F1Fo-ATPase subunit e gene isolated in a screen for diet regulated genes

Described is a protocol for isolating genes differentially regulated by the level of an essential nutrient in the diet. One gene, designated LFM-1 (Low Fat Mammary), was identified by subtractive hybridization and plus/minus screening in a lambda-cDNA library constructed with mRNA from mammary glands of virgin, tumor-free Balb/c mice fed a low fat diet; a second gene, stearoyl CoA desaturase, known to be regulated by the level of fat intake, was also isolated. The procedure can be modified for use with other constituents. The differential expression of LFM-1 was noted in mammary glands, liver, and kidney but not other tissues of mice fed low fat compared to high fat. LFM-1 is 86% identical to the gene encoding the e subunit of bovine F1-Fo ATPase and 89% identical to an UV-light induced gene (DDIU4) from Chinese hamster fibroblasts. Differential hybridization analyses indicated that LFM-1 may belong to a gene family.