Genome-Wide Association Study of Fiber Diameter in Alpacas

Area of Science:

• Animal Genetics
• Genomics
• Quantitative Trait Loci (QTL) analysis

Background:

• Fiber diameter is a crucial trait in alpaca production, influencing textile quality and economic value.
• Understanding the genetic basis of fiber diameter is essential for improving alpaca breeding programs.

Purpose of the Study:

• To identify candidate genomic regions associated with fiber diameter in Huacaya alpacas.
• To perform the first whole-genome association analysis for fiber diameter in alpacas using a custom SNP microarray.

Main Methods:

• Genotyping of 960 Huacaya alpacas from Peru using an Affymetrix Custom Alpaca array (51,742 SNPs).
• Employed three association methodologies: Genome-Wide Association Study (GWAS) using a linear model, haplotype analysis, and cross-population extended haplotype homozygosity (XP-EHH).

Main Results:

• GWAS identified 11 and 35 significant SNPs associated with fiber diameter.
• Haplotype analysis revealed nine significant haplotypes, and XP-EHH identified 180 significant SNPs.
• Four candidate genomic regions on VPA6, VPA9, VPA29, and an unassigned scaffold were identified through combined association methods.

Conclusions:

• This study provides valuable insights into the genetic architecture of alpaca fiber diameter.
• Identified candidate regions offer targets for marker-assisted selection to improve fiber quality in alpacas.