Pelage, or a mammal’s coat, consists of hair, fur, wool, or other soft covering. Pelage provides body temperature regulation and protection against injury and the environment. It also provides camouflage, recognition within a species, and sexual allurement to promote courtship and mating. In addition, cat breed pelage has aesthetic value to humans. The Cornish Rex have a rexoid (curly/wooly) coat consisting of a wavy coat that falls in washboard-like waves known as marcel waves. The coat lies close to the body and is very soft due to the lack of guard and various awn hairs. The majority of Cornish Rex also have bent and twisted whiskers.
Hair follicles have a complex structure dependent on hundreds of gene products. The Cornish Rex coat variant is inherited as an autosomal recessive single gene trait. Researchers from University of California, Davis and their colleagues used genome-wide analyses to identify the gene locus controlling the rexoid hair texture in this breed. Approximately 63,000 single nucleotide polymorphisms (SNPs) were included in the analysis of the Cornish Rex breed, 11 phenotypically diverse breeds, and two random bred cat populations. A candidate gene was located on chromosome A1, and led to the identification of a 4 base pair deletion mutation in the lysophosphatidic acid receptor 6 (LPAR6) gene causing complete loss or reduction of the receptor function. Lysophosphatidic acid and its receptor are expressed in the inner root sheath of the hair follicle and are involved in structural integrity of the hair shaft. Mutations in this lipid-signaling pathway are associated with hypotrichosis (loss or reduction of hair growth) and wooly hair syndromes in humans. This is the first characterized mutation within LPAR6 associated with curly hair in an animal other than humans. [GO]
FUNDING: This project was partially funded by Winn Feline Foundation grants W10-14 and W11-14.
See also:
Mullikin JC, Hansen NF, Shen L, et al. Light whole genome sequence for SNP discovery across domestic cat breeds. BMC Genomics 2010;11:406. [Free, full text]