REGION-SPECIFIC EXPRESSION OF MULTIPLE LACTASE-PHLORHIZIN HYDROLASE GENES IN INTESTINE OF RABBIT

We have identified a total of 4 sequences coding for lactase-phlorizin hydrolase (LPH) in the rabbit. Individual rabbits each yielded three different LPH cDNA sequences, or three chromosomal segments containing exon 1 of the LPH gene, representing either three genes or allelic va riants of two genes. The three sequences were found in differing propo rtions in intestinal mRNA depending on the position along the small in testine from which the RNA was isolated. If all these mRNAs are transl ated, posttranslational mechanisms previously implicated in the regula tion of LPH in the rabbit will be acting on different enzyme species i n different parts of the intestine. However, we find no evidence for m ore than one LPH gene in the rat, and have previously shown that human s have only one LPH gene.