated into three aims: Aim 1: Develop a new generation of tags/data logger for marine mammals that will

  8. 77 FR 14352 - Marine Mammals

    Science.gov (United States)

    2012-03-09

    ... National Oceanic and Atmospheric Administration RIN 0648-XB065 Marine Mammals AGENCY: National Marine... permit has been issued under the authority of the Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR...

  9. 76 FR 76949 - Marine Mammals

    Science.gov (United States)

    2011-12-09

    ... National Oceanic and Atmospheric Administration RIN 0648-XR52 Marine Mammals AGENCY: National Marine... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the Endangered Species Act of 1973, as amended...

  10. 76 FR 72681 - Marine Mammals

    Science.gov (United States)

    2011-11-25

    ... National Oceanic and Atmospheric Administration RIN 0648-XU87 Marine Mammals AGENCY: National Marine... Mammal Laboratory, (Responsible Party: Dr. John Bengtson, Director), Seattle, WA, has applied for an amendment to Scientific Research Permit No. 15126-01 for studies of marine mammals in Alaska. DATES: Written...

  11. 76 FR 25308 - Marine Mammals

    Science.gov (United States)

    2011-05-04

    ... National Oceanic and Atmospheric Administration RIN 0648-XA165 Marine Mammals AGENCY: National Marine... ] scientific research on marine mammal parts. ADDRESSES: The permit and related documents are available for..., and export marine mammal parts for scientific research studies. The requested permit has been issued...

  12. 75 FR 77616 - Marine Mammals

    Science.gov (United States)

    2010-12-13

    ... National Oceanic and Atmospheric Administration RIN 0648-XP18 Marine Mammals AGENCY: National Marine... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing the taking and importing of marine mammals (50 CFR part 216), the Endangered Species Act of 1973, as amended...

  13. Role of mouse Wdr13 in placental growth; a genetic evidence for lifetime body weight determination by placenta during development.

    Science.gov (United States)

    Singh, Vijay Pratap; Alex, Jomini Liza; Lakshmi, B Jyothi; Sailasree, S Purnima; Raj, T Avinash; Kumar, Satish

    2015-08-26

    Placental development is essential for implantation and growth of foetus in the uterus of eutherian mammals. Numerous growth factors are responsible for placental development and cell lineage differentiation. Gene knockout mice have shown role of various genes in the placenta. Here using Wdr13 knockout mice, we show that this gene is important for proper placental development. Wdr13, a X-linked gene, expresses in multiple trophoblast cell types of placenta and the mutant placenta had reduced size after 17.5 dpc due to reduction of junctional zone (JZ) and labyrinth zone (LZ). We observed reduction in levels of angiopoietin-2 and cd44 mRNA in Wdr13 mutant placenta as compared to that in the wild type. Our findings show that Wdr13 is required for normal placental development and cell differentiation. Wdr13 heterozygous female placenta when the mutant allele was of maternal origin showed similar defects as those in case of Wdr13 null placenta. Using two types of heterozygous females carrying either maternally and paternally derived mutant Wdr13 allele we provide genetic evidence that development of placenta determines body weight of mice for the entire life.

  14. High-Performance Phylogeny Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Tiffani L. Williams

    2004-11-10

    Under the Alfred P. Sloan Fellowship in Computational Biology, I have been afforded the opportunity to study phylogenetics--one of the most important and exciting disciplines in computational biology. A phylogeny depicts an evolutionary relationship among a set of organisms (or taxa). Typically, a phylogeny is represented by a binary tree, where modern organisms are placed at the leaves and ancestral organisms occupy internal nodes, with the edges of the tree denoting evolutionary relationships. The task of phylogenetics is to infer this tree from observations upon present-day organisms. Reconstructing phylogenies is a major component of modern research programs in many areas of biology and medicine, but it is enormously expensive. The most commonly used techniques attempt to solve NP-hard problems such as maximum likelihood and maximum parsimony, typically by bounded searches through an exponentially-sized tree-space. For example, there are over 13 billion possible trees for 13 organisms. Phylogenetic heuristics that quickly analyze large amounts of data accurately will revolutionize the biological field. This final report highlights my activities in phylogenetics during the two-year postdoctoral period at the University of New Mexico under Prof. Bernard Moret. Specifically, this report reports my scientific, community and professional activities as an Alfred P. Sloan Postdoctoral Fellow in Computational Biology.

  15. Molecular phylogeny of Arthrotardigrada (Tardigrada).

    Science.gov (United States)

    Jørgensen, Aslak; Faurby, Søren; Hansen, Jesper G; Møbjerg, Nadja; Kristensen, Reinhardt M

    2010-03-01

    Tardigrades are microscopic ecdysozoans with a worldwide distribution covering marine, limnic and terrestrial habitats. They are regarded as a neglected phylum with regard to studies of their phylogeny. During the last decade molecular data have been included in the investigation of tardigrades. However, the marine arthrotardigrades are still poorly sampled due to their relative rarity, difficult identification and minute size even for tardigrades. In the present study, we have sampled various arthrotardigrades and sequenced the 18S and partial 28S ribosomal subunits. The phylogenetic analyses based on Bayesian inference and maximum parsimony inferred Heterotardigrada (Arthrotardigrada+Echiniscoidea) and Eutardigrada to be monophyletic. Arthrotardigrada was inferred to be paraphyletic as the monophyletic Echiniscoidea is included within the arthrotardigrades. The phylogenetic positions of Stygarctidae and Batillipedidae are poorly resolved with low branch support. The Halechiniscidae is inferred to be polyphyletic as the currently recognized Styraconyxinae is not part of the family. Archechiniscus is the sister-group to the Halechiniscidae and Orzeliscus is placed as one of the basal halechiniscids. The phylogeny of the included eutardigrade taxa resembles the current molecular phylogenies. The genetic diversity within Arthrotardigrada is much larger (18S 15.1-26.5%, 28S 7.2-20.7%) than within Eutardigrada (18S 1.0-12.6%, 28S 1.3-8.2%). This can be explained by higher substitution rates in the arthrotardigrades or by a much younger evolutionary age of the sampled eutardigrades.

  16. Fossil evidence on evolution of inner ear cochlea in Jurassic mammals.

    Science.gov (United States)

    Luo, Zhe-Xi; Ruf, Irina; Schultz, Julia A; Martin, Thomas

    2011-01-07

    The coiled cochlea is a key evolutionary innovation of modern therian mammals. We report that the Late Jurassic mammal Dryolestes, a relative to modern therians, has derived bony characteristics of therian-like innervation, but its uncoiled cochlear canal is less derived than the coiled cochlea of modern therians. This suggests a therian-like innervation evolved before the fully coiled cochlea in phylogeny. The embryogenesis of the cochlear nerve and ganglion in the inner ear of mice is now known to be patterned by neurogenic genes, which we hypothesize to have influenced the formation of the auditory nerve and its ganglion in Jurassic therian evolution, as shown by their osteological correlates in Dryolestes, and by the similar base-to-apex progression in morphogenesis of the ganglion in mice, and in transformation of its canal in phylogeny. The cochlear innervation in Dryolestes is the precursory condition in the curve-to-coil transformation of the cochlea in mammalian phylogeny. This provides the timing of the evolution, and where along the phylogeny the morphogenetic genes were co-opted into patterning the cochlear innervation, and the full coiling of the cochlea in modern therians.

  17. Evolution from XIST-independent to XIST-controlled X-chromosome inactivation: epigenetic modifications in distantly related mammals.

    Directory of Open Access Journals (Sweden)

    Julie Chaumeil

    Full Text Available X chromosome inactivation (XCI is the transcriptional silencing of one X in female mammals, balancing expression of X genes between females (XX and males (XY. In placental mammals non-coding XIST RNA triggers silencing of one X (Xi and recruits a characteristic suite of epigenetic modifications, including the histone mark H3K27me3. In marsupials, where XIST is missing, H3K27me3 association seems to have different degrees of stability, depending on cell-types and species. However, the complete suite of histone marks associated with the Xi and their stability throughout cell cycle remain a mystery, as does the evolution of an ancient mammal XCI system. Our extensive immunofluorescence analysis (using antibodies against specific histone modifications in nuclei of mammals distantly related to human and mouse, revealed a general absence from the mammalian Xi territory of transcription machinery and histone modifications associated with active chromatin. Specific repressive modifications associated with XCI in human and mouse were also observed in elephant (a distantly related placental mammal, as was accumulation of XIST RNA. However, in two marsupial species the Xi either lacked these modifications (H4K20me1, or they were restricted to specific windows of the cell cycle (H3K27me3, H3K9me2. Surprisingly, the marsupial Xi was stably enriched for modifications associated with constitutive heterochromatin in all eukaryotes (H4K20me3, H3K9me3. We propose that marsupial XCI is comparable to a system that evolved in the common therian (marsupial and placental ancestor. Silent chromatin of the early inactive X was exapted from neighbouring constitutive heterochromatin and, in early placental evolution, was augmented by the rise of XIST and the stable recruitment of specific histone modifications now classically associated with XCI.

  18. Evolution from XIST-Independent to XIST-Controlled X-Chromosome Inactivation: Epigenetic Modifications in Distantly Related Mammals

    Science.gov (United States)

    Koina, Edda; Gilbert, Clément; Robinson, Terence J.; Marshall Graves, Jennifer A.

    2011-01-01

    X chromosome inactivation (XCI) is the transcriptional silencing of one X in female mammals, balancing expression of X genes between females (XX) and males (XY). In placental mammals non-coding XIST RNA triggers silencing of one X (Xi) and recruits a characteristic suite of epigenetic modifications, including the histone mark H3K27me3. In marsupials, where XIST is missing, H3K27me3 association seems to have different degrees of stability, depending on cell-types and species. However, the complete suite of histone marks associated with the Xi and their stability throughout cell cycle remain a mystery, as does the evolution of an ancient mammal XCI system. Our extensive immunofluorescence analysis (using antibodies against specific histone modifications) in nuclei of mammals distantly related to human and mouse, revealed a general absence from the mammalian Xi territory of transcription machinery and histone modifications associated with active chromatin. Specific repressive modifications associated with XCI in human and mouse were also observed in elephant (a distantly related placental mammal), as was accumulation of XIST RNA. However, in two marsupial species the Xi either lacked these modifications (H4K20me1), or they were restricted to specific windows of the cell cycle (H3K27me3, H3K9me2). Surprisingly, the marsupial Xi was stably enriched for modifications associated with constitutive heterochromatin in all eukaryotes (H4K20me3, H3K9me3). We propose that marsupial XCI is comparable to a system that evolved in the common therian (marsupial and placental) ancestor. Silent chromatin of the early inactive X was exapted from neighbouring constitutive heterochromatin and, in early placental evolution, was augmented by the rise of XIST and the stable recruitment of specific histone modifications now classically associated with XCI. PMID:21541345

  19. Comment on "Impacts of the Cretaceous Terrestrial Revolution and KPg extinction on mammal diversification".

    Science.gov (United States)

    Bininda-Emonds, Olaf R P; Purvis, Andy

    2012-07-01

    Meredith et al. (Reports, 28 October 2011, p. 521) question three findings of our delayed-rise hypothesis for present-day mammals made with reference to the Cretaceous-Paleogene (KPg) boundary, based on their new time tree of the group. We show that their own data do not support their objections and that the macroevolutionary patterns from the respective phylogenies are not statistically different.

  20. Placental Development in Ongoing Pregnancy and Miscarriage

    NARCIS (Netherlands)

    A.D. Reus (Averil)

    2015-01-01

    markdownabstract__Abstract__ In this thesis three-dimensional ultrasound, three-dimensional power Doppler ultrasound, virtual reality and histologic examination of the chorionic villous vascularization were used to investigate early placental development in normal ongoing pregnancy as well as misca

  1. A RADIOIMMUNOASSAY FOR PLACENTAL PROTEIN PP5

    Institute of Scientific and Technical Information of China (English)

    WANGShui-Long; DUGuo-Guang; ZHENGShu-Rong; LIUXin-Jun; YANRen-Ying

    1989-01-01

    A radioimmunoasay of high sendtivity end smbility was developed For placental proteinPP5 (PP5), a syncytiotrophoblast product oF the human placenta. We measured 94 samples from 17 normal nonpregnant women, 47 normal pregnant women, and 30 samples

  2. Placental specializations in lecithotrophic viviparous squamate reptiles.

    Science.gov (United States)

    Stewart, James R

    2015-09-01

    Squamate reptiles have been thought to be predisposed to evolution of viviparity because embryos of most oviparous species undergo considerable development in the uterus prior to oviposition. A related hypothesis proposes that prolonged intrauterine gestation, an intermediate condition leading to viviparity, requires little or no physiological adjustment, other than reduction in thickness of the eggshell. This logical framework is often accompanied by an assumption that mode of parity (oviparity, viviparity) and pattern of embryonic nutrition (lecithotrophy, placentotrophy) are independent traits that evolve in sequence. Thus, specializations for viviparity should be absent in some lecithotrophic viviparous species. Studies of species of lizards with geographic variation in mode of parity challenge this scenario by demonstrating that placental specializations are correlated with viviparity. Uterine specializations for placental transport of calcium to viviparous embryos alter uterine physiology compared to oviparous females. In addition, comparative studies of oviparous and viviparous species, i.e., in which gene flow is disrupted, reveal that both uterine and embryonic structural modifications are commonly associated with viviparity, suggesting relatively rapid evolution of placental specializations. Studies of squamate reproductive biology support two hypotheses: 1) evolution of viviparity requires physiological adjustments of the uterine environment, and 2) evolution of viviparity promotes relatively rapid adaptations for placentation. Models for the evolution of viviparity from oviparity, or for reversals from viviparity to oviparity, should reflect current understanding of squamate reproductive biology and future studies should be designed to challenge these models.

  3. Pregnancy Complications: Placental Accreta, Increta and Percreta

    Science.gov (United States)

    ... Being 35 or older Being pregnant before Having placenta previa How can you reduce your risk for placental conditions? One way to reduce your chances for having these ... In some cases, the placenta doesn’t develop correctly or work as well ...

  4. Placental Malaria: From Infection to Malfunction

    OpenAIRE

    2013-01-01

    Malaria during pregnancy is a major factor in infant morbidity and mortality. In this issue of Cell Host and Microbe, Conroy et al. (2013) propose that C5a, a product of complement cascade activation, counteracts the placental vascular remodeling response induced by Plasmodium infection and contributes to fetal growth restriction. Fundação para a Ciência e Tecnologia.

  5. Placental Mesenchymal Dysplasia: A Case Report

    Directory of Open Access Journals (Sweden)

    Rachna Agarwal

    2012-01-01

    Full Text Available Introduction. A rare case of histologically proven placental mesenchymal dysplasia (PMD with fetal omphalocele in a 22-year-old patient is reported. Material and Methods. Antenatal ultrasound of this patient showed hydropic placenta with a live fetus of 17 weeks period of gestation associated with omphalocele. Cordocentesis detected the diploid karyotype of the fetus. Patient, when prognosticated, choose to terminate the pregnancy in view of high incidence of fetal and placental anomalies. Subsequent histopathological examination of placenta established the diagnosis to be placental mesenchymal dysplasia. Conclusion. On clinical and ultrasonic grounds, suspicion of P.M.D. arises when hydropic placenta with a live fetus presents in second trimester of pregnancy. Cordocentesis can detect the diploid karyotype of the fetus in such cases. As this condition is prognostically better than triploid partial mole, continuation of pregnancy can sometimes be considered after through antenatal screening and patient counseling. However, a definite diagnosis of P.M.D. is made only on placental histology by absence of trophoblast hyperplasia and trophoblastic inclusions.

  6. Evolution of factors affecting placental oxygen transfer

    DEFF Research Database (Denmark)

    Carter, A M

    2009-01-01

    states, are more amenable to analysis. This is exemplified by factors contributing, respectively, to blood oxygen affinity and placental diffusing capacity. Comparative genomics has given fresh insight into the evolution of the beta-globin gene complex. In higher primates, duplication of an embryonic...

  7. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    ZHANG YiJun; QU LiangHu

    2009-01-01

    Genomic imprinting, representing parent-specific expression of alleles at a locus, Is mainly evident in flowering plants and placental mammals. Most imprinted genes, including numerous non-coding RNAs, are located in clusters regulated by imprinting control regions (ICRs). The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions. Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors, especially recent studies undertaken on the most ancient mammalian clades - the marsupials and monotremes from which model species genomes have recently been sequenced, are of high value. By reviewing and analyzing these studies, a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated. The evidence comes from two observations accompanied with the ac-quisition of the imprinting: (i) many novel non-coding RNA genes emerged in imprinted regions; (ii) the expressions of some conserved non-coding RNAs have changed dramatically. Furthermore, a system-atical analysis of imprinted snoRNA (small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials, followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals. Involved in the regulation of imprinted silencing and mediating the ohromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  8. Evolution of the patellar sesamoid bone in mammals

    Science.gov (United States)

    Samuels, Mark E.; Regnault, Sophie

    2017-01-01

    The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition) and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution

  9. Evolution of the patellar sesamoid bone in mammals

    Directory of Open Access Journals (Sweden)

    Mark E. Samuels

    2017-03-01

    Full Text Available The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa. Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across

  10. PLACENTAL PATHOLOGY IN INTRA UTERINE GROWTH RETARDATION

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    Vijaya Sheela

    2015-04-01

    Full Text Available INTRODUCTION: The placental development is an essential step in developing effective strategies or the prediction of various maternal and fetal medical and developmental problems . Oxygen transfer and nutrients to the fetus will be actively regulated by the placenta . AIM AND OBJECTIVE: To study morphological changes of placenta in Intrauterine growth Retardation and to correlate morphological changes of placenta with fetal outcome . MATERIALS AND METHODS: Placental tissue samples were obtained from 50 pregnancies complicated by IUGR and 50 normal uncomplicated pregnancies with gestational age between 28 to 42 weeks attending King George hospital Visakhapatnam . INCLUSIVE CRITERIA : An IUGR fetuses whose estimated fetal weight less than those in 10 th percentile are included in the study . Birth weight percentiles were determined by previously published normal curves . EXCLUSIVE CRITERIA: fetuses with known syndromes , chromosomal anomalies and twins . For all patients included in the data set gestational age was estimated from the last menstrual period or early ultra - sonogram before the 12 th week of gestation . The final data set was composed of 50pregnancies complicated by IUGR and APGAR scores . Because preeclampsia is an important maternal factor associated with IUGR , these cases were further divided into t wo subgroups according to presence of hypertension . Samples were taken both from vaginal deliveries and caesarean sections . All the placentas were examined by pathologists . The placentas were weighed . For each case one or two samples from the umbilical cor ds , extra placental membrane , and parenchyma were taken . Gross pathological findings were confirmed by histology . Histological data included are ischemic necrosis , decidual vascularity , acute chorioamni oni tis , fibrinoid necrosis and choriangiosis . Appropriate statistical parameters were used . Chi - square test was conducted to compare placental pathological changes

  11. Origin of INSL3-mediated testicular descent in therian mammals.

    Science.gov (United States)

    Park, Jae-Il; Semyonov, Jenia; Chang, Chia Lin; Yi, Wei; Warren, Wesley; Hsu, Sheau Yu Teddy

    2008-06-01

    Testicular descent is a unique physiological adaptation found in therian mammals allowing optimal spermatogenesis below core body temperature. Recent studies show that INSL3, produced by Leydig cells, and its receptor LGR8 (RXFP2) are essential for mediating the transabdominal phase of testicular descent during early development. However, the origin and genetic basis for this physiological adaptation is not clear. Using syntenic mapping and the functional characterization of contemporary and resurrected relaxin family hormones, we show that derivation of INSL3-mediated testicular descent involved the duplication of an ancestral RLN3-like gene that encodes an indiscriminate ligand for LGR7 (RXFP1) and LGR8. This event was followed by acquisition of the LGR7-selective characteristics by a daughter gene (RLN3) prior to the evolution of the common ancestor of monotremes, marsupials, and placentals. A subsequent mutation of the other daughter gene (INSL3) occurred before the emergence of therian mammals, which then led to the derivation of the reciprocal LGR8-specific characteristics of INSL3. The stepwise evolution of these independent signaling pathways through gene duplication and subsequent divergence is consistent with Darwinian theory of selection and adaptation, and the temporal proximity suggests an association between these genetic events and the concurrent evolution of testicular descent in ancestral therian mammals.

  12. Measuring Asymmetry in Time-Stamped Phylogenies.

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    Bethany L Dearlove

    2015-07-01

    Full Text Available Previous work has shown that asymmetry in viral phylogenies may be indicative of heterogeneity in transmission, for example due to acute HIV infection or the presence of 'core groups' with higher contact rates. Hence, evidence of asymmetry may provide clues to underlying population structure, even when direct information on, for example, stage of infection or contact rates, are missing. However, current tests of phylogenetic asymmetry (a suffer from false positives when the tips of the phylogeny are sampled at different times and (b only test for global asymmetry, and hence suffer from false negatives when asymmetry is localised to part of a phylogeny. We present a simple permutation-based approach for testing for asymmetry in a phylogeny, where we compare the observed phylogeny with random phylogenies with the same sampling and coalescence times, to reduce the false positive rate. We also demonstrate how profiles of measures of asymmetry calculated over a range of evolutionary times in the phylogeny can be used to identify local asymmetry. In combination with different metrics of asymmetry, this combined approach offers detailed insights of how phylogenies reconstructed from real viral datasets may deviate from the simplistic assumptions of commonly used coalescent and birth-death process models.

  13. Phylogeny Constructed by Using Dsing Diversity Increment

    Institute of Scientific and Technical Information of China (English)

    Shi Feng; Li Na-na; Li Yuan-xiang; Zhou Huai-bei

    2003-01-01

    A new approach based on the concept of the diversity increment is applied to reconstruct a phylogeny. The phylogeny of the Eutherian orders use concatenated H-stranded amino acid sequences, and the result is consistent with the commonly accepted one for the Eutherians.

  14. Doppler indicates of uterine artery Doppler velocimetry by placental location

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sung Shik; Park, Yong Won; Cho, Jae Sung; Kwon, Hye Kyeung; Kim, Jae Wook [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2001-09-15

    Our purpose was to investigate the relation between the vascular resistance of uterine artery and placental location and to establish the reference value of Doppler index in uterine artery by placental location. Placental location and flow velocity waveforms of both uterine arteries in 7,016 pregnant women after 18 weeks gestation were examined using color Doppler ultrasonography. Placental location was classified as central and lateral placental and the uterine artery with lateral placental were divided into ipsilateral uterine artery (same side of the placental) and contralateral uterine artery (opposite side of the placenta). The uterine artery with central placental was classified as the central uterine artery. Systolic-Diastolic ratio (S/D ratio) of uterine arteries by gestational weeks were calculated and compared with the placental location and perinatal outcomes. In the lateral placental group, the S/D ratio of the contralateral uterine artery was higher than the ipsilateral one (mean=2.08+0.34 vs 1.89+0.34, p=0.0001). S/D ratio of the uterine artery decreased during second trimester and the ratio after 27 weeks was a tendency to have a constant values(ipsilateral: 1.85+ 0.34, central : 1.96+ 0.40, contralateral: 2.01+0.54). S/D ratio of the uterine artery was affected by placental location. So when we evaluate Doppler spectrum of uterine artery, placental location should be considered and we established the reference value of Doppler index of uterine artery by placental location.

  15. Human placental lactogen and intrauterine growth retardation.

    Science.gov (United States)

    Spellacy, W N; Buhi, W C; Birk, S A

    1976-04-01

    Serum human placental lactogen levels were measured after 36 weeks' gestation in 264 serum samples from 109 women with normal pregnancies and in 137 serum samples from 70 women with pregnancies complicated by fetal intrauterine growth retardation (IGR). The fetal and placental weights were significantly lower in the IGR groups while the maternal ages were not different. There was a significantly lower hPL value at each week from 36 to 41 (except for the 39th) in the IGR group. Sixty percent of the women with IGR had hPL values less than 6 mug/ml, and 18.6% were less than 4 mug/ml. It is suggested that a low serum hPL value obtained during the last month of pregnancy should alert the physician to the possibility of intrauterine problems, including IGR.

  16. Neurotrophins: Role in Placental Growth and Development.

    Science.gov (United States)

    Sahay, A S; Sundrani, D P; Joshi, S R

    2017-01-01

    Neurotrophins, a family of closely related proteins, were originally identified as growth factors for survival, development, and function of neurons in both the central and peripheral nervous systems. Subsequently, neurotrophins have been shown to have functions in immune and reproductive systems. Neurotrophins like nerve growth factor and brain-derived neurotrophic factor (BDNF) are known to play an important role during pregnancy in the process of placental angiogenesis and maturation. Several studies have demonstrated the presence of neurotrophins in the human placenta. The current chapter reviews studies demonstrating the role of neurotrophins during pregnancy particularly in placental development. This chapter also focuses on the regional changes in neurotrophins in the human placenta and its interactions with other growth factors. Future research is needed to understand the mechanisms through which neurotrophins influence the growth and development of the placenta and pregnancy outcome.

  17. Placentation in the Amazonian manatee (Trichechus inunguis)

    DEFF Research Database (Denmark)

    Carter, A M; Miglino, M A; Ambrosio, C E;

    2008-01-01

    Evidence from several sources supports a close phylogenetic relationship between elephants and sirenians. To explore whether this was reflected in similar placentation, we examined eight delivered placentae from the Amazonian manatee using light microscopy and immunohistochemistry. In addition......, the fetal placental circulation was described by scanning electron microscopy of vessel casts. The manatee placenta was zonary and endotheliochorial, like that of the elephant. The interhaemal barrier comprised maternal endothelium, cytotrophoblasts and fetal endothelium. We found columnar trophoblast...... beneath the chorionic plate and lining lacunae in this region, but there was no trace in the term placenta of haemophagous activity. The gross anatomy of the cord and fetal membranes was consistent with previous descriptions and included a four-chambered allantoic sac, as also found in the elephant...

  18. Adenoviral-mediated placental gene transfer of IGF-1 corrects placental insufficiency via enhanced placental glucose transport mechanisms.

    Directory of Open Access Journals (Sweden)

    Helen N Jones

    Full Text Available Previous work in our laboratory demonstrated that over-expression of human insulin-like growth factor -1 (hIGF-1 in the placenta corrects fetal weight deficits in mouse, rat, and rabbit models of intrauterine growth restriction without changes in placental weight. The underlying mechanisms of this effect have not been elucidated. To investigate the effect of intra-placental IGF-1 over-expression on placental function we examined glucose transporter expression and localization in both a mouse model of IUGR and a model of human trophoblast, the BeWo Choriocarcinoma cell line.At gestational day 18, animals were divided into four groups; sham-operated controls, uterine artery branch ligation (UABL, UABL+Ad-hIGF-1 (10(8 PFU, UABL+Ad-LacZ (10(8 PFU. At gestational day 20, pups and placentas were harvested by C-section. For human studies, BeWo choriocarcinoma cells were grown in F12 complete medium +10%FBS. Cells were incubated in serum-free control media ± Ad-IGF-1 or Ad-LacZ for 48 hours. MOIs of 10∶1 and 100∶1 were utilized. The RNA, protein expression and localization of glucose transporters GLUT1, 3, 8, and 9 were analyzed by RT-PCR, Western blot and immunohistochemistry.In both the mouse placenta and BeWo, GLUT1 regulation was linked to altered protein localization. GLUT3, localized to the mouse fetal endothelial cells, was reduced in placental insufficiency but maintained with Ad-I GF-1 treatment. Interestingly, GLUT8 expression was reduced in the UABL placenta but up-regulated following Ad-IGF-1 in both mouse and human systems. GLUT9 expression in the mouse was increased by Ad-IGF-1 but this was not reflected in the BeWo, where Ad-IGF-1 caused moderate membrane relocalization.Enhanced GLUT isoform transporter expression and relocalization to the membrane may be an important mechanism in Ad-hIGF-1mediated correction of placental insufficiency.

  19. Preeclampsia, biomarkers, syncytiotrophoblast stress, and placental capacity.

    Science.gov (United States)

    Redman, Christopher W G; Staff, Anne Cathrine

    2015-10-01

    The maternal syndrome of preeclampsia is mediated by dysfunctional syncytiotrophoblast (STB). When this is stressed by uteroplacental malperfusion, its signaling to the mother changes, as part of a highly coordinated stress response. The STB signals are both proinflammatory and dysangiogenic such that the preeclamptic mother has a stronger vascular inflammatory response than normal, with an antiangiogenic bias. Angiogenic factors have limitations as preeclampsia biomarkers, especially for prediction and diagnosis of preeclampsia at term. However, if they are recognized as markers of STB stress, their physiological changes at term demonstrate that STB stress develops in all pregnancies. The biomarkers reveal that the duration of pregnancies is restricted by placental capacity, such that there is increasing placental dysfunction, at and beyond term. This capacity includes limitations imposed by the size of the uterus, the capacity of the uteroplacental circulation and, possibly, the supply of villous progenitor trophoblast cells. Limited placental capacity explains the increasing risks of postmaturity, including preeclampsia. Early-onset preeclampsia is predictable because STB stress and changes in its biomarkers are intrinsic to poor placentation, an early pregnancy pathology. Prediction of preeclampsia at term is not good because there is no early STB pathology. Moreover, biomarkers cannot accurately diagnose term preeclampsia against a background of universal STB dysfunction, which may or may not be clinically revealed before spontaneous or induced delivery. In this sense, postterm pregnancy is, at best, a pseudonormal state. However, the markers may prove useful in screening for women with more severe problems of postmaturity. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Placental lactogen levels in rhesus isoimmunization.

    Science.gov (United States)

    Ward, R H; Letchworth, A T; Niven, P A; Chard, T

    1974-03-02

    A prospective study of the plasma levels of human placental lactogen (HPL) in pregnancies complicated by rhesus isoimmunization showed that in mild and moderately affected cases the levels were normal, while in severely affected cases they were raised. Serial levels of HPL before the 26th week provide a valuable indication of fetal outcome, and we suggest that this estimation should be used routinely as an adjunct to other tests in the management of rhesus isoimmunization.

  1. PLACENTAL PATHOLOGY IN PREGNANCY INDUCED HYPERTENSION

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    Sreechithra

    2014-08-01

    Full Text Available BACKGROUND: Hypertensive disorders complicating pregnancy are common and form one of the deadly triad along with hemorrhage and infection, that results in a large number of maternal deaths and there of fetal deaths. Since all anabolites needed for foetal metabolism come from the mothers blood and foetal catabolites are passed back into the mothers circulation through the placenta, the examination of placenta gives a clear idea of what had happened with it, when it was in the mother, s womb and what is going to happen with the foetus in future. With this objective the present study was carried out. MATERIALS AND METHODS: Retrospective study was done for a period of 21 months from April1st 2008 to December 31st 2009..Fifty mothers with uncomplicated pregnancy (control group and 100 mothers (test group diagnosed as having pregnancy induced hypertension were selected from patients of our institution of the age range from 20-40 years, and parity –primi, para2 and 3.Placental morphometric parameters, gross and histopathological features were examined in both test and control groups. STATISTICAL ANALYSIS USED: Fishers exact test RESULTS: Placental morphometric parameters were significantly reduced in the control group. Acute atherosis, endothelial proliferation and fibrinoid necrosis were the significant histological findings noted in our study. CONCLUSION: Placental findings can be confirmatory of PIH, but its absence does not exclude the diseases. These findings will become more evident only when there is significant reduction in the uteroplacental bloodflow

  2. Social mating system and sex-biased dispersal in mammals and birds: a phylogenetic analysis.

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    Karen E Mabry

    Full Text Available The hypothesis that patterns of sex-biased dispersal are related to social mating system in mammals and birds has gained widespread acceptance over the past 30 years. However, two major complications have obscured the relationship between these two behaviors: 1 dispersal frequency and dispersal distance, which measure different aspects of the dispersal process, have often been confounded, and 2 the relationship between mating system and sex-biased dispersal in these vertebrate groups has not been examined using modern phylogenetic comparative methods. Here, we present a phylogenetic analysis of the relationship between mating system and sex-biased dispersal in mammals and birds. Results indicate that the evolution of female-biased dispersal in mammals may be more likely on monogamous branches of the phylogeny, and that females may disperse farther than males in socially monogamous mammalian species. However, we found no support for a relationship between social mating system and sex-biased dispersal in birds when the effects of phylogeny are taken into consideration. We caution that although there are larger-scale behavioral differences in mating system and sex-biased dispersal between mammals and birds, mating system and sex-biased dispersal are far from perfectly associated within these taxa.

  3. Placental dysfunction and fetal programming: the importance of placental size, shape, histopathology, and molecular composition.

    Science.gov (United States)

    Longtine, Mark S; Nelson, D Michael

    2011-05-01

    Normal function of the placenta is pivotal for optimal fetal growth and development. Fetal programming commonly is associated with placental dysfunction that predisposes to obstetric complications and suboptimal fetal outcomes. We consider several clinical phenotypes for placental dysfunction that likely predispose to fetal programming. Some of these reflect abnormal development of the chorioallantoic placenta in size, shape, or histopathology. Others result when exogenous stressors in the maternal environment combine with maladaptation of the placental response to yield small placentas with limited reserve, as typical of early-onset intrauterine growth restriction and preeclampsia. Still others reflect epigenetic changes, including altered expression of imprinted genes, altered enzymatic activity, or altered efficiencies in nutrient transport. Although the human placenta is a transient organ that persists only 9 months, the effects of this organ on the offspring remain for a lifetime.

  4. Phylogeny of hard- and soft-tick taxa (Acari: Ixodida) based on mitochondrial 16S rDNA sequences.

    Science.gov (United States)

    Black, W C; Piesman, J

    1994-01-01

    Ticks are parasitiform mites that are obligate hematophagous ectoparasites of amphibians, reptiles, birds, and mammals. A phylogeny for tick families, subfamilies, and genera has been described based on morphological characters, life histories, and host associations. To test the existing phylogeny, we sequenced approximately 460 bp from the 3' end of the mitochondrial 16S rRNA gene (rDNA) in 36 hard- and soft-tick species; a mesostigmatid mite, Dermanyssus gallinae, was used as an outgroup. Phylogenies derived using distance, maximum-parsimony, or maximum-likelihood methods were congruent. The existing phylogeny was largely supported with four exceptions. In hard ticks (Ixodidae), members of Haemaphysalinae were monophyletic with the primitive Amblyomminae and members of Hyalomminae grouped within the Rhipicephalinae. In soft ticks (Argasidae), the derived phylogeny failed to support a monophyletic relationship among members of Ornithodorinae and supported placement of Argasinae as basal to the Ixodidae, suggesting that hard ticks may have originated from an Argas-like ancestor. Because most Argas species are obligate bird octoparasites, this result supports earlier suggestions that hard ticks did not evolve until the late Cretaceous. PMID:7937832

  5. Sperm competition and the evolution of sperm design in mammals

    Directory of Open Access Journals (Sweden)

    Gomendio Montserrat

    2011-01-01

    Full Text Available Abstract Background The influence of sperm competition upon sperm size has been a controversial issue during the last 20 years which remains unresolved for mammals. The hypothesis that, when ejaculates compete with rival males, an increase in sperm size would make sperm more competitive because it would increase sperm swimming speed, has generated contradictory results from both theoretical and empirical studies. In addition, the debate has extended to which sperm components should increase in size: the midpiece to accommodate more mitochondria and produce more energy to fuel motility, or the principal piece to generate greater propulsion forces. Results In this study we examined the influence of sperm competition upon sperm design in mammals using a much larger data set (226 species than in previous analyses, and we corrected for phylogenetic effects by using a more complete and resolved phylogeny, and more robust phylogenetic control methods. Our results show that, as sperm competition increases, all sperm components increase in an integrated manner and sperm heads become more elongated. The increase in sperm length was found to be associated with enhanced swimming velocity, an adaptive trait under sperm competition. Conclusions We conclude that sperm competition has played an important role in the evolution of sperm design in mammals, and discuss why previous studies have failed to detect it.

  6. Body size evolution in mammals: complexity in tempo and mode.

    Science.gov (United States)

    Cooper, Natalie; Purvis, Andy

    2010-06-01

    Body size correlates with virtually every aspect of species biology, so understanding the tempo and mode of its evolution is of key importance in macroecology and macroevolution. Here we use body mass data from 3,473 of 4,510 extant mammalian species and an almost complete species-level phylogeny to determine the best model of log(body mass) evolution across all mammals, split taxonomically and spatially. An early-burst model fits better across all mammals than do models based on either Brownian motion or an Ornstein-Uhlenbeck process, suggesting that mammals experienced a burst of morphological evolution relatively early in their history that was followed by slower change. We also use spatial models to investigate rates of body mass evolution within ecoregions. These models show that around 50% of the variation in rate can be explained by just a few predictors. High estimated rates are associated with cold, low-lying, species-poor, high-energy, mainland ecoregions. We conclude that the evolution of mammalian body size has been influenced by a complex interplay among geography, climate, and history.

  7. Sperm competition and the evolution of sperm design in mammals.

    Science.gov (United States)

    Tourmente, Maximiliano; Gomendio, Montserrat; Roldan, Eduardo R S

    2011-01-13

    The influence of sperm competition upon sperm size has been a controversial issue during the last 20 years which remains unresolved for mammals. The hypothesis that, when ejaculates compete with rival males, an increase in sperm size would make sperm more competitive because it would increase sperm swimming speed, has generated contradictory results from both theoretical and empirical studies. In addition, the debate has extended to which sperm components should increase in size: the midpiece to accommodate more mitochondria and produce more energy to fuel motility, or the principal piece to generate greater propulsion forces. In this study we examined the influence of sperm competition upon sperm design in mammals using a much larger data set (226 species) than in previous analyses, and we corrected for phylogenetic effects by using a more complete and resolved phylogeny, and more robust phylogenetic control methods. Our results show that, as sperm competition increases, all sperm components increase in an integrated manner and sperm heads become more elongated. The increase in sperm length was found to be associated with enhanced swimming velocity, an adaptive trait under sperm competition. We conclude that sperm competition has played an important role in the evolution of sperm design in mammals, and discuss why previous studies have failed to detect it.

  8. Evolutionary transition of dental formula in Late Cretaceous eutherian mammals

    Science.gov (United States)

    Averianov, Alexander O.; Archibald, J. David

    2015-10-01

    Kulbeckia kulbecke, stem placental mammal from the Late Cretaceous of Uzbekistan, shows a transitional stage of evolution in the dental formula from five to four premolars. A non-replaced dP3/dp3 may occur as individual variation. In other specimens, the lower premolars are crowded with no space for development of dp3. As is evident from the CT scanning of one juvenile specimen, the development of dp3 started in a late ontogenetic stage and was confined to the pulp cavity of the developing p2. This dp3 would have been resorbed in a later ontogenetic stage, as the roots of p2 formed. The initial stage of reduction of the third premolar can be traced to stem therians ( Juramaia and Eomaia), which have both dP3 and P3 present in the adult dentition. Further delay in the development of dP3/dp3 led to the loss of the permanent P3/p3 (a possible synapomorphy for Eutheria). The dP3/dp3 was present during most of the adult stages in the Late Cretaceous stem placentals Zhelestidae and Gypsonictops. This tooth is totally absent in basal taxa of Placentalia, which normally have at most four premolars.

  9. Elevated placental adenosine signaling contributes to the pathogenesis of preeclampsia.

    Science.gov (United States)

    Iriyama, Takayuki; Sun, Kaiqi; Parchim, Nicholas F; Li, Jessica; Zhao, Cheng; Song, Anren; Hart, Laura A; Blackwell, Sean C; Sibai, Baha M; Chan, Lee-Nien L; Chan, Teh-Sheng; Hicks, M John; Blackburn, Michael R; Kellems, Rodney E; Xia, Yang

    2015-02-24

    Preeclampsia is a prevalent hypertensive disorder of pregnancy and a leading cause of maternal and neonatal morbidity and mortality worldwide. This pathogenic condition is speculated to be caused by placental abnormalities that contribute to the maternal syndrome. However, the specific factors and signaling pathways that lead to impaired placentas and maternal disease development remain elusive. Using 2 independent animal models of preeclampsia (genetically engineered pregnant mice with elevated adenosine exclusively in placentas and a pathogenic autoantibody-induced preeclampsia mouse model), we demonstrated that chronically elevated placental adenosine was sufficient to induce hallmark features of preeclampsia, including hypertension, proteinuria, small fetuses, and impaired placental vasculature. Genetic and pharmacological approaches revealed that elevated placental adenosine coupled with excessive A₂B adenosine receptor (ADORA2B) signaling contributed to the development of these features of preeclampsia. Mechanistically, we provided both human and mouse evidence that elevated placental CD73 is a key enzyme causing increased placental adenosine, thereby contributing to preeclampsia. We determined that elevated placental adenosine signaling is a previously unrecognized pathogenic factor for preeclampsia. Moreover, our findings revealed the molecular basis underlying the elevation of placental adenosine and the detrimental role of excess placental adenosine in the pathophysiology of preeclampsia, and thereby, we highlight novel therapeutic targets. © 2014 American Heart Association, Inc.

  10. Placental localization by scanning with indium 113m

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Wook; Choe, Yong Kyu; Choi, Byung Sook [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1972-09-15

    The application of radioactive tracers for placental localization has been introduced as the worthwhile diagnostic method in placenta previa. Recently {sup 113m}In has been applied as the broad spectrum agent for the visualization of various organs. The advantage of {sup 113m}In are a short half-life with 1.7 hours and no beta particle emission. During the period from May 1970 to August 1971, the placental scanning with {sup 113m}In was carried out at Yonsei Medical Center on 19 cases of Korean pregnant females who had painless vaginal bleeding with suspicious placenta previa or other placental lesions, clinically. Followings are the results of placental scanning with Indium-113m. 1) Eight cases out of 19 cases were suggested as placenta previa and the remaining 11 cases were turned out to be normal placental location. 2) Among these 8 case of positive scanning, placenta previa totalis was 6 cases, placental previa partialis was 1 case and placenta previa marginalis was also 1 case. 3) Among 11 cases of normal placental localization, right side placenta was 7 cases and left side, 4 cases. The placental scanning with Indium-113m is thought to be one of the simple, safe and rapid method with high accuracy for clinical diagnosis of the placenta previa and placental localization.

  11. Placental Abnormalities and Preeclampsia in Trisomy 13 Pregnancies

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2009-03-01

    Full Text Available Women who are carrying a trisomy 13 fetus are prone to have an abnormal placenta as well as to develop preeclampsia in the second and third trimesters. This article provides a comprehensive review of placental abnormalities, such as small placental volume, reduced placental vascularization, a partial molar appearance of the placenta and placental mesenchymal dysplasia, and preeclampsia associated with trisomy 13 pregnancies. The candidate preeclampsia-causing genes on chromosome 13, such as sFlt1, COL4A2 and periostin, are discussed.

  12. Cesarean Delivery for a Life-threatening Preterm Placental Abruption

    Science.gov (United States)

    Okafor, II; Ugwu, EO

    2015-01-01

    Placental abruption is one of the major life-threatening obstetric conditions. The fetomaternal outcome of a severe placental abruption depends largely on prompt maternal resuscitation and delivery. A case of severe preterm placental abruption with intrauterine fetal death. Following a failed induction of labor with a deteriorating maternal condition despite resuscitation, emergency cesarean delivery was offered with good maternal outcome. Cesarean delivery could avert further disease progression and possible maternal death in cases of severe preterm placental abruption where vaginal delivery is not imminent. However, further studies are necessary before this could be recommended for routine clinical practice. PMID:27057388

  13. Clinical development of placental malaria vaccines and immunoassays harmonization

    DEFF Research Database (Denmark)

    Chêne, Arnaud; Houard, Sophie; Nielsen, Morten A;

    2016-01-01

    Placental malaria caused by Plasmodium falciparum infection constitutes a major health problem manifesting as severe disease and anaemia in the mother, impaired fetal development, low birth weight or spontaneous abortion. Prevention of placental malaria currently relies on two key strategies...... that are losing efficacy due to spread of resistance: long-lasting insecticide-treated nets and intermittent preventive treatment during pregnancy. A placental malaria vaccine would be an attractive, cost-effective complement to the existing control tools. Two placental malaria vaccine candidates are currently...

  14. Circulating placental proteins in pregnancies complicated by RH isoimmunization.

    Science.gov (United States)

    Lee, J N; Huang, S C; Ouyang, P C; Chard, T

    1984-07-01

    Nine pregnant women with Rh isoimmunization who delivered newborns with hydrops fetalis were studied. The placental proteins, pregnancy specific beta 1-glycoprotein (SP1), human placental lactogen, and placental protein 5 (PP5) were measured in maternal serum by radioimmunoassays. The results indicate that both the serum human placental lactogen and PP5 levels were significantly higher than those observed in normal pregnancy. The strikingly higher circulating PP5 levels found in all nine patients with Rh isoimmunization studied suggests that serum PP5 may be specifically elevated in pregnant patients with Rh isoimmunization and hydrops fetalis.

  15. Prevention of Defective Placentation and Pregnancy Loss by Blocking Innate Immune Pathways in a Syngeneic Model of Placental Insufficiency.

    Science.gov (United States)

    Gelber, Shari E; Brent, Elyssa; Redecha, Patricia; Perino, Giorgio; Tomlinson, Stephen; Davisson, Robin L; Salmon, Jane E

    2015-08-01

    Defective placentation and subsequent placental insufficiency lead to maternal and fetal adverse pregnancy outcome, but their pathologic mechanisms are unclear, and treatment remains elusive. The mildly hypertensive BPH/5 mouse recapitulates many features of human adverse pregnancy outcome, with pregnancies characterized by fetal loss, growth restriction, abnormal placental development, and defects in maternal decidual arteries. Using this model, we show that recruitment of neutrophils triggered by complement activation at the maternal/fetal interface leads to elevation in local TNF-α levels, reduction of the essential angiogenic factor vascular endothelial growth factor, and, ultimately, abnormal placentation and fetal death. Blockade of complement with inhibitors specifically targeted to sites of complement activation, depletion of neutrophils, or blockade of TNF-α improves spiral artery remodeling and rescues pregnancies. These data underscore the importance of innate immune system activation in the pathogenesis of placental insufficiency and identify novel methods for treatment of pregnancy loss mediated by abnormal placentation.

  16. Genomic Imprinting in Mammals

    Science.gov (United States)

    Barlow, Denise P.

    2014-01-01

    Genomic imprinting affects a subset of genes in mammals and results in a monoallelic, parental-specific expression pattern. Most of these genes are located in clusters that are regulated through the use of insulators or long noncoding RNAs (lncRNAs). To distinguish the parental alleles, imprinted genes are epigenetically marked in gametes at imprinting control elements through the use of DNA methylation at the very least. Imprinted gene expression is subsequently conferred through lncRNAs, histone modifications, insulators, and higher-order chromatin structure. Such imprints are maintained after fertilization through these mechanisms despite extensive reprogramming of the mammalian genome. Genomic imprinting is an excellent model for understanding mammalian epigenetic regulation. PMID:24492710

  17. How mammals detect pheromones.

    Science.gov (United States)

    Silvotti, L; Montani, G; Tirindelli, R

    2003-01-01

    One of the most intriguing discoveries in mammalian pheromone research is the report that a short exposure of women to volatile compounds from sweat can significantly alter their menstrual cycle. This work suggests that specific molecules are produced by women at different stages of the menstrual cycle and that this putative 'pheromonal' blend has effects on the timing of the cycle in women that were briefly exposed to it. What human pheromones are and how they work are not known, however a considerable progress has been made in understanding how other mammals are likely to detect pheromones with the discovery of pheromone receptors. Even though it is proved that pheromones affect human responses, it remains unlikely that similar receptors account for these effects.

  18. The nocturnal bottleneck and the evolution of activity patterns in mammals

    Science.gov (United States)

    Gerkema, Menno P.; Davies, Wayne I. L.; Foster, Russell G.; Menaker, Michael; Hut, Roelof A.

    2013-01-01

    In 1942, Walls described the concept of a ‘nocturnal bottleneck’ in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail. PMID:23825205

  19. The nocturnal bottleneck and the evolution of activity patterns in mammals.

    Science.gov (United States)

    Gerkema, Menno P; Davies, Wayne I L; Foster, Russell G; Menaker, Michael; Hut, Roelof A

    2013-08-22

    In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail.

  20. Eumetazoan cryptochrome phylogeny and evolution.

    Science.gov (United States)

    Haug, Marion F; Gesemann, Matthias; Lazović, Viktor; Neuhauss, Stephan C F

    2015-01-18

    Cryptochromes (Crys) are light sensing receptors that are present in all eukaryotes. They mainly absorb light in the UV/blue spectrum. The extant Crys consist of two subfamilies, which are descendants of photolyases but are now involved in the regulation of circadian rhythms. So far, knowledge about the evolution, phylogeny, and expression of cry genes is still scarce. The inclusion of cry sequences from a wide range of bilaterian species allowed us to analyze their phylogeny in detail, identifying six major Cry subgroups. Selective gene inactivations and stabilizations in multiple chordate as well as arthropod lineages suggest several sub- and/or neofunctionalization events. An expression study performed in zebrafish, the model organism harboring the largest amount of crys, showed indeed only partially overlapping expression of paralogous mRNA, supporting gene sub- and/or neofunctionalization. Moreover, the daily cry expression in the adult zebrafish retina indicated varying oscillation patterns in different cell types. Our extensive phylogenetic analysis provides for the first time an overview of cry evolutionary history. Although several, especially parasitic or blind species, have lost all cry genes, crustaceans have retained up to three crys, teleosts possess up to seven, and tetrapods up to four crys. The broad and cyclic expression pattern of all cry transcripts in zebrafish retinal layers implies an involvement in retinal circadian processes and supports the hypothesis of several autonomous circadian clocks present in the vertebrate retina. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. 50 CFR 216.25 - Exempted marine mammals and marine mammal products.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Exempted marine mammals and marine mammal... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS General Exceptions § 216.25 Exempted marine mammals and marine mammal...

  2. The placental exposome: Placental determinants of fetal adiposity and postnatal body composition

    NARCIS (Netherlands)

    R.M. Lewis (R.); H. Demmelmair (Hans); R. Gaillard (Romy); N. Godfrey; S. Hauguel-De Mouzon (S.); B. Huppertz (B.); E. Larque (E.); R. Saffery (R.); M.E. Symonds (M.); G. Desoye (G.)

    2013-01-01

    textabstractOffspring of obese and diabetic mothers are at increased risk of being born with excess adiposity as a consequence of their intrauterine environment. Excessive fetal fat accretion reflects additional placental nutrient transfer, suggesting an effect of the maternal environment on

  3. Copy number variation is a fundamental aspect of the placental genome.

    Science.gov (United States)

    Hannibal, Roberta L; Chuong, Edward B; Rivera-Mulia, Juan Carlos; Gilbert, David M; Valouev, Anton; Baker, Julie C

    2014-05-01

    Discovery of lineage-specific somatic copy number variation (CNV) in mammals has led to debate over whether CNVs are mutations that propagate disease or whether they are a normal, and even essential, aspect of cell biology. We show that 1,000 N polyploid trophoblast giant cells (TGCs) of the mouse placenta contain 47 regions, totaling 138 Megabases, where genomic copies are underrepresented (UR). UR domains originate from a subset of late-replicating heterochromatic regions containing gene deserts and genes involved in cell adhesion and neurogenesis. While lineage-specific CNVs have been identified in mammalian cells, classically in the immune system where V(D)J recombination occurs, we demonstrate that CNVs form during gestation in the placenta by an underreplication mechanism, not by recombination nor deletion. Our results reveal that large scale CNVs are a normal feature of the mammalian placental genome, which are regulated systematically during embryogenesis and are propagated by a mechanism of underreplication.

  4. Copy number variation is a fundamental aspect of the placental genome.

    Directory of Open Access Journals (Sweden)

    Roberta L Hannibal

    2014-05-01

    Full Text Available Discovery of lineage-specific somatic copy number variation (CNV in mammals has led to debate over whether CNVs are mutations that propagate disease or whether they are a normal, and even essential, aspect of cell biology. We show that 1,000 N polyploid trophoblast giant cells (TGCs of the mouse placenta contain 47 regions, totaling 138 Megabases, where genomic copies are underrepresented (UR. UR domains originate from a subset of late-replicating heterochromatic regions containing gene deserts and genes involved in cell adhesion and neurogenesis. While lineage-specific CNVs have been identified in mammalian cells, classically in the immune system where V(DJ recombination occurs, we demonstrate that CNVs form during gestation in the placenta by an underreplication mechanism, not by recombination nor deletion. Our results reveal that large scale CNVs are a normal feature of the mammalian placental genome, which are regulated systematically during embryogenesis and are propagated by a mechanism of underreplication.

  5. Evolution of placental specializations in viviparous African and South American lizards.

    Science.gov (United States)

    Flemming, Alexander F; Blackburn, Daniel G

    2003-09-01

    Phylogenetic information offers an important resource in analyses of reproductive diversity, including interpretations of fetal membrane evolution. In this paper, we draw upon ongoing studies of South American and African lizards to consider the value of combining phylogenetic and reproductive evidence in the construction of evolutionary interpretations. South American lizards of the genus Mabuya exhibit several reproductive specializations that are convergent on those of eutherian mammals, including viviparity, long gestation periods, ovulation of tiny eggs, and placental supply of the nutrients for development. Studies of placental morphology and development indicate that New World Mabuya share several other derived features, including chorionic areolae and a "Type IV" epitheliochorial placenta with a villous, mesometrial placentome. Some characteristics of these lizards are shared by two African skinks, M. ivensii and Eumecia anchietae, including minuscule eggs, placentotrophy, an absorptive chorioallantois, and features of the yolk sac. Available evidence is consistent with two explanations: (1) placentotrophy originated in Africa, predating a trans-Atlantic colonization by Mabuya of the New World; and (2) placentotrophy arose two or three separate times among these closely related skinks. As illustrated by analysis of these animals, not only can data on fetal membrane morphology yield phylogenetic information, but phylogenetic evidence in turn provides a valuable way to reconstruct the evolution of fetal membranes in a biogeographic context. When appropriately interpreted, morphological and phylogenetic evidence can be combined to yield robust evolutionary conclusions that avoid the pitfalls of circular reasoning.

  6. Placental adaptations to the maternal-fetal environment: implications for fetal growth and developmental programming.

    Science.gov (United States)

    Sandovici, Ionel; Hoelle, Katharina; Angiolini, Emily; Constância, Miguel

    2012-07-01

    The placenta is a transient organ found in eutherian mammals that evolved primarily to provide nutrients for the developing fetus. The placenta exchanges a wide array of nutrients, endocrine signals, cytokines and growth factors with the mother and the fetus, thereby regulating intrauterine development. Recent studies show that the placenta is not just a passive organ mediating maternal-fetal exchange. It can adapt its capacity to supply nutrients in response to intrinsic and extrinsic variations in the maternal-fetal environment. These dynamic adaptations are thought to occur to maximize fetal growth and viability at birth in the prevailing conditions in utero. However, some of these adaptations may also affect the development of individual fetal tissues, with patho-physiological consequences long after birth. Here, this review summarizes current knowledge on the causes, possible mechanisms and consequences of placental adaptive responses, with a focus on the regulation of transporter-mediated processes for nutrients. This review also highlights the emerging roles that imprinted genes and epigenetic mechanisms of gene regulation may play in placental adaptations to the maternal-fetal environment. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Prenatal endotoxemia and placental drug transport in the mouse: placental size-specific effects.

    Directory of Open Access Journals (Sweden)

    Enrrico Bloise

    Full Text Available Lipopolysaccharide (LPS in high doses inhibits placental multidrug resistance P-glycoprotein (P-gp--Abcb1a/b and breast cancer resistance protein (BCRP--Abcg2. This potentially impairs fetal protection against harmful factors in the maternal circulation. However, it is unknown whether LPS exposure, at doses that mimic sub-lethal clinical infection, alters placental multidrug resistance. We hypothesized that sub-lethal (fetal LPS exposure reduces placental P-gp activity. Acute LPS (n = 19;150 µg/kg; ip or vehicle (n = 19 were given to C57BL/6 mice at E15.5 and E17.5. Placentas and fetal-units were collected 4 and 24 h following injection. Chronic LPS (n = 6; 5 µg/kg/day; ip or vehicle (n = 5 were administered from E11.5-15.5 and tissues were collected 4 h after final treatment. P-gp activity was assessed by [³H]digoxin accumulation. Placental Abcb1a/b, Abcg2, interleukin-6 (Il-6, Tnf-α, Il-10 and toll-like receptor-4 (Tlr-4 mRNA were measured by qPCR. Maternal plasma IL-6 was determined. At E15.5, maternal IL-6 was elevated 4 h after single (p<0.001 and chronic (p<0.05 LPS, but levels had returned to baseline by 24 h. Placental Il-6 mRNA was also increased after acute and chronic LPS treatments (p<0.05, whereas Abcb1a/b and Abcg2 mRNA were unaffected. However, fetal [³H]digoxin accumulation was increased (p<0.05 4 h after acute LPS, and maternal [³H]digoxin myocardial accumulation was increased (p<0.05 in mice exposed to chronic LPS treatments. There was a negative correlation between fetal [³H]digoxin accumulation and placental size (p<0.0001. Acute and chronic sub-lethal LPS exposure resulted in a robust inflammatory response in the maternal systemic circulation and placenta. Acute infection decreased placental P-gp activity in a time- and gestational age-dependent manner. Chronic LPS decreased P-gp activity in the maternal myocardium and there was a trend for fetuses with smaller placentas to accumulate more P

  8. Placental glucose dehydrogenase polymorphism in Koreans.

    Science.gov (United States)

    Kim, Y J; Paik, S G; Park, H Y

    1994-12-01

    The genetic polymorphism of placental glucose dehydrogenase (GDH) was investigated in 300 Korean placentae using horizontal starch gel electrophoresis. The allele frequencies for GDH1, GDH2 and GDH3 were 0.537, 0.440 and 0.005, respectively, which were similar to those in Japanese. We also observed an anodal allele which was similar to the GDH4 originally reported in Chinese populations at a low frequency of 0.015. An additional new cathodal allele (named GDH6) was observed in the present study with a very low frequency of 0.003.

  9. Hans Strahl's pioneering studies in comparative placentation

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, A

    2010-01-01

    and relationship to maternal tissues. This greatly influenced the work of Otto Grosser, who became better known in part because his work was more accessible to other scientists and clinicians. Strahl described the development of the fetal membranes across a broad range of mammalian orders extending his...... observations beyond parturition to the post partum involution of the uterus. He paid close attention to structures designed for histotrophic nutrition including the areolae of moles, haemophagous organs of carnivores and tenrecs and chorionic vesicles of lemurs and lorises. We here provide a summary of some...... of the most important findings made by Strahl including work on placentation in carnivores and higher primates that remains unsurpassed....

  10. Placental characteristics in women with polycystic ovary syndrome

    NARCIS (Netherlands)

    Koster, Maria P H; de Wilde, Marlieke A; Veltman-Verhulst, Susanne M; Houben, ML; Nikkels, Peter G J; van Rijn, Bas B; Fauser, Bart C J M

    2015-01-01

    STUDY QUESTION: Are macroscopic and microscopic placental characteristics in a heterogeneous group of women diagnosed with polycystic ovary syndrome (PCOS) different from those of a low-risk general population? SUMMARY ANSWER: Women with PCOS have significantly different microscopic placental charac

  11. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    Background: The placenta is the base for the exchange of nutrients, oxygen and waste products for the fetus. The placental vessels hold a crucial role in regulation the blood flow, and a compromised placental function leads to serious complications such as fetal death or growth retardation. An in...

  12. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    Background. The placenta is the base for the exchange of nutrients, oxygen and waste products for the fetus.The placental vessels hold a crucial role in regulation the blood flow, and a compromised placental function leads to serious complications such as fetal death or growth retardation...

  13. Placental transport and in vitro effects of Bisphenol A

    DEFF Research Database (Denmark)

    Mørck, Thit J; Sorda, Giuseppina; Bechi, Nicoletta

    2010-01-01

    Bisphenol A (BPA), an estrogen-like chemical, leaches from consumer products potentially causing human exposure. To examine the effects of BPA exposure during pregnancy, we performed studies using the BeWo trophoblast cell line, placental explant cultures, placental perfusions and skin diffusion...

  14. Of mice and women: rodent models of placental malaria

    DEFF Research Database (Denmark)

    Hviid, Lars; Marinho, Claudio R F; Staalsoe, Trine

    2010-01-01

    Pregnant women are at increased malaria risk. The infections are characterized by placental accumulation of infected erythrocytes (IEs) with adverse consequences for mother and baby. Placental IE sequestration in the intervillous space is mediated by variant surface antigens (VSAs) selectively ex...

  15. Arrangement of collagen fibers in human placental stem villi

    NARCIS (Netherlands)

    Sati, Leyla; Demir, Ayse Yasemin; Sarikcioglu, Levent; Demir, Ramazan

    2008-01-01

    The aim of the study was to investigate the arrangements and related localization patterns of different collagen types in the stroma of placental stem villi by immunohistochemistry and electron microscopy. A total of 14 normal human term placental tissue samples were studied. Immunohistochemistry wa

  16. Arrangement of collagen fibers in human placental stem villi

    NARCIS (Netherlands)

    Sati, Leyla; Demir, Ayse Yasemin; Sarikcioglu, Levent; Demir, Ramazan

    2008-01-01

    The aim of the study was to investigate the arrangements and related localization patterns of different collagen types in the stroma of placental stem villi by immunohistochemistry and electron microscopy. A total of 14 normal human term placental tissue samples were studied. Immunohistochemistry

  17. Providing a Placental Transfusion in Newborns Who Need Resuscitation

    Science.gov (United States)

    Katheria, Anup C.; Brown, Melissa K.; Rich, Wade; Arnell, Kathy

    2017-01-01

    Over the past decade, there have been several studies and reviews on the importance of providing a placental transfusion to the newborn. Allowing a placental transfusion to occur by delaying the clamping of the umbilical cord is an extremely effective method of enhancing arterial oxygen content, increasing cardiac output, and improving oxygen delivery. However, premature and term newborns who require resuscitation have impaired transitional hemodynamics and may warrant different methods to actively provide a placental transfusion while still allowing for resuscitation. In this review, we will provide evidence for providing a placental transfusion in these circumstances and methods for implementation. Several factors including cord clamping time, uterine contractions, umbilical blood flow, respirations, and gravity play an important role in determining placental transfusion volumes. Finally, while many practitioners agree that a placental transfusion is beneficial, it is not always straightforward to implement and can be performed using different methods, making this basic procedure important to discuss. We will review three placental transfusion techniques: delayed cord clamping, intact umbilical cord milking, and cut-umbilical cord milking. We will also review resuscitation with an intact cord and the evidence in term and preterm newborns supporting this practice. We will discuss perceived risks versus benefits of these procedures. Finally, we will provide key straightforward concepts and implementation strategies to ensure that placental-to-newborn transfusion can become routine practice at any institution. PMID:28180126

  18. Longitudinal study of serum placental GH in 455 normal pregnancies

    DEFF Research Database (Denmark)

    Chellakooty, Marla; Skibsted, Lillian; Skouby, Sven Olaf

    2002-01-01

    Placental GH is thought to be responsible for the rise in maternal IGF-I during pregnancy and is considered to be important for fetal growth. In this prospective longitudinal study of healthy pregnant women, we investigated determinants of placental GH in maternal serum. Serum was obtained from 4...

  19. Pheromone reception in mammals.

    Science.gov (United States)

    Bigiani, A; Mucignat-Caretta, C; Montani, G; Tirindelli, R

    2005-01-01

    Pheromonal communication is the most convenient way to transfer information regarding gender and social status in animals of the same species with the holistic goal of sustaining reproduction. This type of information exchange is based on pheromones, molecules often chemically unrelated, that are contained in body fluids like urine, sweat, specialized exocrine glands, and mucous secretions of genitals. So profound is the relevance of pheromones over the evolutionary process that a specific peripheral organ devoted to their recognition, namely the vomeronasal organ of Jacobson, and a related central pathway arose in most vertebrate species. Although the vomeronasal system is well developed in reptiles and amphibians, most mammals strongly rely on pheromonal communication. Humans use pheromones too; evidence on the existence of a specialized organ for their detection, however, is very elusive indeed. In the present review, we will focus our attention on the behavioral, physiological, and molecular aspects of pheromone detection in mammals. We will discuss the responses to pheromonal stimulation in different animal species, emphasizing the complicacy of this type of communication. In the light of the most recent results, we will also discuss the complex organization of the transduction molecules that underlie pheromone detection and signal transmission from vomeronasal neurons to the higher centers of the brain. Communication is a primary feature of living organisms, allowing the coordination of different behavioral paradigms among individuals. Communication has evolved through a variety of different strategies, and each species refined its own preferred communication medium. From a phylogenetic point of view, the most widespread and ancient way of communication is through chemical signals named pheromones: it occurs in all taxa, from prokaryotes to eukaryotes. The release of specific pheromones into the environment is a sensitive and definite way to send messages to

  20. Comparative aspects of gait, scaling and mechanics in mammals.

    Science.gov (United States)

    Gasc, J P

    2001-12-01

    In phylogenetically based systematics, Mammalia is the nomenclatural term which designates the clade stemming from the most recent common ancestry of monotremes and theria [, Sys. Biol. 43 (1994) 497]. Considering that locomotor performance is a prevalent function to provide the necessary conditions to survive and transmit genes, it may be questioned if the diverse types of locomotion exhibited by extant mammals could have played a role in their evolution, or have only followed it. We may look after the structural and behavioural features which are involved in mammal locomotion compared to other tetrapods and test if they fit with the proposed phylogeny. Several factors may be checked: scaling effect in relation to gravitational constraints; geometrical distribution of masses in the body, and relative mechanical role of the limbs in the production of the external forces necessary to forward motion. Classically, it was thought that the fastest gaits used by terrestrial mammals were based upon a unique kind of limb motion co-ordination, called asymmetrical gaits, which in turn may be thought to be related to a peculiar neuronal wiring. Kinematic analysis brings an insight to this topic. Is the search for an ancestral mammalian locomotor pattern judicious? Notice the small size of many of the first mammals and their probable locomotor plasticity. (relation between grain size of the elements within the substrate and the organism scale). At a small size, the gravitational constraint is less important, and the distinction between terrestrial and arboreal has probably no sense when the limbs are the principal motor elements. There remains the importance of the geometrical distribution of body elements, the proportions of the limbs and of the head-neck complex, the tail merely as an appendix, a set of factors which may have generated the frame of constraints within which diverse locomotor modes have evolved.

  1. Use of magnetic resonance imaging in evaluation of placental invasion

    Energy Technology Data Exchange (ETDEWEB)

    Teo, T.H. [Department of Diagnostic Radiology, Singapore General Hospital (Singapore)], E-mail: thteo76@gmail.com; Law, Y.M.; Tay, K.H.; Tan, B.S.; Cheah, F.K. [Department of Diagnostic Radiology, Singapore General Hospital (Singapore)

    2009-05-15

    Aim: To review and describe the magnetic resonance imaging (MRI) features in patients with suspected placental invasion and correlate the findings with surgery and pathology findings. Materials and Methods: A retrospective review was undertaken of the MRI images of seven consecutive patients with ultrasound findings suspicious for placental invasion. Two experienced MRI radiologists, blinded to the pathology and surgery findings, reviewed the MRI. The pathology or surgical findings were used as the reference standard to establish accuracy and concordance with the MRI findings. Results: Three MRI features described in an earlier series were consistently present in the patients with placental invasion: lower uterine bulging, heterogeneous placenta, and dark intraplacental linear bands on T2-weighted images. Conclusion: MRI features, which were described in patients with placental invasion in an earlier series, were useful in establishing the presence and depth of placental invasion.

  2. Clinical development of placental malaria vaccines and immunoassays harmonization

    DEFF Research Database (Denmark)

    Chêne, Arnaud; Houard, Sophie; Nielsen, Morten A

    2016-01-01

    Placental malaria caused by Plasmodium falciparum infection constitutes a major health problem manifesting as severe disease and anaemia in the mother, impaired fetal development, low birth weight or spontaneous abortion. Prevention of placental malaria currently relies on two key strategies...... that are losing efficacy due to spread of resistance: long-lasting insecticide-treated nets and intermittent preventive treatment during pregnancy. A placental malaria vaccine would be an attractive, cost-effective complement to the existing control tools. Two placental malaria vaccine candidates are currently...... in Phase Ia/b clinical trials. During two workshops hosted by the European Vaccine Initiative, one in Paris in April 2014 and the other in Brussels in November 2014, the main actors in placental malaria vaccine research discussed the harmonization of clinical development plans and of the immunoassays...

  3. Multimodality imaging of placental masses: a pictorial review.

    Science.gov (United States)

    Jha, Priyanka; Paroder, Viktoriya; Mar, Winnie; Horowtiz, Jeanne M; Poder, Liina

    2016-12-01

    Placental masses are uncommonly identified at the time of obstetric ultrasound evaluation. Understanding the pathologies presenting as placental masses is key for providing a differential diagnosis and guiding subsequent management, which may include additional imaging with magnetic resonance (MR) imaging. Potential benign entities include chorioangiomas and teratomas. Larger chorioangiomas can cause fetal cardiovascular issues from volume overload. Placental mesenchymal dysplasia has an association with fetal anomalies and detailed fetal evaluation should be performed when it is suspected. Identifying other cystic masses such as partial and complete moles is crucial to prevent erroneous pregnancy termination. This review addresses normal imaging appearance of the placenta on ultrasound and MR imaging and describes various trophoblastic and nontrophoblastic placental masses. Potential placental mass mimics including uterine contractions and thrombo-hematomas are also presented.

  4. Placental Growth during Normal Pregnancy - A Magnetic Resonance Imaging Study

    DEFF Research Database (Denmark)

    Langhoff, Lasse; Grønbeck, Lene; von Huth, Sebastian

    2017-01-01

    was 640 g (range 500-787 g). All pregnancies were carried to term, resulting in the delivery of healthy infants with good correlation between placental size and birth weight (R = 0.56, p = 0.009). CONCLUSION: Placental growth was measured systematically in a longitudinal study through the second and third......OBJECTIVE: To investigate normal human placental growth longitudinally throughout the second and third trimesters using MRI. METHODS: Twenty normal, first-time singleton pregnancies were scanned 7 times between the 14th and 38th week of gestation, at 4-week intervals, using MRI. Placental volumes...... were measured in both sagittal and transversal slices. All placentas were weighed after delivery to make a comparative study. RESULTS: Sixteen of the 20 women had increasing placental volumes from the 14th to 38th week of gestation. The 6th and 7th scan showed that 4 women had placentas of the same...

  5. Ecological causes of decelerating diversification in carnivoran mammals.

    Science.gov (United States)

    Machac, Antonin; Storch, David; Wiens, John J

    2013-08-01

    Clade diversification is a central topic in macroevolutionary studies. Recently, it has been shown that diversification rates appear to decelerate over time in many clades. What causes this deceleration remains unclear, but it has been proposed that competition for limited resources between sympatric, ecologically similar species slows diversification. Employing carnivoran mammals as a model system, we test this hypothesis using a comprehensive time-calibrated phylogeny. We also explore several conceptually related explanations including limited geographic area and limited rates of niche evolution. We find that diversification slowdowns are strong in carnivorans. Surprisingly, these slowdowns are independent of geographic range overlap between related species and are also decoupled from rates of niche evolution, suggesting that slowdowns are unrelated to competition and niche filling. When controlling for the effects of clade diversity, diversification slowdowns appear independent of geographic area. There is a significant effect of clade diversity on diversification slowdowns, but simulations show that this relationship may arise as a statistical artifact (i.e., greater clade diversity increases the ability of the gamma statistic to refute constant diversification). Overall, our results emphasize the need to test hypotheses about the causes of diversification slowdowns with ecological data, rather than assuming ecological processes from phylogenies alone.

  6. Alabama ESI: M_MAMMAL (Marine Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for dolphins and manatees in Alabama. Vector polygons in this data set represent marine mammal distribution...

  7. Western Alaska ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for brown bears in Western Alaska. Vector polygons in this data set represent terrestrial mammal...

  8. Maryland ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for river otters in Maryland. Vector polygons in this data set represent the terrestrial mammal...

  9. Virginia ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for the northern river otter in Virginia. Vector polygons in this data set represent terrestrial mammal...

  10. American Samoa ESI: M_MAMMAL (Marine Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for whales and dolphins in American Samoa. Vector polygons in this data set represent marine mammal...

  11. Epigenetic memory in mammals

    Directory of Open Access Journals (Sweden)

    Zoe eMigicovsky

    2011-06-01

    Full Text Available Epigenetic information can be passed on from one generation to another via DNA methylation, histone modifications and changes in small RNAs, a process called epigenetic memory. During a mammal’s lifecycle epigenetic reprogramming, or the resetting of most epigenetic marks, occurs twice. The first instance of reprogramming occurs in primordial germ cells and the second occurs following fertilization. These processes may be both passive and active. In order for epigenetic inheritance to occur the epigenetic modifications must be able to escape reprogramming. There are several examples supporting this non-Mendelian mechanism of inheritance including the prepacking of early developmental genes in histones instead of protamines in sperm, genomic imprinting via methylation marks, the retention of CenH3 in mammalian sperm and the inheritance of piwi-associated interfering RNAs. The ability of mammals to pass on epigenetic information to their progeny provides clear evidence that inheritance is not restricted to DNA sequence and epigenetics plays a key role in producing viable offspring.

  12. An estimation of Erinaceidae phylogeny: a combined analysis approach.

    Directory of Open Access Journals (Sweden)

    Kai He

    Full Text Available BACKGROUND: Erinaceidae is a family of small mammals that include the spiny hedgehogs (Erinaceinae and the silky-furred moonrats and gymnures (Galericinae. These animals are widely distributed across Eurasia and Africa, from the tundra to the tropics and the deserts to damp forests. The importance of these animals lies in the fact that they are the oldest known living placental mammals, which are well represented in the fossil record, a rarity fact given their size and vulnerability to destruction during fossilization. Although the Family has been well studied, their phylogenetic relationships remain controversial. To test previous phylogenetic hypotheses, we combined molecular and morphological data sets, including representatives of all the genera. METHODOLOGY AND PRINCIPAL FINDINGS: We included in the analyses 3,218 bp mitochondrial genes, one hundred and thirty-five morphological characters, twenty-two extant erinaceid taxa, and five outgroup taxa. Phylogenetic relationships were reconstructed using both partitioned and combined data sets. As in previous analyses, our results strongly support the monophyly of both subfamilies (Galericinae and Erinaceinae, the Hylomys group (to include Neotetracus and Neohylomys, and a sister-relationship of Atelerix and Erinaceus. As well, we verified that the extremely long branch lengths within the Galericinae are consistent with their fossil records. Not surprisingly, we found significant incongruence between the phylogenetic signals of the genes and the morphological characters, specifically in the case of Hylomys parvus, Mesechinus, and relationships between Hemiechinus and Paraechinus. CONCLUSIONS: Although we discovered new clues to understanding the evolutionary relationships within the Erinaceidae, our results nonetheless, strongly suggest that more robust analyses employing more complete taxon sampling (to include fossils and multiple unlinked genes would greatly enhance our understanding of the

  13. The ghosts of mammals past

    DEFF Research Database (Denmark)

    Turvey, Samuel T; Fritz, Susanne A

    2011-01-01

    Although the recent historical period is usually treated as a temporal base-line for understanding patterns of mammal extinction, mammalian biodiversity loss has also taken place throughout the Late Quaternary. We explore the spatial, taxonomic and phylogenetic patterns of 241 mammal species...... extinctions have been phylogenetically and spatially concentrated in specific taxa and geographical regions, which are often not congruent with those disproportionately at risk today. Large-bodied mammals have also been more extinction-prone in most geographical regions across the Holocene. Our data support...

  14. Protein Profiling of Preeclampsia Placental Tissues

    Science.gov (United States)

    Shu, Chang; Liu, Zitao; Cui, Lifeng; Wei, Chengguo; Wang, Shuwen; Tang, Jian Jenny; Cui, Miao; Lian, Guodong; Li, Wei; Liu, Xiufen; Xu, Hongmei; Jiang, Jing; Lee, Peng; Zhang, David Y.

    2014-01-01

    Preeclampsia is a multi-system disorder involved in pregnancy without an effective treatment except delivery. The precise pathogenesis of this complicated disorder is still not completely understood. The objective of this study is to evaluate the alterations of protein expression and phosphorylations that are important in regulating placental cell function in preterm and term preeclampsia. Using the Protein Pathway Array, 38 proteins in placental tissues were found to be differentially expressed between preterm preeclampsia and gestational age matched control, while 25 proteins were found to be expressed differentially between term preeclampsia and matched controls. Among these proteins, 16 proteins and their associated signaling pathways overlapped between preterm and term preeclampsia, suggesting the common pathogenesis of two subsets of disease. On the other hand, many proteins are uniquely altered in either preterm or term preeclampsia and correlated with severity of clinical symptoms and outcomes, therefore, providing molecular basis for these two subsets of preeclampsia. Furthermore, the expression levels of some of these proteins correlated with neonatal small for gestational age (PAI-1 and PAPP-A) and adverse outcomes (Flt-1) in women with preterm preeclampsia. These proteins could potentially be used as candidate biomarkers for predicting outcomes of preeclampsia. PMID:25392996

  15. Confined placental mosaicisms and uniparental disomy

    Energy Technology Data Exchange (ETDEWEB)

    Kalousek, D.K.; Langlois, S.; Harrison, K.J. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1994-09-01

    Approximately 2% of pregnancies studied with chorionic villous sampling (CVS) show confined placental mosaicism (CPM) which persists to term in 50-70% of cases. An increased frequency of complications, such as intrauterine fetal growth restriction or intrauterine death, is observed in these pregnancies. As trisomic zygote rescue is a common mechanism responsible for CPM, fetal uniparental disomy (UPD), resulting from the loss of the extra trisomic chromosome in the embryonic stem cells, would be expected to occur in a proportion of pregnancies with CPM. We have studied 27 pregnancies with CPM involving trisomies for chromosomes 2, 7, 9, 10, 12, and 16 for involvement of specific cell lineage(s) and levels of mosaicism in term placentas. Also, DNA from the parents and infant was analyzed for UPD or biparental disomy (BPD). Five infants with UPD for chromosome 16 and one infant with UPD for chromosome 7 were detected. All other infants showed BPD for the chromosome involved in CPM. For trisomy 16 mosaic gestations, a close correlation between high levels of trisomic cells in placenta and intrauterine fetal growth restriction has been found irrespective of the type of disomy present in the infant. The effect of other trisomies (2, 7, 9, 10, 12) on placental function appears to be similar, but the low numbers of pregnancies studied and lack of detection of UPD for chromosomes 2, 9, 10 and 12 does not allow a definitive conclusion.

  16. Protein profiling of preeclampsia placental tissues.

    Science.gov (United States)

    Shu, Chang; Liu, Zitao; Cui, Lifeng; Wei, Chengguo; Wang, Shuwen; Tang, Jian Jenny; Cui, Miao; Lian, Guodong; Li, Wei; Liu, Xiufen; Xu, Hongmei; Jiang, Jing; Lee, Peng; Zhang, David Y; He, Jin; Ye, Fei

    2014-01-01

    Preeclampsia is a multi-system disorder involved in pregnancy without an effective treatment except delivery. The precise pathogenesis of this complicated disorder is still not completely understood. The objective of this study is to evaluate the alterations of protein expression and phosphorylations that are important in regulating placental cell function in preterm and term preeclampsia. Using the Protein Pathway Array, 38 proteins in placental tissues were found to be differentially expressed between preterm preeclampsia and gestational age matched control, while 25 proteins were found to be expressed differentially between term preeclampsia and matched controls. Among these proteins, 16 proteins and their associated signaling pathways overlapped between preterm and term preeclampsia, suggesting the common pathogenesis of two subsets of disease. On the other hand, many proteins are uniquely altered in either preterm or term preeclampsia and correlated with severity of clinical symptoms and outcomes, therefore, providing molecular basis for these two subsets of preeclampsia. Furthermore, the expression levels of some of these proteins correlated with neonatal small for gestational age (PAI-1 and PAPP-A) and adverse outcomes (Flt-1) in women with preterm preeclampsia. These proteins could potentially be used as candidate biomarkers for predicting outcomes of preeclampsia.

  17. The Role of Placental Tryptophan Catabolism

    Science.gov (United States)

    Sedlmayr, Peter; Blaschitz, Astrid; Stocker, Roland

    2014-01-01

    This review discusses the mechanisms and consequences of degradation of tryptophan (Trp) in the placenta, focusing mainly on the role of indoleamine 2,3-dioxygenase-1 (IDO1), one of three enzymes catalyzing the first step of the kynurenine pathway of Trp degradation. IDO1 has been implicated in regulation of feto-maternal tolerance in the mouse. Local depletion of Trp and/or the presence of metabolites of the kynurenine pathway mediate immunoregulation and exert antimicrobial functions. In addition to the decidual glandular epithelium, IDO1 is localized in the vascular endothelium of the villous chorion and also in the endothelium of spiral arteries of the decidua. Possible consequences of IDO1-mediated catabolism of Trp in the endothelium encompass antimicrobial activity and immunosuppression, as well as relaxation of the placental vasotonus, thereby contributing to placental perfusion and growth of both placenta and fetus. It remains to be evaluated whether other enzymes mediating Trp oxidation, such as indoleamine 2,3-dioxygenase-2, Trp 2,3-dioxygenase, and Trp hydroxylase-1 are of relevance to the biology of the placenta. PMID:24904580

  18. Transport of nanoparticles through the placental barrier.

    Science.gov (United States)

    Kulvietis, Vytautas; Zalgeviciene, Violeta; Didziapetriene, Janina; Rotomskis, Ricardas

    2011-12-01

    Nanoparticles (NP) are organic or inorganic substances, the size of which ranges from 1 to 100 nm, and they possess specific properties which are different from those of the bulk materials in the macroscopic scale. In a recent decade, NP were widely applied in biomedicine as potential probes for imaging, drug-delivery systems and regenerative medicine. However, rapid development of nanotechnologies and their applications in clinical research have raised concerns about the adverse effects of NP on human health and environment. In the present review, special attention is paid to the fetal exposure to NP during the period of pregnancy. The ability to control the beneficial effects of NP and to avoid toxicity during treatment requires comprehensive knowledge about the distribution of NP in maternal body and possible penetration through the maternal-fetal barrier that might impair the embryogenesis. The initial in vivo and ex vivo studies imply that NP are able to cross the placental barrier, but the passage to the fetus depends on the size and the surface coating of NP as well as on the experimental model. The toxicity assays indicate that NP might induce adverse physiological effects and impede embryogenesis. The molecular transport mechanisms which are responsible for the transport of nanomaterials across the placental barrier are still poorly understood, and there is a high need for further studies in order to resolve the NP distribution patterns in the organism and to control the beneficial effects of NP applications during pregnancy without impeding the embryogenesis.

  19. Placental thrombomodulin expression in recurrent miscarriage

    Directory of Open Access Journals (Sweden)

    Turi Angelo

    2010-01-01

    Full Text Available Abstract Background Early pregnancy loss can be associated with trophoblast insufficiency and coagulation defects. Thrombomodulin is an endothelial-associated anticoagulant protein involved in the control of hemostasis and inflammation at the vascular beds and it's also a cofactor of the protein C anticoagulant pathway. Discussion We evaluate the Thrombomodulin expression in placental tissue from spontaneous recurrent miscarriage and voluntary abortion as controls. Thrombomodulin mRNA was determined using real-time quantitative polymerase chain reaction. Reduced expression levels of thrombomodulin were found in recurrent miscarriage group compared to controls (1.82-fold of reduction, that corresponds to a reduction of 45% (from control group Delta CT of thrombomodulin expression in spontaneous miscarriage group respect the control groups. Summary We cannot state at present the exact meaning of a reduced expression of Thrombomodulin in placental tissue. Further studies are needed to elucidate the biological pathway of this important factor in the physiopathology of the trophoblast and in reproductive biology.

  20. A Case of Placental Mesenchymal Dysplasia

    Directory of Open Access Journals (Sweden)

    Shigeki Taga

    2013-01-01

    Full Text Available Placental mesenchymal dysplasia (PMD rarely complicates with pregnancy. A 30-year-old woman, gravida 3, para 3, presenting with placentomegaly, was referred to our department at 18 weeks of gestation. An ultrasonography revealed a normal fetus with a large multicystic placenta, measuring 125 × 42 × 80 mm. The border between the lesion and normal region was not clear. Color doppler revealed little blood flow in the lesion. Magnetic resonance imaging revealed normal fetus and a large multicystic placenta. Serum human chorionic gonadotropin level was 20124.97 U/L, which was normal at 20 weeks of gestation. Thus, placental mesenchymal dysplasia rather than hydatidiform mole with coexistent fetus was suspected. Then, routine checkup was continued. Because she had the history of Cesarean section, an elective Cesarean section was performed at 37 weeks of gestation, and 2520 g female infant with apgar score 8/9 was delivered. The baby was normal with no evidence of Beckwith-Wiedemann syndrome. Placenta of 20 × 16 × 2 cm, weighing 720 g, was bulky with grape like vesicles involving whole placenta. Microscopic examination revealed dilated villi and vessels with thick wall which was lacking trophoblast proliferation. Large hydropic stem villi with myxomatous struma and cistern formation were seen. PMD was histopathologically confirmed.

  1. BLM Summer Fieldwork Mammal Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Through the support of the Bureau of Land Management, the UAM Mammal Collection was able to survey some extremely remote and inaccessible areas of lower Alaska. Many...

  2. Ancient DNA from marine mammals

    DEFF Research Database (Denmark)

    Foote, Andrew David; Hofreiter, Michael; Morin, Philip A.

    2012-01-01

    Marine mammals have long generation times and broad, difficult to sample distributions, which makes inferring evolutionary and demographic changes using field studies of extant populations challenging. However, molecular analyses from sub-fossil or historical materials of marine mammals...... such as bone, tooth, baleen, skin, fur, whiskers and scrimshaw using ancient DNA (aDNA) approaches provide an oppor- tunity for investigating such changes over evolutionary and ecological timescales. Here, we review the application of aDNA techniques to the study of marine mammals. Most of the studies have...... in distribution and range of marine mammal species; we review these studies and discuss the limitations of such ‘presence only’ studies. Combining aDNA data with stable isotopes can provide further insights into changes in ecology and we review past studies and suggest future potential applications. We also...

  3. 75 FR 76399 - Marine Mammals

    Science.gov (United States)

    2010-12-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XZ66 Marine Mammals AGENCY: National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Commerce. ACTION: Notice; receipt of...

  4. Impacts of the Cretaceous Terrestrial Revolution and KPg extinction on mammal diversification.

    Science.gov (United States)

    Meredith, Robert W; Janečka, Jan E; Gatesy, John; Ryder, Oliver A; Fisher, Colleen A; Teeling, Emma C; Goodbla, Alisha; Eizirik, Eduardo; Simão, Taiz L L; Stadler, Tanja; Rabosky, Daniel L; Honeycutt, Rodney L; Flynn, John J; Ingram, Colleen M; Steiner, Cynthia; Williams, Tiffani L; Robinson, Terence J; Burk-Herrick, Angela; Westerman, Michael; Ayoub, Nadia A; Springer, Mark S; Murphy, William J

    2011-10-28

    Previous analyses of relations, divergence times, and diversification patterns among extant mammalian families have relied on supertree methods and local molecular clocks. We constructed a molecular supermatrix for mammalian families and analyzed these data with likelihood-based methods and relaxed molecular clocks. Phylogenetic analyses resulted in a robust phylogeny with better resolution than phylogenies from supertree methods. Relaxed clock analyses support the long-fuse model of diversification and highlight the importance of including multiple fossil calibrations that are spread across the tree. Molecular time trees and diversification analyses suggest important roles for the Cretaceous Terrestrial Revolution and Cretaceous-Paleogene (KPg) mass extinction in opening up ecospace that promoted interordinal and intraordinal diversification, respectively. By contrast, diversification analyses provide no support for the hypothesis concerning the delayed rise of present-day mammals during the Eocene Period.

  5. Phylogeny and taxonomy of Chlorobiaceae.

    Science.gov (United States)

    Imhoff, Johannes F; Thiel, Vera

    2010-06-01

    Based on phylogenetic relationships found according to gene sequences of the 16S rRNA and the FMO (Fenna-Matthews-Olson protein) genes, and supported by the G + C content of the DNA and sequence signatures, the strains and species of green sulfur bacteria have been grouped into a phylogenetic system. Since properties used previously for classification such as cell morphology, photosynthetic pigments and substrate utilization do not conform with their phylogeny, a reassignment of strains to species, and a rearrangement among the species were necessary. The comparison of the traditional classification system of these bacteria with their phylogenetic relationship yielded a confusing picture. As a consequence of this rearrangement, species of the green sulfur bacteria were classified into the genera Chlorobium, Chlorobaculum, Prosthecochloris, and Chloroherpeton. Strains were assigned to the species according to their phylogenetic similarity and a number of new combinations, and new species were defined. New isolates and also environmental gene sequences fit very well into the established groups or may form new species, some of which have been described and others are awaiting their description. New strains and available gene sequences are included into the phylogenetic system, and a taxonomic classification on the species level is proposed.

  6. IFPA meeting 2015 workshop report I: placental mitochondrial function, transport systems and epigenetics.

    Science.gov (United States)

    Bianco-Miotto, T; Blundell, C; Buckberry, S; Chamley, L; Chong, S; Cottrell, E; Dawson, P; Hanna, C; Holland, O; Lewis, R M; Moritz, K; Myatt, L; Perkins, A V; Powell, T; Saffery, R; Sferruzzi-Perri, A; Sibley, C; Simmons, D; O'Tierney-Ginn, P F

    2016-12-01

    Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops covered areas of placental regulation and nutrient handling: 1) placental epigenetics; 2) placental mitochondrial function; 3) placental transport systems.

  7. Associations between intrapartum death and piglet, placental, and umbilical characteristics.

    Science.gov (United States)

    Rootwelt, V; Reksen, O; Farstad, W; Framstad, T

    2012-12-01

    Intrapartum death in multiparous gestations in sows (Sus scrofa) is often caused by hypoxia. There is little information in the literature on the assessment of the placenta in relation to intrapartum death in piglets. The aim of this study was to evaluate the impact of the placental area and weight upon piglet birth characteristics and intrapartum death. Litters from 26 Landrace-Yorkshire sows were monitored during farrowing and the status of each piglet was recorded, including blood parameters of piglets and their umbilical veins. Of 413 piglets born, 6.5% were stillborn. Blood concentrations of glucose, lactate, and CO(2) partial pressure were increased in the stillborn piglets (P piglets, whereas pH and base excess were decreased (P piglets born dead vs. live (P piglets born dead was not different from live-born piglets (P = 0.631), whereas mean body mass index was reduced (P piglets were not different from live-born piglets (P = 0.662 and P = 0.253, respectively). Blood concentrations of lactate, hemoglobin, and hematocrit recorded in all piglets pooled were associated with placental area (P 0.2). Piglet BW was positively correlated with placental area and placental weight (P piglet birth weight, but not with the probability of being born dead. Placental area was a better predictor of piglet vitality than placental weight. Because umbilical cord rupture and prolonged birth time were associated with being born dead, umbilical cord rupture and placental detachment seem to be probable causes of intrapartum death.

  8. 50 CFR 14.18 - Marine mammals.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Marine mammals. 14.18 Section 14.18....18 Marine mammals. Any person subject to the jurisdiction of the United States who has lawfully taken a marine mammal on the high seas and who is authorized to import such marine mammal in accordance...

  9. Placental exosomes in normal and complicated pregnancy.

    Science.gov (United States)

    Mitchell, Murray D; Peiris, Hassendrini N; Kobayashi, Miharu; Koh, Yong Q; Duncombe, Gregory; Illanes, Sebastian E; Rice, Gregory E; Salomon, Carlos

    2015-10-01

    While there is considerable contemporary interest in elucidating the role of placenta-derived extracellular vesicles in normal and complicated pregnancies and their utility as biomarkers and therapeutic interventions, progress in the field is hindered by a lack of standardized extracellular vesicle taxonomy and isolation protocols. The term "extracellular vesicle" is nonspecific and refers to all membrane-bound vesicles from nanometer to micrometer diameters and of different biogenic origins. To meaningfully ascribe biological function and/or diagnostic and therapeutic utility to extracellular vesicles, and in particular exosomes, greater specificity and vesicle characterization is required. The current literature relating to exosome biology must be interpreted in this context. Exosomes are a subtype of extracellular vesicle that are specifically defined by an endosomal biogenesis and particle size (40-120 nm) and density (1.13-1.19 g/mL(-1)). Exosomes are specifically package with signaling molecules (including protein, messenger RNA, microRNA, and noncoding RNA) and are released by exocytosis into biofluid compartments. Exosomes regulate the activity of both proximal and distal target cells, including translational activity, angiogenesis, proliferation, metabolism, and apoptosis. As such, exosomal signaling represents an integral pathway mediating intercellular communication. During pregnancy, the placenta releases exosomes into the maternal circulation from as early as 6 weeks of gestation. Release is regulated by factors that include both oxygen tension and glucose concentration and correlates with placental mass and perfusion. The concentration of placenta-derived exosomes in maternal plasma increases progressively during gestation. Exosomes isolated from maternal plasma are bioactive in vitro and are incorporated into target cells by endocytosis. While the functional significance of placental exosomes in pregnancy remains to be fully elucidated, available

  10. Developmental programing: impact of testosterone on placental differentiation.

    Science.gov (United States)

    Beckett, E M; Astapova, O; Steckler, T L; Veiga-Lopez, A; Padmanabhan, V

    2014-08-01

    Gestational testosterone treatment causes maternal hyperinsulinemia, intrauterine growth retardation (IUGR), low birth weight, and adult reproductive and metabolic dysfunctions. Sheep models of IUGR demonstrate placental insufficiency as an underlying cause of IUGR. Placental compromise is probably the cause of fetal growth retardation in gestational testosterone-treated sheep. This study tested whether testosterone excess compromises placental differentiation by its androgenic action and/or via altered insulin sensitivity. A comparative approach of studying gestational testosterone (aromatizable androgen) against dihydrotestosterone (non-aromatizable androgen) or testosterone plus androgen antagonist, flutamide, was used to determine whether the effects of testosterone on placental differentiation were programed by its androgenic actions. Co-treatment of testosterone with the insulin sensitizer, rosiglitazone, was used to establish whether the effects of gestational testosterone on placentome differentiation involved compromised insulin sensitivity. Parallel cohorts of pregnant females were maintained for lambing and the birth weight of their offspring was recorded. Placental studies were conducted on days 65, 90, or 140 of gestation. Results indicated that i) gestational testosterone treatment advances placental differentiation, evident as early as day 65 of gestation, and culminates in low birth weight, ii) placental advancement is facilitated at least in part by androgenic actions of testosterone and is not a function of disrupted insulin homeostasis, and iii) placental advancement, while helping to increase placental efficiency, was insufficient to prevent IUGR and low-birth-weight female offspring. Findings from this study may be of relevance to women with polycystic ovary syndrome, whose reproductive and metabolic phenotype is captured by the gestational testosterone-treated offspring. © 2014 Society for Reproduction and Fertility.

  11. Risk of placental abruption in relation to migraines and headaches

    Directory of Open Access Journals (Sweden)

    Ananth Cande V

    2010-10-01

    Full Text Available Abstract Background Migraine, a common chronic-intermittent disorder of idiopathic origin characterized by severe debilitating headaches and autonomic nervous system dysfunction, and placental abruption, the premature separation of the placenta, share many common pathophysiological characteristics. Moreover, endothelial dysfunction, platelet activation, hypercoagulation, and inflammation are common to both disorders. We assessed risk of placental abruption in relation to maternal history of migraine before and during pregnancy in Peruvian women. Methods Cases were 375 women with pregnancies complicated by placental abruption, and controls were 368 women without an abruption. During in-person interviews conducted following delivery, women were asked if they had physician-diagnosed migraine, and they were asked questions that allowed headaches and migraine to be classified according to criteria established by the International Headache Society. Logistic regression procedures were used to calculate odds ratios (aOR and 95% confidence intervals (CI adjusted for confounders. Results Overall, a lifetime history of any headaches or migraine was associated with an increased odds of placental abruption (aOR = 1.60; 95% CI 1.16-2.20. A lifetime history of migraine was associated with a 2.14-fold increased odds of placental abruption (aOR = 2.14; 95% CI 1.22-3.75. The odds of placental abruption was 2.11 (95% CI 1.00-4.45 for migraineurs without aura; and 1.59 (95% 0.70-3.62 for migraineurs with aura. A lifetime history of tension-type headache was also increased with placental abruption (aOR = 1.61; 95% CI 1.01-2.57. Conclusions This study adds placental abruption to a growing list of pregnancy complications associated with maternal headache/migraine disorders. Nevertheless, prospective cohort studies are needed to more rigorously evaluate the extent to which migraines and/or its treatments are associated with the occurrence of placental abruption.

  12. Epithelial membrane protein 2 (EMP2) deficiency alters placental angiogenesis, mimicking features of human placental insufficiency.

    Science.gov (United States)

    Williams, Carmen J; Chu, Alison; Jefferson, Wendy N; Casero, David; Sudhakar, Deepthi; Khurana, Nevil; Hogue, Claire P; Aryasomayajula, Chinmayi; Patel, Priya; Sullivan, Peggy; Padilla-Banks, Elizabeth; Mohandessi, Shabnam; Janzen, Carla; Wadehra, Madhuri

    2017-03-14

    Epithelial membrane protein-2 (EMP2) is a tetraspan protein predicted to regulate placental development. Highly expressed in secretory endometrium and trophectoderm cells, previous studies suggest that it may regulate implantation by orchestrating the surface expression of integrins and other membrane proteins. In order to test the role of EMP2 in pregnancy, mice lacking EMP2 (Emp2(-/-) ) were generated. Emp2(-/-) females are fertile but have reduced litter sizes when carrying Emp2(-/-) but not Emp2(+/-) fetuses. Placentas of Emp2(-/-) fetuses exhibit dysregulation in pathways related to neoangiogenesis, coagulation, and oxidative stress, and have increased fibrin deposition and altered vasculature. Given that these findings often occur due to placental insufficiency resulting in an oxygen-poor environment, the expression of hypoxia-inducible factor-1 alpha (HIF-1α) was examined. Placentas from Emp2(-/-) fetuses had increased total HIF-1α expression in large part through an increase in uterine NK (uNK) cells, demonstrating a unique interplay between uNK cells and trophoblasts modulated through EMP2. To determine if these results translated to human pregnancy, placentas from normal, term deliveries or those complicated by placental insufficiency resulting in intrauterine growth restriction (IUGR) were stained for EMP2. EMP2 was significantly reduced in both villous and extravillous trophoblast populations in IUGR placentas. Experiments in vitro using human trophoblast cells lines indicate that EMP2 modulates angiogenesis by altering HIF-1α expression. Our results reveal a novel role for EMP2 in regulating trophoblast function and vascular development in mice and humans and suggest it may be a new biomarker for placental insufficiency.

  13. Perfect Phylogeny Problems with Missing Values.

    Science.gov (United States)

    Kirkpatrick, Bonnie; Stevens, Kristian

    2014-01-01

    The perfect phylogeny problem is of central importance to both evolutionary biology and population genetics. Missing values are a common occurrence in both sequence and genotype data, but they make the problem of finding a perfect phylogeny NPhard even for binary characters. We introduce new and efficient perfect phylogeny algorithms for broad classes of binary and multistate data with missing values. Specifically, we address binary missing data consistent with the rich data hypothesis (RDH) introduced by Halperin and Karp and give an efficient algorithm for enumerating phylogenies. This algorithm is useful for computing the probability of data with missing values under the coalescent model. In addition, we use the partition intersection (PI) graph and chordal graph theory to generalize the RDH to multi-state characters with missing values. For a bounded number of states, we provide a fixed parameter tractable algorithm for the perfect phylogeny problem with missing data. Utilizing the PI graph, we are able to show that under multiple biologically motivated models for character data, our generalized RDH holds with high probability, and we evaluate our results with extensive empirical analysis.

  14. Longitudinal study of serum placental GH in 455 normal pregnancies

    DEFF Research Database (Denmark)

    Chellakooty, Marla; Skibsted, Lillian; Skouby, Sven O

    2002-01-01

    women with normal singleton pregnancies at approximately 19 and 28 wk gestation. Serum placental GH concentrations were measured by a highly specific immunoradiometric assay, and fetal size was measured by ultrasound. Data on birth weight, gender, prepregnancy body mass index (BMI), parity, and smoking.......002). Placental GH at second examination was positively correlated with gestational age (P = 0.002) and negatively correlated with prepregnancy BMI (P = 0.039). Placental GH correlated with fetal weight at approximately 28 wk gestation (P = 0.002) but did not predict birth weight at term. Our study supports...

  15. [How to stimulate the placental function (author's transl)].

    Science.gov (United States)

    Fanard, A; Picazo, J J

    1976-01-01

    Imminent abortion, habitual abortion and threatened premature labor, all constitute difficult clinical problems. Those cases require on every occasion a diagnosis as acurate as possible, and unfortunately our present methods of biochemical determinations only represent a means to evaluate placental function. On those cases where a faulty placental function is detected thru the tests presently available, the authors recommend the utilization of a placentotropic substance, Gestanon, that is capable to stimulate and normalize the placental function, a is demostrated by the statistical results published in the international medical bibliography.

  16. Predicting dispersal distance in mammals: a trait-based approach.

    Science.gov (United States)

    Whitmee, Sarah; Orme, C David L

    2013-01-01

    Dispersal is one of the principal mechanisms influencing ecological and evolutionary processes but quantitative empirical data are unfortunately scarce. As dispersal is likely to influence population responses to climate change, whether by adaptation or by migration, there is an urgent need to obtain estimates of dispersal distance. Cross-species correlative approaches identifying predictors of dispersal distance can provide much-needed insights into this data-scarce area. Here, we describe the compilation of a new data set of natal dispersal distances and use it to test life-history predictors of dispersal distance in mammals and examine the strength of the phylogenetic signal in dispersal distance. We find that both maximum and median dispersal distances have strong phylogenetic signals. No single model performs best in describing either maximum or median dispersal distances when phylogeny is taken into account but many models show high explanatory power, suggesting that dispersal distance per generation can be estimated for mammals with comparatively little data availability. Home range area, geographic range size and body mass are identified as the most important terms across models. Cross-validation of models supports the ability of these variables to predict dispersal distances, suggesting that models may be extended to species where dispersal distance is unknown.

  17. Absence of mammals and the evolution of New Zealand grasses.

    Science.gov (United States)

    Antonelli, Alexandre; Humphreys, Aelys M; Lee, William G; Linder, H Peter

    2011-03-07

    Anthropogenic alteration of biotic distributions and disturbance regimes has dramatically changed the evolutionary context for the differentiation of species traits. Some of the most striking examples in recent centuries have been on islands where flightless birds, which evolved in the absence of mammalian carnivores, have been decimated following the widespread introduction of exotic predators. Until now, no equivalent case has been reported for plants. Here, we make use of robust analytical tools and an exceptionally well-sampled molecular phylogeny to show that a majority of New Zealand danthonioid grasses (Poaceae) may have adapted to the relaxed vertebrate herbivore pressure during the late Cenozoic through the development of a distinctive and unusual habit: abscission of old leaves. This feature occurs in only about 3 per cent of the world's roughly 11,000 grass species and has been empirically shown to increase plant productivity but to reduce protection against mammal grazing. This result suggests that release from a selective pressure can lead to species radiations. This seemingly anachronistic adaptation may represent an overlooked factor contributing to the severe decline in the geographical extent and species diversity of New Zealand's indigenous grasslands following the introduction of herbivorous terrestrial mammals in the 19th century.

  18. 50 CFR 18.25 - Exempted marine mammals or marine mammal products.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Exempted marine mammals or marine mammal... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MARINE MAMMALS General Exceptions § 18.25 Exempted marine mammals or marine mammal products. (a) The provisions of the Act and these regulations shall not apply: (1...

  19. Maternal regulation of offspring development in mammals is an ancient adaptation tied to lactation

    Directory of Open Access Journals (Sweden)

    Michael L. Power

    2013-12-01

    Full Text Available The developmental origins of health and disease (DOHaD is a paradigm for understanding metabolic diseases of modern humans. Vulnerability to disease is linked to perturbations in development during critical time periods in fetal and neonatal life. These perturbations are caused by environmental signals, often generated or transduced by the mother. The regulation of mammalian development depends to a large extent on maternal biochemical signals to her offspring. We argue that this adaptation is ancient, and originated with the evolution of lactation. Lactation evolved earlier than live birth and before the extensive placental development of modern eutherian mammals. Milk contains a host of signaling molecules including nutrients, immunoglobulins, growth factors and metabolic hormones. As evidenced by marsupials, lactation originally served to supply the biochemical factors for growth and development for what is essentially a fetus to a weanling transitioning to independent existence. In placental mammals maternal signaling in earliest life is accomplished through the maternal–placental–fetal connection, with more of development shifted to in utero life. However, significant development occurs postpartum, supported by milk. Mothers of all taxa provide biochemical signals to their offspring, but for non-mammalian mothers the time window is short. Developing mammals receive maternal biochemical signals over an extended period. These signals serve to guide normal development, but also can vary in response to environmental conditions. The ancient adaptation of lactation resulted in a lineage (mammals in which maternal regulation of offspring development evolved to a heightened degree, with the ability to modify development at multiple time points. Modern metabolic diseases may arise due to a mismatch between maternal regulation and eventual circumstances of the offspring, and due to a large proportion of mothers that exceed past evolutionary norms

  20. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Genomic imprinting,representing parent-specific expression of alleles at a locus,is mainly evident in flowering plants and placental mammals.Most imprinted genes,including numerous non-coding RNAs,are located in clusters regulated by imprinting control regions(ICRs).The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions.Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors,especially recent studies undertaken on the most ancient mammalian clades-the marsupials and monotremes from which model species genomes have recently been sequenced,are of high value.By reviewing and analyzing these studies,a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated.The evidence comes from two observations accompanied with the acquisition of the imprinting:(i) many novel non-coding RNA genes emerged in imprinted regions;(ii) the expressions of some conserved non-coding RNAs have changed dramatically.Furthermore,a systematical analysis of imprinted snoRNA(small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials,followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals.Involved in the regulation of imprinted silencing and mediating the chromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  1. Factors affecting the placental transfer of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Sikov, M.R.; Kelman, B.J. (Pacific Northwest Laboratory, Richland, WA (USA))

    1989-01-01

    The primary goal of this paper is to consider factors that affect the availability and transport of actinides from maternal blood, through the placenta, to the conceptus. These factors, of particular importance in scaling results from animals to man, include the route and temporal pattern of administration, the mass and physicochemical state of material administered, metabolism of the pregnant animal and fetal organs or tissue, and species-specific changes in placental structure relative to stage of gestation at exposure. Preliminary concepts for descriptive and kinetic models are proposed to integrate these results, to identify additional information required for developing more comprehensive models, and to provide a basis for scaling to human pregnancies for purposes of radiation dosimetry.

  2. Plasmodium vivax adherence to placental glycosaminoglycans.

    Directory of Open Access Journals (Sweden)

    Kesinee Chotivanich

    Full Text Available BACKGROUND: Plasmodium vivax infections seldom kill directly but do cause indirect mortality by reducing birth weight and causing abortion. Cytoadherence and sequestration in the microvasculature are central to the pathogenesis of severe Plasmodium falciparum malaria, but the contribution of cytoadherence to pathology in other human malarias is less clear. METHODOLOGY: The adherence properties of P. vivax infected red blood cells (PvIRBC were evaluated under static and flow conditions. PRINCIPAL FINDINGS: P. vivax isolates from 33 patients were studied. None adhered to immobilized CD36, ICAM-1, or thrombospondin, putative ligands for P. falciparum vascular cytoadherence, or umbilical vein endothelial cells, but all adhered to immobilized chondroitin sulphate A (CSA and hyaluronic acid (HA, the receptors for adhesion of P. falciparum in the placenta. PvIRBC also adhered to fresh placental cells (N = 5. Pre-incubation with chondroitinase prevented PvIRBC adherence to CSA, and reduced binding to HA, whereas preincubation with hyaluronidase prevented adherence to HA, but did not reduce binding to CSA significantly. Pre-incubation of PvIRBC with soluble CSA and HA reduced binding to the immobilized receptors and prevented placental binding. PvIRBC adhesion was prevented by pre-incubation with trypsin, inhibited by heparin, and reduced by EGTA. Under laminar flow conditions the mean (SD shear stress reducing maximum attachment by 50% was 0.06 (0.02 Pa but, having adhered, the PvIRBC could then resist detachment by stresses up to 5 Pa. At 37 °C adherence began approximately 16 hours after red cell invasion with maximal adherence at 30 hours. At 39 °C adherence began earlier and peaked at 24 hours. SIGNIFICANCE: Adherence of P. vivax-infected erythrocytes to glycosaminoglycans may contribute to the pathogenesis of vivax malaria and lead to intrauterine growth retardation.

  3. Intestinal and placental zinc transport pathways.

    Science.gov (United States)

    Ford, Dianne

    2004-02-01

    Mammalian members of the cation diffusion facilitator (CDF) and zrt-, irt-like protein (ZIP) families of Zn transporters, initially identified in Saccharomyces cerevisiae and Arabidopsis thalania spp., have been cloned during the last 8 years and have been classified as families SLC30 and SLC39 respectively. The cloning of human Zn transporters ZnT-like transporter 1 (hZTL1)/ZnT5 (SLC30A5) and hZIP4 (SLC39A4) were major advances in the understanding of the molecular mechanisms of dietary Zn absorption. Both transporters are localised at the enterocyte apical membrane and are, therefore, potentially of fundamental importance in dietary Zn uptake. hZTL1 mediates Zn uptake when expressed in Xenopus laevis oocytes and hZIP4 is mutated in most cases of the inherited Zn deficiency disease acrodermatitis enteropathica. Localisation of hZTL1/ZnT5 at the apical membrane of the placental syncytiotrophoblast indicates a fundamental role in the transfer of Slc30 Zn to the foetus. Observations in rodent models indicate that in the intestine increased Zn availability increases expression of Zn transporters. Human intestinal Caco-2 cells show a similar response to increasing the Zn2+ concentration of the nutrient medium in relation to the expression of mRNA corresponding to several Zn transporters and that of ZnT1 (SLC30A1) and hZTL1/ZnT5 proteins. In the human placental cell line JAR, however, expression at the mRNA level of a number of Zn transporters is not modified by Zn availability, whilst ZnT1 and hZTL1/ZnT5 proteins are reduced under Zn-supplemented conditions. These differences between Caco-2 and JAR cells in Zn transporter gene responses to Zn supply may reflect the different extracellular Zn concentrations encountered by the corresponding cell types in vitro.

  4. Juvenile morphology in baleen whale phylogeny.

    Science.gov (United States)

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  5. Juvenile morphology in baleen whale phylogeny

    Science.gov (United States)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  6. The phylogeny of Orussidae (Insecta: Hymenoptera) revisited

    DEFF Research Database (Denmark)

    Vilhelmsen, Lars

    2007-01-01

    The phylogeny of the parasitic wasp family Orussidae is analyzed with a slightly expanded version of a previously published data set. The basal splitting events in the family between two fossil taxa and the extant members are not unambiguously resolved. Intergeneric relationships in general...... are poorly supported and change under different analytical conditions. This corroborates earlier fi ndings regarding the phylogeny of the family. A resumé of the evolutionary history of the Orussidae is provided. Leptorussus madagascarensis sp.n. is described. Udgivelsesdato: 7/12...

  7. The phylogeny graphs of doubly partial orders

    CERN Document Server

    Park, Boram

    2011-01-01

    The competition graph of a doubly partial order is known to be an interval graph. The CCE graph and the niche graph of a doubly partial order are also known to be interval graphs if the graphs do not contain a cycle of length four and three as an induced subgraph, respectively. Phylogeny graphs are variant of competition graphs. The phylogeny graph $P(D)$ of a digraph $D$ is the (simple undirected) graph defined by $V(P(D)):=V(D)$ and $E(P(D)):=\\{xy \\mid N^+_D(x) \\cap N^+_D(y) \

  8. Ribosomal RNA: a key to phylogeny

    Science.gov (United States)

    Olsen, G. J.; Woese, C. R.

    1993-01-01

    As molecular phylogeny increasingly shapes our understanding of organismal relationships, no molecule has been applied to more questions than have ribosomal RNAs. We review this role of the rRNAs and some of the insights that have been gained from them. We also offer some of the practical considerations in extracting the phylogenetic information from the sequences. Finally, we stress the importance of comparing results from multiple molecules, both as a method for testing the overall reliability of the organismal phylogeny and as a method for more broadly exploring the history of the genome.

  9. Ribosomal RNA: a key to phylogeny

    Science.gov (United States)

    Olsen, G. J.; Woese, C. R.

    1993-01-01

    As molecular phylogeny increasingly shapes our understanding of organismal relationships, no molecule has been applied to more questions than have ribosomal RNAs. We review this role of the rRNAs and some of the insights that have been gained from them. We also offer some of the practical considerations in extracting the phylogenetic information from the sequences. Finally, we stress the importance of comparing results from multiple molecules, both as a method for testing the overall reliability of the organismal phylogeny and as a method for more broadly exploring the history of the genome.

  10. Loss of Thrombomodulin in Placental Dysfunction in Preeclampsia

    NARCIS (Netherlands)

    Turner, Rosanne J; Bloemenkamp, Kitty W M; Bruijn, Jan A; Baelde, Hans J

    OBJECTIVE: Preeclampsia is a pregnancy-specific syndrome characterized by placental dysfunction and an angiogenic imbalance. Systemically, levels of thrombomodulin, an endothelium- and syncytiotrophoblast-bound protein that regulates coagulation, inflammation, apoptosis, and tissue remodeling, are

  11. Placental polyp: a rare cause of iron deficiency anemia

    Directory of Open Access Journals (Sweden)

    Fernando Peixoto Ferraz de Campos

    2011-12-01

    Full Text Available Placental polyps are defined as pedunculated or polypoid fragments of placentaor ovular membranes retained for an indefinite period of time into the uterus afterabortion or child birth. An important cause of retention is placental accretism, anabnormal adherence of the placenta into the uterine wall. Chronic cases are rarelyreported in the literature. In these cases, the placental retention in the immediatepostpartum is not followed by heavy bleeding what makes the diagnosischallenging. We report a rare case of iron-deficiency anemia in a multiparous29-year-old female patient two years after the last delivery. She sought medicalcare with clinical symptoms of anemia and recent menses alterations. Therewas no history of abortion. On gynecological examination, there was a twofoldenlarged uterus, and the pelvic ultrasound revealed an image compatible with anendometrial polyp. She underwent open hysterectomy because of uncontrollablebleeding followed by hypotension after curettage. The histolopathologicexamination revealed a partially hyalinized and necrotic placental polyp.

  12. Loss of Thrombomodulin in Placental Dysfunction in Preeclampsia

    NARCIS (Netherlands)

    Turner, Rosanne J; Bloemenkamp, Kitty W M; Bruijn, Jan A; Baelde, Hans J

    2016-01-01

    OBJECTIVE: Preeclampsia is a pregnancy-specific syndrome characterized by placental dysfunction and an angiogenic imbalance. Systemically, levels of thrombomodulin, an endothelium- and syncytiotrophoblast-bound protein that regulates coagulation, inflammation, apoptosis, and tissue remodeling, are i

  13. The effect of smoking on serum human placental lactogen levels.

    Science.gov (United States)

    Spellacy, W N; Buhi, W C; Birk, S A

    1977-02-01

    Serial serum samples (162) were drawn weekly from normal pregnant women (53) during the last month of gestation and measurements were made of the human placental lactogen (HPL) content. The women were interviewed as to their smoking habits and divided into nonsmokers (32) and smokers of from one to two packages of cigarettes per day (21). The infant birth weight and placental weights were not significantly different. The HPL levels were elevated in the women who smoked and the differences were significant at the thirty-sixth and thirty-eighth weeks. The importance of this in interpreting HPL as a placental function test and in terms of the biology of placental function and the control of protein hormone synthesis is emphasized.

  14. Placental loctogen levels associated with gross fetal abnormality.

    Science.gov (United States)

    Gau, G S; Cadle, G

    1977-02-01

    Four cases of severe congenital abnormality associated with persistently low maternal serum human placental lactogen levels are described. It is thought that this pattern might act as a warning of severe fetal abnormality.

  15. Comparative Placentation: Some Interesting Modifications for Histotrophic Nutrition - A Review

    DEFF Research Database (Denmark)

    Enders; Carter, Anthony M.

    2006-01-01

    In considering the diversity of Eutherian mammalian placental structure, it is helpful to keep in mind that both phylogenetically and ontogenetically a functional yolk sac placenta precedes development of the chorioallantoic placenta. Usually the chorioallantoic placenta progressively displaces t...

  16. Placental fetal vascular thrombosis lesions and maternal thrombophilia

    NARCIS (Netherlands)

    Beeksma, F. A.; Erwich, J. J. H. M.; Khong, T. Y.

    Aims: Following intrauterine fetal death (IUFD), the placental fetal vessels undergo regressive changes. These changes are virtually indistinguishable from lesions that are the result of fetal vascular thrombosis (FVT). This study investigated the relation between these lesions and maternal

  17. Maternal serum placental growth hormone, but not human placental lactogen or insulin growth factor-1, is positively associated with fetal growth in the first half of pregnancy

    DEFF Research Database (Denmark)

    Pedersen, N G; Juul, A; Christiansen, M

    2010-01-01

    To investigate if maternal levels of human placental lactogen (hPL), placental growth hormone (PGH) and insulin-like growth factor-1 (IGF-1) are associated with growth rate of the biparietal diameter (BPD) in the first half of pregnancy.......To investigate if maternal levels of human placental lactogen (hPL), placental growth hormone (PGH) and insulin-like growth factor-1 (IGF-1) are associated with growth rate of the biparietal diameter (BPD) in the first half of pregnancy....

  18. Placental Vascular Tree as Biomarker of Autism/ASD Risk

    Science.gov (United States)

    2013-09-01

    Carolyn M. Salafia, MD, MS, NYS Institute for Basic Research in Developmental Disabilities (IBR), 1050 Forest Hill Road, Staten Island, NY, 10314. Co...Carolyn M Salafia, MD, Institute for Basic Research (IBR), 1050 Forest Hill Road, Staten Island, NY, 10314. Co-Investigators: Michael Yampolsky, PhD...computer platforms; and Maplesoft Maple 9.0 Math & Engineering software. Placental histopathology diagnoses Placental disease was characterized by gross

  19. Multiscale modelling of the feto–placental vasculature

    Science.gov (United States)

    Clark, A. R.; Lin, M.; Tawhai, M.; Saghian, R.; James, J. L.

    2015-01-01

    The placenta provides all the nutrients required for the fetus through pregnancy. It develops dynamically, and, to avoid rejection of the fetus, there is no mixing of fetal and maternal blood; rather, the branched placental villi ‘bathe’ in blood supplied from the uterine arteries. Within the villi, the feto–placental vasculature also develops a complex branching structure in order to maximize exchange between the placental and maternal circulations. To understand the development of the placenta, we must translate functional information across spatial scales including the interaction between macro- and micro-scale haemodynamics and account for the effects of a dynamically and rapidly changing structure through the time course of pregnancy. Here, we present steps towards an anatomically based and multiscale approach to modelling the feto–placental circulation. We assess the effect of the location of cord insertion on feto–placental blood flow resistance and flow heterogeneity and show that, although cord insertion does not appear to directly influence feto–placental resistance, the heterogeneity of flow in the placenta is predicted to increase from a 19.4% coefficient of variation with central cord insertion to 23.3% when the cord is inserted 2 cm from the edge of the placenta. Model geometries with spheroidal and ellipsoidal shapes, but the same volume, showed no significant differences in flow resistance or heterogeneity, implying that normal asymmetry in shape does not affect placental efficiency. However, the size and number of small capillary vessels is predicted to have a large effect on feto–placental resistance and flow heterogeneity. Using this new model as an example, we highlight the importance of taking an integrated multi-disciplinary and multiscale approach to understand development of the placenta. PMID:25844150

  20. Multiscale modelling of the feto-placental vasculature.

    Science.gov (United States)

    Clark, A R; Lin, M; Tawhai, M; Saghian, R; James, J L

    2015-04-06

    The placenta provides all the nutrients required for the fetus through pregnancy. It develops dynamically, and, to avoid rejection of the fetus, there is no mixing of fetal and maternal blood; rather, the branched placental villi 'bathe' in blood supplied from the uterine arteries. Within the villi, the feto-placental vasculature also develops a complex branching structure in order to maximize exchange between the placental and maternal circulations. To understand the development of the placenta, we must translate functional information across spatial scales including the interaction between macro- and micro-scale haemodynamics and account for the effects of a dynamically and rapidly changing structure through the time course of pregnancy. Here, we present steps towards an anatomically based and multiscale approach to modelling the feto-placental circulation. We assess the effect of the location of cord insertion on feto-placental blood flow resistance and flow heterogeneity and show that, although cord insertion does not appear to directly influence feto-placental resistance, the heterogeneity of flow in the placenta is predicted to increase from a 19.4% coefficient of variation with central cord insertion to 23.3% when the cord is inserted 2 cm from the edge of the placenta. Model geometries with spheroidal and ellipsoidal shapes, but the same volume, showed no significant differences in flow resistance or heterogeneity, implying that normal asymmetry in shape does not affect placental efficiency. However, the size and number of small capillary vessels is predicted to have a large effect on feto-placental resistance and flow heterogeneity. Using this new model as an example, we highlight the importance of taking an integrated multi-disciplinary and multiscale approach to understand development of the placenta.

  1. [Fetal circulation in normal pregnancy and in placental insufficiency].

    Science.gov (United States)

    Ivanov, B; Malinova, M

    2010-01-01

    The fetal circulation is different from the adult circulation. One of the quite common conditions that are challenging to the developing fetus is placental hypoxia. Regardless of its cause, placental vascular insufficiency is commonly assumed to be an important factor in the development of intrauterine growth retardation. Several mechanisms are involved in the fetal adaptation to the decompensation during hypoxemia. Doppler Ultrasound technologies can help to evaluate of the fetal wellbeing.

  2. PLACENTAL LOCATION AT SECOND TRIMESTER AND PREGNANCY OUTCOMES

    Directory of Open Access Journals (Sweden)

    Seadati N

    2013-04-01

    Full Text Available The aimed of this study was to find association between location of placental at second trimester and pregnancy outcomes. It was a descriptive -analytic epidemiological study which has performed on 250 pregnant women by simple random sampling in Razi hospital and Imam Khomeini hospital during July 2011 – October 2012 in Ahvaz city, Iran. Placental location was determined by sonography at 18 - 22 weeks of gestation, and it was classified to high / low category and anterior / posterior category. In this study has been assessed placental location with incidence of preeclampsia, intrauterine growth restriction and preterm birth. The incidence of preeclampsia and intrauterine growth restriction was 5.6%, 1.6% respectively, these parameters were not associated with placental location (p=0.84, p=0.69. The incidence of preterm birth was 7.2% and it was associated with low placental location (p=0.01.There was no significant difference between anterior and posterior placenta in all of outcomes. Low placental location was associated with increased risk of preterm labor and preterm delivery.

  3. Metabolism of bupropion by baboon hepatic and placental microsomes.

    Science.gov (United States)

    Wang, Xiaoming; Abdelrahman, Doaa R; Fokina, Valentina M; Hankins, Gary D V; Ahmed, Mahmoud S; Nanovskaya, Tatiana N

    2011-08-01

    The aim of this investigation was to determine the biotransformation of bupropion by baboon hepatic and placental microsomes, identify the enzyme(s) catalyzing the reaction(s) and determine its kinetics. Bupropion was metabolized by baboon hepatic and placental microsomes to hydroxybupropion (OH-BUP), threo- (TB) and erythrohydrobupropion (EB). OH-bupropion was the major metabolite formed by hepatic microsomes (Km 36±6 μM, Vmax 258±32 pmol mg protein(-1) min(-1)), however the formation of OH-BUP by placental microsomes was below the limit of quantification. The apparent Km values of bupropion for the formation of TB and EB by hepatic and placental microsomes were similar. The selective inhibitors of CYP2B6 (ticlopidine and phencyclidine) and monoclonal antibodies raised against human CYP2B6 isozyme caused 80% inhibition of OH-BUP formation by baboon hepatic microsomes. The chemical inhibitors of aldo-keto reductases (flufenamic acid), carbonyl reductases (menadione), and 11β-hydroxysteroid dehydrogenases (18β-glycyrrhetinic acid) significantly decreased the formation of TB and EB by hepatic and placental microsomes. Data indicate that CYP2B of baboon hepatic microsomes is responsible for biotransformation of bupropion to OH-BUP, while hepatic and placental short chain dehydrogenases/reductases and to a lesser extent aldo-keto reductases are responsible for the reduction of bupropion to TB and EB.

  4. Progesterone and testosterone production by dispersed rat placental cells.

    Science.gov (United States)

    Matt, D W; Gibney, J A; Malamed, S; Macdonald, G J

    1986-04-01

    Isopycnic separation and unit gravity sedimentation were employed to identify the rat placental cell types capable of producing progesterone and testosterone. Subdivision of Day 12-dispersed placental cells in Percoll gradients revealed that fractions (less than 1.048 g/ml) containing giant cytotrophoblast cells produced greater quantities of progesterone (p less than 0.01) than did fractions (greater than 1.048 g/ml) with equal numbers of placental cells but void of giant cytotrophoblasts. Unit gravity sedimentation of Day 16-dispersed placental cells revealed that when incubated, isolated giant cytotrophoblast cells were capable of producing both progesterone and testosterone. Both of the separation studies strongly suggested that other cell types also produce steroids. However, the biosynthetic capacity of the giant cytotrophoblast cell appeared to be 1000-fold greater than that of the other cell types. Incubation of Day 12-dispersed placental cells with human chorionic gonadotropin or 3',5'-cyclic adenosine monophosphate did not further increase progesterone production as compared to untreated control incubates, suggesting rat placental steroidogenesis is not under trophic hormone control. Electron microscopic observations of giant cytotrophoblast cells revealed a complex ultrastructure suggesting a variety of physiological functions.

  5. Microvessel density in the placental bed among preeclampsia patients

    Directory of Open Access Journals (Sweden)

    Tarcisio Mota Coelho

    Full Text Available CONTEXT AND OBJECTIVE: Morphological changes in the spiral arteries of the placental bed have been studied in patients with preeclampsia, one of the largest causes of maternal and perinatal morbidity and mortality. The reports show that vasospasm and vascular endothelial injury were two major pathological conditions for preeclampsia. The aim of this study was to investigate the microvessel density of spiral arteries in the placental bed, in pregnancies complicated by hypertension and proteinuria, and in normal pregnancies. DESIGN AND SETTING: This was a cross-sectional survey of immunohistochemical studies on biopsies from the spiral arteries of the placental bed, among women undergoing cesarean sections for clinical and obstetrical reasons at Universidade Federal de São Paulo, São Paulo, Brazil. METHODS: Placental bed biopsies were obtained during cesarean section after placenta removal, with direct viewing of the central area of placenta insertion. The microvessel density of spiral arteries was measured by immunohistochemical methods in decidual and myometrial segments, using CD34 antibody. RESULTS: Biopsies containing spiral arteries were obtained from 34 hypertensive pregnant women with proteinuria, and 26 normotensive pregnant women. The microvessel densities in decidual and myometrial segments of the placental bed were compared between the groups. It was observed that, with increasing blood pressure and proteinuria, the microvessel density gradually decreased. CONCLUSION: The presence of high levels of hypertension and proteinuria may be associated with a progressive decrease in microvessel density in the placental bed.

  6. What do placental function tests predict? Observations on placental lactogen levels in growth retardation and fetal distress.

    Science.gov (United States)

    Obiekwe, B C; Chard, T

    1982-11-01

    Single blood samples were obtained from an unselected population of 527 women between 36 and 40 wk gestation. Serum placental lactogen levels were lower than normal in patients whose infants were growth retarded or developed fetal distress in labor. These associations were independent; the fetal distress group did not contain an excess of subjects with growth retardation. Thus, the results of a biochemical test reflect dynamic aspects of placental function and not simply the overall growth of fetus and placenta.

  7. Placentation in the colugos Cynocephalus volans and Galeopterus variegatus (Dermoptera) and the transition from labyrinthine to villous placentation in primates

    DEFF Research Database (Denmark)

    Carter, A. M.; Mess, A. M.

    2017-01-01

    Introduction Phylogenetics and genomics place colugos as the sister group to primates. Therefore their placentation is of interest in an evolutionary perspective. Previous accounts are fragmentary, not readily accessible and sometimes contradictory. Methods We have examined archival material...... covering the early development of fetal membranes and placenta, the fate of the yolk sac and definitive placentation. Results Initially the trophoblast extended over a rather broad but shallow area, enclosing maternal blood spaces. After expansion of the exocoelom it became covered by somatic mesoderm...

  8. Primate diversification inferred from phylogenies and fossils.

    Science.gov (United States)

    Herrera, James P

    2017-09-14

    Biodiversity arises from the balance between speciation and extinction. Fossils record the origins and disappearance of organisms, and the branching patterns of molecular phylogenies allow estimation of speciation and extinction rates, but the patterns of diversification are frequently incongruent between these two data sources. I tested two hypotheses about the diversification of primates based on ∼600 fossil species and 90% complete phylogenies of living species: 1) diversification rates increased through time; 2) a significant extinction event occurred in the Oligocene. Consistent with the first hypothesis, analyses of phylogenies consistently supported increasing speciation rates and negligible extinction rates. In contrast, fossils showed that while speciation rates increased, speciation and extinction rates tended to be nearly equal, resulting in zero net diversification. Partially supporting the second hypothesis, the fossil data recorded a clear pattern of diversity decline in the Oligocene, although diversification rates were near zero. The phylogeny supported increased extinction ∼34 Ma, but also elevated extinction ∼10 Ma, coinciding with diversity declines in some fossil clades. The results demonstrated that estimates of speciation and extinction ignoring fossils are insufficient to infer diversification and information on extinct lineages should be incorporated into phylogenetic analyses. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. Bayesian inference of the metazoan phylogeny

    DEFF Research Database (Denmark)

    Glenner, Henrik; Hansen, Anders J; Sørensen, Martin V

    2004-01-01

    Metazoan phylogeny remains one of evolutionary biology's major unsolved problems. Molecular and morphological data, as well as different analytical approaches, have produced highly conflicting results due to homoplasy resulting from more than 570 million years of evolution. To date, parsimony has...

  10. The Binary Perfect Phylogeny with Persistent characters

    CERN Document Server

    Braghin, Chiara; Trucco, Gabriella; Bonizzoni, Paola

    2011-01-01

    The near-perfect phylogeny over binary set of characters has been proposed as an extension of the too restrictive model of the perfect phylogeny in order to model biological events such as homoplasy. However the model appears to be too general to model some situations and is computationally inefficient on some instances. In this paper we consider the problem of reconstructing a near-perfect phylogeny where only a type of homoplasy is allowed in the tree: we consider back mutations according to notion of {\\em persistency}, that is characters can be gained and lost at most once. The notion of persistency leads to the problem of the Persistent Perfect Phylogeny (referred as P-PPH). By exploring combinatorial properties of the problem we develop an exact algorithm for solving the P-PPH problem that in the worst case runs in time that is exponential in the number of characters, but is polynomial in the number of species. Indeed, we show that the P-PPH problem can be restated as a special case of the Incomplete Per...

  11. Estimating the duration of speciation from phylogenies.

    Science.gov (United States)

    Etienne, Rampal S; Morlon, Hélène; Lambert, Amaury

    2014-08-01

    Speciation is not instantaneous but takes time. The protracted birth-death diversification model incorporates this fact and predicts the often observed slowdown of lineage accumulation toward the present. The mathematical complexity of the protracted speciation model has barred estimation of its parameters until recently a method to compute the likelihood of phylogenetic branching times under this model was outlined (Lambert et al. ). Here, we implement this method and study using simulated phylogenies of extant species how well we can estimate the model parameters (rate of initiation of speciation, rate of extinction of incipient and good species, and rate of completion of speciation) as well as the duration of speciation, which is a combination of the aforementioned parameters. We illustrate our approach by applying it to a primate phylogeny. The simulations show that phylogenies often do not contain enough information to provide unbiased estimates of the speciation-initiation rate and the extinction rate, but the duration of speciation can be estimated without much bias. The estimate of the duration of speciation for the primate clade is consistent with literature estimates. We conclude that phylogenies combined with the protracted speciation model provide a promising way to estimate the duration of speciation.

  12. Blood rheology in marine mammals

    Directory of Open Access Journals (Sweden)

    Michael Castellini

    2010-12-01

    Full Text Available The field of blood oxygen transport and delivery to tissues has been studied by comparative physiologists for many decades. Within this general area, the particular differences in oxygen delivery between marine and terrestrial mammals has focused mainly on oxygen supply differences and delivery to the tissues under low blood flow diving conditions. Yet, the study of the inherent flow properties of the blood itself (hemorheology is rarely discussed when addressing diving. However, hemorheology is important to the study of marine mammals because of the critical nature of the oxygen stores that are carried in the blood during diving periods. This review focuses on the essential elements of hemorheology, how they are defined and on fundamental rheological applications to marine mammals. While the comparative rationale used throughout the review is much broader than the particular problems associated with diving, the basic concepts focus on how changes in the flow properties of whole blood would be critical to oxygen delivery during diving. This review introduces the reader to most of the major rheological concepts that are relevant to the unique and unusual aspects of the diving physiology of marine mammals.

  13. Morbillivirus infections in aquatic mammals

    NARCIS (Netherlands)

    I.K.G. Visser (Ilona); M.F. van Bressem; T. Barrett (Thomas); A.D.M.E. Osterhaus (Albert)

    1993-01-01

    textabstractInfections with morbilliviruses have caused heavy losses among different populations of aquatic mammals during the last 5 years. Two different morbilliviruses were isolated from disease outbreaks among seals in Europe and Siberia: phocid distemper virus-1 (PDV-1) and phocid distemper vir

  14. A new Mammal from Sumatra

    NARCIS (Netherlands)

    Hubrecht, A.A.W.

    1891-01-01

    A few years ago a new and interesting mammal, which is exceedingly rare, even in its native haunts, was brought to the then Resident of Palembang, Mr. A. Pruys van der Hoeven. This gentleman who is not only an eager sportsman, but also well-versed in natural history, recognised it to be new to scien

  15. Small Mammals, Reptiles, and Amphibians

    Science.gov (United States)

    Bryce Rickel

    2005-01-01

    This chapter focuses on small mammals, reptiles, and amphibians that inhabit the grasslands within the Southwestern Region of the USDA Forest Service. The chapter is not intended to be an all inclusive list of species, but rather to address the species that play important roles in grassland ecosystems and that often are associated with the management of grasslands....

  16. Allometry in dinosaurs and mammals

    Science.gov (United States)

    Lee, Scott

    2015-03-01

    The proportions of the leg bones change as the size of an animal becomes larger since the mass of the animal increases at a faster rate than the cross-sectional area of its leg bones. For the case of elastic similarity (in which the longitudinal stress in the legs remains constant in animals of all sizes), the diameter d and length L of the femur should be related as d = A L3/2. For geometric similarity (in which all dimensions are scaled by the same factor), d = A L. For animals with femora longer than 20 cm, we find the power law relationship to be d = A Lb with b = 1.13 +/- 0.06 for extant mammals (the largest mammal being Loxodonta africana with a 1.00-m-long femur) and b = 1.18 +/- 0.02 for dinosaurs (the largest dinosaur being Brachiosaurus brancai with a 2.03-m-long femur). These data show that extinct dinosaurs and extant animals scale in the same basic manner. The large sauropods (with femora twice as long as found in elephants) scale in a manner consistent with extrapolation of the scaling shown by extant mammals. These results argue that extinct dinosaurs moved in a manner very similar to extant mammals.

  17. Morbillivirus infections in aquatic mammals

    NARCIS (Netherlands)

    I.K.G. Visser (Ilona); M.F. van Bressem; T. Barrett (Thomas); A.D.M.E. Osterhaus (Albert)

    1993-01-01

    textabstractInfections with morbilliviruses have caused heavy losses among different populations of aquatic mammals during the last 5 years. Two different morbilliviruses were isolated from disease outbreaks among seals in Europe and Siberia: phocid distemper virus-1 (PDV-1) and phocid distemper

  18. Physiological Monitoring in Diving Mammals

    Science.gov (United States)

    2014-09-30

    currently developing two different units, one based upon the succesful construction of an oximeter used in Weddel seals ( Guyton , Stanek et al. 1995), and...responses to NGO concerns. This should be of value to the US Navy Marine Mammal Program. REFERENCES Guyton , G. P., K. S. Stanek, R. C. Schneider, P

  19. Forelimb preferences in quadrupedal marsupials and their implications for laterality evolution in mammals.

    Science.gov (United States)

    Giljov, Andrey; Karenina, Karina; Malashichev, Yegor

    2013-03-06

    Acquisition of upright posture in evolution has been argued to facilitate manual laterality in primates. Owing to the high variety of postural habits marsupials can serve as a suitable model to test whether the species-typical body posture shapes forelimb preferences in non-primates or this phenomenon emerged only in the course of primate evolution. In the present study we aimed to explore manual laterality in marsupial quadrupeds and compare them with the results in the previously studied bipedal species. Forelimb preferences were assessed in captive grey short-tailed opossum (Monodelphis domestica) and sugar glider (Petaurus breviceps) in four different types of unimanual behaviour per species, which was not artificially evoked. We examined the possible effects of sex, age and task, because these factors have been reported to affect motor laterality in placental mammals. In both species the direction of forelimb preferences was strongly sex-related. Male grey short-tailed opossums showed right-forelimb preference in most of the observed unimanual behaviours, while male sugar gliders displayed only a slight, not significant rightward tendency. In contrast, females in both species exhibited consistent group-level preference of the left forelimb. We failed to reveal significant differences in manual preferences between tasks of potentially differing complexity: reaching a stable food item and catching live insects, as well as between the body support and food manipulation. No influence of subjects' age on limb preferences was found. The direction of sex-related differences in the manual preferences found in quadrupedal marsupials seems to be not typical for placental mammals. We suggest that the alternative way of interhemispheric connection in absence of corpus callosum may result in a fundamentally distinct mechanism of sex effect on limb preferences in marsupials compared to placentals. Our data confirm the idea that non-primate mammals differ from primates in

  20. Erasmus Darwin's enlightened views on placental function.

    Science.gov (United States)

    Pijnenborg, R; Vercruysse, L

    2007-01-01

    In his major work "Zoonomia", Erasmus Darwin (1731-1802) devoted one chapter to the placenta, in which the new knowledge of the recently discovered element oxygen was applied to the functioning of this organ. He considered the "cavities" or "lacunae" in the placenta as the main areas for oxygenation of the fetal blood, as he thought them to be structurally comparable to the lungs and the gills of fish. He obviously was aware of species differences in the uterine arterial blood supply to the placenta between humans and cows, assuming a higher contractility of the vasculature in the latter species. The new evidence for a primarily respiratory role overshadowed ideas of a possible nutritive function of the placenta. Since Hunter's definitive demonstration of separate maternal and fetal blood circulations, nutritive functions of the placenta needed to be explained by transmembrane transport processes, which were unknown at that time. Instead Erasmus Darwin erroneously considered the amniotic fluid as the main source of nutrients for the fetus. His understanding of placental respiration found expression in his long poem on the history of life on earth.

  1. Human placental lactogen levels in multiple pregnancies.

    Science.gov (United States)

    Spellacy, W N; Buhi, W C; Birk, S A

    1978-08-01

    Serum human placental lactogen (hPL) levels were measured in duplicate with a radioimmunoassay in 206 serum samples at 30 and 36 weeks' gestation from women with normal singleton pregnancies (75) or pregnancies with twins (37). One triplet pregnancy was also studied. The results show a significant elevation of hPL in the women with twin pregnancies at both the 30th (7.0 vs 6.0 microgram/ml) and the 36th (9.2 vs 7.4 microgram/ml) weeks. One-third of the twin pregnancies had values of hPL in excess of 8.0 microgram/ml at 30 weeks and more than half had values in excess of 9.0 microgram/ml at 36 weeks. The triplet pregnancy had an hPL value of 11.0 microgram/ml at 36 weeks' gestation. These data support the potential usefulness of serum hPL measurements in the screening profile for the detection of high-risk pregnancies.

  2. Southeast US Historical Marine Mammal Stranding Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data on marine mammal strandings are collected by the Southeast Marine Mammal Stranding Network. Basic data on the location, species identification, animal...

  3. Mammals of Erie National Wildlife Refuge 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of this study is to compile a list of mammals currently living on the refuge property. Habitats and behavioral features of the refuge's mammals were also...

  4. SMALL MAMMAL USE OF MICROHABITAT REVIEWED

    Science.gov (United States)

    Small mammal microhabitat research has greatly influenced vertebrate community ecologists. There exists a "microhabitat paradigm" that states that sympatry among small mammal species is enabled by differential use of microhabitat (i.e., microhabitat partitioning). However, seve...

  5. Placental Cadmium Levels Are Associated with Increased Preeclampsia Risk.

    Science.gov (United States)

    Laine, Jessica E; Ray, Paul; Bodnar, Wanda; Cable, Peter H; Boggess, Kim; Offenbacher, Steven; Fry, Rebecca C

    2015-01-01

    Environmental exposure to heavy metals is a potentially modifiable risk factor for preeclampsia (PE). Toxicologically, there are known interactions between the toxic metal cadmium (Cd) and essential metals such as selenium (Se) and zinc (Zn), as these metals can protect against the toxicity of Cd. As they relate to preeclampsia, the interaction between Cd and these essential metals is unknown. The aims of the present study were to measure placental levels of Cd, Se, and Zn in a cohort of 172 pregnant women from across the southeast US and to examine associations of metals levels with the odds of PE in a nested case-control design. Logistic regressions were performed to assess odds ratios (OR) for PE with exposure to Cd controlling for confounders, as well as interactive models with Se or Zn. The mean placental Cd level was 3.6 ng/g, ranging from 0.52 to 14.5 ng/g. There was an increased odds ratio for PE in relationship to placental levels of Cd (OR = 1.5; 95% CI: 1.1-2.2). The Cd-associated OR for PE increased when analyzed in relationship to lower placental Se levels (OR = 2.0; 95% CI: 1.1-3.5) and decreased with higher placental Se levels (OR = 0.98; 95% CI: 0.5-1.9). Similarly, under conditions of lower placental Zn, the Cd-associated OR for PE was elevated (OR = 1.8; 95% CI: 0.8-3.9), whereas with higher placental Zn it was reduced (OR = 1.3; 95% CI: 0.8-2.0). Data from this pilot study suggest that essential metals may play an important role in reducing the odds of Cd-associated preeclampsia and that replication in a larger cohort is warranted.

  6. The natural history of sound localization in mammals – a story of neuronal inhibition

    Science.gov (United States)

    Grothe, Benedikt; Pecka, Michael

    2014-01-01

    Our concepts of sound localization in the vertebrate brain are widely based on the general assumption that both the ability to detect air-borne sounds and the neuronal processing are homologous in archosaurs (present day crocodiles and birds) and mammals. Yet studies repeatedly report conflicting results on the neuronal circuits and mechanisms, in particular the role of inhibition, as well as the coding strategies between avian and mammalian model systems. Here we argue that mammalian and avian phylogeny of spatial hearing is characterized by a convergent evolution of hearing air-borne sounds rather than by homology. In particular, the different evolutionary origins of tympanic ears and the different availability of binaural cues in early mammals and archosaurs imposed distinct constraints on the respective binaural processing mechanisms. The role of synaptic inhibition in generating binaural spatial sensitivity in mammals is highlighted, as it reveals a unifying principle of mammalian circuit design for encoding sound position. Together, we combine evolutionary, anatomical and physiological arguments for making a clear distinction between mammalian processing mechanisms and coding strategies and those of archosaurs. We emphasize that a consideration of the convergent nature of neuronal mechanisms will significantly increase the explanatory power of studies of spatial processing in both mammals and birds. PMID:25324726

  7. The natural history of sound localization in mammals – a story of neuronal inhibition

    Directory of Open Access Journals (Sweden)

    Benedikt eGrothe

    2014-10-01

    Full Text Available Our concepts of sound localization in the vertebrate brain are widely based on the general assumption that both the ability to detect air-borne sounds and the neuronal processing are homologous in archosaurs (present day crocodiles and birds and mammals. Yet studies repeatedly report conflicting results on the neuronal circuits and mechanisms, in particular the role of inhibition, as well as the coding strategies between avian and mammalian model systems.Here we argue that mammalian and avian phylogeny of spatial hearing is characterized by a convergent evolution of hearing air-borne sounds rather than by homology. In particular, the different evolutionary origins of tympanic ears and the different availability of binaural cues in early mammals and archosaurs imposed distinct constraints on the respective binaural processing mechanisms. The role of synaptic inhibition in generating binaural spatial sensitivity in mammals is highlighted, as it reveals a unifying principle of mammalian circuit design for encoding sound position. Together, we combine evolutionary, anatomical and physiological arguments for making a clear distinction between mammalian processing mechanisms and coding strategies and those of archosaurs. We emphasize that a consideration of the convergent nature of neuronal mechanisms will significantly increase the explanatory power of studies of spatial processing in both mammals and birds.

  8. Transferência placentária de drogas Placental drug transfer

    Directory of Open Access Journals (Sweden)

    Ricardo de Carvalho Cavalli

    2006-09-01

    Full Text Available Grávidas podem depender do uso de medicações para minimizar os agravos da doença preexistente. A gravidez, por si só, pode causar situações que comprometem o bem-estar materno, como náuseas e vômitos, as quais necessitam de tratamento. O obstetra deve estar atento à transferência placentária de drogas e à exposição do feto a agentes teratogênicos ou tóxicos, que podem comprometer o seu desenvolvimento ou mesmo sua vida futura.O transporte através da placenta envolve o movimento de moléculas entre três compartimentos: sangue materno, citoplasma do sinciciotrofoblasto e sangue fetal. Esse movimento pode ocorrer pelos seguintes mecanismos: difusão simples, difusão facilitada, transporte ativo, bombas classe P, V, F e grande família ABC e endocitose. Com o uso de anticonvulsivantes a incidência de malformações maiores em recém-nascidos expostos é de 4 a 6%, comparado com 2 a 4% na população geral. A politerapia é mais lesiva, especialmente se o ácido valpróico e a hidantoína fazem parte da associação. Para as pacientes epilépticas clinicamente assintomáticas há dois anos recomenda-se a suspensão da drogas em uso, porém se apresentam crises, torna-se prudente consultar neurologista para discussão da terapia anticonvulsivante com melhores benefícios e menores efeitos colaterais. Os anestésicos locais e os opióides são largamente utilizados durante a resolução da gestação. A lidocaína utilizada como anestésico por via perineal para episiotomia, na dose fixa de 400 mg, apresenta alta concentração plasmática materna e alta taxa de transferência placentária no momento do nascimento, que vem alertar para o cuidado no uso de doses repetidas. A bupivacaína administrada por via epidural representa anestésico seguro, apresentando-se na forma racêmica e com transferência placentária em torno de 30%. A fentanila, anestésico opióide, utilizado por via epidural na resolução por cesariana, na dose

  9. Maternal risk factors for abnormal placental growth: The national collaborative perinatal project

    Directory of Open Access Journals (Sweden)

    Nicholson Wanda K

    2008-09-01

    Full Text Available Abstract Background Previous studies of maternal risk factors for abnormal placental growth have focused on placental weight and placental ratio as measures of placental growth. We sought to identify maternal risk factors for placental weight and two neglected dimensions of placental growth: placental thickness and chorionic plate area. Methods We conducted an analysis of 24,135 mother-placenta pairs enrolled in the National Collaborative Perinatal Project, a prospective cohort study of pregnancy and child health. We defined growth restriction as th percentile and hypertrophy as > 90th percentile for three placental growth dimensions: placental weight, placental thickness and chorionic plate area. We constructed parallel multinomial logistic regression analyses to identify (a predictors of restricted growth (vs. normal and (b predictors of hypertrophic growth (vs. normal. Results Black race was associated with an increased likelihood of growth restriction for placental weight, thickness and chorionic plate area, but was associated with a reduced likelihood of hypertrophy for these three placental growth dimensions. We observed an increased likelihood of growth restriction for placental weight and chorionic plate area among mothers with hypertensive disease at 24 weeks or beyond. Anemia was associated with a reduced likelihood of growth restriction for placental weight and chorionic plate area. Pre-pregnancy BMI and pregnancy weight gain were associated with a reduced likelihood of growth restriction and an increased likelihood of hypertrophy for all three dimensions of placental growth. Conclusion Maternal risk factors are either associated with placental growth restriction or placental hypertrophy not both. Our findings suggest that the placenta may have compensatory responses to certain maternal risk factors suggesting different underlying biological mechanisms.

  10. NPS Ocean Acoustics Laboratory Marine Mammal Research

    OpenAIRE

    Chiu, Ching-Sang; Collins, Curtis; Joseph, John; Margolina, Tetyana; Stimpert, Alison; Miller, Chris

    2014-01-01

    The Marine Mammal Group within the Ocean Acoustics Laboratory at NPS is involved with a range of research studying marine mammal acoustics , both sound production and effects of anthropogenic sound on marine mammals. A sampling of our research is described below.

  11. 76 FR 41486 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Operation and...

    Science.gov (United States)

    2011-07-14

    .... Potential acoustic effects on marine mammals relate to sound produced by thrusters during maneuvering of the... National Oceanic and Atmospheric Administration Taking and Importing Marine Mammals; Taking Marine Mammals... Mammal Protection Act (MMPA), as amended, and implementing regulations, notification is hereby given that...

  12. Bidirectional Transfer Study of Polystyrene Nanoparticles across the Placental Barrier in an ex Vivo Human Placental Perfusion Model

    Science.gov (United States)

    Grafmueller, Stefanie; Manser, Pius; Diener, Liliane; Diener, Pierre-André; Maeder-Althaus, Xenia; Maurizi, Lionel; Jochum, Wolfram; Krug, Harald F.; Buerki-Thurnherr, Tina; von Mandach, Ursula

    2015-01-01

    Background Nanoparticle exposure in utero might not be a major concern yet, but it could become more important with the increasing application of nanomaterials in consumer and medical products. Several epidemiologic and in vitro studies have shown that nanoparticles can have potential toxic effects. However, nanoparticles also offer the opportunity to develop new therapeutic strategies to treat specifically either the pregnant mother or the fetus. Previous studies mainly addressed whether nanoparticles are able to cross the placental barrier. However, the transport mechanisms underlying nanoparticle translocation across the placenta are still unknown. Objectives In this study we examined which transport mechanisms underlie the placental transfer of nanoparticles. Methods We used the ex vivo human placental perfusion model to analyze the bidirectional transfer of plain and carboxylate modified polystyrene particles in a size range between 50 and 300 nm. Results We observed that the transport of polystyrene particles in the fetal to maternal direction was significantly higher than for the maternal to fetal direction. Regardless of their ability to cross the placental barrier and the direction of perfusion, all polystyrene particles accumulated in the syncytiotrophoblast of the placental tissue. Conclusions Our results indicate that the syncytiotrophoblast is the key player in regulating nanoparticle transport across the human placenta. The main mechanism underlying this translocation is not based on passive diffusion, but is likely to involve an active, energy-dependent transport pathway. These findings will be important for reproductive toxicology as well as for pharmaceutical engineering of new drug carriers. Citation Grafmueller S, Manser P, Diener L, Diener PA, Maeder-Althaus X, Maurizi L, Jochum W, Krug HF, Buerki-Thurnherr T, von Mandach U, Wick P. 2015. Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human

  13. Histopathological placental lesions in mild gestational hyperglycemic and diabetic women

    Directory of Open Access Journals (Sweden)

    Rudge Marilza VC

    2011-08-01

    Full Text Available Abstract Objective To investigate and compare the incidence of histopathological placental lesions in mild gestational hyperglycemia, gestational diabetes and overt diabetes at term and preterm gestation. Research design and methods One-hundred-and-thirty-one placental samples were collected from Diabetes mellitus (DM positive screened patients. Two diagnostic tests, glycemic profile and 100 g oral glucose tolerance test (OGTT in parallel identified 4 groups normoglycemic, mild gestational hyperglycemia (MGH, gestational DM (GDM or overt DM (DM. Placental tissue specimens and sections from 4 groups were obtained by uniform random sampling and stained with hematoxylin-eosin. Results Placentas from MGH group presented 17 types of histopathological change and higher rates of syncytial nodes and endarteritis. GDM placentas presented only nine types of histopathological change, high rates of dysmaturity, low rates of calcification and no syncytial nodes. Overt DM placentas showed 22 types of histopathological change, 21 of which were present in the preterm period. There were histopathological similarities between MGH and DM placentas, but the former exhibited a higher incidence of endarteritis, which has been described as a "post-mortem" phenomenon. Conclusion Our results confirmed that the distinct placental changes associated with DM and MGH depend on gestational period during which the diabetic insult occurs. It may reasonably be inferred that subclinical maternal hyperglycemia during pregnancy, as showed in MGH group, is responsible for increased placental endarteritis, a postmortem lesion in the live fetus.

  14. Regional changes of placental vascularization in preeclampsia: a review.

    Science.gov (United States)

    Sahay, Akriti S; Sundrani, Deepali P; Joshi, Sadhana R

    2015-08-01

    Preeclampsia is characterized by vascular dysfunction and results in maternal and fetal morbidity and mortality. The placenta plays a critical role in the growth and development of the fetus, and recent studies indicate that placental architecture, oxygen availability, and oxidative stress indices vary across different regions of the placenta. Our earlier studies have reported altered maternal angiogenesis and differential placental gene expression and methylation patterns of angiogenic factors in women with preeclampsia when compared with normotensive women. We have also demonstrated lower maternal and placental neurotrophin (NT) levels in women with preeclampsia. Studies suggest that oxidative stress is associated with proteases like matrix metalloproteinases (MMPs) and growth factors like NTs and angiogenic factors known to be involved in the process of angiogenesis. Recently, we have reported regionwise differential oxidative stress, antioxidant enzyme activity, and NT levels in placenta from normotensive control women and women with preeclampsia. The current review describes the regional changes in the placenta and highlights the role of placental oxidative stress in influencing regional differences in the expression of angiogenic factors, MMPs, and NTs. This review discusses the need for further research on various growth factors and proteins involved in the process of placental development across different regions of the placenta. This would help to understand whether regional differences in these factors affect the growth and development of the fetus.

  15. Adenylate kinase locus 1 polymorphism and feto-placental development.

    Science.gov (United States)

    Fulvia, Gloria-Bottini; Antonio, Pietroiusti; Anna, Neri; Patrizia, Saccucci; Ada, Amante; Egidio, Bottini; Andrea, Magrini

    2011-12-01

    Recently our group has found that the correlation between birth weight and placental weight - an index of a balanced feto-placental unit development - is influenced by genetic factors. Since adenylate kinase locus 1 (AK₁) is a polymorphic enzyme that plays an important role in the synthesis of nucleotides required for many metabolic functions, we have investigated the possible role of its genetic variability in the correlation between birth weight and placental weight. 342 consecutive healthy newborn infants from the population of Rome (Italy) and 286 puerperae from another population from Central Italy were studied. The correlation coefficient between birth weight and placental weight is much higher in infants with low activity AK₁2-1 phenotype than in those with high activity AK₁1 phenotype. The difference between AK₁ and AK₁2-1 is well marked only in newborns with a gestational age greater than 38 weeks and it is not influenced by sex, maternal age and maternal smoking. A similar pattern is observed with maternal AK₁ phenotype. These results suggest that the difference in enzymatic activity between AK₁ phenotypes influencing the equilibrium among ATP, ADP, AMP and adenosine could have an important role in a balanced development of feto-placental unit. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Important aspects of placental-specific gene transfer.

    Science.gov (United States)

    Kaufman, Melissa R; Albers, Renee E; Keoni, Chanel; Kulkarni-Datar, Kashmira; Natale, David R; Brown, Thomas L

    2014-10-15

    The placenta is a unique and highly complex organ that develops only during pregnancy and is essential for growth and survival of the developing fetus. The placenta provides the vital exchange of gases and wastes, the necessary nutrients for fetal development, acts as immune barrier that protects against maternal rejection, and produces numerous hormones and growth factors that promote fetal maturity to regulate pregnancy until parturition. Abnormal placental development is a major underlying cause of pregnancy-associated disorders that often result in preterm birth. Defects in placental stem cell propagation, growth, and differentiation are the major factors that affect embryonic and fetal well-being and dramatically increase the risk of pregnancy complications. Understanding the processes that regulate placentation is important in determining the underlying factors behind abnormal placental development. The ability to manipulate genes in a placenta-specific manner provides a unique tool to analyze development and eliminates potentially confounding results that can occur with traditional gene knockouts. Trophoblast stem cells and mouse embryos are not overly amenable to traditional gene transfer techniques. Most viral vectors, however, have a low infection rate and often lead to mosaic transgenesis. Although the traditional method of embryo transfer is intrauterine surgical implantation, the methodology reported here, combining lentiviral blastocyst infection and nonsurgical embryo transfer, leads to highly efficient and placental-specific gene transfer. Numerous advantages of our optimized procedures include increased investigator safety, a reduction in animal stress, rapid and noninvasive embryo transfer, and higher a rate of pregnancy and live birth.

  17. Compensatory placental growth after restricted maternal nutrition in early pregnancy.

    Science.gov (United States)

    Lumey, L H

    1998-01-01

    This study examined the effects of undernutrition in pregnancy on fetal and placental growth among infants born in 1944-1946 in The Netherlands, including infants born during the war-induced Dutch famine of 1944-1945. There was an increase in placental weight, but not in birthweight, in infants whose mothers' nutrition was compromised around conception or in the first trimester of pregnancy. Therefore, the placental index was also increased. Compared to pre-famine controls, the relative increase after first trimester exposure to undernutrition was larger in the northern part of the country (5.2 per cent, 95 per cent confidence interval 1.4, 9.0) where nutritional deprivation was presumably moderate compared to the west (3.5 per cent, 95 per cent confidence interval 0.2, 7.2) where nutritional deprivation was severe. The increase in placental weight is interpreted as compensatory for the reduction in maternal caloric intake. Whereas this suggests that pregnancy undernutrition can stimulate compensatory placental growth, the latter was only seen after first trimester undernutrition, which does not affect infant size at birth. For these infants, therefore, birthweight is not an appropriate proxy measure of undernutrition in pregnancy. These factors need to be considered in future studies relating pregnancy nutrition to adult health outcomes.

  18. Placental pathologies in fetal MRI with pathohistological correlation.

    Science.gov (United States)

    Linduska, N; Dekan, S; Messerschmidt, A; Kasprian, G; Brugger, P C; Chalubinski, K; Weber, M; Prayer, D

    2009-06-01

    The purpose of this study was to evaluate whether currently available fetal Magnetic Resonance Imaging (MRI/MR) techniques are sufficient for the assessment of placental pathologies. We hypothesized that placental pathologies as detected and evaluated by MRI, would correlate with histological findings. In a retrospective study, 45 singleton pregnancies from 19 to 35 gestational weeks, with placental pathologies on MR scans, were included. MRI was performed on a 1.5T unit using T2-, T1-, and diffusion-weighted and echo-planar sequences. Pathologies were categorized into infarction with/without hemorrhagic components, subchorionic/intervillous thrombi/hemorrhages, retroplacental hematoma, massive perivillous fibrin deposition, and chorioamnionitis. Pathohistological examination was performed postnatally within a median of seven days between MR examination and delivery. Pathologically, 26 placentas showed infarctions (96.2% on MR scans), two retroplacental hematomas were detected by MRI and confirmed by pathology, and 9 of 14 subchorionic hematomas were confirmed. Six of eight intervillous hemorrhages were seen on MRI, and three of six cases of severe chorioamnionitis were diagnosed prenatally. Placental hemorrhages (retroplacental hematoma, intervillous thrombi, subchorionic hematoma), and ischemic lesions could be detected with fetal MRI, while chorioamnionitis and even massive perivillous fibrin deposition showed few signal changes, probably reflecting small macroscopic changes in the placenta. Fetal MRI, therefore, seems to be a promising tool for the assessment of placental insufficiency.

  19. A new estimate of afrotherian phylogeny based on simultaneous analysis of genomic, morphological, and fossil evidence

    Directory of Open Access Journals (Sweden)

    Seiffert Erik R

    2007-11-01

    Full Text Available Abstract Background The placental mammalian clade Afrotheria is now supported by diverse forms of genomic data, but interordinal relationships within, and morphological support for, the group remains elusive. As a means for addressing these outstanding problems, competing hypotheses of afrotherian interordinal relationships were tested through simultaneous parsimony analysis of a large data set (> 4,590 parsimony informative characters containing genomic data (> 17 kb of nucleotide data, chromosomal associations, and retroposons and 400 morphological characters scored across 16 extant and 35 extinct afrotherians. Results Parsimony analysis of extant taxa alone recovered the interordinal topology (Afrosoricida, ((Macroscelidea, Tubulidentata, (Hyracoidea, (Proboscidea, Sirenia. Analysis following addition of extinct taxa instead supported Afroinsectivora (Afrosoricida + Macroscelidea and Pseudoungulata (Tubulidentata + Paenungulata, as well as Tethytheria (Proboscidea + Sirenia. This latter topology is, however, sensitive to taxon deletion and different placements of the placental root, and numerous alternative interordinal arrangements within Afrotheria could not be statistically rejected. Relationships among extinct stem members of each afrotherian clade were more stable, but one alleged stem macroscelidean (Herodotius never grouped with that clade and instead consistently joined pseudoungulates or paenungulates. When character transformations were optimized onto a less resolved afrotherian tree that reflects uncertainty about the group's interordinal phylogeny, a total of 21 morphological features were identified as possible synapomorphies of crown Afrotheria, 9 of which optimized unambiguously across all character treatments and optimization methods. Conclusion Instability in afrotherian interordinal phylogeny presumably reflects rapid divergences during two pulses of cladogenesis – the first in the Late Cretaceous, at and just after the

  20. Transformation and diversification in early mammal evolution.

    Science.gov (United States)

    Luo, Zhe-Xi

    2007-12-13

    Evolution of the earliest mammals shows successive episodes of diversification. Lineage-splitting in Mesozoic mammals is coupled with many independent evolutionary experiments and ecological specializations. Classic scenarios of mammalian morphological evolution tend to posit an orderly acquisition of key evolutionary innovations leading to adaptive diversification, but newly discovered fossils show that evolution of such key characters as the middle ear and the tribosphenic teeth is far more labile among Mesozoic mammals. Successive diversifications of Mesozoic mammal groups multiplied the opportunities for many dead-end lineages to iteratively evolve developmental homoplasies and convergent ecological specializations, parallel to those in modern mammal groups.

  1. Massive dysregulation of genes involved in cell signaling and placental development in cloned cattle conceptus and maternal endometrium.

    Science.gov (United States)

    Biase, Fernando H; Rabel, Chanaka; Guillomot, Michel; Hue, Isabelle; Andropolis, Kalista; Olmstead, Colleen A; Oliveira, Rosane; Wallace, Richard; Le Bourhis, Daniel; Richard, Christophe; Campion, Evelyne; Chaulot-Talmon, Aurélie; Giraud-Delville, Corinne; Taghouti, Géraldine; Jammes, Hélène; Renard, Jean-Paul; Sandra, Olivier; Lewin, Harris A

    2016-12-20

    A major unresolved issue in the cloning of mammals by somatic cell nuclear transfer (SCNT) is the mechanism by which the process fails after embryos are transferred to the uterus of recipients before or during the implantation window. We investigated this problem by using RNA sequencing (RNA-seq) to compare the transcriptomes in cattle conceptuses produced by SCNT and artificial insemination (AI) at day (d) 18 (preimplantation) and d 34 (postimplantation) of gestation. In addition, endometrium was profiled to identify the communication pathways that might be affected by the presence of a cloned conceptus, ultimately leading to mortality before or during the implantation window. At d 18, the effects on the transcriptome associated with SCNT were massive, involving more than 5,000 differentially expressed genes (DEGs). Among them are 121 genes that have embryonic lethal phenotypes in mice, cause defects in trophoblast and placental development, and/or affect conceptus survival in mice. In endometria at d 18, genes were affected by the presence of a cloned conceptus, whereas at d 34, ∼36% and genes were differentially expressed in intercaruncular and caruncular tissues, respectively. Functional analysis of DEGs in placental and endometrial tissues suggests a major disruption of signaling between the cloned conceptus and the endometrium, particularly the intercaruncular tissue. Our results support a "bottleneck" model for cloned conceptus survival during the periimplantation period determined by gene expression levels in extraembryonic tissues and the endometrial response to altered signaling from clones.

  2. Specializations of the chorioallantoic placenta in the Brazilian scincid lizard, Mabuya heathi: a new placental morphotype for reptiles.

    Science.gov (United States)

    Blackburn, Daniel G; Vitt, Laurie J

    2002-11-01

    New World skinks of the genus Mabuya exhibit a unique form of viviparity that involves ovulation of tiny (1 mm) eggs and provision of virtually all of the nutrients for embryonic development by placental means. Studies of the Brazilian species M. heathi reveal that the chorioallantoic placenta is unlike those reported in any other squamate genus and exhibits striking specializations for maternal-fetal nutrient transfer. The uterine lining is intimately apposed to the chorioallantois, with no trace of an intervening shell membrane or of epithelial erosion; thus, the placenta is epitheliochorial. The uterus exhibits multicellular glands that secrete organic material into the uterine lumen. Opposite the openings of these glands, the chorion develops areolae, invaginated pits that are lined by absorptive, columnar epithelium. A single, mesometrial placentome develops, formed by radially oriented uterine folds that project into a deep invagination of the chorion. Uterine epithelium of the placentome appears to be syncytial and secretory and overlies a rich vascular supply. The apposed chorionic epithelium is absorptive in morphology and contains giant binucleated cells that bear microvilli. Several specializations of the placental membranes of M. heathi are found among eutherian mammals, signifying evolutionary convergence that extends to histological and cytological levels. The chorioallantoic placenta of M. heathi and its relatives warrants recognition as a new morphotype for reptiles, defined here as the "Type IV" placenta. This is the first new type of chorioallantoic placenta to be defined formally for reptiles in over half a century.

  3. Dietary characterization of terrestrial mammals.

    Science.gov (United States)

    Pineda-Munoz, Silvia; Alroy, John

    2014-08-22

    Understanding the feeding behaviour of the species that make up any ecosystem is essential for designing further research. Mammals have been studied intensively, but the criteria used for classifying their diets are far from being standardized. We built a database summarizing the dietary preferences of terrestrial mammals using published data regarding their stomach contents. We performed multivariate analyses in order to set up a standardized classification scheme. Ideally, food consumption percentages should be used instead of qualitative classifications. However, when highly detailed information is not available we propose classifying animals based on their main feeding resources. They should be classified as generalists when none of the feeding resources constitute over 50% of the diet. The term 'omnivore' should be avoided because it does not communicate all the complexity inherent to food choice. Moreover, the so-called omnivore diets actually involve several distinctive adaptations. Our dataset shows that terrestrial mammals are generally highly specialized and that some degree of food mixing may even be required for most species.

  4. Anatomical adaptations of aquatic mammals.

    Science.gov (United States)

    Reidenberg, Joy S

    2007-06-01

    This special issue of the Anatomical Record explores many of the anatomical adaptations exhibited by aquatic mammals that enable life in the water. Anatomical observations on a range of fossil and living marine and freshwater mammals are presented, including sirenians (manatees and dugongs), cetaceans (both baleen whales and toothed whales, including dolphins and porpoises), pinnipeds (seals, sea lions, and walruses), the sea otter, and the pygmy hippopotamus. A range of anatomical systems are covered in this issue, including the external form (integument, tail shape), nervous system (eye, ear, brain), musculoskeletal systems (cranium, mandible, hyoid, vertebral column, flipper/forelimb), digestive tract (teeth/tusks/baleen, tongue, stomach), and respiratory tract (larynx). Emphasis is placed on exploring anatomical function in the context of aquatic life. The following topics are addressed: evolution, sound production, sound reception, feeding, locomotion, buoyancy control, thermoregulation, cognition, and behavior. A variety of approaches and techniques are used to examine and characterize these adaptations, ranging from dissection, to histology, to electron microscopy, to two-dimensional (2D) and 3D computerized tomography, to experimental field tests of function. The articles in this issue are a blend of literature review and new, hypothesis-driven anatomical research, which highlight the special nature of anatomical form and function in aquatic mammals that enables their exquisite adaptation for life in such a challenging environment.

  5. Phylogeny and subgeneric taxonomy of Aspergillus

    DEFF Research Database (Denmark)

    Peterson, S.W.; Varga, Janos; Frisvad, Jens Christian

    2008-01-01

    The phylogeny of the genus Aspergillus and its teleomorphs is discussed based on multilocus sequence data. DNA sequence analysis was used to formulate a nucleotide sequence framework of the genus and to analyze character changes in relationship to the phylogeny hypothesized from the DNA sequence...... analysis. The sequence data used to delimitate subgeneric taxa included partial calmodulin, rDNA and RNA polymerase gene sequences. In our phylogenic structure of Aspergillus extrolite data of the various Aspergillus taxa collected from ex-type cultures and numerous other isolates are also discussed. A new...... subgeneric classification is proposed which includes 8 subgenera and 22 sections within the Aspergillus genus. Characteristics of these taxa are shortly discussed in this chapter....

  6. Phylogeny and subgeneric taxonomy of Aspergillus

    DEFF Research Database (Denmark)

    Peterson, S.W.; Varga, Janos; Frisvad, Jens Christian

    2008-01-01

    The phylogeny of the genus Aspergillus and its teleomorphs is discussed based on multilocus sequence data. DNA sequence analysis was used to formulate a nucleotide sequence framework of the genus and to analyze character changes in relationship to the phylogeny hypothesized from the DNA sequence...... analysis. The sequence data used to delimitate subgeneric taxa included partial calmodulin, rDNA and RNA polymerase gene sequences. In our phylogenic structure of Aspergillus extrolite data of the various Aspergillus taxa collected from ex-type cultures and numerous other isolates are also discussed. A new...... subgeneric classification is proposed which includes 8 subgenera and 22 sections within the Aspergillus genus. Characteristics of these taxa are shortly discussed in this chapter....

  7. A Molecular Phylogeny of Living Primates

    Science.gov (United States)

    Perelman, Polina; Johnson, Warren E.; Roos, Christian; Seuánez, Hector N.; Horvath, Julie E.; Moreira, Miguel A. M.; Kessing, Bailey; Pontius, Joan; Roelke, Melody; Rumpler, Yves; Schneider, Maria Paula C.; Silva, Artur; O'Brien, Stephen J.; Pecon-Slattery, Jill

    2011-01-01

    Comparative genomic analyses of primates offer considerable potential to define and understand the processes that mold, shape, and transform the human genome. However, primate taxonomy is both complex and controversial, with marginal unifying consensus of the evolutionary hierarchy of extant primate species. Here we provide new genomic sequence (∼8 Mb) from 186 primates representing 61 (∼90%) of the described genera, and we include outgroup species from Dermoptera, Scandentia, and Lagomorpha. The resultant phylogeny is exceptionally robust and illuminates events in primate evolution from ancient to recent, clarifying numerous taxonomic controversies and providing new data on human evolution. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution, and disparate distributions of insertions/deletions among the reconstructed primate lineages are uncovered. Our resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species. PMID:21436896

  8. NODC Standard Format Marine Mammals of Coastal Alaska Data (1975-1981): Marine Mammal Specimens (F025) (NODC Accession 0014150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC maintains data in three NODC Standard Format Marine Mammal Data Sets: Marine Mammal Sighting and Census (F127); Marine Mammal Specimens (F025); Marine Mammal...

  9. Social disparity affects the incidence of placental abruption among multiparous but not nulliparous women

    DEFF Research Database (Denmark)

    Räisänen, Sari; Gissler, Mika; Nielsen, Henriette Svarre

    2013-01-01

    To identify risk factors for placental abruption and to evaluate associations between adverse perinatal outcomes and placental abruption stratified by parity among women with singleton births from 1991 to 2010 in Finland.......To identify risk factors for placental abruption and to evaluate associations between adverse perinatal outcomes and placental abruption stratified by parity among women with singleton births from 1991 to 2010 in Finland....

  10. Role of the endothelium in placental dysfunction after fetal cardiac bypass.

    Science.gov (United States)

    Reddy, V M; McElhinney, D B; Rajasinghe, H A; Liddicoat, J R; Hendricks-Munoz, K; Fineman, J R; Hanley, F L

    1999-02-01

    Fetal cardiac bypass causes placental dysfunction, characterized by increased placental vascular resistance, decreased placental blood flow, hypoxia, and acidosis. Vasoactive factors produced by the vascular endothelium, such as nitric oxide and endothelin 1, are important regulators of placental vascular tone and may contribute to this placental dysfunction. To investigate the role of the vascular endothelium in placental dysfunction related to fetal cardiac bypass, we studied 3 groups of fetal sheep. In the first group (n = 7) we determined placental hemodynamic responses before and after bypass to an endothelium-dependent vasodilator (acetylcholine), an endothelium-independent vasodilator (nitroprusside), and endothelin 1. In the second group (n = 8) a nonspecific endothelin receptor blocker (PD 145065) was administered and placental hemodynamic values were measured before and after bypass. In the third group (n = 5) endothelin 1 levels were measured before and after bypass. Before fetal cardiac bypass exogenous endothelin 1 decreased placental blood flow by 9% and increased placental resistance by 9%. After bypass endothelin 1 decreased placental flow by 47% and increased resistance by 106%. There was also a significant attenuation of the placental vascular relaxation response to acetylcholine after bypass, whereas the response to nitroprusside was not significantly altered. In fetuses that received the PD 145065, placental vascular resistance increased significantly less than in control fetuses (28% versus 62%). Similarly, placental blood flow decreased significantly more (from 6. 3 +/- 3.1 to 28.3 +/- 10.4 pg/mL; P =.01) in control fetuses than in fetuses receiving PD 145065 (33% versus 20%). Umbilical venous endothelin 1 levels increased significantly in fetuses exposed to fetal bypass but did not change in control fetuses. The basal endothelial regulatory mechanisms of placental vascular tone were deranged after fetal cardiac bypass. Endothelin receptor

  11. Blocking Endogenous Leukemia Inhibitory Factor During Placental Development in Mice Leads to Abnormal Placentation and Pregnancy Loss.

    Science.gov (United States)

    Winship, Amy; Correia, Jeanne; Krishnan, Tara; Menkhorst, Ellen; Cuman, Carly; Zhang, Jian-Guo; Nicola, Nicos A; Dimitriadis, Evdokia

    2015-08-14

    The placenta forms the interface between the maternal and fetal circulation and is critical for the establishment of a healthy pregnancy. Specialized trophoblast cells derived from the embryonic trophectoderm play a pivotal role in the establishment of the placenta. Leukemia inhibitory factor (LIF) is one of the predominant cytokines present in the placenta during early pregnancy. LIF has been shown to regulate trophoblast adhesion and invasion in vitro, however its precise role in vivo is unknown. We hypothesized that LIF would be required for normal placental development in mice. LIF and LIFRα were immunolocalized to placental trophoblasts and fetal vessels in mouse implantation sites during mid-gestation. Temporally blocking LIF action during specific periods of placental development via intraperitoneal administration of our specific LIFRα antagonist, PEGLA, resulted in abnormal placental trophoblast and vascular morphology and reduced activated STAT3 but not ERK. Numerous genes regulating angiogenesis and oxidative stress were altered in the placenta in response to LIF inhibition. Pregnancy viability was also significantly compromised in PEGLA treated mice. Our data suggest that LIF plays an important role in placentation in vivo and the maintenance of healthy pregnancy.

  12. Indications of anti-HY immunity in recurrent placental abruption

    DEFF Research Database (Denmark)

    Nielsen, Henriette Svarre; Mogensen, Marie; Steffensen, Rudi

    2007-01-01

    PROBLEM: Placental abruption is a potential life-threatening condition for both the fetus and the mother, being significantly more common in pregnancies with male fetuses. The pathogenesis of placental abruption remains unknown. However, some recent reports point toward a maternal immune response...... the fetus died. Seven patients (88%) had first-born boys, and 15 abruptions (68%) involved male fetuses. All patients with a first-born boy, except one, had HLA-class II alleles known to restrict CD4+ T-cell responses against male-specific minor histocompatibility (HY)-antigens (HLA-DRB1*15, HLA-DRB3...... abruption is exclusively almost preceded by the birth of a boy and the majority of patients have HLA-class II known to restrict CD4 T-cell reactions against HY-antigens. This indicates that maternal immunological responses against HY-antigens play a role in recurrent placental abruption. Udgivelsesdato...

  13. Non-placental causes of intrauterine growth restriction.

    Science.gov (United States)

    Hendrix, Nancy; Berghella, Vincenzo

    2008-06-01

    Placental insufficiency, in some form or fashion, is associated with the majority of cases of intrauterine growth restriction (IUGR). There are numerous causes of IUGR which are not caused primarily by placental insufficiency, but indirectly lead to it. The causes of IUGR can be subdivided into fetal and maternal etiologies. The fetal etiologies consist of genetic diseases, congenital malformations, infections, multiple gestations, and placental/cord abnormalities. The maternal etiologies are categorized as follows: (1) decreased uteroplacental blood flow, (2) reduced blood volume, (3) decreased oxygen carrying capacity, (4) nutrition status, (5) teratogens, and (6) miscellaneous causes such as short interpregnancy intervals, race, maternal age, and low socioeconomic status. Knowledge of the etiologies of fetal growth restriction is essential, so that future care can be targeted at prevention. There are several primary and secondary prevention strategies that can be adopted.

  14. Placental leptin gene methylation and macrosomia during normal pregnancy.

    Science.gov (United States)

    Xu, Xinyun; Yang, Xinjun; Liu, Ziwei; Wu, Kele; Liu, Zheng; Lin, Chong; Wang, Yuhuan; Yan, Hongtao

    2014-03-01

    The present study examined the placental leptin (LEP) DNA methylation and mRNA levels in macrosomic infants from normal pregnancies. In total, 49 neonates with macrosomia, i.e., high birth weights of ≥ 4,000 g, and 52 neonates with normal birth weights between 2,500 g and 4,000 g were recruited from The Second Affiliated Hospital of Wenzhou Medical University (Wenzhou, Zhejiang) in China. Placental LEP promoter methylation and LEP transcript levels were determined by Sequenom MassARRAY and quantitative PCR, respectively. LEP promoter methylation and mRNA levels were not significantly different between the individuals with macrosomia and the controls. However, stratification revealed that individual CpG dinucleotides were hypermethylated in macrosomia (Pmacrosomia following a normal pregnancy and under certain conditions. However, placental LEP expression was not affected.

  15. The feto-placental endothelium in pregnancy pathologies.

    Science.gov (United States)

    Wadsack, Christian; Desoye, Gernot; Hiden, Ursula

    2012-05-01

    This review aims to provide a comprehensive summary of the aspects of endothelial and vascular dysfunction in the feto-placental vasculature occurring in pregnancy pathologies. This endothelium is continuous with the fetal circulation. Its function and potential dysfunction in pathologies will have a profound impact on fetal development. Gestational diabetes mellitus represents one of these pathologies, in which its associated metabolic derangements will alter feto-placental endothelial functions. These, in turn, may result in functional changes of the placenta, which may entail impaired fetal development. By contrast, changes in the feto-placental vasculature observed in cases of fetal growth restriction and preeclampsia may be causative (fetal growth restriction) or secondary (preeclampsia) for the pathology.

  16. Clinical use of placental hormones in pregnancy management.

    Science.gov (United States)

    De Bonis, M; Vellucci, F L; Di Tommaso, M; Voltolini, C; Torricelli, M; Petraglia, F

    2012-09-01

    Across human pregnancy, placenta represents a transit of oxygen and nutrients from the mother to the fetus and actively produces a large number of hormones that serve to regulate and balance maternal and fetal physiology. An abnormal secretion of placental hormones may be part of the pathogenesis of the main obstetric syndrome, from early to late pregnancy, in particular chromosomopathies, miscarriage, gestational trophoblastic diseases, preeclampsia, gestational diabetes, and pre-term delivery. The possibility to measure placental hormones represents an important tool not only for the diagnosis and management of gestational disorders, but it is also fundamental in the early identification of women at risk for these pregnancy complications. In the last decades, the use of ultrasound examination has provided additional biophysical markers, improving the early diagnosis of gestational diseases. In conclusion, while few placental hormones have sufficient sensitivity for clinical application, there are promising new biochemical and biophysical markers that, if used in combination, may provide a valid screening tool.

  17. Whole genome phylogenies for multiple Drosophila species

    Directory of Open Access Journals (Sweden)

    Seetharam Arun

    2012-12-01

    Full Text Available Abstract Background Reconstructing the evolutionary history of organisms using traditional phylogenetic methods may suffer from inaccurate sequence alignment. An alternative approach, particularly effective when whole genome sequences are available, is to employ methods that don’t use explicit sequence alignments. We extend a novel phylogenetic method based on Singular Value Decomposition (SVD to reconstruct the phylogeny of 12 sequenced Drosophila species. SVD analysis provides accurate comparisons for a high fraction of sequences within whole genomes without the prior identification of orthologs or homologous sites. With this method all protein sequences are converted to peptide frequency vectors within a matrix that is decomposed to provide simplified vector representations for each protein of the genome in a reduced dimensional space. These vectors are summed together to provide a vector representation for each species, and the angle between these vectors provides distance measures that are used to construct species trees. Results An unfiltered whole genome analysis (193,622 predicted proteins strongly supports the currently accepted phylogeny for 12 Drosophila species at higher dimensions except for the generally accepted but difficult to discern sister relationship between D. erecta and D. yakuba. Also, in accordance with previous studies, many sequences appear to support alternative phylogenies. In this case, we observed grouping of D. erecta with D. sechellia when approximately 55% to 95% of the proteins were removed using a filter based on projection values or by reducing resolution by using fewer dimensions. Similar results were obtained when just the melanogaster subgroup was analyzed. Conclusions These results indicate that using our novel phylogenetic method, it is possible to consult and interpret all predicted protein sequences within multiple whole genomes to produce accurate phylogenetic estimations of relatedness between

  18. Explaining evolution via constrained persistent perfect phylogeny.

    Science.gov (United States)

    Bonizzoni, Paola; Carrieri, Anna Paola; Della Vedova, Gianluca; Trucco, Gabriella

    2014-01-01

    The perfect phylogeny is an often used model in phylogenetics since it provides an efficient basic procedure for representing the evolution of genomic binary characters in several frameworks, such as for example in haplotype inference. The model, which is conceptually the simplest, is based on the infinite sites assumption, that is no character can mutate more than once in the whole tree. A main open problem regarding the model is finding generalizations that retain the computational tractability of the original model but are more flexible in modeling biological data when the infinite site assumption is violated because of e.g. back mutations. A special case of back mutations that has been considered in the study of the evolution of protein domains (where a domain is acquired and then lost) is persistency, that is the fact that a character is allowed to return back to the ancestral state. In this model characters can be gained and lost at most once. In this paper we consider the computational problem of explaining binary data by the Persistent Perfect Phylogeny model (referred as PPP) and for this purpose we investigate the problem of reconstructing an evolution where some constraints are imposed on the paths of the tree. We define a natural generalization of the PPP problem obtained by requiring that for some pairs (character, species), neither the species nor any of its ancestors can have the character. In other words, some characters cannot be persistent for some species. This new problem is called Constrained PPP (CPPP). Based on a graph formulation of the CPPP problem, we are able to provide a polynomial time solution for the CPPP problem for matrices whose conflict graph has no edges. Using this result, we develop a parameterized algorithm for solving the CPPP problem where the parameter is the number of characters. A preliminary experimental analysis shows that the constrained persistent perfect phylogeny model allows to explain efficiently data that do not

  19. Primate jumping genes elucidate strepsirrhine phylogeny

    OpenAIRE

    2004-01-01

    Transposable elements provide a highly informative marker system for analyzing evolutionary histories. To solve controversially discussed topics in strepsirrhine phylogeny, we characterized 61 loci containing short interspersed elements (SINEs) and determined the SINE presence–absence pattern at orthologous loci in a representative strepsirrhine panel. This SINE monolocus study was complemented by a Southern blot analysis tracing multiple loci of two different strepsirrhine specific SINEs. Th...

  20. An enkephalin degrading aminopeptidase of human brain preserved during the vertebrate phylogeny.

    Science.gov (United States)

    de Souza, A N; Bruno, J A; Carvalho, K M

    1991-01-01

    1. A soluble human brain aminopeptidase which hydrolyses the Tyr-Gly bond of Met-enkephalin and Leu-enkephalin was identified in the brains of the following vertebrates: mammals (Callithrix jacchus and Rattus norvegicus), bird (Gallus domesticus), reptile (Tupinambis teguixin), amphibia (Bufo paracnemis), fish (Sarotherdon niloticus) and elasmobranchy (Galeocerdo cuvieri). 2. The properties of this enzyme are: molecular weight near 100,000 Da, isoelectric point near 4.9, optimum pH near 7.5, activation by dithiothreitol, strong inhibition by Cu2+, Zn2+, Ni2+, puromycin and bacitracin, hydrolysis of enkephalins and basic and neutral aminoacid-beta-naphythylamide substrates. 3. The results indicate the preservation of this human brain aminopeptidase during the course of vertebrate phylogeny.

  1. The sequence, structure and evolutionary features of HOTAIR in mammals

    Science.gov (United States)

    2011-01-01

    Background An increasing number of long noncoding RNAs (lncRNAs) have been identified recently. Different from all the others that function in cis to regulate local gene expression, the newly identified HOTAIR is located between HoxC11 and HoxC12 in the human genome and regulates HoxD expression in multiple tissues. Like the well-characterised lncRNA Xist, HOTAIR binds to polycomb proteins to methylate histones at multiple HoxD loci, but unlike Xist, many details of its structure and function, as well as the trans regulation, remain unclear. Moreover, HOTAIR is involved in the aberrant regulation of gene expression in cancer. Results To identify conserved domains in HOTAIR and study the phylogenetic distribution of this lncRNA, we searched the genomes of 10 mammalian and 3 non-mammalian vertebrates for matches to its 6 exons and the two conserved domains within the 1800 bp exon6 using Infernal. There was just one high-scoring hit for each mammal, but many low-scoring hits were found in both mammals and non-mammalian vertebrates. These hits and their flanking genes in four placental mammals and platypus were examined to determine whether HOTAIR contained elements shared by other lncRNAs. Several of the hits were within unknown transcripts or ncRNAs, many were within introns of, or antisense to, protein-coding genes, and conservation of the flanking genes was observed only between human and chimpanzee. Phylogenetic analysis revealed discrete evolutionary dynamics for orthologous sequences of HOTAIR exons. Exon1 at the 5' end and a domain in exon6 near the 3' end, which contain domains that bind to multiple proteins, have evolved faster in primates than in other mammals. Structures were predicted for exon1, two domains of exon6 and the full HOTAIR sequence. The sequence and structure of two fragments, in exon1 and the domain B of exon6 respectively, were identified to robustly occur in predicted structures of exon1, domain B of exon6 and the full HOTAIR in mammals

  2. Phylogeny and evolution of RNA structure.

    Science.gov (United States)

    Gesell, Tanja; Schuster, Peter

    2014-01-01

    Darwin's conviction that all living beings on Earth are related and the graph of relatedness is tree-shaped has been essentially confirmed by phylogenetic reconstruction first from morphology and later from data obtained by molecular sequencing. Limitations of the phylogenetic tree concept were recognized as more and more sequence information became available. The other path-breaking idea of Darwin, natural selection of fitter variants in populations, is cast into simple mathematical form and extended to mutation-selection dynamics. In this form the theory is directly applicable to RNA evolution in vitro and to virus evolution. Phylogeny and population dynamics of RNA provide complementary insights into evolution and the interplay between the two concepts will be pursued throughout this chapter. The two strategies for understanding evolution are ultimately related through the central paradigm of structural biology: sequence ⇒ structure ⇒ function. We elaborate on the state of the art in modeling both phylogeny and evolution of RNA driven by reproduction and mutation. Thereby the focus will be laid on models for phylogenetic sequence evolution as well as evolution and design of RNA structures with selected examples and notes on simulation methods. In the perspectives an attempt is made to combine molecular structure, population dynamics, and phylogeny in modeling evolution.

  3. GO4genome: A Prokaryotic Phylogeny Based on Genome Organization

    OpenAIRE

    Merkl, Rainer; Wiezer, Arnim

    2009-01-01

    Determining the phylogeny of closely related prokaryotes may fail in an analysis of rRNA or a small set of sequences. Whole-genome phylogeny utilizes the maximally available sample space. For a precise determination of genome similarity, two aspects have to be considered when developing an algorithm of whole-genome phylogeny: (1) gene order conservation is a more precise signal than gene content; and (2) when using sequence similarity, failures in identifying orthologues or the in situ replac...

  4. Phylogeny mandalas for illustrating the Tree of Life.

    Science.gov (United States)

    Hasegawa, Masami

    2016-11-02

    A circular phylogeny with photos or drawings of species is named a phylogeny mandala. This is one of the ways for illustrating the Tree of Life, and is suitable to show visually how the biodiversity has developed in the course of evolution as clarified by the molecular phylogenetics. To demonstrate the recent progress of molecular phylogenetics, six phylogeny mandalas for various taxonomic groups of life were presented; i.e., (1) Eukaryota, (2) Metazoa, (3) Hexapoda, (4) Tetrapoda, (5) Eutheria, and (6) Primates.

  5. Loss of Thrombomodulin in Placental Dysfunction in Preeclampsia.

    Science.gov (United States)

    Turner, Rosanne J; Bloemenkamp, Kitty W M; Bruijn, Jan A; Baelde, Hans J

    2016-04-01

    Preeclampsia is a pregnancy-specific syndrome characterized by placental dysfunction and an angiogenic imbalance. Systemically, levels of thrombomodulin, an endothelium- and syncytiotrophoblast-bound protein that regulates coagulation, inflammation, apoptosis, and tissue remodeling, are increased. We aimed to investigate placental thrombomodulin dysregulation and consequent downstream effects in the pathogenesis of preeclampsia. Placentas from 28 preeclampsia pregnancies, 30 uncomplicated pregnancies, and 21 pregnancies complicated by growth restriction as extra controls were included. Immunohistochemical staining of thrombomodulin, caspase-3, and fibrin was performed. Placental mRNA expression of thrombomodulin, inflammatory markers, matrix metalloproteinases 2 and 9, and soluble Flt-1 were measured with quantitative polymerase chain reaction. Thrombomodulin mRNA expression was determined in vascular endothelial growth factor-transfected trophoblast cell lines. Thrombomodulin protein and mRNA expression were decreased in preeclampsia as compared with both control groups (P=0.001). Thrombomodulin mRNA expression correlated with maternal body mass index (Ppreeclampsia. An increase in placental apoptotic cells was associated with preeclampsia (Ppreeclampsia, but not with fibrin deposits or inflammatory markers. Placental soluble Flt-1 expression correlated with decreased thrombomodulin expression. Vascular endothelial growth factor induced upregulation of thrombomodulin expression in trophoblast cells. Decreased thrombomodulin expression in preeclampsia may play a role in placental dysfunction in preeclampsia and is possibly caused by an angiogenic imbalance. Hypertension and obesity are associated with thrombomodulin downregulation. These results set the stage for further basic and clinical research on thrombomodulin in the pathogenesis of preeclampsia and other syndromes characterized by endothelial dysfunction. © 2016 American Heart Association, Inc.

  6. Macrosomia has its roots in early placental development.

    Science.gov (United States)

    Schwartz, N; Quant, H S; Sammel, M D; Parry, S

    2014-09-01

    We sought to determine if early placental size, as measured by 3-dimensional ultrasonography, is associated with an increased risk of delivering a macrosomic or large-for-gestational age (LGA) infant. We prospectively collected 3-dimensional ultrasound volume sets of singleton pregnancies at 11-14 weeks and 18-24 weeks. Birth weights were collected from the medical records. After delivery, the ultrasound volume set were used to measure the placental volume (PV) and placental quotient (PQ = PV/gestational age), as well as the mean placental and chorionic diameters (MPD and MCD, respectively). Placental measures were analyzed as predictors of macrosomia (birth weight ≥4000 g) and LGA (birth weight ≥90th percentile). The 578 pregnancies with first trimester volumes included 44 (7.6%) macrosomic and 43 (7.4%) LGA infants. 373 subjects also had second trimester volumes available. A higher PV and PQ were both significantly associated with macrosomia and LGA in both the first and second trimesters. Second trimester MPD was significantly associated with both outcomes as well, while second trimester MCD was only associated with LGA. The above associations remained significant after adjusting for maternal demographic variables such as race, ethnicity, age and diabetes. Adjusted models yielded moderate prediction of macrosomia and LGA (AUC: 0.71-0.77). Sonographic measurement of the early placenta can identify pregnancies at greater risk of macrosomia and LGA. Macrosomia and LGA are already determined in part by early placental growth and development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Association between PAPP-A and placental thickness

    Directory of Open Access Journals (Sweden)

    Elaheh Mesdaghi-nia

    2016-06-01

    Full Text Available Background: Measuring of maternal serum pregnancy-associated plasma protein-A (PAPP-A in first trimester can be a way for early detection of adverse prenatal outcome due to faulty placenta. Objective: The aim was to Determination of association between placental thickness in second trimester with low level of PAPP-A in first trimester. Materials and Methods: In this cohort study, serum PAPP-A of 187 pregnant women was measured in the first trimester of pregnancy. Patients who had PAPP-A ≤0.8 MOM were in exposed and others who had PAPP-A >0.8 defined as unexposed group. The criteria of placental thickness in ultrasound study was thickness of 4 cm or more than 50% of placental length. Results: Of 187 patients, 87 patients had PAPP-A >0.8 and 93 patients had PAPP-A ≤0.8. Women with low levels of PAPP-A in the first trimester, had an increased incidence placental thickness of 34.4%, whereas another group had about 15% (p=0.002. Also, PAPP-A levels had acceptable sensitivity and specificity for placental thickness detection (71.1% and 54.8%, respectively. Conclusion: Our study showed that serum level of PAPP-A generally was low (≤0.8 in women with a thick placenta (>4 cm or >50% of placental length. The first trimester of pregnancy measurement of PAPP-A will be more predictable for healthy placenta.

  8. HIV-1 Nef breaches placental barrier in rat model.

    Science.gov (United States)

    Singh, Poonam; Agnihotri, Saurabh Kumar; Tewari, Mahesh Chandra; Kumar, Sadan; Sachdev, Monika; Tripathi, Raj Kamal

    2012-01-01

    The vertical transmission of HIV-1 from the mother to fetus is known, but the molecular mechanism regulating this transmission is not fully characterized. The fetus is highly protected by the placenta, which does not permit microbial pathogens to cross the placental barrier. In the present study, a rat model was established to observe the effect of HIV-1 protein Nef on placental barrier. Evans blue dye was used to assay permeability of placental barrier and fourteen day pregnant Sprague Dawley rats were injected intravenously with 2% Evans blue dye along with various concentrations of recombinant Nef. After an hour, animals were sacrificed and dye migration was observed through the assimilation of peripheral blood into fetus. Interestingly, traces of recombinant Nef protein were detected in the embryo as well as amniotic fluid and amniotic membrane along with placenta and uterus. Our study indicates that recombinant HIV-1-Nef protein breaches the placental barrier and allows the migration of Evans blue dye to the growing fetus. Further the concentration of Nef protein in blood is directly proportional to the intensity of dye migration and to the amount of Nef protein detected in uterus, placenta, amniotic membrane, amniotic fluid and embryo. Based on this study, it can be concluded that the HIV-1 Nef protein has a direct effect on breaching of the placental barrier in the model we have established in this study. Our observations will be helpful to understand the molecular mechanisms related to this breach of placental barrier by Nef in humans and may be helpful to identify specific Nef inhibitors.

  9. Molecular phylogeny and systematics of the Echinostomatoidea Looss, 1899 (Platyhelminthes: Digenea).

    Science.gov (United States)

    Tkach, Vasyl V; Kudlai, Olena; Kostadinova, Aneta

    2016-03-01

    The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae

  10. Evolutionary diversity of bile salts in reptiles and mammals, including analysis of ancient human and extinct giant ground sloth coprolites

    Directory of Open Access Journals (Sweden)

    Hofmann Alan F

    2010-05-01

    Full Text Available Abstract Background Bile salts are the major end-metabolites of cholesterol and are also important in lipid and protein digestion and in influencing the intestinal microflora. We greatly extend prior surveys of bile salt diversity in both reptiles and mammals, including analysis of 8,000 year old human coprolites and coprolites from the extinct Shasta ground sloth (Nothrotherium shastense. Results While there is significant variation of bile salts across species, bile salt profiles are generally stable within families and often within orders of reptiles and mammals, and do not directly correlate with differences in diet. The variation of bile salts generally accords with current molecular phylogenies of reptiles and mammals, including more recent groupings of squamate reptiles. For mammals, the most unusual finding was that the Paenungulates (elephants, manatees, and the rock hyrax have a very different bile salt profile from the Rufous sengi and South American aardvark, two other mammals classified with Paenungulates in the cohort Afrotheria in molecular phylogenies. Analyses of the approximately 8,000 year old human coprolites yielded a bile salt profile very similar to that found in modern human feces. Analysis of the Shasta ground sloth coprolites (approximately 12,000 years old showed the predominant presence of glycine-conjugated bile acids, similar to analyses of bile and feces of living sloths, in addition to a complex mixture of plant sterols and stanols expected from an herbivorous diet. Conclusions The bile salt synthetic pathway has become longer and more complex throughout vertebrate evolution, with some bile salt modifications only found within single groups such as marsupials. Analysis of the evolution of bile salt structures in different species provides a potentially rich model system for the evolution of a complex biochemical pathway in vertebrates. Our results also demonstrate the stability of bile salts in coprolites

  11. Transferência placentária de drogas Placental drug transfer

    OpenAIRE

    Ricardo de Carvalho Cavalli; Cláudia de Oliveira Baraldi; Sérgio Pereira da Cunha

    2006-01-01

    Grávidas podem depender do uso de medicações para minimizar os agravos da doença preexistente. A gravidez, por si só, pode causar situações que comprometem o bem-estar materno, como náuseas e vômitos, as quais necessitam de tratamento. O obstetra deve estar atento à transferência placentária de drogas e à exposição do feto a agentes teratogênicos ou tóxicos, que podem comprometer o seu desenvolvimento ou mesmo sua vida futura.O transporte através da placenta envolve o movimento de moléculas e...

  12. Placental transport of large molecules –a study using human ex vivo placental perfusion

    DEFF Research Database (Denmark)

    Mathiesen, Line

    2011-01-01

    To maintain a healthy pregnancy, the exchange of substances between mother and fetus is vital. All transport of these substances takes place through the placenta, which is a temporary organ that serves its purpose from the implantation of the blastula to the birth of the term fetus, supplying...... nutrients, gas and waste transport between the maternal blood and the developing fetus and maintaining pregnancy by producing hormones. The placenta consists of cells of both maternal and fetal origin and forms a complex barrier between the maternal and fetal blood that allows for passage of different...... within two hours of perfusion with a fetal flow rate of 3 mL/min. Negative controls are added to ensure that substance transfer is not due to leakage, e.g. high molecular weight substances that only pass the placental barrier with bulk flow through a leakage in the fetal system. Dextran (40kD) can...

  13. Altered placental development in undernourished rats: role of maternal glucocorticoids

    Directory of Open Access Journals (Sweden)

    Chen Chun-Hung

    2011-08-01

    Full Text Available Abstract Maternal undernutrition (MUN during pregnancy may lead to fetal intrauterine growth restriction (IUGR, which itself predisposes to adult risk of obesity, hypertension, and diabetes. IUGR may stem from insufficient maternal nutrient supply or reduced placental nutrient transfer. In addition, a critical role for maternal stress-induced glucocorticoids (GCs has been suggested to contribute to both IUGR and the ensuing risk of adult metabolic syndrome. While GC-induced fetal organ defects have been examined, there have been few studies on placental responses to MUN-induced maternal stress. Therefore, we hypothesize that 50% MUN associates with increased maternal GC levels and decreased placental HSD11B. This in turn leads to decreased placental and fetal growth, hence the need to investigate nutrient transporters. We measured maternal serum levels of corticosterone, and the placental basal and labyrinth zone expression of glucocorticoid receptor (NR3C1, 11-hydroxysteroid dehydrogenase B 1 (HSD11B-1 predominantly activates cortisone to cortisol and 11-dehydrocorticosterone (11-DHC to corticosterone, although can sometimes drive the opposing (inactivating reaction, and HSD11B-2 (only inactivates and converts corticosterone to 11-DHC in rodents in control and MUN rats at embryonic day 20 (E20. Moreover, we evaluated the expression of nutrient transporters for glucose (SLC2A1, SLC2A3 and amino acids (SLC38A1, 2, and 4. Our results show that MUN dams displayed significantly increased plasma corticosterone levels compared to control dams. Further, a reduction in fetal and placental weights was observed in both the mid-horn and proximal-horn positions. Notably, the placental labyrinth zone, the site of feto-maternal exchange, showed decreased expression of HSD11B1-2 in both horns, and increased HSD11B-1 in proximal-horn placentas, but no change in NR3C1. The reduced placental GCs catabolic capacity was accompanied by downregulation of SLC2A3, SLC

  14. Placental histopathological changes associated with Plasmodium vivax infection during pregnancy.

    Directory of Open Access Journals (Sweden)

    Rodrigo M Souza

    Full Text Available Histological evidence of Plasmodium in the placenta is indicative of placental malaria, a condition associated with severe outcomes for mother and child. Histological lesions found in placentas from Plasmodium-exposed women include syncytial knotting, syncytial rupture, thickening of the placental barrier, necrosis of villous tissue and intervillositis. These histological changes have been associated with P. falciparum infections, but little is known about the contribution of P. vivax to such changes. We conducted a cross-sectional study with pregnant women at delivery and assigned them to three groups according to their Plasmodium exposure during pregnancy: no Plasmodium exposure (n = 41, P. vivax exposure (n = 59 or P. falciparum exposure (n = 19. We evaluated their placentas for signs of Plasmodium and placental lesions using ten histological parameters: syncytial knotting, syncytial rupture, placental barrier thickness, villi necrosis, intervillous space area, intervillous leucocytes, intervillous mononucleates, intervillous polymorphonucleates, parasitized erythrocytes and hemozoin. Placentas from P. vivax-exposed women showed little evidence of Plasmodium or hemozoin but still exhibited more lesions than placentas from women not exposed to Plasmodium, especially when infections occurred twice or more during pregnancy. In the Brazilian state of Acre, where diagnosis and primary treatment are readily available and placental lesions occur in the absence of detected placental parasites, relying on the presence of Plasmodium in the placenta to evaluate Plasmodium-induced placental pathology is not feasible. Multivariate logistic analysis revealed that syncytial knotting (odds ratio [OR], 4.21, P = 0.045, placental barrier thickness (OR, 25.59, P = 0.021 and mononuclear cells (OR, 4.02, P = 0.046 were increased in placentas from P. vivax-exposed women when compared to women not exposed to Plasmodium during pregnancy. A

  15. The surrounding tissue modifies the placental stem villous vascular responses

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn; Forman, Axel; Aalkjær, Christian;

    2014-01-01

    Background: The placenta is the base for the exchange of nutrients, oxygen and waste products for the fetus. The placental vessels hold a crucial role in regulation of blood flow, and compromised function may lead to complications like growth retardation and preeclampsia where no specific treatment...... is available. In-depth understanding of the mechanisms involved in control of placental vascular tone are needed to develop new tissue targets for therapeutic intervention. Method: From fresh born placentas segments of stem villous arteries were carefully dissected. The artery branches were divided...

  16. Placental mesenchymal dysplasia associated with hepatic and pulmonary hamartoma.

    Science.gov (United States)

    Tortoledo, Maria; Galindo, A; Ibarrola, C

    2010-01-01

    This report describes a 31-week stillborn female infant with placental mesenchymal dysplasia (PMD) in association with hepatic mesenchymal hamartoma (HMH) and pulmonary hamartoma. Placental mesenchymal dysplasia was initially misdiagnosed as a partial mole. However, histologically, no trophoblastic proliferation or inclusions were observed. Differential diagnosis of the hepatic mass with similar tumors is discussed. To our knowledge, this is the first case of lung hamartoma reported in a fetus and the first case related to PMD and HMH. A common anomalous development of the mesoderm, a reparative post-injury process and a genetic mechanism, have been proposed to explain their pathogenesis.

  17. Metabolism of bupropion by baboon hepatic and placental microsomes

    OpenAIRE

    2011-01-01

    The aim of this investigation was to determine the biotransformation of bupropion by baboon hepatic and placental microsomes, identify the enzyme(s) catalyzing the reaction(s) and determine its kinetics. Bupropion was metabolized by baboon hepatic and placental microsomes to hydroxybupropion (OH-BUP), threo- (TB) and erythrohydrobupropion (EB). OH-bupropion was the major metabolite formed by hepatic microsomes (Km 36 ± 6 µM, Vmax 258 ± 32 pmol mg protein−1 min−1), however the formation of OH-...

  18. Influence of placental position on obstetric morbidity in placenta previa

    Directory of Open Access Journals (Sweden)

    Shripad S. Hebbar

    2014-06-01

    Conclusions: It is difficult to assign a maternal or perinatal morbidity risk to a particular type of placental location. The need for specialized surgical intervention such as uterine / internal iliac artery ligation, peripartum hysterectomy can arise irrespective of placental location, whether underneath the surgical incision (anterior, proximity to main uterine trunks (lateral or encountered after the delivery of the baby (posterior. Pregnancies complicated by placenta previa must be delivered in the hospitals having expertise of senior and skilled surgeons and well equipped blood bank and good neonatal intensive care unit. [Int J Reprod Contracept Obstet Gynecol 2014; 3(3.000: 585-591

  19. Metallothionein expression in placental tissue in Menkes' disease

    DEFF Research Database (Denmark)

    Hærslev, T.; Krag Jacobsen, G.; Horn, N.

    1995-01-01

    Menkes' disease is a recessive X-linked disturbance of copper metabolism, resulting in accumulation of copper in several extra-hepatic tissues including the placenta. Metallothionein (MT) is a low-molecular weight protein with a high affinity for group II metal ions, such as copper. Its synthesis....... The avidin-biotin-complex (ABC)-technique was used. The copper content was measured by neutron activation analysis (NAA). In all placental tissue sections positive MT immunostaining appeared only in the trophoblast and only in proliferating cells. In placental tissue sections obtained from foetuses...

  20. Infant sex-specific placental cadmium and DNA methylation associations

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, April F., E-mail: april.mohanty@va.gov [Cardiovascular Health Research Unit, University of Washington, 1730 Minor Ave, Seattle, WA 98101 (United States); Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Farin, Fred M., E-mail: freddy@u.washington.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way N.E., Suite #100, Seattle, WA 98105 (United States); Bammler, Theo K., E-mail: tbammler@u.washington.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way N.E., Suite #100, Seattle, WA 98105 (United States); MacDonald, James W., E-mail: jmacdon@uw.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way N.E., Suite #100, Seattle, WA 98105 (United States); Afsharinejad, Zahra, E-mail: zafshari@u.washington.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way N.E., Suite #100, Seattle, WA 98105 (United States); Burbacher, Thomas M., E-mail: tmb@uw.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Box: 357234, 1705 N.E. Pacific Street, Seattle, WA 98195 (United States); Siscovick, David S., E-mail: dsiscovick@nyam.org [Cardiovascular Health Research Unit, University of Washington, 1730 Minor Ave, Seattle, WA 98101 (United States); Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Department of Medicine, University of Washington, Seattle, WA (United States); and others

    2015-04-15

    Background: Recent evidence suggests that maternal cadmium (Cd) burden and fetal growth associations may vary by fetal sex. However, mechanisms contributing to these differences are unknown. Objectives: Among 24 maternal-infant pairs, we investigated infant sex-specific associations between placental Cd and placental genome-wide DNA methylation. Methods: We used ANOVA models to examine sex-stratified associations of placental Cd (dichotomized into high/low Cd using sex-specific Cd median cutoffs) with DNA methylation at each cytosine-phosphate-guanine site or region. Statistical significance was defined using a false discovery rate cutoff (<0.10). Results: Medians of placental Cd among females and males were 5 and 2 ng/g, respectively. Among females, three sites (near ADP-ribosylation factor-like 9 (ARL9), siah E3 ubiquitin protein ligase family member 3 (SIAH3), and heparin sulfate (glucosamine) 3-O-sulfotransferase 4 (HS3ST4) and one region on chromosome 7 (including carnitine O-octanoyltransferase (CROT) and TP5S target 1 (TP53TG1)) were hypomethylated in high Cd placentas. Among males, high placental Cd was associated with methylation of three sites, two (hypomethylated) near MDS1 and EVI1 complex locus (MECOM) and one (hypermethylated) near spalt-like transcription factor 1 (SALL1), and two regions (both hypomethylated, one on chromosome 3 including MECOM and another on chromosome 8 including rho guanine nucleotide exchange factor (GEF) 10 (ARHGEF10). Differentially methylated sites were at or close to transcription start sites of genes involved in cell damage response (SIAH3, HS3ST4, TP53TG1) in females and cell differentiation, angiogenesis and organ development (MECOM, SALL1) in males. Conclusions: Our preliminary study supports infant sex-specific placental Cd-DNA methylation associations, possibly accounting for previously reported differences in Cd-fetal growth associations across fetal sex. Larger studies are needed to replicate and extend these

  1. Human placental alkaline phosphatase electrophoretic alleles: Quantitative studies

    Science.gov (United States)

    Lucarelli, Paola; Scacchi, Renato; Corbo, Rosa Maria; Benincasa, Alberto; Palmarino, Ricciotti

    1982-01-01

    Human placental alkaline phosphatase (ALP) activity has been determined in specimens obtained from 562 Italian subjects. The mean activities of the three common homozygotes (Pl 2 = 4.70 ± 0.24, Pl 1 = 4.09 ± 0.08, and Pl 3 = 2.15 ± 0.71 μmol of p-nitrophenol produced) were significantly different. The differences among the various allelic forms account for 10% of the total quantitative variation of the human placental alkaline phosphatase. PMID:7072721

  2. Studying placental transfer of highly purified non-dioxin-like PCBs in two models of the placental barrier

    DEFF Research Database (Denmark)

    Correia Carreira, S; Cartwright, L; Mathiesen, L

    2011-01-01

    Currently, toxicology and toxicokinetics of purified non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are poorly characterised. Transplacental kinetics of NDL-PCBs can be studied in a variety of models, but careful validation of each model is crucial. We aimed to develop a standard operating...... procedure for establishing an in vitro model of the human placental barrier. Using this model, we sought to investigate placental transport kinetics of two NDL-PCB congeners. Firstly, we compared the BeWo cell line of the American Type Culture Collection with the BeWo b30 clone and determined parameters...... for monolayer formation. Secondly, we performed placental perfusions to validate the in vitro model. To that end, the transport of radiolabelled PCB52 and 180 was investigated in both models. We were not able to grow the ATCC cell line to confluency, but determined monolayer formation using BeWo b30...

  3. Weird mammals provide insights into the evolution of mammalian sex chromosomes and dosage compensation

    Indian Academy of Sciences (India)

    Jennifer A. Marshall Graves

    2015-12-01

    The deep divergence of mammalian groups 166 and 190 million years ago (MYA) provide genetic variation to explore the evolution of DNA sequence, gene arrangement and regulation of gene expression in mammals. With encouragement from the founder of the field, Mary Lyon, techniques in cytogenetics and molecular biology were progressively adapted to characterize the sex chromosomes of kangaroos and other marsupials, platypus and echidna—and weird rodent species. Comparative gene mapping reveals the process of sex chromosome evolution from their inception 190 MYA (they are autosomal in platypus) to their inevitable end (the Y has disappeared in two rodent lineages). Our X and Y are relatively young, getting their start with the evolution of the sex-determining gene, which triggered progressive degradation of the Y chromosome. Even more recently, sex chromosomes of placental mammals fused with an autosomal region which now makes up most of the Y. Exploration of gene activity patterns over four decades showed that dosage compensation via X-chromosome inactivation is unique to therian mammals, and that this whole chromosome control process is different in marsupials and absent in monotremes and reptiles, and birds. These differences can be exploited to deduce how mammalian sex chromosomes and epigenetic silencing evolved.

  4. Placental Hypoxia During Early Pregnancy Causes Maternal Hypertension and Placental Insufficiency in the Hypoxic Guinea Pig Model.

    Science.gov (United States)

    Thompson, Loren P; Pence, Laramie; Pinkas, Gerald; Song, Hong; Telugu, Bhanu P

    2016-12-01

    Chronic placental hypoxia is one of the root causes of placental insufficiencies that result in pre-eclampsia and maternal hypertension. Chronic hypoxia causes disruption of trophoblast (TB) development, invasion into maternal decidua, and remodeling of maternal spiral arteries. The pregnant guinea pig shares several characteristics with humans such as hemomonochorial placenta, villous subplacenta, deep TB invasion, and remodeling of maternal arteries, and is an ideal animal model to study placental development. We hypothesized that chronic placental hypoxia of the pregnant guinea pig inhibits TB invasion and alters spiral artery remodeling. Time-mated pregnant guinea pigs were exposed to either normoxia (NMX) or three levels of hypoxia (HPX: 16%, 12%, or 10.5% O2) from 20 day gestation until midterm (39-40 days) or term (60-65 days). At term, HPX (10.5% O2) increased maternal arterial blood pressure (HPX 57.9 ± 2.3 vs. NMX 40.4 ± 2.3, P < 0.001), decreased fetal weight by 16.1% (P < 0.05), and increased both absolute and relative placenta weights by 10.1% and 31.8%, respectively (P < 0.05). At midterm, there was a significant increase in TB proliferation in HPX placentas as confirmed by increased PCNA and KRT7 staining and elevated ESX1 (TB marker) gene expression (P < 0.05). Additionally, quantitative image analysis revealed decreased invasion of maternal blood vessels by TB cells. In summary, this animal model of placental HPX identifies several aspects of abnormal placental development, including increased TB proliferation and decreased migration and invasion of TBs into the spiral arteries, the consequences of which are associated with maternal hypertension and fetal growth restriction.

  5. Lung Mechanics in Marine Mammals

    Science.gov (United States)

    2014-09-30

    Mammal Science, 2007. 23: p. 888-925. 3. Falke, K.J., et al., Seal lung collapse during free diving: evidence from arterial nitrogen tensions . Science...compression and gas exchange. We will run the model with dive data and arterial and venous PO2 for California sea lions provided by Drs. Gitte McDonald and...used to re-parameterize a gas exchange model [13]. Dive data and measured venous and arterial PO2 data from California sea lions have been obtained from

  6. Absence of Y chromosome in human placental site trophoblastic tumor.

    Science.gov (United States)

    Hui, Pei; Wang, Hanlin L; Chu, Peiguo; Yang, Bin; Huang, Jiaoti; Baergen, Rebecca N; Sklar, Jeffrey; Yang, Ximing J; Soslow, Robert A

    2007-10-01

    Placental site trophoblastic tumor is a neoplasm of extravillous intermediate trophoblast at the implantation site, preceded in the majority of cases by a female gestational event. Our pilot investigation suggested that the development of this tumor might require a paternally derived X chromosome and the absence of a Y chromosome. Twenty cases of placental site trophoblastic tumor were included in this study. Genotyping at 15 polymorphic loci and one sex determination locus was performed by multiplex PCR followed by capillary electrophoresis. X chromosome polymorphisms were determined by PCR amplification of exon 1 of the human androgen receptor gene using primers flanking the polymorphic CAG repeats within this region. Genotyping at 15 polymorphic loci was informative and paternal alleles were present in all tumors, confirming the trophoblastic origin of the tumors. The presence of an X chromosome and the absence of a Y chromosome were observed in all tumors. Among 13 cases in which analysis of the X chromosome polymorphism was informative, all but one demonstrated at least two X alleles and seven cases showed one identifiable paternal X allele. These results confirm a unique pathogenetic mechanism in placental site trophoblastic tumor, involving an exclusion of the Y chromosome from the genome and, therefore, a tumor arising from the trophectoderm of a female conceptus. As epigenetic regulations of imprinting during X chromosome inactivation are of significant biological implications, placental site trophoblastic tumor may provide an important model for studying the sex chromosome biology and the proliferative advantage conferred by the paternal X chromosome.

  7. Early studies of placental ultrastructure by electron microscopy

    DEFF Research Database (Denmark)

    Carter, A M; Enders, A C

    2016-01-01

    many other scientists to Washington University in St. Louis. Work on human placental ultrastructure was initiated at Cambridge and Kyoto whilst domestic animals were initially studied by Björkman in Stockholm and electron micrographs of bat placenta were published by Wimsatt of Cornell University...

  8. Placentation in dolphins from the Amazon River Basin

    DEFF Research Database (Denmark)

    da Silva, Vera M F; Carter, Anthony M; Ambrosio, Carlos E

    2007-01-01

    A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched...

  9. Pathologic evaluation of normal and perfused term placental tissue

    DEFF Research Database (Denmark)

    Maroun, Lisa Leth; Mathiesen, Line; Hedegaard, Morten

    2014-01-01

    This study reports for the 1st time the incidence and interobserver variation of morphologic findings in a series of 34 term placentas from pregnancies with normal outcome used for perfusion studies. Histologic evaluation of placental tissue is challenging, especially when it comes to defining "n...

  10. Prevalence and predictors of placental malaria in human ...

    African Journals Online (AJOL)

    2016-02-16

    Feb 16, 2016 ... immunity that increase the risks to placental malaria infection. ... Materials and Methods: It was a longitudinal cohort study of pregnant women receiving ... their infants antenatally and peripartum. ... Plasmodium falciparum is stable. ..... immune responses during HIV‑malaria co‑infection in pregnancy. Trends.

  11. Oxidative stress and maternal obesity: feto-placental unit interaction.

    Science.gov (United States)

    Malti, N; Merzouk, H; Merzouk, S A; Loukidi, B; Karaouzene, N; Malti, A; Narce, M

    2014-06-01

    To determine oxidative stress markers in maternal obesity during pregnancy and to evaluate feto-placental unit interaction, especially predictors of fetal metabolic alterations. 40 obese pregnant women (prepregnancy BMI > 30 kg/m²) were compared to 50 control pregnant women. Maternal, cord blood and placenta samples were collected at delivery. Biochemical parameters (total cholesterol and triglycerides) and oxidative stress markers (malondialdehyde, carbonyl proteins, superoxide anion expressed as reduced Nitroblue Tetrazolium, nitric oxide expressed as nitrite, reduced glutathione, catalase, superoxide dismutase) were assayed by biochemical methods. Maternal, fetal and placental triglyceride levels were increased in obese group compared to control. Maternal malondialdehyde, carbonyl proteins, nitric oxide and superoxide anion levels were high while reduced glutathione concentrations and superoxide dismutase activity were low in obesity. In the placenta and in newborns of these obese mothers, variations of redox balance were also observed indicating high oxidative stress. Maternal and placental interaction constituted a strong predictor of fetal redox variations in obese pregnancies. Maternal obesity compromised placental metabolism and antioxidant status which strongly impacted fetal redox balance. Oxidative stress may be one of the key downstream mediators that initiate programming of the offspring. Maternal obesity is associated with metabolic alterations and dysregulation of redox balance in the mother-placenta - fetus unit. These perturbations could lead to maternal and fetal complications and should be carefully considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Polyaromatic compounds alter placental protein synthesis in pregnant rats

    Energy Technology Data Exchange (ETDEWEB)

    Shiverick, K.T.; Ogilvie, S.; Medrano, T. (Univ. of Florida, Gainesville (United States))

    1991-03-15

    The administration of the polyaromatic compounds {beta}-naphthoflavone ({beta}NF) and 3-methylcholanthrene (3MC) to pregnant rats during mid-gestation has been shown to produce marked feto-placental growth retardation. This study examined secretory protein synthesis in placental tissue from rats following administration of {beta}NF on gestation days (gd) 11-14 or 3MC on gd 12-14. Explants of placental basal zone tissue were cultured for 24 hours in serum-free medium in the presence of ({sup 3}H)leucine. Secreted proteins were analyzed by two-dimensional SDS-polyacrylamide gel electrophoresis followed by either fluorography or immunostaining. Total incorporation of ({sup 3}H)leucine into secreted proteins was not altered in BZ explants from {beta}NF or 3MC-treated animals. However a selective decrease was observed in ({sup 3}H)leucine incorporation into a major complex of proteins with apparent molecular weight of 25-30,000 and isoelectric point between 5.3 to 5.7. This group of proteins has been further identified as being related to rat pituitary growth hormone (GH) using N-terminal amino acid microsequencing of individual spots from 2-D SDS-PA gels. This is the first report that synthesis of GH-related proteins by rat placenta is decreased following {beta}NF and 3MC administration, a change which may underlie the feto-placental growth retardation associated with these polyaromatic compounds.

  13. Placentation in the Hottentot golden mole, Amblysomus hottentotus (Afrosoricida: Chrysochloridae)

    DEFF Research Database (Denmark)

    Jones, C J P; Carter, A M; Bennett, N C;

    2009-01-01

    The placentation of the Hottentot golden mole (Amblysomus hottentotus) has been examined using light and electron microscopy and lectin histochemistry of nine specimens at both mid and late gestation. The placentae were lobulated towards the allantoic surface and the lobules contained roughly par...

  14. Notch signalling in placental development and gestational diseases.

    Science.gov (United States)

    Haider, S; Pollheimer, J; Knöfler, M

    2017-01-16

    Activation of Notch signalling upon cell-cell contact of neighbouring cells controls a plethora of cellular processes such as stem cell maintenance, cell lineage determination, cell proliferation, and survival. Accumulating evidence suggests that the pathway also critically regulates these events during placental development and differentiation. Herein, we summarize our present knowledge about Notch signalling in murine and human placentation and discuss its potential role in the pathophysiology of gestational disorders. Studies in mice suggest that Notch controls trophectoderm formation, decidualization, placental branching morphogenesis and endovascular trophoblast invasion. In humans, the particular signalling cascade promotes formation of the extravillous trophoblast lineage and regulates trophoblast proliferation, survival and differentiation. Expression patterns as well as functional analyses indicate distinct roles of Notch receptors in different trophoblast subtypes. Altered effects of Notch signalling have been detected in choriocarcinoma cells, consistent with its role in cancer development and progression. Moreover, deregulation of Notch signalling components were observed in pregnancy disorders such as preeclampsia and fetal growth restriction. In summary, Notch plays fundamental roles in different developmental processes of the placenta. Abnormal signalling through this pathway could contribute to the pathogenesis of gestational diseases with aberrant placentation and trophoblast function.

  15. A checklist of mammals of Kerala, India

    Directory of Open Access Journals (Sweden)

    P. O. Nameer

    2015-11-01

    Full Text Available A checklist of mammals of Kerala State is presented in this paper. Accepted English names, scientific binomen, prevalent vernacular names in Malayalam, IUCN conservation status, endemism, Indian Wildlife (Protection Act schedules, and the appendices in the CITES, pertaining to the mammals of Kerala are also given. The State of Kerala has 118 species of mammals, 15 of which are endemic to Western Ghats, and 29 species fall under the various threatened categories of IUCN.  

  16. Marine mammals of Puerto Rico: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Payne, S.F.

    1981-08-01

    This bibliography is the product of a literature survey on marine mammals at a proposed OTEC site near Punta Tuna, Puerto Rico. Included are reports of mammal sightings and strandings from Puerto Rico and adjacent Caribbean islands, reports containing information on distribution and abundance migration routes, and feeding ecology of those species known from the area. A few works on the general biology of marine mammals are also included. 96 references.

  17. Algorithms For Phylogeny Reconstruction In a New Mathematical Model

    NARCIS (Netherlands)

    Lenzini, Gabriele; Marianelli, Silvia

    1997-01-01

    The evolutionary history of a set of species is represented by a tree called phylogenetic tree or phylogeny. Its structure depends on precise biological assumptions about the evolution of species. Problems related to phylogeny reconstruction (i.e., finding a tree representation of information regard

  18. Does malaria affect placental development? Evidence from in vitro models.

    Directory of Open Access Journals (Sweden)

    Alexandra J Umbers

    Full Text Available BACKGROUND: Malaria in early pregnancy is difficult to study but has recently been associated with fetal growth restriction (FGR. The pathogenic mechanisms underlying malarial FGR are poorly characterized, but may include impaired placental development. We used in vitro methods that model migration and invasion of placental trophoblast into the uterine wall to investigate whether soluble factors released into maternal blood in malaria infection might impair placental development. Because trophoblast invasion is enhanced by a number of hormones and chemokines, and is inhibited by pro-inflammatory cytokines, many of which are dysregulated in malaria in pregnancy, we further compared concentrations of these factors in blood between malaria-infected and uninfected pregnancies. METHODOLOGY/PRINCIPAL FINDINGS: We measured trophoblast invasion, migration and viability in response to treatment with serum or plasma from two independent cohorts of Papua New Guinean women infected with Plasmodium falciparum or Plasmodium vivax in early pregnancy. Compared to uninfected women, serum and plasma from women with P. falciparum reduced trophoblast invasion (P = .06 and migration (P = .004. P. vivax infection did not alter trophoblast migration (P = .64. The P. falciparum-specific negative effect on placental development was independent of trophoblast viability, but associated with high-density infections. Serum from P. falciparum infected women tended to have lower levels of trophoblast invasion promoting hormones and factors and higher levels of invasion-inhibitory inflammatory factors. CONCLUSION/SIGNIFICANCE: We demonstrate that in vitro models of placental development can be adapted to indirectly study the impact of malaria in early pregnancy. These infections could result in impaired trophoblast invasion with reduced transformation of maternal spiral arteries due to maternal hormonal and inflammatory disturbances, which may contribute to FGR by

  19. Placental ABC transporters, cellular toxicity and stress in pregnancy.

    Science.gov (United States)

    Aye, Irving L M H; Keelan, Jeffrey A

    2013-04-25

    The human placenta, in addition to its roles as a nutrient transfer and endocrine organ, functions as a selective barrier to protect the fetus against the harmful effects of exogenous and endogenous toxins. Members of the ATP-binding cassette (ABC) family of transport proteins limit the entry of xenobiotics into the fetal circulation via vectorial efflux from the placenta to the maternal circulation. Several members of the ABC family, including proteins from the ABCA, ABCB, ABCC and ABCG subfamilies, have been shown to be functional in the placenta with clinically significant roles in xenobiotic efflux. However, recent findings suggest that these transporters also protect placental tissue by preventing the cellular accumulation of cytotoxic compounds such as lipids, sterols and their derivatives. Such protective functions are likely to be particularly important in pregnancies complicated by inflammatory or oxidative stress, where the generation of toxic metabolites is enhanced. For example, ABC transporters have been shown to protect against the harmful effects of hypoxia and oxidative stress through increased expression and efflux of oxysterols and glutathione conjugated xenobiotics. However, this protective capacity may be diminished in response to the same stressors. Several studies in primary human trophoblast cells and animal models have demonstrated decreased expression and activity of placental ABC transporters with inflammatory, oxidative or metabolic stress. Several clinical studies in pregnancies complicated by inflammatory conditions such as preeclampsia and gestational diabetes support these findings, although further studies are required to determine the clinical relevance of the relationships between placental ABC transporter expression and activity, and placental function in stressed pregnancies. Such studies are necessary to fully understand the consequences of pregnancy disorders on placental function and viability in order to optimise pregnancy

  20. Construction of random perfect phylogeny matrix

    Directory of Open Access Journals (Sweden)

    Mehdi Sadeghi

    2010-11-01

    Full Text Available Mehdi Sadeghi1,2, Hamid Pezeshk4, Changiz Eslahchi3,5, Sara Ahmadian6, Sepideh Mah Abadi61National Institute of Genetic Engineering and Biotechnology, Tehran, Iran; 2School of Computer Science, 3School of Mathematics, Institute for Research in Fundamental Sciences (IPM, Tehran, Iran; 4School of Mathematics, Statistics and Computer Sciences, Center of Excellence in Biomathematics, College of Science, University of Tehran, Tehran, Iran; 5Department of Mathematics, Shahid Beheshti University, G.C., Tehran, Iran; 6Department of Computer Engineering, Sharif University of Technology, Tehran, IranPurpose: Interest in developing methods appropriate for mapping increasing amounts of genome-wide molecular data are increasing rapidly. There is also an increasing need for methods that are able to efficiently simulate such data.Patients and methods: In this article, we provide a graph-theory approach to find the necessary and sufficient conditions for the existence of a phylogeny matrix with k nonidentical haplotypes, n single nucleotide polymorphisms (SNPs, and a population size of m for which the minimum allele frequency of each SNP is between two specific numbers a and b.Results: We introduce an O(max(n2, nm algorithm for the random construction of such a phylogeny matrix. The running time of any algorithm for solving this problem would be Ω (nm.Conclusion: We have developed software, RAPPER, based on this algorithm, which is available at http://bioinf.cs.ipm.ir/softwares/RAPPER.Keywords: perfect phylogeny, minimum allele frequency (MAF, tree, recursive algorithm 

  1. Testing for Depéret's Rule (Body Size Increase) in Mammals using Combined Extinct and Extant Data.

    Science.gov (United States)

    Bokma, Folmer; Godinot, Marc; Maridet, Olivier; Ladevèze, Sandrine; Costeur, Loïc; Solé, Floréal; Gheerbrant, Emmanuel; Peigné, Stéphane; Jacques, Florian; Laurin, Michel

    2016-01-01

    Whether or not evolutionary lineages in general show a tendency to increase in body size has often been discussed. This tendency has been dubbed "Cope's rule" but because Cope never hypothesized it, we suggest renaming it after Depéret, who formulated it clearly in 1907. Depéret's rule has traditionally been studied using fossil data, but more recently a number of studies have used present-day species. While several paleontological studies of Cenozoic placental mammals have found support for increasing body size, most studies of extant placentals have failed to detect such a trend. Here, we present a method to combine information from present-day species with fossil data in a Bayesian phylogenetic framework. We apply the method to body mass estimates of a large number of extant and extinct mammal species, and find strong support for Depéret's rule. The tendency for size increase appears to be driven not by evolution toward larger size in established species, but by processes related to the emergence of new species. Our analysis shows that complementary data from extant and extinct species can greatly improve inference of macroevolutionary processes.

  2. Bayesian coestimation of phylogeny and sequence alignment

    Directory of Open Access Journals (Sweden)

    Jensen Jens

    2005-04-01

    Full Text Available Abstract Background Two central problems in computational biology are the determination of the alignment and phylogeny of a set of biological sequences. The traditional approach to this problem is to first build a multiple alignment of these sequences, followed by a phylogenetic reconstruction step based on this multiple alignment. However, alignment and phylogenetic inference are fundamentally interdependent, and ignoring this fact leads to biased and overconfident estimations. Whether the main interest be in sequence alignment or phylogeny, a major goal of computational biology is the co-estimation of both. Results We developed a fully Bayesian Markov chain Monte Carlo method for coestimating phylogeny and sequence alignment, under the Thorne-Kishino-Felsenstein model of substitution and single nucleotide insertion-deletion (indel events. In our earlier work, we introduced a novel and efficient algorithm, termed the "indel peeling algorithm", which includes indels as phylogenetically informative evolutionary events, and resembles Felsenstein's peeling algorithm for substitutions on a phylogenetic tree. For a fixed alignment, our extension analytically integrates out both substitution and indel events within a proper statistical model, without the need for data augmentation at internal tree nodes, allowing for efficient sampling of tree topologies and edge lengths. To additionally sample multiple alignments, we here introduce an efficient partial Metropolized independence sampler for alignments, and combine these two algorithms into a fully Bayesian co-estimation procedure for the alignment and phylogeny problem. Our approach results in estimates for the posterior distribution of evolutionary rate parameters, for the maximum a-posteriori (MAP phylogenetic tree, and for the posterior decoding alignment. Estimates for the evolutionary tree and multiple alignment are augmented with confidence estimates for each node height and alignment column

  3. Confusing dinosaurs with mammals: tetrapod phylogenetics and anatomical terminology in the world of homology.

    Science.gov (United States)

    Harris, Jerald D

    2004-12-01

    At present, three different systems of anatomical nomenclature are available to researchers describing new tetrapod taxa: a nonstandardized traditional system erected in part by Sir Richard Owen and subsequently elaborated by Alfred Romer; a standardized system created for avians, the Nomina Anatomica Avium (NAA); and a standardized system for extant (crown-group) mammals, the Nomina Anatomica Veterinaria (NAV). Conserved homologous structures widely distributed within the Tetrapoda are often granted different names in each system. The recent shift toward a phylogenetic system based on homology requires a concomitant shift toward a single nomenclatural system also based on both evolutionary and functional morphological homology. Standardized terms employed in the NAA and NAV should be perpetuated as far as possible basally in their respective phylogenies. Thus, NAA terms apply to nonavian archosaurs (or even all diapsids) and NAV terms apply to noncrown-group mammals and more basal synapsids. Taxa equally distant from both avians and crown-group mammals may maintain the traditional nonstandardized terminology until a universal anatomical nomenclature for all tetrapods is constructed. (c) 2004 Wiley-Liss, Inc.

  4. Prenatal diagnosis of a placental infarction hematoma associated with fetal growth restriction, preeclampsia and fetal death: clinicopathological correlation.

    Science.gov (United States)

    Aurioles-Garibay, Alma; Hernandez-Andrade, Edgar; Romero, Roberto; Qureshi, Faisal; Ahn, Hyunyoung; Jacques, Suzanne M; Garcia, Maynor; Yeo, Lami; Hassan, Sonia S

    2014-01-01

    The lesion termed 'placental infarction hematoma' is associated with fetal death and adverse perinatal outcome. Such a lesion has been associated with a high risk of fetal death and abruption placentae. The fetal and placental hemodynamic changes associated with placental infarction hematoma have not been reported. This paper describes a case of early and severe growth restriction with preeclampsia, and progressive deterioration of the fetal and placental Doppler parameters in the presence of a placental infarction hematoma.

  5. 78 FR 51147 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2013-08-20

    ... marine mammal habitat are associated with elevated sound levels produced by airguns and vessels and their... National Oceanic and Atmospheric Administration RIN 0648-XC563 Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Marine Seismic Survey in the Chukchi Sea, Alaska...

  6. 77 FR 23547 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Columbia River Crossing...

    Science.gov (United States)

    2012-04-19

    ... Columbia River originates on the west slope of the Rocky Mountains in Canada and flows approximately 1,200... Part 217 Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Columbia River... Administration 50 CFR Part 217 RIN 0648-BB16 Taking and Importing Marine Mammals; Taking Marine...

  7. 77 FR 27321 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2012-05-09

    ... mammals exposed to the sounds produced by the drillship, ice management/icebreaking vessels, support... have the potential to disturb marine mammals. Response: Shell's application and NMFS' Notice of... than a negligible impact on the affected marine mammal species or stock (see response to Comment 7...

  8. Health risks for marine mammal workers.

    Science.gov (United States)

    Hunt, Tania D; Ziccardi, Michael H; Gulland, Frances M D; Yochem, Pamela K; Hird, David W; Rowles, Teresa; Mazet, Jonna A K

    2008-08-19

    Marine mammals can be infected with zoonotic pathogens and show clinical signs of disease, or be asymptomatic carriers of such disease agents. While isolated cases of human disease from contact with marine mammals have been reported, no evaluation of the risks associated with marine mammal work has been attempted. Therefore, we designed a survey to estimate the risk of work-related injuries and illnesses in marine mammal workers and volunteers. The 17-question survey asked respondents to describe their contact with marine mammals, injuries sustained, and/or illnesses acquired during their period of marine mammal exposure. Most respondents, 88% (423/483), were researchers and rehabilitators. Of all respondents, 50% (243/483) reported suffering an injury caused by a marine mammal, and 23% (110/483) reported having a skin rash or reaction. Marine mammal work-related illnesses commonly reported included: 'seal finger' (Mycoplasma spp. or Erysipelothrix rhusiopathiae), conjunctivitis, viral dermatitis, bacterial dermatitis, and non-specific contact dermatitis. Although specific diagnoses could not be confirmed by a physician through this study, severe illnesses were reported and included tuberculosis, leptospirosis, brucellosis, and serious sequelae to seal finger. Risk factors associated with increased odds of injury and illness included prolonged and frequent exposure to marine mammals; direct contact with live marine mammals; and contact with tissue, blood, and excretions. Diagnosis of zoonotic disease was often aided by veterinarians; therefore, workers at risk should be encouraged to consult with a marine mammal veterinarian as well as a physician, especially if obtaining a definitive diagnosis for an illness becomes problematic.

  9. Effects of transcutaneous electrical nerve stimulation on fetal and placental development in an experimental model of placental insufficiency.

    Science.gov (United States)

    Guimarães, Camila S O; Gomes, Bruno B F; Oliveira, Rafael A; Yamamoto, Leandro R; Rocha, Laura P; Glória, Maria A; Machado, Juliana R; Câmara, Niels O S; Reis, Marlene A; Corrêa, Rosana R M

    2016-01-01

    To elucidate the effects of transcutaneous electrical nerve stimulation (TENS) in pregnancies with placental insufficiency. Pregnant rats were subjected to uterine artery ligation and to TENS according to the following groups: ligated stimulated (LS); ligated non-stimulated (LN), control stimulated (CS); and control non-stimulated (CN). Fetal external measurements, such as crown-rump length (CRL), fronto-occipital distance (FOD), thoracic ventral-dorsal (TVDD) and abdominal ventral-dorsal (AVDD) distances were analyzed together with the area occupied by fetal internal organs. Glucose transporter 1 (GLUT-1) expression was evaluated by immunohistochemistry in fetal organs. Thickness of junctional, labyrinth and intermediate placental zones was analyzed by morphometric evaluation in HE-stained slides, and placental hypoxia-inducible factor 1 alfa expression was measured by real-time polymerase chain reaction. In LN and CS groups compared to the CN group, CRL was reduced (27.51/28.95 versus 30.16 mm), as well as FOD (6.63/6.63 versus 7.36 mm), AVDD (7.38/8.00 versus 8.61 mm) and TVDD (6.46/6.87 versus 7.23 mm). Brain GLUT-1 expression was higher in LS (1.3%) and CS (1.8%). The area occupied by placental vessels in the labyrinth zone (29.67 ± 3.51 versus 20.83 ± 7.63) and intermediate zone (26.46 ± 10.21 versus 10.86 ± 8.94) was larger in the LS group than in the LN group. Our results suggest a negative effect of TENS on placental development, thus compromising the maintenance of adequate blood flow to the fetus.

  10. Introduced species: domestic mammals are more significant transmitters of parasites to native mammals than are feral mammals.

    Science.gov (United States)

    Landaeta-Aqueveque, Carlos; Henríquez, Analía; Cattan, Pedro E

    2014-03-01

    The study of parasitism related to biological invasion has focused on attributes and impacts of parasites as invaders and the impact of introduced hosts on endemic parasitism. Thus, there is currently no study of the attributes of hosts which influence the invasiveness of parasites. We aimed to determine whether the degree of domestication of introduced mammalian species - feral introduced mammals, livestock or pets, hereafter 'D' - is important in the spillover of introduced parasites. The literature on introduced parasites of mammals in Chile was reviewed. We designed an index for estimating the relevance of the introduced host species to parasite spillover and determined whether the D of introduced mammals predicted this index. A total of 223 introduced parasite species were found. Our results indicate that domestic mammals have a higher number of introduced parasites and spillover parasites, and the index indicates that these mammals, particularly pets, are more relevant introducers than introduced feral mammals. Further analyses indicated that the higher impact is due to higher parasite richness, a longer time since introduction and wider dispersal, as well as how these mammals are maintained. The greater relevance of domestic mammals is important given that they are basically the same species distributed worldwide and can become the main transmitters of parasites to native mammals elsewhere. This finding also underlines the feasibility of management in order to reduce the transmission of parasites to native fauna through anti-parasitic treatment of domestic mammals, animal-ownership education and the prevention of importing new parasite species. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  11. 50 CFR 216.83 - Importation of birds or mammals.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Importation of birds or mammals. 216.83... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Pribilof Islands Administration § 216.83 Importation of birds or mammals. No mammals or birds...

  12. 50 CFR 216.37 - Marine mammal parts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Marine mammal parts. 216.37 Section 216.37..., DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Special Exceptions § 216.37 Marine mammal parts. With respect to marine mammal parts acquired by take or...

  13. Distribution of mammals in Albania

    Directory of Open Access Journals (Sweden)

    Claudio Prigioni

    1996-12-01

    Full Text Available Abstract Some 63 species have been recorded in Albania from 1950 to 1994, with the exclusion of Cetacea. Another 15 species, including 5 found on the eastern border between Albania and Greece, are considered probably present. Hence 78 species could occur in Albania. According to IUCN red list of threatened animals, 8 species are defined as vulnerable, 15 as lower risk and one (the Mediterranean monk seal as critically endangered. In Albania, the legal protection of mammals includes all bat species, carnivores (except the stone marten, the red fox and the wolf, the chamois, the roe deer and the Mediterranean monk seal. General information on the distributional pattern and the population size is reported for some species, mainly carnivores.

  14. A supertree approach to shorebird phylogeny

    Directory of Open Access Journals (Sweden)

    Thomas Gavin H

    2004-08-01

    Full Text Available Abstract Background Order Charadriiformes (shorebirds is an ideal model group in which to study a wide range of behavioural, ecological and macroevolutionary processes across species. However, comparative studies depend on phylogeny to control for the effects of shared evolutionary history. Although numerous hypotheses have been presented for subsets of the Charadriiformes none to date include all recognised species. Here we use the matrix representation with parsimony method to produce the first fully inclusive supertree of Charadriiformes. We also provide preliminary estimates of ages for all nodes in the tree. Results Three main lineages are revealed: i the plovers and allies; ii the gulls and allies; and iii the sandpipers and allies. The relative position of these clades is unresolved in the strict consensus tree but a 50% majority-rule consensus tree indicates that the sandpiper clade is sister group to the gulls and allies whilst the plover group is placed at the base of the tree. The overall topology is highly consistent with recent molecular hypotheses of shorebird phylogeny. Conclusion The supertree hypothesis presented herein is (to our knowledge the only complete phylogenetic hypothesis of all extant shorebirds. Despite concerns over the robustness of supertrees (see Discussion, we believe that it provides a valuable framework for testing numerous evolutionary hypotheses relating to the diversity of behaviour, ecology and life-history of the Charadriiformes.

  15. Towards a mitogenomic phylogeny of Lepidoptera.

    Science.gov (United States)

    Timmermans, Martijn J T N; Lees, David C; Simonsen, Thomas J

    2014-10-01

    The backbone phylogeny of Lepidoptera remains unresolved, despite strenuous recent morphological and molecular efforts. Molecular studies have focused on nuclear protein coding genes, sometimes adding a single mitochondrial gene. Recent advances in sequencing technology have, however, made acquisition of entire mitochondrial genomes both practical and economically viable. Prior phylogenetic studies utilised just eight of 43 currently recognised lepidopteran superfamilies. Here, we add 23 full and six partial mitochondrial genomes (comprising 22 superfamilies of which 16 are newly represented) to those publically available for a total of 24 superfamilies and ask whether such a sample can resolve deeper lepidopteran phylogeny. Using recoded datasets we obtain topologies that are highly congruent with prior nuclear and/or morphological studies. Our study shows support for an expanded Obtectomera including Gelechioidea, Thyridoidea, plume moths (Alucitoidea and Pterophoroidea; possibly along with Epermenioidea), Papilionoidea, Pyraloidea, Mimallonoidea and Macroheterocera. Regarding other controversially positioned higher taxa, Doidae is supported within the new concept of Drepanoidea and Mimallonidae sister to (or part of) Macroheterocera, while among Nymphalidae butterflies, Danainae and not Libytheinae are sister to the remainder of the family. At the deepest level, we suggest that a tRNA rearrangement occurred at a node between Adeloidea and Ditrysia+Palaephatidae+Tischeriidae.

  16. Progress in nemertean biology: development and phylogeny.

    Science.gov (United States)

    Turbeville, J M

    2002-07-01

    This paper reviews progress in developmental biology and phylogeny of the Nemertea, a common but poorly studied spiralian taxon of considerable ecological and evolutionary significance. Analyses of reproductive biology (including calcium dynamics during fertilization and oocyte maturation), larval morphology and development and developmental genetics have significantly extended our knowledge of spiralian developmental biology. Developmental genetics studies have in addition provided characters useful for reconstructing metazoan phylogeny. Reinvestigation of the cell lineage of Cerebratulus lacteus using fluorescent tracers revealed that endomesoderm forms from the 4d cell as in other spiralians and that ectomesoderm is derived from the 3a and 3b cells as in annelids, echiurans and molluscs. Studies examining blastomere specification show that cell fates are established precociously in direct developers and later in indirect developers. Morphological characters used to estimate the phylogenetic position of nemerteans are critically re-evaluated, and cladistic analyses of morphology reveal that conflicting hypotheses of nemertean relationships result because of different provisional homology statements. Analyses that include disputed homology statements (1, gliointerstitial cell system 2, coelomic circulatory system) suggest that nemerteans form the sister taxon to the coelomate spiralian taxa rather than the sister taxon to Platyhelminthes. Analyses of small subunit rRNA (18S rDNA) sequences alone or in combination with morphological characters support the inclusion of the nemerteans in a spiralian coelomate clade nested within a more inclusive lophotrochozoan clade. Ongoing evaluation of nemertean relationships with mitochondrial gene rearrangements and other molecular characters is discussed.

  17. Evolution, phylogeny, and molecular epidemiology of Chlamydia.

    Science.gov (United States)

    Nunes, Alexandra; Gomes, João P

    2014-04-01

    The Chlamydiaceae are a family of obligate intracellular bacteria characterized by a unique biphasic developmental cycle. It encompasses the single genus Chlamydia, which involves nine species that affect a wide range of vertebral hosts, causing infections with serious impact on human health (mainly due to Chlamydia trachomatis infections) and on farming and veterinary industries. It is believed that Chlamydiales originated ∼700mya, whereas C. trachomatis likely split from the other Chlamydiaceae during the last 6mya. This corresponds to the emergence of modern human lineages, with the first descriptions of chlamydial infections as ancient as four millennia. Chlamydiaceae have undergone a massive genome reduction, on behalf of the deletional bias "use it or lose it", stabilizing at 1-1.2Mb and keeping a striking genome synteny. Their phylogeny reveals species segregation according to biological properties, with huge differences in terms of host range, tissue tropism, and disease outcomes. Genome differences rely on the occurrence of mutations in the >700 orthologous genes, as well as on events of recombination, gene loss, inversion, and paralogous expansion, affecting both a hypervariable region named the plasticity zone, and genes essentially encoding polymorphic and transmembrane head membrane proteins, type III secretion effectors and some metabolic pathways. Procedures for molecular typing are still not consensual but have allowed the knowledge of molecular epidemiology patterns for some species as well as the identification of outbreaks and emergence of successful clones for C. trachomatis. This manuscript intends to provide a comprehensive review on the evolution, phylogeny, and molecular epidemiology of Chlamydia.

  18. The evolution of active vibrissal sensing in mammals: evidence from vibrissal musculature and function in the marsupial opossum Monodelphis domestica.

    Science.gov (United States)

    Grant, Robyn A; Haidarliu, Sebastian; Kennerley, Natalie J; Prescott, Tony J

    2013-09-15

    Facial vibrissae, or whiskers, are found in nearly all extant mammal species and are likely to have been present in early mammalian ancestors. A sub-set of modern mammals, including many rodents, move their long mystacial whiskers back and forth at high speed whilst exploring in a behaviour known as 'whisking'. It is not known whether the vibrissae of early mammals moved in this way. The grey short-tailed opossum, Monodelphis domestica, is considered a useful species from the perspective of tracing the evolution of modern mammals. Interestingly, these marsupials engage in whisking bouts similar to those seen in rodents. To better assess the likelihood that active vibrissal sensing was present in ancestral mammals, we examined the vibrissal musculature of the opossum using digital miscroscopy to see whether this resembles that of rodents. Although opossums have fewer whiskers than rats, our investigation found that they have a similar vibrissal musculature. In particular, in both rats and opossums, the musculature includes both intrinsic and extrinsic muscles with the intrinsic muscles positioned as slings linking pairs of large vibrissae within rows. We identified some differences in the extrinsic musculature which, interestingly, matched with behavioural data obtained through high-speed video recording, and indicated additional degrees of freedom for positioning the vibrissae in rats. These data show that the whisker movements of opossum and rat exploit similar underlying mechanisms. Paired with earlier results suggesting similar patterns of vibrissal movement, this strongly implies that early therian (marsupial and placental) mammals were whisking animals that actively controlled their vibrissae.

  19. Introduced mammals on Western Indian Ocean islands

    Directory of Open Access Journals (Sweden)

    James C. Russell

    2016-04-01

    Full Text Available The diversity of introduced mammals and their introduction history varies greatly across the Western Indian Ocean (WIO islands, from ancient introductions in the past millennia on islands off the East coast of Africa where extant terrestrial native mammal communities exist, to very recent invasions in the past decades on islands in the Mascarene archipelago. We compile the distribution of 16 introduced mammal taxa on 28 island groups comprising almost 2000 islands. Through an exhaustive literature review and expert consultation process we recorded all mammal eradications, and species recoveries which could be attributed to introduced mammal eradication or control. All island groups have been invaded by mammals, and invasive cats and rats in particular are ubiquitous, but cultural contingency has also led to regional invasions by other mammals such as lemurs, civets and tenrecs. Mammal eradications have been attempted on 45 islands in the WIO, the majority in the Seychelles and Mauritius, and where successful have resulted in spectacular recovery of species and ecosystems. Invasive mammalian predator eradication or control in association with habitat management has led to improved conservation prospects for at least 24 species, and IUCN red-list down-listing of eight species, in the Mascarene Islands. Future island conservation prioritisation in the region will need to take account of global climate change and predicted sea-level rises and coastal inundation. Greater investment and prioritisation in island conservation in the region is warranted, given its high biodiversity values and the extent of invasions.

  20. Evolution of the Placenta in Eutherian Mammals

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, A

    2007-01-01

    of eutherian mammals had an endotheliochorial placenta or a haemochorial one. Research has been stimulated by improved understanding of the relations between the orders of mammals provided by molecular phylogenetics. In part, the uncertainties arise from doubt about how to root the mammalian tree. Resolution...

  1. MARINE MAMMAL DISEASES: PATHOGENS AND PROCESSES

    Science.gov (United States)

    The purpose of this chapter is to provide a concise overview of the pathogens and processes that alter the health of marine mammals. Viral disease is the most common etiology of significant mortality events in marine mammals. Discussion of viral disease focuses on effects in the ...

  2. Evolution of the relaxin/insulin-like gene family in placental mammals: implications for its early evolution.

    Science.gov (United States)

    Hoffmann, Federico G; Opazo, Juan C

    2011-01-01

    The relaxin (RLN) and insulin-like (INSL) gene family is a group of genes involved in a variety of physiological roles that includes bone formation, testicular descent, trophoblast development, and cell differentiation. This family appears to have expanded in vertebrates relative to non-vertebrate chordates, but the relative contribution of whole genome duplications (WGDs) and tandem duplications to the observed diversity of genes is still an open question. Results from our comparative analyses favor a model of divergence post vertebrate WGDs in which a single-copy progenitor found in the last common ancestor of vertebrates experienced two rounds of WGDs before the functional differentiation that gave rise to the RLN and INSL genes. One of the resulting paralogs was subsequently lost, resulting in three proto-RLN/INSL genes on three separate chromosomes. Subsequent rounds of tandem gene duplication and divergence originated the set of paralogs found on a given cluster in extant vertebrates. Our study supports the hypothesis that differentiation of the RLN and INSL genes took place independently in each RLN/INSL cluster after the two WGDs during the evolutionary history of vertebrates. In addition, we show that INSL4 represents a relatively old gene that has been apparently lost independently in all Euarchontoglires other than apes and Old World monkeys, and that RLN2 derives from an ape-specific duplication.

  3. Elevated Adenosine Induces Placental DNA Hypomethylation Independent of A2B Receptor Signaling in Preeclampsia.

    Science.gov (United States)

    Huang, Aji; Wu, Hongyu; Iriyama, Takayuki; Zhang, Yujin; Sun, Kaiqi; Song, Anren; Liu, Hong; Peng, Zhangzhe; Tang, Lili; Lee, Minjung; Huang, Yun; Ni, Xin; Kellems, Rodney E; Xia, Yang

    2017-07-01

    Preeclampsia is a prevalent pregnancy hypertensive disease with both maternal and fetal morbidity and mortality. Emerging evidence indicates that global placental DNA hypomethylation is observed in patients with preeclampsia and is linked to altered gene expression and disease development. However, the molecular basis underlying placental epigenetic changes in preeclampsia remains unclear. Using 2 independent experimental models of preeclampsia, adenosine deaminase-deficient mice and a pathogenic autoantibody-induced mouse model of preeclampsia, we demonstrate that elevated placental adenosine not only induces hallmark features of preeclampsia but also causes placental DNA hypomethylation. The use of genetic approaches to express an adenosine deaminase minigene specifically in placentas, or adenosine deaminase enzyme replacement therapy, restored placental adenosine to normal levels, attenuated preeclampsia features, and abolished placental DNA hypomethylation in adenosine deaminase-deficient mice. Genetic deletion of CD73 (an ectonucleotidase that converts AMP to adenosine) prevented the elevation of placental adenosine in the autoantibody-induced preeclampsia mouse model and ameliorated preeclampsia features and placental DNA hypomethylation. Immunohistochemical studies revealed that elevated placental adenosine-mediated DNA hypomethylation predominantly occurs in spongiotrophoblasts and labyrinthine trophoblasts and that this effect is independent of A2B adenosine receptor activation in both preeclampsia models. Extending our mouse findings to humans, we used cultured human trophoblasts to demonstrate that adenosine functions intracellularly and induces DNA hypomethylation without A2B adenosine receptor activation. Altogether, both mouse and human studies reveal novel mechanisms underlying placental DNA hypomethylation and potential therapeutic approaches for preeclampsia. © 2017 American Heart Association, Inc.

  4. Molecular phylogeny of the antiangiogenic and neurotrophic serpin, pigment epithelium derived factor in vertebrates

    Science.gov (United States)

    Xu, Xuming; Zhang, Samuel Shao-Min; Barnstable, Colin J; Tombran-Tink, Joyce

    2006-01-01

    Background Pigment epithelium derived factor (PEDF), a member of the serpin family, regulates cell proliferation, promotes survival of neurons, and blocks growth of new blood vessels in mammals. Defining the molecular phylogeny of PEDF by bioinformatic analysis is one approach to understanding the link between its gene structure and its function in these biological processes. Results From a comprehensive search of available DNA databases we identified a single PEDF gene in all vertebrate species examined. These included four mammalian and six non-mammalian vertebrate species in which PEDF had not previously been described. A five gene cluster around PEDF was found in an approximate 100 kb region in mammals, birds, and amphibians. In ray-finned fish these genes are scattered over three chromosomes although only one PEDF gene was consistently found. The PEDF gene is absent in invertebrates including Drosophila melanogaster (D. melanogaster), Caenorhabditis elegans (C. elegans), and sea squirt (C. intestinalis). The PEDF gene is transcribed in all vertebrate phyla, suggesting it is biologically active throughout vertebrate evolution. The multiple actions of PEDF are likely conserved in evolution since it has the same gene structure across phyla, although the size of the gene ranges from 48.3 kb in X. tropicalis to 2.9 kb in fugu, with human PEDF at a size of 15.6 kb. A strong similarity in the proximal 200 bp of the PEDF promoter in mammals suggests the existence of a possible regulatory region across phyla. Using a non-synonymous/synonymous substitution rate ratio we show that mammalian and fish PEDFs have similar ratios of vertebrates and our studies suggest that the regulation and biological actions of this gene are preserved across vertebrates. This comprehensive analysis of the PEDF gene across phyla provides new information that will aid further characterization of common functional motifs of this serpin in biological processes. PMID:17020603

  5. Molecular phylogeny of the antiangiogenic and neurotrophic serpin, pigment epithelium derived factor in vertebrates

    Directory of Open Access Journals (Sweden)

    Barnstable Colin J

    2006-10-01

    Full Text Available Abstract Background Pigment epithelium derived factor (PEDF, a member of the serpin family, regulates cell proliferation, promotes survival of neurons, and blocks growth of new blood vessels in mammals. Defining the molecular phylogeny of PEDF by bioinformatic analysis is one approach to understanding the link between its gene structure and its function in these biological processes. Results From a comprehensive search of available DNA databases we identified a single PEDF gene in all vertebrate species examined. These included four mammalian and six non-mammalian vertebrate species in which PEDF had not previously been described. A five gene cluster around PEDF was found in an approximate 100 kb region in mammals, birds, and amphibians. In ray-finned fish these genes are scattered over three chromosomes although only one PEDF gene was consistently found. The PEDF gene is absent in invertebrates including Drosophila melanogaster (D. melanogaster, Caenorhabditis elegans (C. elegans, and sea squirt (C. intestinalis. The PEDF gene is transcribed in all vertebrate phyla, suggesting it is biologically active throughout vertebrate evolution. The multiple actions of PEDF are likely conserved in evolution since it has the same gene structure across phyla, although the size of the gene ranges from 48.3 kb in X. tropicalis to 2.9 kb in fugu, with human PEDF at a size of 15.6 kb. A strong similarity in the proximal 200 bp of the PEDF promoter in mammals suggests the existence of a possible regulatory region across phyla. Using a non-synonymous/synonymous substitution rate ratio we show that mammalian and fish PEDFs have similar ratios of Conclusion The PEDF gene first appears in vertebrates and our studies suggest that the regulation and biological actions of this gene are preserved across vertebrates. This comprehensive analysis of the PEDF gene across phyla provides new information that will aid further characterization of common functional motifs of

  6. Ultrasound assessment of placental function: the effectiveness of placental biometry in a low-risk population as a predictor of a small for gestational age neonate.

    LENUS (Irish Health Repository)

    McGinty, Patricia

    2012-07-01

    The aims of the study were to establish reference ranges for placental length and thickness in a low-risk obstetric population and to assess the likelihood of a small for gestational age (SGA) neonate on the basis of placental length at 18-24 weeks\\' gestation.

  7. The first multituberculate mammal from India.

    Science.gov (United States)

    Parmar, Varun; Prasad, Guntupalli V R; Kumar, Deepak

    2013-06-01

    Mesozoic deposits of the former Gondwanaland are depauperate in early mammals, in general, and multituberculate mammals, in particular. Until now, the oldest multituberculate mammals known from the Gondwanan continents come from the Early Cretaceous of Morocco, NW Africa. Here, we report the presence of a new multituberculate mammal, Indobaatar zofiae gen. et sp. nov., from the Lower/Middle Jurassic Kota Formation, Pranhita-Godavari valley in peninsular India. This is the first record of a multituberculate from the Mesozoic rocks of India and possibly predates the oldest known multituberculates from Gondwanan continents. The new specimen, representing an upper premolar (P(4)), compares well with the upper premolar morphology of Eobaatariinae multituberculates known from the Early Cretaceous of Mongolia, China, England, and Spain. Together with the recent findings of cimolodontan multituberculates from the Early Cretaceous of Australia and Late Cretaceous of South America, the new discovery indicates a wide temporal and spatial distribution for multituberculate mammals in the former Gondwanaland.

  8. Second-Trimester 3-Dimensional Placental Sonography as a Predictor of Small-for-Gestational-Age Birth Weight.

    Science.gov (United States)

    Quant, Hayley S; Sammel, Mary D; Parry, Samuel; Schwartz, Nadav

    2016-08-01

    We previously reported the association between first-trimester 3-dimensional (3D) placental measurements and small-for-gestational-age (SGA) neonates. In this study, we sought to determine whether second-trimester measurements further contribute to the antenatal detection of SGA and preeclampsia. We prospectively collected 3D sonographic volume sets and uterine artery pulsatility indices of singleton pregnancies at 18 to 24 weeks. Placental volume, placental quotient (placental volume/gestational age), mean placental diameter and chorionic diameter, placental morphologic index (mean placental diameter/placental quotient), placental chorionic index (mean chorionic diameter/placental quotient), and placental growth (volume per week) were assessed and evaluated as predictors of SGA and preeclampsia as a composite and alone. Of 373 pregnancies, the composite outcome occurred in 67 (18.0%): 36 (9.7%) manifested SGA alone; 27 (7.2%) developed preeclampsia alone, and 4 (1.1%) developed both. The placental volume, placental quotient, mean placental diameter, mean chorionic diameter, and volume per week were significantly smaller, whereas the placental morphologic index and chorionic index were significantly larger in pregnancies with the composite outcome (P < .01). Further analyses revealed that the significant associations with placental parameters were limited to the SGA outcome. Each placental measure remained significantly associated with SGA after adjusting for confounders. The mean uterine artery pulsatility index was not associated with either outcome. Placental parameters were moderately predictive of SGA, with adjusted areas under the curve ranging from 0.72 to 0.76. Sensitivity for detection of SGA ranged from 32.5% to 45.0%, with positive predictive values ranging from 17.3% to 22.7%. Second-trimester 3D placental measurements can identify pregnancies at risk of SGA. However, there appears to be no significant improvement compared to those obtained in the first

  9. Placental transfer of radiopharmaceuticals and dosimetry in pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Russell, J.R. [Univ. of Maryland, Baltimore, MD (United States); Stabin, M.G.; Sparks, R.B. [Oak Ridge Inst. for Science and Education, TN (United States)

    1999-01-01

    The calculation of radiation dose estimates to the fetus is often important in nuclear medicine. To obtain the best estimates of radiation dose to the fetus, the best biological and physical models should be employed. In this paper, after identification of radiopharmaceuticals often administered to women of childbearing age, the most recent data available on the placental crossover of these radiopharmaceuticals was used (with standard kinetic models describing the maternal distribution and retention and with the best available physical models) to obtain fetal dose estimates for these radiopharmaceuticals were identified as those most commonly administered to women of childbearing years. The literature yielded information on placental crossover of 15 radiopharmaceuticals, from animal or human data. Radiation dose estimates are presented in early pregnancy and at 3-, 6-, and 9-months gestation for these radiopharmaceuticals, as well as for many others used in nuclear medicine (the latter considering only maternal organ contributions to fetal dose). 46 refs., 1 fig., 5 tabs.

  10. Parvovirus infection: an immunohistochemical study using fetal and placental tissue.

    Science.gov (United States)

    Li, Jing Jing; Henwood, Tony; Van Hal, Sebastian; Charlton, Amanda

    2015-01-01

    Parvovirus B19 infection causes 5% to 15% of cases of nonimmune hydrops fetalis. The aim of our study was to evaluate the use of immunohistochemistry in diagnosing parvovirus infection in fetal and placental tissue during routine fetal and perinatal autopsies. Histology slides of 20 cases of confirmed parvovirus infection were reviewed, and immunohistochemistry was applied to selected blocks of fetal and placental tissue. Immunohistochemistry was positive in all 20 cases, and histologic viral inclusions were seen in 19 cases. Immunohistochemical staining was closely correlated with histology and was more sensitive than histology in detecting virally infected cells, especially in autolyzed tissue. All cases also had confirmatory evidence of parvovirus infection by polymerase chain reaction of fetal liver and positive maternal serology, where it was available. We conclude that parvovirus immunohistochemistry is a reliable method for diagnosing parvovirus infection, especially in autolyzed tissue where histologic assessment may be suboptimal.

  11. Placental lactogen levels as guide to outcome of threatened abortion.

    Science.gov (United States)

    Niven, P A; Landon, J; Chard, T

    1972-09-30

    The clinical value has been assessed of circulating placental lactogen levels as a pointer to the outcome in a patient with vaginal bleeding in early pregnancy. By using a semiautomated radioimmunoassay the normal range of values for the first and second trimesters has been established. In patients admitted with vaginal bleeding after the eighth week of gestation estimation of plasma human placental lactogen showed that patients with low levels were those in whom the abortion was completed during the first admission. Women whose pregnancies continued normally or who aborted after their first discharge from hospital had normal levels. In a small group sampled before the onset of bleeding but who later aborted the mean levels were lower than normal. This simple and inexpensive test can indicate those women in whom abortion is inevitable and could be used to reduce substantially the length of hospital stay in this common complication of early pregnancy.

  12. Placental extracellular vesicles and feto-maternal communication.

    Science.gov (United States)

    Tong, M; Chamley, L W

    2015-01-29

    The human placenta is an anatomically unique structure that extrudes a variety of extracellular vesicles into the maternal blood (including syncytial nuclear aggregates, microvesicles, and nanovesicles). Large quantities of extracellular vesicles are produced by the placenta in both healthy and diseased pregnancies. Since their first description more than 120 years ago, placental extracellular vesicles are only now being recognized as important carriers for proteins, lipids, and nucleic acids, which may play a crucial role in feto-maternal communication. Here, we summarize the current literature on the cargos of placental extracellular vesicles and the known effects of such vesicles on maternal cells/systems, especially those of the maternal immune and vascular systems. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  13. Radioimmunoassay of human placental protein 14 (PP14)

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, A.E.; Stoker, R.J. (North East London Polytechnic (UK)); Chapman, M.G.; Wass, D. (Queen Charlotte' s Maternity Hospital, London (UK)); Andrew, C.E. (Edgware General Hospital (UK)); Bohn, H. (Behringwerke AG, Marburg/Lahn (Germany, F.R.). Research Labs.)

    1983-12-30

    The development and validation of a radioimmunoassay for the measurement of human placental protein 14 in maternal serum is described. The mean concentration of this protein in serum from 22 normal pregnant women showed a decline during the third trimester from 120 ..mu..g/l at 27 weeks gestation to 65 ..mu..g/l at term. Serum samples from 16 patients with intra-uterine growth retardation tended to contain lower concentrations of placental protein 14, these results reaching significance at weeks 36-38 of gestation. Of seven patients with pre-eclampsia from whom two or more blood samples were taken, four showed increases in concentration of this protein as pregnancy proceeded, compared with the normal pattern of decreasing values.

  14. Persistent Phylogeny: A Galled-Tree and Integer Linear Programming Approach

    OpenAIRE

    Gusfield, Dan

    2015-01-01

    The Persistent-Phylogeny Model is an extension of the widely studied Perfect-Phylogeny Model, encompassing a broader range of evolutionary phenomena. Biological and algorithmic questions concerning persistent phylogeny have been intensely investigated in recent years. In this paper, we explore two alternative approaches to the persistent-phylogeny problem that grow out of our previous work on perfect phylogeny, and on galled trees. We develop an integer programming solution to the Persistent-...

  15. A microphysiological model of the human placental barrier.

    Science.gov (United States)

    Blundell, Cassidy; Tess, Emily R; Schanzer, Ariana S R; Coutifaris, Christos; Su, Emily J; Parry, Samuel; Huh, Dongeun

    2016-08-02

    During human pregnancy, the fetal circulation is separated from maternal blood in the placenta by two cell layers - the fetal capillary endothelium and placental trophoblast. This placental barrier plays an essential role in fetal development and health by tightly regulating the exchange of endogenous and exogenous materials between the mother and the fetus. Here we present a microengineered device that provides a novel platform to mimic the structural and functional complexity of this specialized tissue in vitro. Our model is created in a multilayered microfluidic system that enables co-culture of human trophoblast cells and human fetal endothelial cells in a physiologically relevant spatial arrangement to replicate the characteristic architecture of the human placental barrier. We have engineered this co-culture model to induce progressive fusion of trophoblast cells and to form a syncytialized epithelium that resembles the syncytiotrophoblast in vivo. Our system also allows the cultured trophoblasts to form dense microvilli under dynamic flow conditions and to reconstitute expression and physiological localization of membrane transport proteins, such as glucose transporters (GLUTs), critical to the barrier function of the placenta. To provide a proof-of-principle for using this microdevice to recapitulate native function of the placental barrier, we demonstrated physiological transport of glucose across the microengineered maternal-fetal interface. Importantly, the rate of maternal-to-fetal glucose transfer in this system closely approximated that measured in ex vivo perfused human placentas. Our "placenta-on-a-chip" platform represents an important advance in the development of new technologies to model and study the physiological complexity of the human placenta for a wide variety of applications.

  16. Is placental iodine content related to dietary iodine intake?

    LENUS (Irish Health Repository)

    Burns, R

    2011-08-01

    Delivery of iodine to the foetus depends not only on maternal dietary iodine intake but also on the presence of a functioning placental transport system. A role for the placenta as an iodine storage organ has been suggested, and this study compares the iodine content of placentas from women giving birth at term in Ireland and Iran, areas with median urinary iodine of 79 and 206 μg\\/l respectively.

  17. The taming of the neural crest: a developmental perspective on the origins of morphological covariation in domesticated mammals

    Science.gov (United States)

    Sánchez-Villagra, Marcelo R.; Geiger, Madeleine; Schneider, Richard A.

    2016-06-01

    Studies on domestication are blooming, but the developmental bases for the generation of domestication traits and breed diversity remain largely unexplored. Some phenotypic patterns of human neurocristopathies are suggestive of those reported for domesticated mammals and disrupting neural crest developmental programmes have been argued to be the source of traits deemed the `domestication syndrome'. These character changes span multiple organ systems and morphological structures. But an in-depth examination within the phylogenetic framework of mammals including domesticated forms reveals that the distribution of such traits is not universal, with canids being the only group showing a large set of predicted features. Modularity of traits tied to phylogeny characterizes domesticated mammals: through selective breeding, individual behavioural and morphological traits can be reordered, truncated, augmented or deleted. Similarly, mammalian evolution on islands has resulted in suites of phenotypic changes like those of some domesticated forms. Many domesticated mammals can serve as valuable models for conducting comparative studies on the evolutionary developmental biology of the neural crest, given that series of their embryos are readily available and that their phylogenetic histories and genomes are well characterized.

  18. Osmotic flow through the placental barrier of chronically prepared sheep.

    Science.gov (United States)

    Armentrout, T; Katz, S; Thornburg, K L; Faber, J J

    1977-10-01

    An electromagnetic flow sensor was placed on the distal aorta of sheep fetuses in utero, and catheters were placed in a femoral artery and the common umbilical vein. Catheters were also placed in a carotid artery and a uterine vein of the pregnant ewe. Three days postoperatively maternal plasma was hyperosmotic with respect to fetal plasma by all methods: +5.8 +/- 1.4 SE by vapor-pressure osmometry, +2.2 +/- 0.7 SE by freezing-point depression osmometry corrected for bicarbonate loss; and +3.26 mosmol/liter by chemical measurement of plasma constituents. Maternal or fetal plasma was made hypertonic in vivo by infusion of concentrated solutions of mannitol, sucrose, or NaCl. Transplacental water flux was calculated from placental blood flows and arteriovenous differences in water content of the blood. The apparent osmotic conductivity of the placenta was 61 ml2-mosmol-1-kg-1, but this value should be divided by an unknown reflection coefficient to yield the true osmotic conductivity. Separate measurements were made of the placental diffusional permeability of Na+ and Cl- in five chronically prepared sheep fetuses: PSNa+ =0.20 +/- 0.04, PSCl- = 0.27 +/- 0.04 ml/(min-kg fetus). There was a highly significant positive regression between (total) placental permeability and fetal weight.

  19. Good practices in collecting umbilical cord and placental blood

    Directory of Open Access Journals (Sweden)

    Lauren Auer Lopes

    Full Text Available Abstract Objective: to identify the factors related to the quality of umbilical cord and placental blood specimens, and define best practices for their collection in a government bank of umbilical cord and placental blood. Method: this was a descriptive study, quantitative approach, performed at a government umbilical cord and placental blood bank, in two steps: 1 verification of the obstetric, neonatal and operational factors, using a specific tool for gathering data as non-participant observers; 2 definition of best practices by grouping non-conformities observed before, during and after blood collection. The data was analyzed using descriptive statistics and the following statistical software: Statistica(r and R(r. Results: while there was a correlation with obstetrical and neonatal factors, there was a larger correlation with operational factors, resulting in the need to adjust the professional practices of the nursing staff and obstetrical team involved in collecting this type of blood. Based on these non-conformities we defined best practices for nurses before, during and after blood collection. Conclusion: the best practices defined in this study are an important management tool for the work of nurses in obtaining blood specimens of high cell quality.

  20. Hemodynamic aspects of normal human feto-placental (umbilical) circulation.

    Science.gov (United States)

    Acharya, Ganesh; Sonesson, Sven-Erik; Flo, Kari; Räsänen, Juha; Odibo, Anthony

    2016-06-01

    Understanding the changes in normal circulatory dynamics that occur during the course of pregnancy is essential for improving our knowledge of pathophysiological mechanisms associated with feto-placental diseases. The umbilical circulation is the lifeline of the fetus, and it is accessible for noninvasive assessment. However, not all hemodynamic parameters can be reliably measured in utero using currently available technology. Experimental animal studies have been crucial in validating major concepts related to feto-placental circulatory physiology, but caution is required in directly translating the findings of such studies into humans due to species differences. Furthermore, it is important to establish normal reference ranges and take into account gestational age associated changes while interpreting the results of clinical investigation. Therefore, it is necessary to critically evaluate, synthesize and summarize the knowledge available from the studies performed on human pregnancies to be able to appropriately apply them in clinical practice. This narrative review is an attempt to present contemporary concepts on hemodynamics of feto-placental circulation based on human studies. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  1. Coloration mechanisms and phylogeny of Morpho butterflies.

    Science.gov (United States)

    Giraldo, M A; Yoshioka, S; Liu, C; Stavenga, D G

    2016-12-15

    Morpho butterflies are universally admired for their iridescent blue coloration, which is due to nanostructured wing scales. We performed a comparative study on the coloration of 16 Morpho species, investigating the morphological, spectral and spatial scattering properties of the differently organized wing scales. In numerous previous studies, the bright blue Morpho coloration has been fully attributed to the multi-layered ridges of the cover scales' upper laminae, but we found that the lower laminae of the cover and ground scales play an important additional role, by acting as optical thin film reflectors. We conclude that Morpho coloration is a subtle combination of overlapping pigmented and/or unpigmented scales, multilayer systems, optical thin films and sometimes undulated scale surfaces. Based on the scales' architecture and their organization, five main groups can be distinguished within the genus Morpho, largely agreeing with the accepted phylogeny.

  2. Gene order phylogeny of the genus Prochlorococcus.

    Directory of Open Access Journals (Sweden)

    Haiwei Luo

    Full Text Available BACKGROUND: Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria. METHODOLOGY/PRINCIPAL FINDINGS: Orthologous gene sets and their genomic positions were identified from 12 species of Prochlorococcus and 1 outgroup species of Synechococcus. From this data, inversion and breakpoint distance-based phylogenetic trees were computed by GRAPPA and FastME. Statistical support of the resulting topology was obtained by application of a 50% jackknife resampling technique. The result was consistent and congruent with nucleotide sequence-based and gene-content based trees. Also, a previously unresolved clade was resolved, that of MIT9211 and SS120. CONCLUSIONS/SIGNIFICANCE: This is the first study to use gene order data to resolve a bacterial phylogeny at the genus level. It suggests that the technique is useful in resolving the Tree of Life.

  3. Haplotyping as perfect phylogeny: a direct approach.

    Science.gov (United States)

    Bafna, Vineet; Gusfield, Dan; Lancia, Giuseppe; Yooseph, Shibu

    2003-01-01

    A full haplotype map of the human genome will prove extremely valuable as it will be used in large-scale screens of populations to associate specific haplotypes with specific complex genetic-influenced diseases. A haplotype map project has been announced by NIH. The biological key to that project is the surprising fact that some human genomic DNA can be partitioned into long blocks where genetic recombination has been rare, leading to strikingly fewer distinct haplotypes in the population than previously expected (Helmuth, 2001; Daly et al., 2001; Stephens et al., 2001; Friss et al., 2001). In this paper we explore the algorithmic implications of the no-recombination in long blocks observation, for the problem of inferring haplotypes in populations. This assumption, together with the standard population-genetic assumption of infinite sites, motivates a model of haplotype evolution where the haplotypes in a population are assumed to evolve along a coalescent, which as a rooted tree is a perfect phylogeny. We consider the following algorithmic problem, called the perfect phylogeny haplotyping problem (PPH), which was introduced by Gusfield (2002) - given n genotypes of length m each, does there exist a set of at most 2n haplotypes such that each genotype is generated by a pair of haplotypes from this set, and such that this set can be derived on a perfect phylogeny? The approach taken by Gusfield (2002) to solve this problem reduces it to established, deep results and algorithms from matroid and graph theory. Although that reduction is quite simple and the resulting algorithm nearly optimal in speed, taken as a whole that approach is quite involved, and in particular, challenging to program. Moreover, anyone wishing to fully establish, by reading existing literature, the correctness of the entire algorithm would need to read several deep and difficult papers in graph and matroid theory. However, as stated by Gusfield (2002), many simplifications are possible and the

  4. A population-based study of race-specific risk for placental abruption

    Directory of Open Access Journals (Sweden)

    Stamilio David M

    2008-09-01

    Full Text Available Abstract Background Efforts to elucidate risk factors for placental abruption are imperative due to the severity of complications it produces for both mother and fetus, and its contribution to preterm birth. Ethnicity-based differences in risk of placental abruption and preterm birth have been reported. We tested the hypotheses that race, after adjusting for other factors, is associated with the risk of placental abruption at specific gestational ages, and that there is a greater contribution of placental abruption to the increased risk of preterm birth in Black mothers, compared to White mothers. Methods We conducted a population-based cohort study using the Missouri Department of Health's maternally-linked database of all births in Missouri (1989–1997 to assess racial effects on placental abruption and the contribution of placental abruption to preterm birth, at different gestational age categories (n = 664,303. Results Among 108,806 births to Black mothers and 555,497 births to White mothers, 1.02% (95% CI 0.96–1.08 of Black births were complicated by placental abruption, compared to 0.71% (95% CI 0.69–0.73 of White births (aOR 1.32, 95% CI 1.22–1.43. The magnitude of risk of placental abruption for Black mothers, compared to White mothers, increased with younger gestational age categories. The risk of placental abruption resulting in term and extreme preterm births ( Conclusion Black women have an increased risk of placental abruption compared to White women, even when controlling for known coexisting risk factors. This risk increase is greatest at the earliest preterm gestational ages when outcomes are the poorest. The relative contribution of placental abruption to term births was greater in Black women, whereas the relative contribution of placental abruption to preterm birth was greater in White women.

  5. The evolution of fetal membranes and placentation in carnivores and ungulates (Ferungulata)

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, Andrea

    2017-01-01

    Molecular phylogenetics has made a substantial contribution to our understanding of the relationships between mammalian orders and has generated trees that can be used to examine the evolution of anatomical and physiological traits. We here summarize findings on fetal membranes and placentation i...... proteins including placental lactogens and pregnancy-associated glycoproteins. Evolutionary innovations of the placental system may contribute to the high diversity of lifestyles within Ferungulata and be linked to the evolution of highly precocial offspring in ungulates....

  6. Phylogenetic correlates of extinction risk in mammals: species in older lineages are not at greater risk.

    Science.gov (United States)

    Verde Arregoitia, Luis Darcy; Blomberg, Simon P; Fisher, Diana O

    2013-08-22

    Phylogenetic information is becoming a recognized basis for evaluating conservation priorities, but associations between extinction risk and properties of a phylogeny such as diversification rates and phylogenetic lineage ages remain unclear. Limited taxon-specific analyses suggest that species in older lineages are at greater risk. We calculate quantitative properties of the mammalian phylogeny and model extinction risk as an ordinal index based on International Union for Conservation of Nature Red List categories. We test for associations between lineage age, clade size, evolutionary distinctiveness and extinction risk for 3308 species of terrestrial mammals. We show no significant global or regional associations, and three significant relationships within taxonomic groups. Extinction risk increases for evolutionarily distinctive primates and decreases with lineage age when lemurs are excluded. Lagomorph species (rabbits, hares and pikas) that have more close relatives are less threatened. We examine the relationship between net diversification rates and extinction risk for 173 genera and find no pattern. We conclude that despite being under-represented in the frequency distribution of lineage ages, species in older, slower evolving and distinct lineages are not more threatened or extinction-prone. Their extinction, however, would represent a disproportionate loss of unique evolutionary history.

  7. Passive electroreception in aquatic mammals.

    Science.gov (United States)

    Czech-Damal, Nicole U; Dehnhardt, Guido; Manger, Paul; Hanke, Wolf

    2013-06-01

    Passive electroreception is a sensory modality in many aquatic vertebrates, predominantly fishes. Using passive electroreception, the animal can detect and analyze electric fields in its environment. Most electric fields in the environment are of biogenic origin, often produced by prey items. These electric fields can be relatively strong and can be a highly valuable source of information for a predator, as underlined by the fact that electroreception has evolved multiple times independently. The only mammals that possess electroreception are the platypus (Ornithorhynchus anatinus) and the echidnas (Tachyglossidae) from the monotreme order, and, recently discovered, the Guiana dolphin (Sotalia guianensis) from the cetacean order. Here we review the morphology, function and origin of the electroreceptors in the two aquatic species, the platypus and the Guiana dolphin. The morphology shows certain similarities, also similar to ampullary electroreceptors in fishes, that provide cues for the search for electroreceptors in more vertebrate and invertebrate species. The function of these organs appears to be very similar. Both species search for prey animals in low-visibility conditions or while digging in the substrate, and sensory thresholds are within one order of magnitude. The electroreceptors in both species are innervated by the trigeminal nerve. The origin of the accessory structures, however, is completely different; electroreceptors in the platypus have developed from skin glands, in the Guiana dolphin, from the vibrissal system.

  8. Running and Breathing in Mammals

    Science.gov (United States)

    Bramble, Dennis M.; Carrier, David R.

    1983-01-01

    Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

  9. Phylogeny and forelimb disparity in waterbirds.

    Science.gov (United States)

    Wang, Xia; Clarke, Julia A

    2014-10-01

    Previous work has shown that the relative proportions of wing components (i.e., humerus, ulna, carpometacarpus) in birds are related to function and ecology, but these have rarely been investigated in a phylogenetic context. Waterbirds including "Pelecaniformes," Ciconiiformes, Procellariiformes, Sphenisciformes, and Gaviiformes form a highly supported clade and developed a great diversity of wing forms and foraging ecologies. In this study, forelimb disparity in the waterbird clade was assessed in a phylogenetic context. Phylogenetic signal was assessed via Pagel's lambda, Blomberg's K, and permutation tests. We find that different waterbird clades are clearly separated based on forelimb component proportions, which are significantly correlated with phylogeny but not with flight style. Most of the traditional contents of "Pelecaniformes" (e.g., pelicans, cormorants, and boobies) cluster with Ciconiiformes (herons and storks) and occupy a reduced morphospace. These taxa are closely related phylogenetically but exhibit a wide range of ecologies and flight styles. Procellariiformes (e.g., petrels, albatross, and shearwaters) occupy a wide range of morphospace, characterized primarily by variation in the relative length of carpometacarpus and ulna. Gaviiformes (loons) surprisingly occupy a wing morphospace closest to diving petrels and penguins. Whether this result may reflect wing proportions plesiomorphic for the waterbird clade or a functional signal is unclear. A Bayesian approach detecting significant rate shifts across phylogeny recovered two such shifts. At the base of the two sister clades Sphenisciformes + Procellariiformes, a shift to an increase evolutionary rate of change is inferred for the ulna and carpometacarpus. Thus, changes in wing shape begin prior to the loss of flight in the wing-propelled diving clade. Several shifts to slower rate of change are recovered within stem penguins. © 2014 The Author(s). Evolution © 2014 The Society for the Study of

  10. Homology and phylogeny and their automated inference

    Science.gov (United States)

    Fuellen, Georg

    2008-06-01

    The analysis of the ever-increasing amount of biological and biomedical data can be pushed forward by comparing the data within and among species. For example, an integrative analysis of data from the genome sequencing projects for various species traces the evolution of the genomes and identifies conserved and innovative parts. Here, I review the foundations and advantages of this “historical” approach and evaluate recent attempts at automating such analyses. Biological data is comparable if a common origin exists (homology), as is the case for members of a gene family originating via duplication of an ancestral gene. If the family has relatives in other species, we can assume that the ancestral gene was present in the ancestral species from which all the other species evolved. In particular, describing the relationships among the duplicated biological sequences found in the various species is often possible by a phylogeny, which is more informative than homology statements. Detecting and elaborating on common origins may answer how certain biological sequences developed, and predict what sequences are in a particular species and what their function is. Such knowledge transfer from sequences in one species to the homologous sequences of the other is based on the principle of ‘my closest relative looks and behaves like I do’, often referred to as ‘guilt by association’. To enable knowledge transfer on a large scale, several automated ‘phylogenomics pipelines’ have been developed in recent years, and seven of these will be described and compared. Overall, the examples in this review demonstrate that homology and phylogeny analyses, done on a large (and automated) scale, can give insights into function in biology and biomedicine.

  11. Petrosal anatomy and inner ear structures of the Late Jurassic Henkelotherium (Mammalia, Cladotheria, Dryolestoidea): insight into the early evolution of the ear region in cladotherian mammals

    Science.gov (United States)

    Ruf, Irina; Luo, Zhe-Xi; Wible, John R; Martin, Thomas

    2009-01-01

    The petrosal anatomy and inner ear structure of Jurassic cladotherian mammals represent the ancestral morphological conditions (groundplan) from which modern therian mammals (marsupials and placentals) have evolved. We present the reconstruction of the petrosal and inner ear features of the Late Jurassic dryolestoid mammal Henkelotherium guimarotae from high-resolution computed tomography and three-dimensional imaging analysis. This study of Henkelotherium revealed a combination of derived and primitive features, including: cladotherian apomorphies, such as the promontorial sulcus for the internal carotid artery and reduced lateral trough; trechnotherian characters, such as an enclosed cochlear canaliculus for the perilymphatic duct, post-promontorial tympanic sinus and caudal tympanic process; in addition to plesiomorphic mammalian features, such as the cavum supracochleare and prootic canal. The inner ear of Henkelotherium shows a division between the utricle and saccule, a cochlear canal coiled through at least 270°, a distinctive primary bony lamina for the basilar membrane, and a secondary bony lamina. The development of the primary and secondary bony laminae in the cochlear canal is suggested here to be correlated with the concurrent coiling of the bony canal and membranous duct of the inner ear cochlea, apomorphies of the more inclusive cladotherian clade that also represent the ancestral morphotype of modern therian mammals. Because these features are crucial for high-frequency hearing in extant therian mammals, their early appearance in Late Jurassic cladotherians suggests a more ancient origination for high-frequency hearing in mammalian history than previously thought. PMID:19438763

  12. The tectonic setting of the Caribbean region and the K/T turnover of the South American land-mammal fauna

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Jaureguizar, E.; Pascual, R.

    2011-07-01

    According to the fossil record, a biotic interchange of land vertebrates (e.g. booid snakes, dinosaurs and mammals) occurred between the Americas during the Late Cretaceous-Early Palaeocene. The arrival of North American immigrants (particularly marsupials and placental) during the latest Cretaceous-earliest Palaeocene had a profound influence on the composition of the South American mammal communities. During the Late Cretaceous these communities were dominated by native groups of Pangeic lineages, which represented more than 95% of the known genera, but during the Early Palaeocene 70% of South American mammals were derived from North American immigrants that had arrived during the Late Cretaceous-earliest Palaeocene, and by the Late Palaeocene all the South American mammals (with the possible exception of the xenarthrans) were descendants of these North American immigrants. In spite of the fact that no geological evidence is currently available to support the existence of a continuous land connection between the Americas during the Late Cretaceousearly Palaeocene, the fossil record is substantial enough to point to a temporary inter-American connection that permitted the beginning of a land-mammal exchange by the end of the Cretaceous. This interpretation is supported by recent geographic reconstructions of the Caribbean region. (Author)

  13. Petrosal anatomy and inner ear structures of the Late Jurassic Henkelotherium (Mammalia, Cladotheria, Dryolestoidea): insight into the early evolution of the ear region in cladotherian mammals.

    Science.gov (United States)

    Ruf, Irina; Luo, Zhe-Xi; Wible, John R; Martin, Thomas

    2009-05-01

    The petrosal anatomy and inner ear structure of Jurassic cladotherian mammals represent the ancestral morphological conditions (groundplan) from which modern therian mammals (marsupials and placentals) have evolved. We present the reconstruction of the petrosal and inner ear features of the Late Jurassic dryolestoid mammal Henkelotherium guimarotae from high-resolution computed tomography and three-dimensional imaging analysis. This study of Henkelotherium revealed a combination of derived and primitive features, including: cladotherian apomorphies, such as the promontorial sulcus for the internal carotid artery and reduced lateral trough; trechnotherian characters, such as an enclosed cochlear canaliculus for the perilymphatic duct, post-promontorial tympanic sinus and caudal tympanic process; in addition to plesiomorphic mammalian features, such as the cavum supracochleare and prootic canal. The inner ear of Henkelotherium shows a division between the utricle and saccule, a cochlear canal coiled through at least 270 degrees, a distinctive primary bony lamina for the basilar membrane, and a secondary bony lamina. The development of the primary and secondary bony laminae in the cochlear canal is suggested here to be correlated with the concurrent coiling of the bony canal and membranous duct of the inner ear cochlea, apomorphies of the more inclusive cladotherian clade that also represent the ancestral morphotype of modern therian mammals. Because these features are crucial for high-frequency hearing in extant therian mammals, their early appearance in Late Jurassic cladotherians suggests a more ancient origination for high-frequency hearing in mammalian history than previously thought.

  14. Is Placental Mitochondrial Function a Regulator that Matches Fetal and Placental Growth to Maternal Nutrient Intake in the Mouse?

    Directory of Open Access Journals (Sweden)

    Marcos R Chiaratti

    Full Text Available Effective fetal growth requires adequate maternal nutrition coupled to active transport of nutrients across the placenta, which, in turn requires ATP. Epidemiological and experimental evidence has shown that impaired maternal nutrition in utero results in an adverse postnatal phenotype for the offspring. Placental mitochondrial function might link maternal food intake to fetal growth since impaired placental ATP production, in response to poor maternal nutrition, could be a pathway linking maternal food intake to reduced fetal growth.We assessed the effects of maternal diet on placental water content, ATP levels and mitochondrial DNA (mtDNA content in mice at embryonic (E day 18 (E18. Females maintained on either low- (LPD or normal- (NPD protein diets were mated with NPD males.To investigate the possibility of an underlying mitochondrial stress response, we studied cultured human trophoblast cells (BeWos. High throughput imaging showed that amino acid starvation induces changes in mitochondrial morphology that suggest stress-induced mitochondrial hyperfusion. This is a defensive response, believed to increase mitochondrial efficiency, that could underlie the increase in ATP observed in placenta.These findings reinforce the pathophysiological links between maternal diet and conceptus mitochondria, potentially contributing to metabolic programming. The quiet embryo hypothesis proposes that pre-implantation embryo survival is best served by a relatively low level of metabolism. This may extend to post-implantation trophoblast responses to nutrition.

  15. Phylogeny and Species Diversity of Gulf of California Oysters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dataset of DNA sequence data from two mitochondrial loci (COI and 16S) used to infer the phylogeny of oysters in the genus Ostrea along the Pacific coast of North...

  16. Biting through constraints: cranial morphology, disparity and convergence across living and fossil carnivorous mammals.

    Science.gov (United States)

    Goswami, Anjali; Milne, Nick; Wroe, Stephen

    2011-06-22

    Carnivory has evolved independently several times in eutherian (including placental) and metatherian (including marsupial) mammals. We used geometric morphometrics to assess convergences associated with the evolution of carnivory across a broad suite of mammals, including the eutherian clades Carnivora and Creodonta and the metatherian clades Thylacoleonidae, Dasyuromorphia, Didelphidae and Borhyaenoidea. We further quantified cranial disparity across eutherians and metatherians to test the hypothesis that the marsupial mode of reproduction has constrained their morphological evolution. This study, to our knowledge the first to extensively sample pre-Pleistocene taxa, analysed 30 three-dimensional landmarks, focused mainly on the facial region, which were digitized on 130 specimens, including 36 fossil taxa. Data were analysed with principal components (PC) analysis, and three measures of disparity were compared between eutherians and metatherians. PC1 showed a shift from short to long faces and seemed to represent diet and ecology. PC2 was dominated by the unique features of sabre-toothed forms: dramatic expansion of the maxilla at the expense of the frontal bones. PC3, in combination with PC1, distinguished metatherians and eutherians. Metatherians, despite common comparisons with felids, were more similar to caniforms, which was unexpected for taxa such as the sabre-toothed marsupial Thylacosmilus. Contrary to previous studies, metatherian carnivores consistently exhibited disparity which exceeded that of the much more speciose eutherian carnivore radiations, refuting the hypothesis that developmental constraints have limited the morphological evolution of the marsupial cranium.

  17. Altered feto-placental vascularization, feto-placental malperfusion and fetal growth restriction in mice with Egfl7 loss of function.

    Science.gov (United States)

    Lacko, Lauretta A; Hurtado, Romulo; Hinds, Samantha; Poulos, Michael G; Butler, Jason M; Stuhlmann, Heidi

    2017-07-01

    EGFL7 is a secreted angiogenic factor produced by embryonic endothelial cells. To understand its role in placental development, we established a novel Egfl7 knockout mouse. The mutant mice have gross defects in chorioallantoic branching morphogenesis and placental vascular patterning. Microangiography and 3D imaging revealed patchy perfusion of Egfl7(-/-) placentas marked by impeded blood conductance through sites of narrowed vessels. Consistent with poor feto-placental perfusion, Egfl7 knockout resulted in reduced placental weight and fetal growth restriction. The placentas also showed abnormal fetal vessel patterning and over 50% reduction in fetal blood space. In vitro, placental endothelial cells were deficient in migration, cord formation and sprouting. Expression of genes involved in branching morphogenesis, Gcm1, Syna and Synb, and in patterning of the extracellular matrix, Mmrn1, were temporally dysregulated in the placentas. Egfl7 knockout did not affect expression of the microRNA embedded within intron 7. Collectively, these data reveal that Egfl7 is crucial for placental vascularization and embryonic growth, and may provide insight into etiological factors underlying placental pathologies associated with intrauterine growth restriction, which is a significant cause of infant morbidity and mortality. © 2017. Published by The Company of Biologists Ltd.

  18. Distance-Based Phylogeny Reconstruction: Safety and Edge Radius

    OpenAIRE

    Gascuel, Olivier; Pardi, Fabio; Truszkowski, Jakub

    2015-01-01

    International audience; A phylogeny is an evolutionary tree tracing the shared history, including common ancestors, of a set of extant species or “taxa”. Phylogenies are increasingly reconstructed on the basis of molecular data (DNA and protein sequences) using statistical techniques such as likelihood and Bayesian methods. Algorithmically, these techniques suffer from the discrete nature of tree topology space. Since the number of tree topologies increases exponentially as a function of the ...

  19. Phylogeny reconstruction based on protein phylogenetic profiles of organisms

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    With the coming of the Post Genomic Era, more and more genomes have been sequenced and it has become possible to study phylogeny reconstruction at genome level. The concept of protein phylogenetic profiles of organisms is defined in this work which is used in phylogeny reconstruction by proteome comparisons. This method is more stable than the prevailing molecular systematics methods and can be used widely. It will develop very fast with the rapid progress in genome sequencing.

  20. Membranes as a possible pacemaker of metabolism in cypriniform fish: does phylogeny matter?

    Science.gov (United States)

    Gonzalez, Alex; Pagé, Benoît; Weber, Jean-Michel

    2015-08-01

    The 'membrane pacemaker theory of metabolism' proposes that membranes set metabolic rate by modulating protein activity, and thus purports to explain membrane fatty acid allometry. This relationship has never been tested across species in ectotherms. After accounting for phylogeny, recent analyses have failed to support this theory based on correlations between muscle membrane composition and body mass across mammals. Therefore, the goal of this study was to seek phylogenetically corrected correlations between membrane composition, body mass and calcium-ATPase activity, using 12 species of closely related cypriniform fish (4-5500 g) covering a much narrower genetic scale than in previous tests. The results show that fish membrane unsaturation decreases with mass, but through different mechanisms from those in endotherms: 16:0 replacing 22:6 in muscle and 18:0 replacing 16:1, 18:1 and 18:2 in liver. This shows that allometric patterns differ between endotherms and ectotherms as well as between tissues. After accounting for phylogeny, however, almost all these relationships lose significance except for overall unsaturation. No relationship between calcium-ATPase activity and mass or phospholipid composition was detected. This study shows that membrane unsaturation of cypriniforms decreases with mass, but that genetic cues unrelated to size account for differences in the relative abundance of individual fatty acids. The membrane pacemaker concept accurately predicts general membrane properties such as unsaturation, but fails to explain finer scale allometric patterns. Future examinations of the membrane pacemaker hypothesis will have to take into account that allometric patterns vary between endotherms and ectotherms and between tissues of the same animal class. © 2015. Published by The Company of Biologists Ltd.