Abstract
Keratin-associated proteins (KAPs) are structural components of wool and variation in them may affect wool characteristics. In this study, we used PCR-SSCP to analyse the ovine KAP6 family which encodes glycine and tyrosine-rich KAPs. Five unique PCR-SSCP patterns were detected in the 250 sheep investigated. Between two and five patterns were observed in individual sheep and none with only one pattern was detected. This suggests the amplicons were heterogeneous and derived from more than one locus. To analyse these heterogeneous PCR amplicons, a sequencing approach using SSCP to separate individual amplified sequences, was developed. Using this approach, five DNA sequences (A–E) representing five unique PCR-SSCP patterns were obtained. D was identical to a published ovine KAP6-1 sequence (GenBank accession no. M95719), whereas the others were novel, but the closest homology was with KAP6 sequences from human, sheep, goats and cattle. The five ovine KAP6 sequences could be assigned into three distinct groups. B and D were identical to each other, with the exception of a 57-bp deletion/insertion and a single nucleotide polymorphism (SNP) in the 3′-UTR region. These appear to be allelic variants of ovine KAP6-1. A and C could form another group, as they were similar to each other (with only one synonymous SNP), but different to the other sequences. This group appears to be related to a sheep KAP6 amino acid sequence, and represent allelic variation at another KAP6 locus (designated KAP6-2). The remaining sequence E did not show high sequence homology with either the KAP6-1 or KAP6-2 sequences, but exhibited homology with a bovine KAP6-3 sequence, with the exception of a deletion/insertion of 30 nucleotides. This suggests that E represents ovine KAP6-3. This sequence was detected in only 11% of the sheep investigated, suggesting either a KAP6-3 null allele, or failure to amplify allleles. These results suggest that ovine KAP6 is a complex gene family, that is not only comprised multiple loci, but that is also polymorphic.
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References
Powell BC, Rogers GE (1997) The role of keratin proteins and their genes in the growth, structure and properties of hair. In: Jolles P, Zahn H, Hocker E (eds) Formation and structure of human hair. Birkhauser Verlag, Basel, pp 59–148
Rogers GE (2006) Biology of the wool follicle: an excursion into a unique tissue interaction system waiting to be re-discovered. Exp Dermatol 15:931–949
Gillespie JM (1990) The proteins of hair and other hard α-keratins. In: Goldman RD, Steinert PM (eds) Cellular and molecular biology of intermediate filaments. Plenum Press, New York, pp 95–128
Kuczek ES, Rogers GE (1987) Sheep wool (glycine + tyrosine)-rich keratin genes. A family of low sequence homology. Eur J Biochem 166:79–85
Fratini A, Powell BC, Rogers GE (1993) Sequence, expression, and evolutionary conservation of a gene encoding a glycine/tyrosine-rich keratin-associated protein of hair. J Biol Chem 266:4511–4518
McLaren RJ, Rogers GR, Davies KP, Maddox JF, Montgomery GW (1997) Linkage mapping of wool keratin and keratin-associated protein genes in sheep. Mamm Genome 8:938–940
Parsons YM, Cooper DW, Piper LR (1994) Evidence of linkage between high-glycine-tyrosine keratin gene loci and wool fibre diameter in a Merino half-sib family. Anim Genet 25:105–108
Zhou H, Hickford JGH, Fang Q (2006) A two-step procedure for extracting genomic DNA from dried blood spots on filter paper for polymerase chain reaction amplification. Anal Biochem 354:159–161
Byun SO, Fang Q, Zhou H, Hickford JGH (2009) An effective method for silver-staining DNA in large numbers of polyacrylamide gels. Anal Biochem 385:174–175
Rogers GR, Hickford JG, Bickerstaffe R (1994) Polymorphism in two genes for B2 high sulfur proteins of wool. Anim Genet 25:407–415
Itenge-Mweza TO, Forrest RH, McKenzie GW, Hogan A, Abbott J, Amoafo O, Hickford JG (2007) Polymorphism of the KAP1.1, KAP1.3 and K33 genes in Merino sheep. Mol Cell Probes 21:338–342
Gong H, Zhou H, Hickford JG (2010) Polymorphism of the ovine keratin-associated protein 1–4 gene (KRTAP1-4). Mol Biol Rep. doi:10.1007/s11033-009-9925-4
Shimomura Y, Aoki N, Schweizer J, Langbein L, Rogers MA, Winter H, Ito M (2002) Polymorphisms in the human high sulphur hair keratin-associated protein 1, KAP1, gene family. J Biol Chem 277:45493–45501
Kariya N, Shimomura Y, Ito M (2005) Size polymorphisms in the human ultrahigh sulphur hair keratin-associated protein 4, KAP4, gene family. J Invest Dermatol 124:1111–1118
Acknowledgements
We would like to thank Q. Fang, S. O. Byun, S. Kunhareang, Y. Guo and J. Han for technical assistance. This work was financially supported by FRST (C10X0710: Keeping New Zealand Wool Products at the Cutting Edge through Enhanced Wool Quality) and the Lincoln University Gene-Marker Laboratory. FRST funding (C10X0710) of Postgraduate Scholarship to HG is also acknowledged.
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Gong, H., Zhou, H. & Hickford, J.G.H. Diversity of the glycine/tyrosine-rich keratin-associated protein 6 gene (KAP6) family in sheep. Mol Biol Rep 38, 31–35 (2011). https://doi.org/10.1007/s11033-010-0074-6
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DOI: https://doi.org/10.1007/s11033-010-0074-6