When one phenotype is not enough: divergent evolutionary trajectories govern venom variation in a widespread rattlesnake species

Artículo 10 páginas, 3 figuras 1 tablaUnderstanding the origin and maintenance of phenotypic variation, particularly across a continuous spatial distribution, represents a key challenge in evolutionary biology. For this, animal venoms represent ideal study systems: they are complex, variable, yet easily quantifiable molecular phenotypes with a clear function. Rattlesnakes display tremendous variation in their venom composition, mostly through strongly dichotomous venom strategies, which may even coexist within a single species. Here, through dense, widespread population-level sampling of the Mojave rattlesnake, Crotalus scutulatus, we show that genomic structural variation at multiple loci underlies extreme geographical variation in venom composition, which is maintained despite extensive gene flow. Unexpectedly, neither diet composition nor neutral population structure explain venom variation. Instead, venom divergence is strongly correlated with environmental conditions. Individual toxin genes correlate with distinct environmental factors, suggesting that different selective pressures can act on individual loci independently of their co-expression patterns or genomic proximity. Our results challenge common assumptions about diet composition as the key selective driver of snake venom evolution and emphasize how the interplay between genomic architecture and local-scale spatial heterogeneity in selective pressures may facilitate the retention of adaptive functional polymorphisms across a continuous space.Funding: Leverhulme Trust Grant RPG 2013-315 to WW, Santander Early Career Research Scholarship to GZ, Ministerio de Economía y Competitividad Grant BFU2013-42833-P to JJC.Peer reviewe

A pilot trial of gender-based motivational interviewing for help-seeking and internalizing symptoms in men.

There has been limited research on interventions addressing the psychosocial barriers to men’s underutilization of formal and informal help. To address this gap in the literature, we report on the development of Gender-Based Motivational Interviewing (GBMI) for men with internalizing symptoms and present the findings of a pilot trial. GBMI is a single session of assessment and feedback that integrates gender-based and motivational interviewing principles. Community-dwelling men (N = 23) with elevated internalizing symptoms and no recent history of formal help-seeking were randomized to either GBMI or control conditions and were followed for three months. The effect of GBMI on internalizing and externalizing symptoms ranged from small to large across follow-ups. GBMI had a small to moderate effect on stigma. There was no effect on help-seeking attitudes or intentions. GBMI increased use of informal help seeking (e.g. parents and partners) and had no effect on formal help seeking. None of these findings were statistically significant. Study weaknesses included baseline differences in help-seeking variables between conditions. This initial evaluation suggested that GBMI shows promise for improving mental health functioning while further research is need to determine its effect on help-seeking

A pilot trial of gender-based motivational interviewing for help-seeking and internalizing symptoms in men

There has been limited research on interventions that address the psychosocial barriers to men\u27s underutilization of formal and informal help. To address this gap in the literature, the authors report on the development of gender-based motivational interviewing (GBMI) for men with internalizing symptoms and present the findings of a pilot trial. GBMI is a single session of assessment and feedback that integrates gender-based and motivational interviewing principles. Community-dwelling men (N = 23) with elevated internalizing symptoms and no recent history of formal help seeking were randomized to either GBMI or control conditions and were followed for 3 months. The effect of GBMI on internalizing and externalizing symptoms ranged from small to large across follow-ups. GBMI had a small-tomoderate effect on stigma. There was no effect on help-seeking attitudes or intentions. GBMI increased use of informal help seeking (e.g., parents and partners) and had no effect on formal help seeking. None of these findings were statistically significant. Study weaknesses included baseline differences in help-seeking variables between conditions. This initial evaluation suggested that GBMI shows promise for improving mental health functioning while further research is need to determine its effect on help seeking. © 2013 American Psychological Association

Data from: When one phenotype is not enough - divergent evolutionary trajectories govern venom variation in a widespread rattlesnake species

Understanding the origin and maintenance of phenotypic variation, particularly across a continuous spatial distribution, represents a key challenge in evolutionary biology. For this, animal venoms represent ideal study systems: they are complex, variable, yet easily quantifiable molecular phenotypes with a clear function. Rattlesnakes display tremendous variation in their venom composition, mostly through strongly dichotomous venom strategies, which may even coexist within single species. Here, through dense, widespread population-level sampling of the Mojave rattlesnake, Crotalus scutulatus, we show that genomic structural variation at multiple loci underlies extreme geographic variation in venom composition, which is maintained despite extensive gene flow. Unexpectedly, neither diet composition nor neutral population structure explain venom variation. Instead, venom divergence is strongly correlated with environmental conditions. Individual toxin genes correlate with distinct environmental factors, suggesting that different selective pressures can act on individual loci independently of their co-expression patterns or genomic proximity. Our results challenge common assumptions about diet composition as the key selective driver of snake venom evolution and emphasise how the interplay between genomic architecture and local-scale spatial heterogeneity in selective pressures may facilitate the retention of adaptive functional polymorphisms across a continuous space