Analysis of the mouse γ-crystallin gene family: Assignment of multiple cDNAs to discrete genomic sequences and characterization of a representative gene

Abstract

Blot hybridization analysis of mouse DNA with γ-crystallin-specific CDNAs has detected the presence of a multigene family comprised of at least four related genes. The detailed structure of one of these genes, mouse γ 4-crystallin (Mγ 4.1), and its corresponding cDNA has been determined. The gene spans approximately 2.6 kilobases (kb) and contains two introns. The gene predicts a polypeptide of 174 amino acids that shares extensive sequence homology with γ-crystallin polypeptides of other species. The two similar structural domains of the protein correspond exactly to the second and third exons of the gene, supporting an exon-duplication model of gene evolution. The similarity in structure of this gene to that recently reported for a γ-crystallin gene of the rat (1) suggests that a common structure may exist for all γ-crystallin genes of the two species. Moreover, a highly conserved region, 50 nucleotides in length, immediately precedes the TATA box of both the mouse and rat genes, suggesting that this sequence may be important in gene regulation. © 1984 IRL Press Limited.