Rat metallothionein multigene family.

Abstract

Southern blot analysis of rat genomic DNA reveals the presence of numerous sequences homologous to the rat MT-1 gene. We have isolated and characterized by sequence analysis the rat MT-1 gene and three related processed pseudogenes. We discuss mechanisms by which these pseudogenes were formed. The rat MT-1 and MT-2 structural genes are shown to be separated by 4 kb of intergenic DNA. By sequence analysis of the MT-2 structural gene, we compare features of the MT gene sequences which regulate promoter activity, and which specify transcription termination and polyadenylation. From an examination of homologous sequences in the MT promoters, we suggest that there may be both regulatory features in common with the MT gene isotypes, and regulatory mechanisms which may allow for differential expression of these genes. We discuss possible applications of recombinant DNA technology to investigating both the expression of MT genes and the functioning of MT proteins, in a tissue specific manner and during development.