The Rex Gene Mutation in Cats and Rabbits: A Complete Guide

The rex gene mutation is a fascinating genetic variation responsible for the distinctive curly or wavy coats found in several domestic cats and rabbits, as well as a few other mammals. This comprehensive guide explores the nature of this mutation, how it is inherited, and the notable breeds showcasing these charming coats. It also includes advice for responsible ownership and care, optimised for keywords such as rex gene mutation, inheritance, curly cat breeds, and rex rabbit breeds.

What Is the Rex Gene Mutation?

The rex mutation is a genetic alteration affecting hair structure, resulting in soft, curly, or wavy fur. This change impacts the shape and texture of individual hairs and how groups of hairs lay over the skin, producing a unique coat that feels noticeably softer and looks distinctively curly compared to straight coats.

These mutations are spontaneous genetic variations that, when selectively bred, have become defining features within certain breeds rather than mere anomalies. The rex coats often involve changes to hair follicle structure or hair shaft composition, caused by mutations in genes critical for hair development and integrity.

In cats, the rex mutation can be caused by several unrelated genes, which means different rex breeds often have different genetic causes of their curly coats. Similarly, in rabbits, rex coats are linked to a mutation in the LIPH gene.

How Is the Rex Gene Mutation Inherited?

Inheritance of the rex mutation depends on the specific gene and mutation involved but is often recessive or dominant depending on the breed and species:

• In rabbits, the rex mutation is due to a deletion mutation in the LIPH gene on exon 9, leading to a truncated protein that changes hair follicle function. This mutation is inherited in an autosomal recessive manner. Rabbits homozygous for this deletion show the rex coat, while heterozygotes do not.
• In cats, different mutations underlie different rex breeds:
  • The Cornish Rex has a 4 base pair deletion in exon 5 of the LPAR6 gene, which causes a frameshift and premature stop codon. This mutation is autosomal recessive and all Cornish Rex cats are homozygous for it.
  • The Devon Rex and Selkirk Rex have mutations in the KRT71 gene affecting keratin 71, a hair fibre protein.

Because these mutations occur in different genes, breeding between different rex breeds does not reliably produce curly-coated kittens, as the mutations do not complement each other genetically.

Notable Cat Breeds Displaying the Rex Mutation

Cornish Rex

One of the most well-known rex breeds, the Cornish Rex features a fine, soft, tightly curled coat caused by the LPAR6 gene mutation. These cats have a slender build, large ears, and a distinctive wavy coat covering their body. They require gentle grooming to maintain coat health.

Devon Rex

Originating from Southwest England, the Devon Rex coat mutation is different genetically from the Cornish Rex but similarly produces soft, curly fur. The Devon Rex usually has a pixie-like appearance with large ears and expressive eyes, and its coat curls from the whiskers to the tail.

Selkirk Rex

The Selkirk Rex breed is known for its plush, curly coat resulting from a mutation in KRT71. Unlike the slender Cornish and Devon Rex, Selkirk Rex cats have a rounder, more robust build. Their coat can be curly or wavy and covers their entire body including whiskers.

LaPerm

Though not traditionally classified within the original rex mutation group, the LaPerm also showcases a curly or wavy coat. The mutation causing its coat is distinct but similar in effect, producing soft, ringlet curls that cover the body.

Rex Breeds of Rabbits

Rabbits also exhibit the rex coat mutation, which provides them a velvety, plush texture due to the altered hair shaft structure. The mutation causes shorter guard hairs and longer, softer undercoat hairs, giving a plush feel.

Rex Rabbit

This foundational breed exhibits the classic rex fur with a thick, plush coat and a gentle, cuddly disposition. The coat stands up more uniformly than in other rabbits, making it very soft to pet.

Miniature Rex

A smaller version of the Rex, this breed carries the same gene mutation resulting in a curly, plush coat but in a compact stature. Miniature Rex rabbits are popular as pets due to their manageable size and friendly nature.

Plush Lop & Velveteen Lop

These lop-eared breeds carry the rex mutation, producing soft curly coats combined with the characteristic lop ears. They have a gentle temperament making them ideal companions.

Astrex

This breed has a distinctive curly rex coat, similar to the others but with unique curl patterns and hair structure resulting from the rex gene mutation lineage.

Other Animals with Rex Coat

Curly or rex coats are unusual but occur in other mammals besides cats and rabbits:

• Certain dogs and rats also exhibit rex or curly hair mutations.
• Some horse breeds display curly coats caused by different mutations.

These occurrences show the broader biological role of hair follicle genetics in mammalian coat diversity.

Responsible Ownership and Care

• Rex coats shed less than straight coats but trap loose hairs, so they require regular gentle grooming to prevent matting and maintain skin health.
• Curly coats often provide less insulation and protection, so rex animals might need extra care in cold or wet weather.
• Responsible breeding is essential as the rex gene mutations can carry health implications if bred irresponsibly. Potential owners should seek well-informed, ethical breeders prioritising genetic health.
• Nutrition supporting skin and coat health benefits rex animals' unique fur.
• Regular veterinary care ensures these breeds remain healthy and active companions.

The rex gene mutation is a remarkable example of how a small genetic change can create beloved breeds with distinct, curly coats loved by pet owners worldwide. From the elegant Cornish Rex and playful Devon Rex cats to the soft and cuddly rex rabbits, these animals bring unique texture and personality into the home.

Curious owners and breeders should continue to prioritise responsible care and genetic diversity to preserve the health and charm of these rex breeds for generations to come.

If you're exploring rex breeds, here are some valuable resources for more details and responsible sourcing:

• Cornish Rex information and adoption
• Devon Rex profiles and breeders
• Selkirk Rex breed guide
• LaPerm curly cats

For rex rabbits, seek out verified breeders knowledgeable about the LIPH mutation to ensure healthy animals.