KAP6 is part of the high glycine-tyrosine keratin-associated protein (HGT-KAP) family.
This family is believed to encompass multiple genes, and the study identifies new members in sheep.
A KRTAP6 coding sequence was utilized to search the Ovine Genome (v3.1).
Five homologous regions (R1–R5) were detected, each containing an open reading frame (ORF).
Regions R1–R5 showed high similarity to sheep skin Expressed Sequence Tags (ESTs).
Phylogenetic analysis classified R1–R5 with KAP6 sequences from various species, separate from other HGT-KAPs.
R1: Similar to characterized KRTAP6-1.
R2–R5: New sequences, distinct from known KAPs.
PCR primers confirmed the presence of these genes, producing amplicons in 96 sheep.
SNP Variations:
KRTAP6-2: 5 SNPs observed.
KRTAP6-3: 3 SNPs and a 45-bp insertion/deletion detected.
KRTAP6-4: 3 SNPs.
KRTAP6-5: 5 SNPs and an 18-bp insertion/deletion.
Allele frequencies varied significantly between Merino and Romney breeds.
KAPs are crucial for wool and hair fibre structures, forming a semi-rigid matrix for keratin filaments.
Compositions mainly consist of cysteine, glycine, and tyrosine.
KAPs are categorized into three groups:
High Sulfur (HS) KAPs
Ultra-High Sulfur (UHS) KAPs
High Glycine-Tyrosine (HGT) KAPs
Presence in wool varies, influencing fibre properties and characteristics.
Study aimed to explore variations in newly identified KAP6 genes.
Four KAP6 genes identified showed polymorphism across different breed samples.
KRTAP6 genes established have similar coding sequences but differ significantly in flanking regions, impacting gene expression.
R1–R5 genes clustered closely with known KAP6 sequences from various species.
Suggested that KAP6 gene family is more diverse in sheep than in other species, such as humans (three members).
PCR experiments confirmed the presence of four new KAP6 genes using region-specific primers.
SSCP analysis identified multiple allele patterns, showing variant sequences:
R2: six alleles with five SNPs (all synonymous).
R3: five alleles, including a 45-bp insertion/deletion.
R4: three alleles, one non-synonymous SNP.
R5: identified six alleles with specific insertions/deletions.
Significant genetic variance identified between NZ Romney and Merino sheep
KRTAP6-3: allele B prevalent in Merino, absent in NZ Romney.
KRTAP6-4: allele C common in NZ Romney, rare in Merino.
KRTAP6-5: allele D found more frequently in Merino than NZ Romney.
Discovery of four new KAP6 genes increases known family members from one to five.
This supports previous studies indicating multiple KAP6 genes exist in sheep.
Identified genes may link to wool traits and potential genetic markers for breeding.
More extensive studies needed to define gene impact on wool characteristics.
Research adhered to Animal Welfare legislation for sheep blood collection.
96 sheep samples analyzed (48 Merino, 48 NZ Romney).
Genomic DNA isolated and analyzed through established protocols, including PCR amplification and SSCP for heterozygote detection.
Allelic variants sequenced for genetic variability assessment.
Revealed a substantial diversity in KAP6 genes with implications for understanding wool genetics and improvement through breeding strategies.