A novel KRT71 variant in curly-coated dogs

Area of Science:

• Canine genetics
• Molecular biology
• Dermatology

Background:

• Curly fur is a common trait in dogs, often linked to a specific keratin 71 (KRT71) gene variant.
• This known variant was not found in Curly Coated Retrievers (CCRs) exhibiting curly coats.

Purpose of the Study:

• To identify the genetic basis of curly fur in CCRs lacking the known KRT71 variant.
• To discover novel genetic causes for curly coat phenotypes in various dog breeds.

Main Methods:

• Whole-genome sequencing of a CCR.
• Identification and analysis of novel structural variants in the KRT71 gene.
• Screening of KRT71 variants in Lagotto Romagnolo, Bichon Frise, Spanish Water Dog, Chesapeake Bay Retriever, and Irish Terrier.

Main Results:

• A novel structural variant (c.1266_1273delinsACA) in KRT71 exon 7 was identified as a cause of curly fur in CCRs.
• This variant leads to a frameshift and stop loss, altering the keratin 71 protein structure.
• The identified variant was also present in other breeds, and some curly-coated dogs lacked both known KRT71 variants, suggesting further genetic diversity.

Conclusions:

• A second KRT71 gene variant is identified as a cause for curly fur in dogs.
• The findings indicate the existence of additional genetic factors influencing canine coat curl.
• This research facilitates the development of new KRT71 gene tests for canine breeders to manage coat types effectively.