SEQUENCE DATA AND CHROMOSOMAL LOCALIZATION OF HUMAN TYPE-I AND TYPE-II HAIR KERATIN GENES

A cDNA Library constructed with poly(A)(+) RNA from human scalp was sc reened with selected fragments of both murine type I and type II hair keratin cDNAs. Two keratin clones, one type I, phKI-2, and one type II , phKII-1, were isolated and sequenced. In Northern blots, cDNA probes containing the 3'-noncoding sequences of the clones specifically hybr idized to scalp mRNA species. Based on sequence homology comparisons w ith the four known murine type I hair keratins mHa1-4, the phKI-2 enco ded keratin could be identified as human hair keratin hHa2. Similarly, sequence comparison with the four type II sheep wool keratins K2.9-12 revealed an orthologous relationship between the largest member of th e type II wool keratin subfamily, K2.9 (i.e., sHb1) and the phKII-1 en coded human hair keratin (hHb1), The specific 3'-noncoding sequences o f hHa2 and hHb1 were also used to isolate genomic fragments for both k eratins from human genomic libraries which were than used for fluoresc ence in situ hybridization to human metaphase chromosomes. The hHa(2) gene could be mapped to the long arm of chromosome 17, whereas the hHb 1 gene was found on the long arm of chromosome 12, DAPI banding of the chromosomes allowed sublocalization of the hHa2 gene to 17q12-q21 and the hHb1 gene to 12q13, i.e., gene loci that have also been previousl y determined for human type I and type II epithelial keratins. (C) 199 5 Academic Press, Inc.