The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Cassandra G. Extavour - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Capacity evolves in response to ecology through common changes in cell number in hawaiian drosophila
Current Biology, 2019Co-Authors: Didem P. Sarikaya, Samuel H. Church, Laura P. Lagomarsino, Steven L. Montgomery, Karl N. Magnacca, Donald K. Price, Kenenth Y. Kaneshiro, Cassandra G. ExtavourAbstract:Summary Lifetime Reproductive Capacity is a critical fitness component. In insects, female Reproductive Capacity is largely determined by the number of ovarioles, the egg-producing subunits of the ovary [e.g., 1 ]. Recent work has provided insights into ovariole number regulation in Drosophila melanogaster. However, whether mechanisms discovered under laboratory conditions explain evolutionary variation in natural populations is an outstanding question. We investigated potential effects of ecology on the developmental processes underlying ovariole number evolution among Hawaiian Drosophila, a large adaptive radiation wherein the highest and lowest ovariole numbers of the family have evolved within 25 million years. Previous studies proposed that ovariole number correlated with oviposition substrate [ 2 , 3 , 4 ] but sampled largely one clade of these flies and were limited by a provisional phylogeny and the available comparative methods. We test this hypothesis by applying phylogenetic modeling to an expanded sampling of ovariole numbers and substrate types and show support for these predictions across all major groups of Hawaiian Drosophila, wherein ovariole number variation is best explained by adaptation to specific substrates. Furthermore, we show that oviposition substrate evolution is linked to changes in the allometric relationship between body size and ovariole number. Finally, we provide evidence that the major changes in ovarian cell number that regulate D. melanogaster ovariole number also regulate ovariole number in Hawaiian drosophilids. Thus, we provide evidence that this remarkable adaptive radiation is linked to evolutionary changes in a key Reproductive trait regulated at least partly by variation in the same developmental parameters that operate in the model species D. melanogaster.
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Reproductive Capacity evolves in response to ecology through common developmental mechanisms in Hawaiian Drosophila
2018Co-Authors: Didem P. Sarikaya, Samuel H. Church, Laura P. Lagomarsino, Steven L. Montgomery, Karl N. Magnacca, Donald K. Price, Kenenth Y. Kaneshiro, Cassandra G. ExtavourAbstract:Lifetime Reproductive Capacity, or the total number of offspring that an individual can give rise to in its lifetime, is a fitness component critical to the evolutionary process. In insects, female Reproductive Capacity is primarily determined by the number of ovarioles, the egg-producing subunits of the ovary. Recent work has provided insights into the genetic and environmental control of ovariole number in Drosophila melanogaster. However, whether regulatory mechanisms discovered under laboratory conditions can explain its evolutionary variation in natural populations is an outstanding question in evolutionary biology. Here we report, for the first time, insights into the mechanisms regulating ovariole number and its evolution among Hawaiian Drosophila, a large adaptive radiation of fruit flies that have evolved the highest and lowest ovariole numbers of the genus within 25 million years. Using comparative phylogenetic methods, we show that ovariole number variation among species with different food sources is best explained by adaptation to specific ecological niches. Further, we show that evolution of reliance on specific rare and ephemeral egg-laying substrates disrupts the allometric relationship between body size and ovariole number that is observed in flies that use widespread and abundant substrates. Finally, we provide evidence that the developmental mechanism principally responsible for controlling ovariole number in D. melanogaster also regulates ovariole number in natural populations of Hawaiian drosophilids. This work explains the evolution of ovariole number variation at the levels of ecology, organismal growth, and cell behavior during development, thus connecting the ultimate and proximate mechanisms of evolutionary change in Reproductive Capacity.
Shannon Atkinson - One of the best experts on this subject based on the ideXlab platform.
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Pacific walrus (Odobenus rosmarus divergens) Reproductive Capacity changes in three time frames during 1975–2010
Polar Biology, 2020Co-Authors: Jenell T. Larsen Tempel, Shannon AtkinsonAbstract:Reductions in sea ice and increases in air and seawater temperatures have been documented in the Arctic, making female Pacific walruses (Odobenus rosmarus divergens) vulnerable to changes in foraging, energy budgets, and Reproductive fitness. The aim of the present study was to assess how walrus Reproductive Capacity has changed over a span of 35 years analyzing ovaries from three distinct time frames: 1975, 1994 to 1999 and 2008 to 2010. Ovarian weights and volumes, corpora lutea diameter, total number of corpora lutea and albicantia, and the percent of females ovulating in their current cycle were used to evaluate Reproductive Capacity. Ovaries were collected from walruses hunted by Alaska Native communities for subsistence purposes. There were no differences in ovarian weights or percent of quiescent females between 1975 and 2008 to 2010. Ovaries from 1994 to 1999 were significantly heavier, exhibited more corpora, and all females from this time frame were ovulating at the time of harvest. Reproductive Capacity was limited during 1975, due to known density-dependent stressors; Reproductive Capacity increased during 1994–1999, as harvests increased and more resources became available, and in 2008–2010, females were as Reproductively limited as those of 1975. The cause for this reduction in Reproductive Capacity is unknown, but maybe a result of multiple factors, including an increase in population size coincident with a decrease in carrying Capacity, and cumulative stressors relating to sea ice loss, contaminants, and anthropogenic impacts.
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pacific walrus odobenus rosmarus divergens Reproductive Capacity changes in three time frames during 1975 2010
Polar Biology, 2020Co-Authors: Jenell Larsen T Tempel, Shannon AtkinsonAbstract:Reductions in sea ice and increases in air and seawater temperatures have been documented in the Arctic, making female Pacific walruses (Odobenus rosmarus divergens) vulnerable to changes in foraging, energy budgets, and Reproductive fitness. The aim of the present study was to assess how walrus Reproductive Capacity has changed over a span of 35 years analyzing ovaries from three distinct time frames: 1975, 1994 to 1999 and 2008 to 2010. Ovarian weights and volumes, corpora lutea diameter, total number of corpora lutea and albicantia, and the percent of females ovulating in their current cycle were used to evaluate Reproductive Capacity. Ovaries were collected from walruses hunted by Alaska Native communities for subsistence purposes. There were no differences in ovarian weights or percent of quiescent females between 1975 and 2008 to 2010. Ovaries from 1994 to 1999 were significantly heavier, exhibited more corpora, and all females from this time frame were ovulating at the time of harvest. Reproductive Capacity was limited during 1975, due to known density-dependent stressors; Reproductive Capacity increased during 1994–1999, as harvests increased and more resources became available, and in 2008–2010, females were as Reproductively limited as those of 1975. The cause for this reduction in Reproductive Capacity is unknown, but maybe a result of multiple factors, including an increase in population size coincident with a decrease in carrying Capacity, and cumulative stressors relating to sea ice loss, contaminants, and anthropogenic impacts.
Didem P. Sarikaya - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Capacity evolves in response to ecology through common changes in cell number in hawaiian drosophila
Current Biology, 2019Co-Authors: Didem P. Sarikaya, Samuel H. Church, Laura P. Lagomarsino, Steven L. Montgomery, Karl N. Magnacca, Donald K. Price, Kenenth Y. Kaneshiro, Cassandra G. ExtavourAbstract:Summary Lifetime Reproductive Capacity is a critical fitness component. In insects, female Reproductive Capacity is largely determined by the number of ovarioles, the egg-producing subunits of the ovary [e.g., 1 ]. Recent work has provided insights into ovariole number regulation in Drosophila melanogaster. However, whether mechanisms discovered under laboratory conditions explain evolutionary variation in natural populations is an outstanding question. We investigated potential effects of ecology on the developmental processes underlying ovariole number evolution among Hawaiian Drosophila, a large adaptive radiation wherein the highest and lowest ovariole numbers of the family have evolved within 25 million years. Previous studies proposed that ovariole number correlated with oviposition substrate [ 2 , 3 , 4 ] but sampled largely one clade of these flies and were limited by a provisional phylogeny and the available comparative methods. We test this hypothesis by applying phylogenetic modeling to an expanded sampling of ovariole numbers and substrate types and show support for these predictions across all major groups of Hawaiian Drosophila, wherein ovariole number variation is best explained by adaptation to specific substrates. Furthermore, we show that oviposition substrate evolution is linked to changes in the allometric relationship between body size and ovariole number. Finally, we provide evidence that the major changes in ovarian cell number that regulate D. melanogaster ovariole number also regulate ovariole number in Hawaiian drosophilids. Thus, we provide evidence that this remarkable adaptive radiation is linked to evolutionary changes in a key Reproductive trait regulated at least partly by variation in the same developmental parameters that operate in the model species D. melanogaster.
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Reproductive Capacity evolves in response to ecology through common developmental mechanisms in Hawaiian Drosophila
2018Co-Authors: Didem P. Sarikaya, Samuel H. Church, Laura P. Lagomarsino, Steven L. Montgomery, Karl N. Magnacca, Donald K. Price, Kenenth Y. Kaneshiro, Cassandra G. ExtavourAbstract:Lifetime Reproductive Capacity, or the total number of offspring that an individual can give rise to in its lifetime, is a fitness component critical to the evolutionary process. In insects, female Reproductive Capacity is primarily determined by the number of ovarioles, the egg-producing subunits of the ovary. Recent work has provided insights into the genetic and environmental control of ovariole number in Drosophila melanogaster. However, whether regulatory mechanisms discovered under laboratory conditions can explain its evolutionary variation in natural populations is an outstanding question in evolutionary biology. Here we report, for the first time, insights into the mechanisms regulating ovariole number and its evolution among Hawaiian Drosophila, a large adaptive radiation of fruit flies that have evolved the highest and lowest ovariole numbers of the genus within 25 million years. Using comparative phylogenetic methods, we show that ovariole number variation among species with different food sources is best explained by adaptation to specific ecological niches. Further, we show that evolution of reliance on specific rare and ephemeral egg-laying substrates disrupts the allometric relationship between body size and ovariole number that is observed in flies that use widespread and abundant substrates. Finally, we provide evidence that the developmental mechanism principally responsible for controlling ovariole number in D. melanogaster also regulates ovariole number in natural populations of Hawaiian drosophilids. This work explains the evolution of ovariole number variation at the levels of ecology, organismal growth, and cell behavior during development, thus connecting the ultimate and proximate mechanisms of evolutionary change in Reproductive Capacity.
Dayong Wang - One of the best experts on this subject based on the ideXlab platform.
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amino modification enhances Reproductive toxicity of nanopolystyrene on gonad development and Reproductive Capacity in nematode caenorhabditis elegans
Environmental Pollution, 2019Co-Authors: Yuexiu Qiu, Ya Kong, Dayong WangAbstract:Although amino modified nanopolystyrene could cause toxicity on environmental organisms, the effect of amino modification on nanopolystyrene toxicity is still largely unclear. We here employed Caenorhabditis elegans as an animal model to compare the effects between pristine and amino modified nanopolystyrene particles in inducing Reproductive toxicity. Nanopolystyrene (35 nm) could cause the damage on gonad development as indicated by the endpoints of number of total germline cells, length of gonad arm, and relative area of gonad arm. Nanopolystyrene exposure also reduced the Reproductive Capacity as reflected by the endpoints of brood size and number of fertilized eggs in uterus. Moreover, amino modification enhanced nanopolystyrene toxicity on both the gonad development and the Reproductive Capacity. Additionally, induction of germline apoptosis and formation of germline DNA damage contributed to the enhancement of nanopolystyrene toxicity in reducing Reproductive Capacity by amino modification. Our results highlight the potential environmental risk of amino modified nanopolystyrene in inducing Reproductive toxicity on gonad development and Reproductive Capacity of environmental organisms.
Sylvia Kaiser - One of the best experts on this subject based on the ideXlab platform.
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Early social instability affects plasma testosterone during adolescence but does not alter Reproductive Capacity or measures of stress later in life.
Physiology & behavior, 2013Co-Authors: Katja Siegeler, Joachim Wistuba, Oliver S. Damm, Nikolaus Von Engelhardt, Norbert Sachser, Sylvia KaiserAbstract:The social environment plays an important role in modulating processes of the hormonal and behavioural profile of an animal in a variety of group-living species. In wild cavies for instance, unstable social environmental conditions during pregnancy and lactation lead to an infantilised biobehavioural profile of the male offspring. In the present study, the influence of the social environment during pregnancy and lactation on the male wild cavy offsprings' plasma testosterone development, Reproductive Capacity and stress system activity was investigated. To this purpose, 12 sons whose mothers had lived in an unstable social environment during pregnancy and lactation were compared with 12 sons whose mothers had lived in a stable social environment during the same time. Plasma testosterone (T) and plasma cortisol (C) concentrations were determined from days 20 to 107 of age. Adrenal tyrosine hydroxylase (TH) activity and different parameters of Reproductive Capacity (weights of testes, epididymides and accessory sex glands, cellular composition of the testes, DNA fragmentation indices and sperm motility parameters) were analysed at day 107 of age. TH activity and plasma C were unaffected by different social environmental conditions early in life. The developmental time course of T concentrations, however, was significantly different: Sons whose mothers had lived in an unstable social environment during pregnancy and lactation showed a delayed increase in T concentrations around adolescence compared to controls. In contrast, no reproduction-related parameters measured within this study differed significantly between the two groups. Thus, early social instability affects plasma testosterone development during adolescence in a significant way but does not alter Reproductive Capacity or measures of stress later in life.