INDUCTION AND REPRESSION OF GENES OF THE RAT SMALL-INTESTINE MUCOSA WITH EXCESS AND INSUFFICIENCY OF ALIMENTARY IRON

Three-month-old Wistar rats were fed with either an iron-deficient die t for 21 days or an iron-excessive diet for 10 days. Fifty thousand cl ones of a cDNA library of small intestine mucosa were hybridized with two radioactive samples synthesized on mRNA from the small intestine o f rats fed with iron-excessive or iron-defrcient diets. As a result, g enes were found with mRNA level depending on the content of alimentary iron. Iron deficiency increased the mRNA level of genes of apolipopro tein AIV and class 1 antigen and decreased the mRNA level of the apoli poprotein AI gene and of an unknown gene, while no change was found in the mRNA level of the gene of fatty acid-binding protein. Excess of d ietary iron resulted in the increase in mRNA of this gene and in a dec rease in the apolipoprotein AI gene and in the unknown gene. The mRNA of apolipoprotein AIV did not change. The data indicate that changes i n the level of alimentary iron influence the expression of genes invol ved in metabolism of lipids.