Fat metabolism in insects

The study of fat metabolism in insects has received considerable attention over the years. Although by no means complete, there is a growing body of i nformation about dietary lipid requirements, and the absolute requirement f or sterol is of particular note. In this review we (a) summarize the state of understanding of the dietary requirements for the major lipids and (b) d escribe in detail the insect lipid transport system. Insects digest and abs orb lipids similarly to vertebrates, but with some important differences. T he hallmark of fat metabolism in insects centers on the lipid transport sys tem. The major lipid transported is diacylglycerol, and it is carried by a high-density lipoprotein called lipophorin. Lipophorin is a reusable shuttl e that picks up lipid from the gut and delivers it to tissues for storage o r utilization without using the endocytic processes common to vertebrate ce lls. The mechanisms by which this occurs are not completely understood and offer fruitful areas for future research.