Characterization of a 300 kbp region of XXXX DNA containing the type II hair keratin gene domain.

@entity1 @entity47597 @entity16920 @entity37936 @entity3587 @entity16552 @entity59201
Screening of an arrayed @entity1 genomic P1 artificial chromosome DNA library by means of the polymerase chain reaction with a specific primer pair from the @entity1 type II hair keratin @entity37936 yielded two P1 artificial chromosome clones covering approximately 300 kb of genomic DNA. The contig contained six type II hair keratin genes, @entity59201 - @entity59201 , and four keratin pseudogenes psihHbA-psihHbD. This hair keratin gene domain was flanked by type II epithelial keratins @entity16552 /K6hf and K7, respectively. The keratin genes/pseudogene are 5-14 kbp in size with intergenic distances of 5-19 kbp of DNA and do not exhibit a single direction of transcription. With one exception, type II hair keratin genes are organized into nine exons and eight introns, with strictly conserved exon-intron boundaries. The functional hair keratin genes are grouped into two distinct subclusters near the extremities of the hair keratin gene domain. One subcluster encodes the highly related hair keratins @entity59201 , @entity47597 , and @entity59201 ; The second cluster encodes the structurally less related hair keratins @entity3587 , @entity16920 , and @entity37936 . Reverse transcription-polymerase chain reaction shows that all hair keratin genes are expressed in the hair follicle. Pseudogene psihHbD is also transcriptionally expressed, albeit with alterations in splicing and frameshift mutations, leading to premature stop codons in the splice forms analyzed. Evolutionary tree analysis revealed a divergence of the type II hair keratin genes from the epithelial keratins, followed by their segregation into the members of the two subclusters over time. We assume that the approximately 200 kbp DNA domain contains the entire complement of @entity1 type II hair keratin genes.
