Their results will help identify genes responsible for atherosclerosis, diseases associated with bile secretion in the liver, and some cancers. The principal investigators, Steven Farber of Marnie Halpern's laboratory at the Carnegie Institution of Washington's Department of Embryology and Michael Pack of the University of Pennsylvania, report their results in today's issue of Science . Currently, there are only a few ongoing genetic screens that study vertebrate physiology. The screening method devised in this study represents an important milestone for the real-time observations of lipid transport and processing in live animals. The scientists used the tiny, clear zebrafish larva for their research because its transparency allows them to watch what happens when fat and cholesterol are digested.
Phospholipids are fats that form cell membranes and potent cellular messengers.
The labeled lipids are able to reveal lipid-processing enzymes that are produced by specific genes in the digestive system. The researchers used the custom lipids to screen zebrafish families that carried a host of unknown mutations. The goal of the screen was to find larvae whose digestive organs exhibited an atypical fluorescence after eating the lipids. This indicates that an important gene for lipid processing is mutated. In their Science paper, the team describes one such mutation, which they named fat free.