Identification of novel variants for KAP 1.1, KAP 8.1 and KAP 13.3 in South African goats

Abstract

The yield and quality of animal fibres such as mohair, cashmere and cashgora are primarily influenced by the expression of various keratin associated protein genes, such as KAP 1.1, KAP 8.1, and KAP 13.3. Recent developments in molecular genetics provide the opportunity to characterize KAP genes at a base-pair level, which can lead to improved selection and genetic progress in mohair fibre production. PCR and sequencing technology was used to identify and characterize KAP 1.1, KAP 8.1, and KAP 13.3 in 108 goats, representing the South African Angora, Boer and Angora x Boer goat populations. The three genes showed varying degrees of polymorphism with between 4 and 18 alleles identified per locus. Some discrepancies in the current gene sequence of KAP 1.1 were discovered. Nineteen novel variants were identified in total, seven for KAP 1.1, one for KAP 8.1 and eleven for KAP 13.3. Observed heterozygosity values closely matched expected heterozygosity values, with Boer goats consistently having the lowest levels of expected and observed heterozygosity (approximately 0.5) for all three of the genes. The greatest variation for each gene existed between the Angora and Boer goat breeds, with FST values of 0.28, 0.13, and 0.24 for KAP 1.1, 8.1, and 13.3 respectively. Predominant alleles differed between the various populations, indicating the need for further research into possible allelic and fibre quality associations.