AUTHOR=Wang Yiwen , Farine Jean-Pierre , Yang Yang , Yang Jing , Tang Weina , Gehring Nicole , Ferveur Jean-François , Moussian Bernard 

TITLE=Transcriptional Control of Quality Differences in the Lipid-Based Cuticle Barrier in Drosophila suzukii and Drosophila melanogaster

JOURNAL=Frontiers in Genetics

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2020.00887

DOI=10.3389/fgene.2020.00887

ISSN=1664-8021

ABSTRACT=<p>Cuticle barrier efficiency in insects depends largely on cuticular lipids. To learn about the evolution of cuticle barrier function, we compared the basic properties of the cuticle inward and outward barrier function in adults of the fruit flies <italic>Drosophila suzukii</italic> and <italic>Drosophila melanogaster</italic> that live on fruits sharing a similar habitat. At low air humidity, <italic>D. suzukii</italic> flies desiccate faster than <italic>D. melanogaster</italic> flies. We observed a general trend indicating that in this respect males are less robust than females in both species. Xenobiotics penetration occurs at lower temperatures in <italic>D. suzukii</italic> than in <italic>D. melanogaster</italic>. Likewise, <italic>D. suzukii</italic> flies are more susceptible to contact insecticides than <italic>D. melanogaster</italic> flies. Thus, both the inward and outward barriers of <italic>D. suzukii</italic> are less efficient. Consistently, <italic>D. suzukii</italic> flies have less cuticular hydrocarbons (CHC) that participate as key components of the cuticle barrier. Especially, the relative amounts of branched and desaturated CHCs, known to enhance desiccation resistance, show reduced levels in <italic>D. suzukii</italic>. Moreover, the expression of <italic>snustorr</italic> (<italic>snu</italic>) that encodes an ABC transporter involved in barrier construction and CHC externalization, is strongly suppressed in <italic>D. suzukii</italic>. Hence, species-specific genetic programs regulate the quality of the lipid-based cuticle barrier in these two Drosophilae. Together, we conclude that the weaker inward and outward barriers of <italic>D. suzukii</italic> may be partly explained by differences in CHC composition and by a reduced Snu-dependent transport rate of CHCs to the surface. In turn, this suggests that <italic>snu</italic> is an ecologically adjustable and therefore relevant gene in cuticle barrier efficiency.</p>