Evolutionarily conserved insulin/insulin-like growth factor (IGF) signaling (IIS) has been identified as a major physiological mechanism underlying the nutrient-dependent regulation of sexually selected weapon in animals. However, molecular mechanisms that couple nutritional state with remain largely unknown. Here, we show one specific subtype insulin-like peptide (ILP) responds to nutrient status and thereby regulates size broad-horned flour beetle Gnatocerus cornutus. By using...

Biologists have been fascinated with the extreme products of sexual selection for decades. However, relatively few studies characterized patterns acting on ornaments and weapons in wild. Here, we measure a wild population weapon-bearing beetles (frog-legged leaf beetles: Sagra femorata) two consecutive breeding seasons. We consider variation both weapon size (hind leg length) relative (deviations from average scaling relationship between hind length body size), provide evidence directional...

Human Sim2 is a product of one the genes located on human chromosome 21q22 and homolog Drosophila single-minded (sim) which critical player in midline development central nervous system fly. Since mRNA expressed facial, skull, palate vertebra primordia rodent embryos, features that are associated with phenotypes Down's syndrome (DS), its trisomic state suspected to contribute symptoms DS. Here we describe mSim2 hippocampus amygdala adult mice, while mice overexpressing under control β-actin...

Ecology Letters (2012) Abstract Males and females frequently have different fitness optima for shared traits, as a result, genotypes that are high males low females, vice versa . When this occurs, biasing of offspring sex‐ratio to reduce the production lower‐fitness sex would be advantageous, so example, broods produced by high‐fitness should contain fewer sons. We tested consistent with these predictions in broad‐horned flour beetles. found both wild‐type beetles populations subject...

Female mate choice and male–male competition are the typical mechanisms of sexual selection. However, these two do not always favour same males. Furthermore, it has recently become clear that female can sometimes benefit males reduce fitness. So whether or different males, females from choice, remain open questions. In horned beetle, Gnatocerus cornutus, have enlarged mandibles used to fight rivals, larger provide a mating advantage when there is direct for mates. prefer highly competitive...

1. The energy available for reproduction is usually limited by resource acquisition (i.e. condition). Because condition known to be strongly affected environmental factors, reproductive investments also vary across heterogeneous environments. 2. Although the dependence of investment common both sexes, traits may exhibit sexually different responses fluctuation due sex‐specific life‐history strategies. However, few direct experimental studies have investigated in sexes. 3. We and males...

Abstract Theory shows how sexual selection can exaggerate male traits beyond naturally selected optima and also natural ultimately halt trait elaboration. Empirical evidence supports this theory, but to our knowledge, there have been no experimental evolution studies directly testing logic, little examination of possible associated effects on female fitness. Here we use replicate populations broad-horned flour beetles test for sex-specific predation an exaggerated sexually (the mandibles),...

Females prefer male traits that are associated with direct and/or indirect benefits to themselves. Male–male competition also drives evolution of represent competitive ability. Because female choice and male–male rarely act independently, exploring how these two mechanisms interact is necessary for integrative understanding the sexually selected traits. Here, we focused on females from attractiveness, courtship, weapon characters in armed bug Riptortus pedestris. The males use their hind...

Exaggerated traits can be the result of both sexual selection, including mate choice and male-male competition, natural selection. Comparing morphology exaggerated between sexes, observing interactions involving that trait, a powerful tool in understanding evolution traits, mating systems, life history. The leaf beetle Sagra femorata has enlarged hind legs, but little attention been paid to this its function. We found dimorphism legs observed competitive involved legs. Males grasped removed...

Predation, a major cause of natural selection, is classically thought to target the weak and sick. However, predators can animals with condition-dependent sexual traits, therefore, high-quality individuals also be focus predation. Thus, it not always clear which are foci or how this affects trait evolution. Here, we tested for evolutionary effects sex-specific predation on male female longevity using replicate populations broad-horned flour beetle Gnatocerus cornutus . We found that...

Exaggerated traits can be costly and are often trade-off against other characters, such as life-history traits. Thus, the evolution of an exaggerated trait is predicted to affect male strategies. However, there has been very little experimental evidence impact sexually selected on This study investigated whether increased investment in generate evolutionary changes strategy for armed males. Male flour beetles, Gnatocerus cornutus, have enlarged mandibles that used male–male competition, but...

Abstract Current concepts of sexual selection suggest that male reproductive success is determined by multiple traits. As expression and production traits are frequently associated with each other, positive or negative correlations among ensue. These relationships may be crucial in the evolution strategies. Here, we investigate phenotypic sexually selected armed bean bug R iptortus pedestris . In this insect, males a larger body weapon more likely to win male–male competitions, higher...

Abstract The seed beetle Callosobruchus maculatus larvae exhibit two types of resource competition: scramble, in which a is shared, and contest, the monopolized. This difference larval behavior results different adult densities. Under contest competition, density remains constant regardless density, but under scramble increases with density. turn affects mating frequency during adulthood, thus, intensity sexual selection operating on males. In this study, we examined relationship between...