Divergent evolution of genetic sex determination mechanisms along environmental gradients

Evolution Letters, Journal Year: 2023, Volume and Issue: 7(3), P. 132 - 147

Published: April 1, 2023

Abstract Sex determination (SD) is a crucial developmental process, but its molecular underpinnings are very diverse, both between and within species. SD mechanisms have traditionally been categorized as either genetic (GSD) or environmental (ESD), depending on the type of cue that triggers sexual differentiation. However, mixed systems, with components, more prevalent than previously thought. Here, we show theoretically effects expression levels genes regulatory can easily trigger within-species evolutionary divergence mechanisms. This may lead to stable coexistence multiple spatial variation in occurrence different along gradients. We applied model system housefly, global species world-wide latitudinal clines frequencies found it correctly predicted these if specific housefly were assumed temperature-dependent levels. conclude sensitivity gene networks play an important role diversification

Language: Английский

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Plasticity and the adaptive evolution of switchlike reaction norms under environmental change

Evolution Letters, Journal Year: 2023, Volume and Issue: 8(1), P. 64 - 75

Published: Aug. 31, 2023

Abstract Phenotypic plasticity is often posited as an avenue for adaptation to environmental change, whereby influences on phenotypes could shift trait expression toward new optimal values. Conversely, plastic may inhibit change by reducing selective pressure ill-adapted traits. While responses are assumed be linear, nonlinear phenotype–environment relationships common, especially in thermally sensitive Here we examine a with great ecological and evolutionary significance: sexual phenotype species sex determination (ESD). In ESD, development switches between male female at threshold (the inflection point). The point key adaptive changing environments should evolve the optimum order maintain evolutionarily stable ratios. We used individual-based theoretical model investigate how two forms of ESD reaction norm—the slope norm linear point—influence evolution under climate warming. found that steeper slopes (high plasticity) promoted (higher points). contrast, increased (shift) hindered evolution. Additionally, populations moderate warming scenarios showed greater compared extreme scenarios, suggesting proximity existing outcomes. Unexpectedly, population persistence high variability, due production rare-sex individuals unusually cold years. Our results demonstrate different phenotypic have crucially effects Plasticity prevented ratio bias point, while exacerbated change.

Language: Английский

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Effects of natural nest temperatures on sex reversal and sex ratios in an Australian alpine skink

Scientific Reports, Journal Year: 2021, Volume and Issue: 11(1)

Published: Oct. 11, 2021

Abstract Altered climate regimes have the capacity to affect physiology, development, ecology and behaviour of organisms dramatically, with consequential changes in individual fitness so ability populations persist under climatic change. More directly, extreme temperatures can directly skew population sex ratio some species, substantial demographic consequences that influence rate decline recovery rates. In contrast, this is particularly true for species whose determined entirely by temperature (TSD). The recent discovery reversal genotypic determination (GSD) due environmental wild broadens range vulnerable changing through an on primary ratio. Here we document levels nests Australian alpine three-lined skink ( Bassiana duperreyi ), a chromosomes at below 20 °C variation rates elevation. frequency B. ranged from 28.6% highest, coolest locations zero lowest, warmest locations. Sex makes it sensitive indicator change, both terms average variability.

Language: Английский

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Asymmetrical sex reversal: Does the type of heterogamety predict propensity for sex reversal?

BioEssays, Journal Year: 2022, Volume and Issue: 44(7)

Published: May 11, 2022

Abstract Sex reversal, a mismatch between phenotypic and genetic sex, can be induced by chemical thermal insults in ectotherms. Therefore, climate change environmental pollution may increase sex‐reversal frequency wild populations, with wide‐ranging implications for sex ratios, population dynamics, the evolution of determination. We propose that reconsidering half‐century old theory “Witschi's rule” should facilitate understanding differences species propensity thereby predicting their vulnerability to anthropogenic change. The idea is reversal asymmetrical: more likely occur homogametic assuming sex‐reversed heterogametic individuals would produce new genotypes reduced fitness. A review existing evidence shows while both individuals, latter seem require stronger stimuli several cases. provide guidelines future studies on data comparability reliability.

Language: Английский

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Does stress make males? An experiment on the role of glucocorticoids in anuran sex reversal

Journal of Experimental Zoology Part A Ecological and Integrative Physiology, Journal Year: 2023, Volume and Issue: 341(2), P. 172 - 181

Published: Dec. 28, 2023

Abstract Environmentally sensitive sex determination may help organisms adapt to environmental change but also makes them vulnerable anthropogenic stressors, with diverse consequences for population dynamics and evolution. The mechanisms translating stimuli are controversial: although several fish experiments supported the mediator role of glucocorticoid hormones, results on some reptiles challenged it. We tested this hypothesis in amphibians by investigating effect corticosterone agile frogs ( Rana dalmatina ). This species is liable reversal whereby genetic females develop into phenotypic males. After exposing tadpoles during waterborne corticosterone, proportion testes or ovotestes increased from 11% up 32% at 3 out 4 concentrations. These differences were not statistically significant except group treated 10 nM there was no monotonous dose‐effect relationship. findings suggest that unlikely mediate frogs. Unexpectedly, animals originating urban habitats had higher sex‐reversal corticosterone‐release rates, reduced body mass development speed, lower survival compared individuals collected woodland habitats. Thus, environments affect both fitness, underlying vary across ectothermic vertebrates.

Language: Английский

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