Complete structure of the alpha B-crystallin gene: conservation of the exon-intron distribution in the two nonlinked alpha-crystallin genes.
We isolated bovine complementary DNA clones for the alpha A- and alpha B-crystallin subunits. The alpha B cDNA clone was used to isolate an alpha B-crystallin gene. This gene, derived from hamster, occurs as a single copy in the genome and is 3.2 kilobases long. The coding sequences are spread on three exons with a total length of 709 nucleotides. The exon-intron distribution of the hamster alpha B-crystallin gene is similar to that of the alpha A-crystallin gene except for the 69 nucleotides that specify the 23 "insert" residues of the alpha AIns chain by means of differential splicing. The 3' noncoding region of the alpha B mRNA (140 bases), which is short compared with the alpha A mRNA (520 bases), shows a remarkable homology between calf and hamster. Both alpha-crystallin cDNA clones have been used to assign the chromosomal location of the corresponding human genes with the aid of somatic cell hybrids. It is shown that the single-copy alpha A- and alpha B-crystallin genes are located on different chromosomes.
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002902:Chromosomes, Human, 16-18; D002904:Chromosomes, Human, 21-22 and Y; D003001:Cloning, Molecular; D006224:Cricetinae; D003459:Crystallins / Q000235:genetics*; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D005796:Genes; D006801:Humans; D011061:Poly A / Q000235:genetics; D011401:Promoter Regions, Genetic
D003459:Crystallins; D011061:Poly A; D004247:DNA