Submitted on February 2, 2006
Revised on March 24, 2006
Accepted on March 31, 2006
Effects of diet and metamorphosis upon the sterol composition of the butterfly (morpho peleides)
William E. Connor, Yingming Wang, Mike Green, and Don S. Lin
Medicine/Clinical Nutrition, Oregon Health & Science University, Portland, OR 97239
Corresponding Author: connorw{at}ohsu.edu
ABSTRACT Whole body sterol metabolism in insects has seldom been studied. We were able to design an appropriate study at a butterfly farm in Belize. We collected six larvas of butterfly (Morpho Peleides), their food (leaves of pterocarpus bayessii) and their excretions. In addition, six adult butterflies were collected. The sterols of the diet, the larva and adult butterfly were analyzed by gas-liquid chromatography (GLC). The structures of these sterols were identified by digitonin precipitation, GC/MS and NMR. Four sterols (cholesterol, campesterol, stigmasterol, sitosterol) and a sterol mixture were found in the food, the body and the excreta of the larva. The tissue sterol content of the larva was 326 mg. They consumed 276 mg sterols per day. Their excretion was 185 mg per day as sterols. The total tissue sterol contents of the larva and butterfly were similar but they had different sterol compositions, which indicated interconversion of sterols during development. There was a progressive increase in the cholesterol content from larva to butterfly and a decrease in the content of sitosterol and other plant sterols, which were likely converted to cholesterol. Our data indicated an active sterol metabolism in butterfly larva. Diet played an important role in determining its sterol composition. During metamorphosis there was an interconversion of sterols. This is the first paper documenting the fecal sterol excretion in insects as related to dietary intakes.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?