Dysfunction of Oskyddad causes Harlequin-type ichthyosis-like defects in < i > Drosophila melanogaster < /i >

by Yiwen Wang, Michaela Norum, Kathrin Oehl, Yang Yang, Renata Zuber, Jing Yang, Jean-Pierre Farine, Nicole Gehring, Matthias Fl ötenmeyer, Jean-François Ferveur, Bernard Moussian Prevention of desiccation is a constant challenge for terrestrial organisms. Land insects have an extracellular coat, the cuticle, that plays a major role in protection against exaggerated water loss. Here, we report that the ABC transporter Oskyddad (Osy)—a human ABCA12 paralog—contributes to the waterproof barrier function of the cuticle in the fruit flyDrosophila melanogaster. We show that the reduction or elimination of Osy function provokes rapid desiccation. Osy is also involved in defining the inward barrier against xenobiotics penetration. Consistently, the amounts of cuticular hydrocarbons that are involved in cuticle impermeability decrease markedly when Osy activity is reduced. GFP-tagged Osy localises to membrane nano-protrusions within the cuticle, likely pore canals. This suggests that Osy is mediating the transport of cuticular hydrocarbons (CHC) through the pore canals to the cuticle surface. The envelope, which is the outermost cuticle layer constituting the main barrier, is unaffected inosy mutant larvae. This contrasts with the function of Snu, another ABC transporter needed for the construction of the cuticular inward and outward barriers, that nevertheless is implicated in CHC deposition. Hence, Osy and Snu have overlapping and independent roles to establish cuticular res...
Source: PLoS Genetics - Category: Genetics & Stem Cells Authors: Source Type: research