Biology subjects

Lognay, G.

Publications and source records attributed to Lognay, G..

2 recordsLinked to original sources

bioRxiv2020

Mosaic evolution of molecular pathways for sex pheromone communication in a butterfly

Unraveling the origin of molecular pathways underlying the evolution of adaptive traits is essential for understanding how new lineages emerge, including the relative contribution of conserved, ancestral traits, and newly evolved, derived traits. Here, we investigated the evolutionary divergence of sex pheromone communication from moths (mostly nocturnal) to butterflies (mostly diurnal) that occurred ~98 million years ago. In moths, females typically emit pheromones to attract male mates, but in butterflies pheromones and used by females for mate choice. The molecular bases of sex pheromone communication are well understood in moths, but have remained virtually unexplored in butterflies. We used a combination of transcriptomics, real time qPCR, and phylogenetics, to identify genes involved in different steps of sex pheromone communication in the butterfly Bicyclus anynana. Our results show that the biosynthesis and reception of sex pheromones relies both on moth-specific gene families (reductases) and on more ancestral insect gene families (desaturases, olfactory receptors, odorant binding proteins). Interestingly, B. anynana further appears to use what was believed to be the moth-specific neuropeptide Pheromone Biosynthesis Activating Neuropeptide (PBAN) for regulation of sex pheromone production. Altogether, our results suggest that a mosaic pattern best explains how sex pheromone communication evolved in butterflies, with some molecular components derived from moths, and others conserved from more ancient insect ancestors. This is the first large-scale analysis of the genetic pathways underlying sex pheromone communication in a butterfly.

evolutionary biology↗

bioRxiv2018

Common practice tissue extraction in solvent does not reflect actual emission of a sex pheromone during courtship in a butterfly

Olfactory communication can be of critical importance for mate choice decisions. Lepidoptera are key model systems for understanding olfactory communication, particularly considering sex pheromone signaling in the context of sexual selection. Solvent extraction or rinsing of pheromone-producing structures is a widespread method for quantifying sex pheromones, but such measures reflect what is stored and may not represent what is actually emitted by an individual during courtship. Here, we address this point for the first time by quantifying the components of the male sex pheromone (MSP) of interacting Bicyclus anynana butterflies, a species for which much information is available onthe role played by MSPs in affecting mating success. Using headspace sampling during courtship and solvent extraction after completion of experiments using the same males, we were able to track individual traits. Our results show that solvent extracts do not reflect quantities of MSP components emitted by live butterflies. We further show that MSP amounts obtained using headspace sampling correlated with male mating success, but solvent extracts did not. Our results further strongly suggest that males actively control MSP emission when faced with increased male-male competition. Common practice solvent extracts may thus not serve as an adequate proxy for male sex pheromone signaling as they are perceived by choosy females. Our study serves as a proof of principle that quantification of male sex pheromone components depends on the method of collection, which could apply to many other insects using short-range chemical signals. This affects our understanding of how sexual selection shapes the evolution of sexually-selected chemical traits.

evolutionary biology↗