Agouti Berkshire Rex rat horn

Rex und Double-(Double)Rex- Fell types of rat

Kathrin Guttmann Fur, Knowledge, Breeding & Genetic

Already in the 1930s, was reported by the first rats with curly fur (Hawthorn Rats). Meanwhile, several mutations have been identified, which lead to more or less curly fur: cU1 (Curly1), Cu2 (Curly2), Cw (Cowlick), Wv (Wavy), Kinky (kk), Shaggy, Re (Rex) . This article Rex allele should only be considered Re, because the locus in question is the only one, in the breeding of pet rats as pet has broad meaning, play a role while the other mutation, especially in laboratory stocks. In England, the first Rex rats were obtained from the geneticist Roy Robinson 1976 bred and incorporated in the standard of the National Fancy Rat Society.

The National Fancy Rat Society describes as follows Rex:

The coat should be uniform dense and not too hard, with so little guard hairs as possible. The coat should be uniform lured, on the belly a little less.

This standard was adopted by the American Fancy Rat and Mouse Association.

Rex rats usually show at birth compared to babies with standard fur corrugated Vibrissae. The first baby fur of Rex rats is usually strongly attracted. However, many lose in the first shedding at the age of 6-8 Week her curls and get a rather wavy fur. At the age Rexe then tend, that the coat is thinner.

Illustration: Agouti Rex

Double-(Double)Rex

In animals, are homozygous for the mutant allele Rex, reveals a different picture. These animals often have severe hair loss and their fur is extremely thin and full of holes.

Illustration: Double-Rex, Picture provided by Hidden Mysteries pet rats breeding, is a lover of animals

Genetics of Rex Rat

Die Rex (Re) Mutation is autosomal dominant and is located on chromosome 7. It causes curly fur in the heterozygous case Re re and hair loss in the homozygous case Re Re. Re re rats indicate extensions to the hair follicles and hair with an unevenly coated cuticle. In homozygous Re Re animals, the effect is more pronounced. The Rex mutation was as a 7-bp Delatation the splicing intron of Accepttor 1 des Keratin 71 (Krt71) gene identified, which lies in the critical for Re chromosome region and plays an important role in the formation of hair. The Deletation triggers a 6-amino acid in the α-frame Deletation in helical rod domain of the protein from KRT71 (Takashi Kuramoto et al. 20071)Takashi KURAMOTO, Ryuji HIRANO, Mitsuru KUWAMURA, Tadao SERIKAWA(2007) Identification of the Rat Rex Mutation as a 7-bp Deletion at Splicing Acceptor Site of the Krt71 Gene, Laboratory Animal Science)

References   [ + ]

1. Takashi KURAMOTO, Ryuji HIRANO, Mitsuru KUWAMURA, Tadao SERIKAWA(2007) Identification of the Rat Rex Mutation as a 7-bp Deletion at Splicing Acceptor Site of the Krt71 Gene, Laboratory Animal Science