Suppression of a thioesterase gene expression and the disappearance of short chain fatty acids in the preen gland of the mallard duck during eclipse, the period following postnuptial molt.
Wax esters of short chain acids (monomethyl-C6) constitute the major products of the uropygial gland of mallard ducks. During eclipse, the period (June and July) immediately following postnuptial molt, the production of short chain acyl groups is severely curtailed and longer chain acyl groups become the dominant components; after this period the composition reverts. These changes in composition were accompanied by corresponding changes in the level of S-acyl fatty acid synthase thioesterase activity, and the level of the immunologically detectable amount of this enzyme. In vitro translation of the poly(A)+ RNA from the gland produced a 30-kDa protein which cross-reacted with rabbit antibodies prepared against this enzyme. The level of translatable mRNA for the thioesterase in the gland dramatically decreased as the birds went into eclipse and all of these changes reverted when the eclipse period was over. These results strongly suggest that the thioesterase is involved in the production of the short chain fatty acids in vivo and that during eclipse the expression of the thioesterase gene is suppressed.
D000375:Aging; D000818:Animals; D003307:Copulation; D004372:Ducks / Q000254:growth & development*; D005227:Fatty Acids / Q000378:metabolism*; D005796:Genes; D006120:Grooming; D008297:Male; D012621:Seasons; D012627:Sebaceous Glands / Q000378:metabolism*; D013869:Thiolester Hydrolases / Q000235:genetics*; D014885:Waxes / Q000378:metabolism
D005227:Fatty Acids; D014885:Waxes; D013869:Thiolester Hydrolases