Selection Signatures Reveal Candidate Genes for the Cornish Rex Breed-Specific Phenotype

Area of Science:

• Genetics and Genomics
• Animal Breeding
• Molecular Biology

Background:

• Specific traits like coat color and morphology are common across cat breeds.
• Rexoid mutations, affecting coat texture, are found in several domestic cat breeds.
• The Cornish Rex breed exhibits a distinctive rexoid coat and unique physical characteristics.

Purpose of the Study:

• To investigate the genetic basis of the Cornish Rex breed's unique traits.
• To identify genes under selective pressure in the Cornish Rex genome.
• To confirm the role of LPAR6 and ALX1 genes in Cornish Rex characteristics.

Main Methods:

• Genotyping of 20 Cornish Rex cats and four F1 hybrids for LPAR6 gene deletion.
• Genome-wide selection signature analysis using Runs of Homozygosity (ROH) islands and integrated haplotype score (iHS) on SNP array data from 11 Cornish Rex cats.
• Comparison of genetic data with known gene functions, including ALX1 in Burmese cats.

Main Results:

• A four base pair deletion in the LPAR6 gene, causing a premature stop codon, was confirmed in Cornish Rex cats and hybrids.
• Genome-wide analysis identified significant selection signatures on chromosomes A1, A3, C2, B1, B4, and D1.
• No deletion in the ALX1 gene was found in the studied Cornish Rex cats.

Conclusions:

• The identified deletion in the LPAR6 gene is causative for the rexoid coat phenotype in Cornish Rex cats.
• Selective pressures have shaped specific regions of the Cornish Rex genome.
• The ALX1 gene is not implicated in the rexoid coat or other studied traits in Cornish Rex cats.