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991.
992.
C. Sismani J. Donoghue A Alexandrou M. Karkaletsi S. Christopoulou A.E. Konstantinidou P. Livanos P.C. Patsalis V. Velissariou 《Gene》2013
Duplications of the X chromosome are rare cytogenetic findings, and have been associated with an abnormal phenotype in the male offspring of apparently normal or near normal female carriers. We report on the prenatal diagnosis of a duplication on the long arm of chromosome X from chromosomal band Xq13.2 to q21.31 in a male fetus with increased nuchal translucency in the first trimester and polyhydramnios at 22 weeks of gestation. Amniocentesis was undertaken and cytogenetic analysis revealed additional chromosomal material in the long arm of chromosome X at position Xq13. Analysis with high resolution array CGH revealed the additional material is in fact a duplication of the region Xq13.2–q21.13. The duplication is 14.8 Mb in size and includes fourteen genes: SLC16A2, KIAA2022, ABCB7, ZDHHC15, ATRX, MAGT1, ATP7A, PGK1, TBX22, BRWD3, POU3F4, ZNF711, POF1B and CHM. Analysis of the parents revealed the mother to be a carrier of the same duplication. After elected termination of the pregnancy at 28 weeks a detailed autopsy of the fetus allowed for genotype–phenotype correlations. 相似文献
993.
Raquel Rodríguez-López José M. Carbonell Pérez Aránzazu Margallo Balsera Guillermo Gervasini Rodríguez Trinidad Herrera Moreno Mayte García de Cáceres Marta González-Carpio Serrano Felipe Casanueva Freijo Juan Ramón González Ruiz Francisco Barros Angueira Pilar Méndez Pérez Manuela Núñez Estévez Enrique Galán Gómez 《Gene》2013
994.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2621-2625
The venomous sea anemone Phyllodiscus semoni causes cases of severe stinging. We isolated Phyllodiscus semoni toxin 20A (PsTX-20A), a hemolytic and lethal polypeptide (20 kDa), from the nematocyst venom of this species for the first time. Furthermore, we sequenced the cDNA encoding PsTX-20A. The deduced amino acid sequence of PsTX-20A showed that this toxin was a new member of the actinoporin family, which consists of several cytolytic polypeptides originating from sea anemones. PsTX-20A showed lethal toxicity to the shrimp Palaemon paucidens when administered via intraperitoneal injection (LD50, 50 μg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED50, 80 ng/ml). 相似文献
995.
Sara Teixeira Karine Olu Carole Decker Regina L. Cunha Sandra Fuchs Stéphane Hourdez Ester A. Serrão Sophie Arnaud‐Haond 《Molecular ecology》2013,22(18):4663-4680
Chemosynthetic ecosystems are distributed worldwide in fragmented habitats harbouring seemingly highly specialized communities. Yet, shared taxa have been reported from highly distant chemosynthetic communities. These habitats are distributed in distinct biogeographical regions, one of these being the so‐called Atlantic Equatorial Belt (AEB). Here, we combined genetic data (COI) from several taxa to assess the possible existence of cryptic or synonymous species and to detect the possible occurrence of contemporary gene flow among populations of chemosynthetic species located on both sides of the Atlantic. Several Evolutionary Significant Units (ESUs) of Alvinocarididae shrimp and Vesicomyidae bivalves were found to be shared across seeps of the AEB. Some were also common to hydrothermal vent communities of the Mid‐Atlantic Ridge (MAR), encompassing taxa morphologically described as distinct species or even genera. The hypothesis of current or very recent large‐scale gene flow among seeps and vents was supported by microsatellite analysis of the shrimp species Alvinocaris muricola/Alvinocaris markensis across the AEB and MAR. Two nonmutually exclusive hypotheses may explain these findings. The dispersion of larvae or adults following strong deep‐sea currents, possibly combined with biochemical cues influencing the duration of larval development and timing of metamorphosis, may result in large‐scale effective migration among distant spots scattered on the oceanic seafloor. Alternatively, these results may arise from the prevailing lack of knowledge on the ocean seabed, apart from emblematic ecosystems (chemosynthetic ecosystems, coral reefs or seamounts), where the widespread classification of endemism associated with many chemosynthetic taxa might hide wider distributions in overlooked parts of the deep sea. 相似文献
996.
Understanding connectivity of coral populations among and within reefs over ecologically significant timescales is essential for developing evidence‐based management strategies, including the design of marineprotected areas. Here, we present the first assessment of contemporary connectivity among populations of two Molecular Operational Taxonomic Units (MOTUs) of the brooding coral Pocillopora damicornis. We used individual‐based genetic assignment methods to identify the proportions of philopatric and migrant larval recruits, settling over 12 months at sites around Lizard Island (northern Great Barrier Reef [GBR]) and over 24 months at sites around the Palms Islands (central GBR). Overall, we found spatially and temporally variable rates of self‐recruitment and dispersal, demonstrating the importance of variation in local physical characteristics in driving dispersal processes. Recruitment patterns and inferred dispersal distances differed between the two P. damicornis MOTUs, with type α recruits exhibiting predominantly philopatric recruitment, while the majority of type β recruits were either migrants from identified putative source populations or assumed migrants based on genetic exclusion from all known populations. While P. damicornis invests much energy into brooding clonal larvae, we found that only 15% and 7% of type α and type β recruits, respectively, were clones of sampled adult colonies or other recruits, challenging the hypothesis that reproduction is predominantly asexual in this species on the GBR. We explain high rates of self‐recruitment and low rates of clonality in these MOTUs by suggesting that locally retained larvae originate predominantly from spawned gametes, while brooded larvae are mainly vagabonds. 相似文献
997.
Understanding levels of connectivity among scleractinian coral populations over a range of temporal and spatial scales is vital for managing tropical coral reef ecosystems. Here, we use multilocus microsatellite genotypes to assess the spatial genetic structure of two molecular operational taxonomic units (MOTUs, types α and β) of the widespread coral Pocillopora damicornis on the Great Barrier Reef (GBR) and infer the extent of connectivity on spatial scales spanning from local habitat types to latitudinal sectors of the GBR. We found high genetic similarities over large spatial scales spanning > 1000 km from the northern to the southern GBR, but also strong genetic differentiation at local scales in both MOTUs. The presence of a considerable number of first‐generation migrants within the populations sampled (12% and 27% for types α and β, respectively) suggests that genetic differentiation over small spatial scales is probably a consequence of stochastic recruitment from different genetic pools into recently opened up spaces on the reef, for example, following major disturbance events. We explain high genetic similarity among populations over hundreds of kilometres by long competency periods of brooded zooxanthellate larvae and multiple larval release events each year, combined with strong longshore currents typical along the GBR. The lack of genetic evidence for predominantly clonal reproduction in adult populations of P. damicornis, which broods predominantly asexually produced larvae, further undermines the paradigm that brooded larvae settle close to parent colonies shortly after the release. 相似文献
998.
Sandeep Sharma Trishna Dutta Jesús E. Maldonado Thomas C. Wood Hemendra Singh Panwar John Seidensticker 《Proceedings. Biological sciences / The Royal Society》2013,280(1767)
Understanding the patterns of gene flow of an endangered species metapopulation occupying a fragmented habitat is crucial for landscape-level conservation planning and devising effective conservation strategies. Tigers (Panthera tigris) are globally endangered and their populations are highly fragmented and exist in a few isolated metapopulations across their range. We used multi-locus genotypic data from 273 individual tigers (Panthera tigris tigris) from four tiger populations of the Satpura–Maikal landscape of central India to determine whether the corridors in this landscape are functional. This 45 000 km2 landscape contains 17% of India''s tiger population and 12% of its tiger habitat. We applied Bayesian and coalescent-based analyses to estimate contemporary and historical gene flow among these populations and to infer their evolutionary history. We found that the tiger metapopulation in central India has high rates of historical and contemporary gene flow. The tests for population history reveal that tigers populated central India about 10 000 years ago. Their population subdivision began about 1000 years ago and accelerated about 200 years ago owing to habitat fragmentation, leading to four spatially separated populations. These four populations have been in migration–drift equilibrium maintained by high gene flow. We found the highest rates of contemporary gene flow in populations that are connected by forest corridors. This information is highly relevant to conservation practitioners and policy makers, because deforestation, road widening and mining are imminent threats to these corridors. 相似文献
999.
Jeffrey M. Leis Jennifer E. Caselle Ian R. Bradbury Trond Kristiansen Joel K. Llopiz Michael J. Miller Mary I. O'Connor Claire B. Paris Alan L. Shanks Susan M. Sogard Stephen E. Swearer Eric A. Treml Russell D. Vetter Robert R. Warner 《Proceedings. Biological sciences / The Royal Society》2013,280(1759)
Several factors lead to expectations that the scale of larval dispersal and population connectivity of marine animals differs with latitude. We examine this expectation for demersal shorefishes, including relevant mechanisms, assumptions and evidence. We explore latitudinal differences in (i) biological (e.g. species composition, spawning mode, pelagic larval duration, PLD), (ii) physical (e.g. water movement, habitat fragmentation), and (iii) biophysical factors (primarily temperature, which could strongly affect development, swimming ability or feeding). Latitudinal differences exist in taxonomic composition, habitat fragmentation, temperature and larval swimming, and each difference could influence larval dispersal. Nevertheless, clear evidence for latitudinal differences in larval dispersal at the level of broad faunas is lacking. For example, PLD is strongly influenced by taxon, habitat and geographical region, but no independent latitudinal trend is present in published PLD values. Any trends in larval dispersal may be obscured by a lack of appropriate information, or use of ‘off the shelf’ information that is biased with regard to the species assemblages in areas of concern. Biases may also be introduced from latitudinal differences in taxa or spawning modes as well as limited latitudinal sampling. We suggest research to make progress on the question of latitudinal trends in larval dispersal. 相似文献
1000.