The main objective of this study was to analyze the possible polymorphisms in 17 primer fragments of six candidate genes of the keratin family, including KRT27 (exons 3 and 8, introns 2 and 5), KRT31 (intron 2), KRT36 (exons 1, 2, and 3), KRT38 (exon 3, introns 2 and 7), KRT81 (exons 1 and 2, introns 1 and 3), KRT85 (exon 3, intron 2) in CMXT using the polymerase chain reaction-based single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods.
On the basis of the sequences of the KRT27, KRT31, KRT36, KRT38, KRT81, and KRT85 genes obtained from the National Center for Biotechnology Information GenBank database (GenBank accession numbers AC_000176, AC_ 000176, AC_000176, NC_00176, AC_000162, AC_000162, respectively), 17 pairs of PCR primers (P1-P17, Table 1) were designed to amplify different PCR products including exon3, exon8, intervening sequence 2 (IVS2), IVS5 of KRT27; IVS2 of KRT31; exon2, exon3 of KRT36; exon3, exon7, IVS2 of KRT38; exon1, exon2, IVS1, IVS3 of KRT81; and exon3, IVS2 of KRT85.
In this study, PCR-SSCP and DNA sequencing methods were used to identify polymorphisms in the sheep KRT27, KRT31, KRT36, KRT38, KRT81, and KRT85 genes.
A full-length cDNA library was constructed from the skin tissue of Xinji fine wool sheep , and the expressed sequence tags showed that the KRT27 gene may affect the performance of wool traits.
In the present study, PCR-SSCP and genomic DNA sequencing methods were used to screen for genetic variation in different exons and their flanking regions within sheep KRT27, KRT31, KRT36, KRT38, KRT81, and KRT85 genes.