The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Dustin J Marshall - One of the best experts on this subject based on the ideXlab platform.
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offspring size plasticity in response to intraspecific competition an adaptive Maternal Effect across life history stages
The American Naturalist, 2008Co-Authors: Richard M Allen, Yvonne M Buckley, Dustin J MarshallAbstract:When provisioning offspring, mothers balance the benefits of producing a few large, fitter offspring with the costs of decreased fecundity. The optimal balance between offspring size and fecundity depends on the environment. Theory predicts that larger offspring have advantages in adverse conditions, but in favorable conditions size is less important. Thus, if environmental quality varies, selection should favor mothers that adaptively allocate resources in response to local conditions to maximize Maternal fitness. In the bryozoan Bugula neritina, we show that the intensity of intraspecific competition dramatically changes the offspring size/performance relationship in the field. In benign or extremely competitive environments, offspring size is less important, but at intermediate levels of competition, colonies from larger larvae have higher performance than colonies from smaller larvae. We predicted mothers should produce larger offspring when intermediate competition is likely and tested these expectations in the field by manipulating the density of brood colonies. Our findings matched expectations: mothers produced larger larvae at high densities and smaller larvae at low densities. In addition, mothers from high-density environments produced larvae that have higher dispersal potential, which may enable offspring to escape crowded environments. It appears mothers can adaptively adjust offspring size to maximize Maternal fitness, altering the offspring phenotype across multiple life-history stages.
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offspring size plasticity in response to intraspecific competition an adaptive Maternal Effect across life history stages
The American Naturalist, 2008Co-Authors: Richard M Allen, Yvonne M Buckley, Dustin J MarshallAbstract:Abstract: When provisioning offspring, mothers balance the benefits of producing a few large, fitter offspring with the costs of decreased fecundity. The optimal balance between offspring size and fecundity depends on the environment. Theory predicts that larger offspring have advantages in adverse conditions, but in favorable conditions size is less important. Thus, if environmental quality varies, selection should favor mothers that adaptively allocate resources in response to local conditions to maximize Maternal fitness. In the bryozoan Bugula neritina, we show that the intensity of intraspecific competition dramatically changes the offspring size/performance relationship in the field. In benign or extremely competitive environments, offspring size is less important, but at intermediate levels of competition, colonies from larger larvae have higher performance than colonies from smaller larvae. We predicted mothers should produce larger offspring when intermediate competition is likely and tested thes...
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when is a Maternal Effect adaptive
Oikos, 2007Co-Authors: Dustin J Marshall, Tobias UllerAbstract:Maternal Effects have become an important field of study in evolutionary ecology and there is an ongoing debate regarding their adaptive significance. Some Maternal Effects can act to increase offspring fitness and are called 'adaptive Maternal Effects'. However, other Maternal Effects decrease offspring fitness and there is confusion regarding whether certain Maternal Effects are indeed adaptive or merely physiological inevitabilities. Here we suggest that the focus on the consequences of Maternal Effects for offspring fitness only and the use of 'snapshot' estimates of fitness have misdirected our effort to understand the evolution of Maternal Effects. We suggest that selection typically acts on Maternal Effects to maximise Maternal rather than (or in addition to) offspring fitness. We highlight the importance of considering how Maternal Effects influence Maternal fitness across a mother's lifetime and describe four broad types of Maternal Effects using an outcome-based approach. Overall, we suggest that many Maternal Effects will have an adaptive basis for mothers, regardless of whether these Effects increase or decrease survival or reproductive success of individual offspring.
Lisa J Funkhouserjones - One of the best experts on this subject based on the ideXlab platform.
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the Maternal Effect gene wds controls wolbachia titer in nasonia
Current Biology, 2018Co-Authors: Lisa J Funkhouserjones, Edward J Van Opstal, Ananya Sharma, Seth R BordensteinAbstract:Summary Maternal transmission of intracellular microbes is pivotal in establishing long-term, intimate symbioses. For germline microbes that exert negative reproductive Effects on their hosts, selection can theoretically favor the spread of host genes that counteract the microbe's harmful Effects. Here, we leverage a major difference in bacterial (Wolbachia pipientis) titers between closely related wasp species with forward genetic, transcriptomic, and cytological approaches to map two quantitative trait loci that suppress bacterial titers via a Maternal Effect. Fine mapping and knockdown experiments identify the gene Wolbachia density suppressor (Wds), which dominantly suppresses bacterial transmission from mother to embryo. Wds evolved by lineage-specific non-synonymous changes driven by positive selection. Collectively, our findings demonstrate that a genetically simple change arose by positive Darwinian selection in less than a million years to regulate Maternally transmitted bacteria via a dominant, Maternal Effect gene.
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the Maternal Effect gene wds controls wolbachia titer in nasonia
bioRxiv, 2018Co-Authors: Lisa J Funkhouserjones, Edward J Van Opstal, Ananya Sharma, Seth R BordensteinAbstract:Maternal transmission of intracellular microbes is pivotal in establishing long-term, intimate symbioses. For germline microbes that exert negative reproductive Effects on their hosts, selection can theoretically favor the spread of host genes that counteract the microbe9s harmful Effects. Here, we leverage a major difference in bacterial (Wolbachia pipientis) titers between closely-related wasp species with forward genetic, transcriptomic, and cytological approaches to map two quantitative trait loci that suppress bacterial titers via a Maternal Effect. Fine mapping and knockdown experiments identify the gene Wolbachia density suppressor (Wds), which dominantly suppresses bacterial transmission from mother to embryo. Wds evolved by lineage-specific non-synonymous changes driven by positive selection. Collectively, our findings demonstrate that a genetically simple change arose by Darwinian selection in less than a million years to regulate Maternally transmitted bacteria via a dominant, Maternal Effect gene.
Seth R Bordenstein - One of the best experts on this subject based on the ideXlab platform.
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the Maternal Effect gene wds controls wolbachia titer in nasonia
Current Biology, 2018Co-Authors: Lisa J Funkhouserjones, Edward J Van Opstal, Ananya Sharma, Seth R BordensteinAbstract:Summary Maternal transmission of intracellular microbes is pivotal in establishing long-term, intimate symbioses. For germline microbes that exert negative reproductive Effects on their hosts, selection can theoretically favor the spread of host genes that counteract the microbe's harmful Effects. Here, we leverage a major difference in bacterial (Wolbachia pipientis) titers between closely related wasp species with forward genetic, transcriptomic, and cytological approaches to map two quantitative trait loci that suppress bacterial titers via a Maternal Effect. Fine mapping and knockdown experiments identify the gene Wolbachia density suppressor (Wds), which dominantly suppresses bacterial transmission from mother to embryo. Wds evolved by lineage-specific non-synonymous changes driven by positive selection. Collectively, our findings demonstrate that a genetically simple change arose by positive Darwinian selection in less than a million years to regulate Maternally transmitted bacteria via a dominant, Maternal Effect gene.
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the Maternal Effect gene wds controls wolbachia titer in nasonia
bioRxiv, 2018Co-Authors: Lisa J Funkhouserjones, Edward J Van Opstal, Ananya Sharma, Seth R BordensteinAbstract:Maternal transmission of intracellular microbes is pivotal in establishing long-term, intimate symbioses. For germline microbes that exert negative reproductive Effects on their hosts, selection can theoretically favor the spread of host genes that counteract the microbe9s harmful Effects. Here, we leverage a major difference in bacterial (Wolbachia pipientis) titers between closely-related wasp species with forward genetic, transcriptomic, and cytological approaches to map two quantitative trait loci that suppress bacterial titers via a Maternal Effect. Fine mapping and knockdown experiments identify the gene Wolbachia density suppressor (Wds), which dominantly suppresses bacterial transmission from mother to embryo. Wds evolved by lineage-specific non-synonymous changes driven by positive selection. Collectively, our findings demonstrate that a genetically simple change arose by Darwinian selection in less than a million years to regulate Maternally transmitted bacteria via a dominant, Maternal Effect gene.
Bruce A Hay - One of the best experts on this subject based on the ideXlab platform.
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a synthetic gene drive system for local reversible modification and suppression of insect populations
Current Biology, 2013Co-Authors: Omar S Akbari, John M Marshall, Kelly Matzen, Haixia Huang, Catherine M Ward, Bruce A HayAbstract:Replacement of wild insect populations with genetically modified individuals unable to transmit disease provides a self-perpetuating method of disease prevention but requires a gene drive mechanism to spread these traits to high frequency. Drive mechanisms requiring that transgenes exceed a threshold frequency in order to spread are attractive because they bring about local but not global replacement, and transgenes can be eliminated through dilution of the population with wild-type individuals and 6]. These features are likely to be important in many social and regulatory contexts. Here we describe the first creation of a synthetic threshold-dependent gene drive system, designated Maternal-Effect lethal underdominance (UD^(MEL)), in which two Maternally expressed toxins, located on separate chromosomes, are each linked with a zygotic antidote able to rescue Maternal-Effect lethality of the other toxin. We demonstrate threshold-dependent replacement in single- and two-locus configurations in Drosophila. Models suggest that transgene spread can often be limited to local environments. They also show that in a population in which single-locus UDMEL has been carried out, repeated release of wild-type males can result in population suppression, a novel method of genetic population manipulation.
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a synthetic Maternal Effect selfish genetic element drives population replacement in drosophila
Science, 2007Co-Authors: Chunhong Chen, Haixia Huang, Catherine M Ward, Lorian Schaeffer, Ming Guo, Bruce A HayAbstract:One proposed strategy for controlling the transmission of insect-borne pathogens uses a drive mechanism to ensure the rapid spread of transgenes conferring disease refractoriness throughout wild populations. Here, we report the creation of Maternal-Effect selfish genetic elements in Drosophila that drive population replacement and are resistant to recombination-mediated dissociation of drive and disease refractoriness functions. These selfish elements use microRNA-mediated silencing of a Maternally expressed gene essential for embryogenesis, which is coupled with early zygotic expression of a rescuing transgene.
Tobias Uller - One of the best experts on this subject based on the ideXlab platform.
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when is a Maternal Effect adaptive
Oikos, 2007Co-Authors: Dustin J Marshall, Tobias UllerAbstract:Maternal Effects have become an important field of study in evolutionary ecology and there is an ongoing debate regarding their adaptive significance. Some Maternal Effects can act to increase offspring fitness and are called 'adaptive Maternal Effects'. However, other Maternal Effects decrease offspring fitness and there is confusion regarding whether certain Maternal Effects are indeed adaptive or merely physiological inevitabilities. Here we suggest that the focus on the consequences of Maternal Effects for offspring fitness only and the use of 'snapshot' estimates of fitness have misdirected our effort to understand the evolution of Maternal Effects. We suggest that selection typically acts on Maternal Effects to maximise Maternal rather than (or in addition to) offspring fitness. We highlight the importance of considering how Maternal Effects influence Maternal fitness across a mother's lifetime and describe four broad types of Maternal Effects using an outcome-based approach. Overall, we suggest that many Maternal Effects will have an adaptive basis for mothers, regardless of whether these Effects increase or decrease survival or reproductive success of individual offspring.