Rex mutation

Last updated April 14, 2024

The rex mutation is a genetic variation in mammals that results in soft curly fur. These effects are due to changes in the structure of groups of hairs and cross-section of individual hairs. The rexed coats are unusual but occur (and have been preserved) in cats, rats, rabbits, horses, and dogs. The mutations, infrequent and spontaneous, occur in a variety of genes and genetic regulatory structures. The diversity of genetic factors results in variable coat thickness/density and fur length. A similar mutation can affect the feathers of birds.

Birds

There are several varieties of curly-feathered domesticated birds:

Sebastopol goose
Frillback pigeon ^[1]
Frizzle chicken ^[2] and other chickens with "frizzled" feathers.
Curly quail ^[3]

Cats

There are four main internationally recognised rex cat breeds: Cornish Rex, Devon Rex, LaPerm, and Selkirk Rex. Rex breeds are sometimes nicknamed "poodle cats" or "poodlecats",^[4] after the curly-coat dog breed group.

There are also a number of rarer, less well known or developing rex-coated breeds, including the German Rex, Ural Rex, Tennessee Rex, Tasman Rex group,^[5] and Skookum. Spontaneous rexed variants have also been observed in breeds such as the Maine Coon and Persian as well as in random-bred cats such as Ohio Rex, Oregon Rex, and California Rex, however there has been no significant attempt to develop or seek recognition for these varieties and most have died out. The Tennessee Rex is a natural-mutation breed of cat dating back to 2004, discovered by Franklin Whittenburg.^[6]

Rex breeds vary considerably in appearance, from the elegant slender build of the Cornish Rex to the larger, cobby and heavy-boned Selkirk Rex. Each results from a separate mutation rather than being bred from a common ancestor. Each mutation causes the hair follicles to be oval in shape, instead of the normal regular round form, which results in hairs curling round as they grow instead of growing straight. Many of the other spontaneously occurring rex mutations have occurred and some have proven to be the same gene as the main four breeds. Some of those mutations, such as the Dutch Rex, were found to have unmanageable or unattractive fur and were not pursued as breeds.

The name rex was taken from the rabbit fancy because the first rex cat breed to be developed, the Cornish Rex, has a coat similar to that of a rex rabbit, in that it comprises only the undercoat with no topcoat or guard hairs.

Named mutations

1930s: Karakul Cat. Occurred in the US and was recorded as a novelty, but not developed as a breed.
1930s: Prussian Rex. Discovered in Königsberg in what was East Prussia in the early 1930s. This rex-coated brown tomcat was named "(Kater) Munk" and has been linked to the later German Rex as he was allowed to mate freely with local cats until his death 1944. His offspring were not recorded.
1944: Ohio Rex. First occurrence of rex-coated cat in Ohio, US
1950s: Buckfast Blue (Buckfast Rex). Locally occurring variety in Devon, England, feral forerunner of Devon Rex
1946 and 1951: German Rex. Rexed cats occurred on several occasions in different parts of Germany and some have been anecdotally linked to Kater Munk. They arose in Berlin, Essen and Sieburg, but it was the Berlin strain that gave rise to the modern German Rex.
1950: Cornish Rex. The British/European style of cat is sufficiently different from the breed in North America that the latter is also referred to as "American Cornish Rex" to differentiate it and to accommodate the different breed standards.
1950: Italian Rex. Three rex-coated kittens were born to a straight-haired female, but these were not pursued as a breed.
1953: Ohio Rex. Second occurrence of rex-coated cat in Ohio, US. At least 4 such cats were born, but this variety lasted only 10 years with no serious attempt at creating a breed.
1959: Oregon Rex. A wavy-coated bicolour female kitten was born to a straight-haired mother and named "Kinky Marcel". Test-matings with proved it to be a recessive mutation incompatible with the Cornish Rex or Devon Rexes so it was not pursued as a breed.
1959: California Rex (Marcel Cat). A rex-coated tortoiseshell female called "Mystery Lady of Rodell" and her rex-coated red tabby son were bred together and resulted in further curly-furred semi-longhair cats. Test-mating found this to be compatible with the Cornish Rex so the Marcel Cat was used to expand the gene pool of Cornish Rexes in the US.
1960: Devon Rex Curly-furred cats had existed in the area for a number of years and were known locally as "Buckfast Blue" because of their grey fur. These predecessors of the Devon Rex are also retrospectively referred to as "Buckfast Rex".
1968–9 and 1985: Dutch Rex. The first occurrence was in Zaandam in 1968 or 1969 when a female cat produced a rexed daughter. The daughter produced rexed offspring when mated to unrelated straight-haired males, including Siamese cats, demonstrating this to be a dominant mutation. The fur tended to form dreadlocks and had a coarse, unruly texture. The cats were also prone to balding. Cat fanciers believed the strain originated from an American Wirehair belonging to military personnel. The mutation reappeared in 1985 and was also known as the Wirehair Rex. These cats were traceable as descendants of the discontinued Dutch Rex breeding program. The last known Dutch Rex was a female cat of unknown origin found in Amsterdam in the late 1990s. The dominant mutation produced a rex type of coat in the heterozygote and a sparse coat in the homozygote.
1972: Victoria Rex. A curly-furred cat named Tuoh was found in the Victoria area of London. The fur was different from the Devon Rex and the cat was to have been test-mated to a Cornish Rex. The outcome of test-matings appears not to have been recorded.
1979: Sieburg Rex. A spontaneously occurring rex-coated bicolour male cat originally named Pushkin, and later renamed Kater Preu, was used in the German Rex breeding programme. He turned out to have a different mutation to the Berlin cats, and produced straight-haired offspring when mated to them, so he was neutered.
1982: LaPerm
1987: Selkirk Rex
1988 and 2002: Maine Waves/Rexed Maine Coon. Originally occurred in British breeding lines in the 1980s and caused controversy as the GCCF rules do not allow for spontaneous mutations to be registered as separate breeds. Test matings with Devon Rexes and Cornish Rexes were inconclusive. Test-matings indicated that the mutation was either recessive or incomplete dominant gene and did not result from mis-mating of a Maine Coon to either of those breeds. Accusations of mis-mating and unhealthy cats persisted. In the 1990s, Rexed Maine Coons (and carriers of the mutation) were neutered to avoid spreading the unwanted gene. In 2002, several Rexed Maine Coons were born in New York, US. Although blamed on the effects of the 9/11 attack, it was more likely due to the rex mutation being in the gene pool.
1990s: Dakota Rex. There were plans to establish this as a breed.
1990s: Missouri Rex. The mutation was found to be different from the Devon Rex and Cornish Rex mutations and it was planned to establish this asa breed. Financial problems led to most of the cats being euthanized.
1991: Urals Rex. Although not recognised until 1991 by the emerging cat fancy in Russia after glasnost, the Urals Rex had been reported in and around Yekaterinburg since the Second World War. There were two breeding populations carrying the same mutation which was known to be different from the German/Cornish Rex rex mutation. By 1991 the cats were greatly inbred and work was needed to expand the gene pool.
1994: Bohemia Rex/Czech Curly Cat. Although not recognised until 1994, this longhair rex of Persian conformation has existed in Liberec, The Czech Republic since 1981. It arose when curly kittens were born in a pedigree Persian litters. The parents were traced back to two blue Persian males imported from Germany in the 1970s. These males may have inherited a spontaneous mutation or may have carried the German Rex mutation due to Persian cats being used in the German Rex breeding program and some of the straight-coated offspring being registered as Persians. Test-matings found that only some Bohemia Rexes have the Cornish (German) Rex mutation and that there is an unknown second rex-causing gene involved. There was little interest in this variety until after the recognition of the Selkirk Rex Longhair.
1994: Poodle Cat (Pudelkatze). A German variety, now possibly extinct due to German legislation, developed from the Scottish Folds and Devon Rexes
1998: Skookum (previously LaMerm). A breed developed in the US. from LaPerms and Munchkins
1998 and 2003: Tasman Manx (also nicknamed Manx Rex). A spontaneously occurring rex-coated Manx cat. This arose spontaneously in pedigree Manx lines in Australia and New Zealand, not from crossbreeding. Test-matings to Devon Rex produced only straight-haired kittens. The fur also appears different from the Cornish Rex mutation, but test-matings are required. Curly-furred Manx cats were all traceable to an outcross mating (to widen the Manx gene pool) in Australia which used a cream Persian male from European bloodlines. It is suggested that these may, therefore, be related to some Bohemia Rex cats.
1998: Australian Rex. Arose in 1998, but not reported until 2005. Cats with coats similar to Cornish Rexes occurred in non-pedigree litters in an area where there were no known Cornish Rex cats. The cats were small and litter sizes were typically 1 or 2 kittens. Breeding was not controlled and many of the cats disappeared or were neutered, leaving only one breeding male. Cat breeding is not encouraged in Australia and this variety may now be extinct.
2001: Iowa Rex. A male cat sired curly-coated kittens, including dreadlocked longhairs, in several litters. The Iowa cats were large and muscular with notably broad muzzles. Their discoverer was seeking an experienced breeder to take these on as a developing breed.
2001: Ruffle. This combined the American Curl's ear type with the Cornish Rex fur type, but was not further developed under this name. There are differing accounts as to whether it occurred spontaneously or through deliberating crossbreeding.
2003: Brooklyn Wooley. Several "Wirehair Rexes" were born in Brooklyn, New York, US, but did not survive. Subsequent litters born to the same parents survived and are being developed into a new breed. Kittens may be born partly bald or go through a bald phase before developing the curly coat. It was initially thought to be identical to the short-haired LaPerm, but was later found to be a new recessive mutation.
2003: Prairie Rex. Rexed cats were found at a farm in Saskatoon, Canada and had been breeding freely for around 10 years. Several cats were taken on by a breeder, but were badly inbred resulting in poor health. They were traceable to a chocolate point rexed male and the line appears to have died out. The last of the line were neutered due to their poor health.
2003: Hoosier Rex. A curly-haired female and 4 curly-haired kittens were found in Indianapolis and given to an animal shelter where they were all neutered. The animal shelter had received similar cats over the previous two years. The mutation cannot be researched due to a legally binding neutering rule.
2004: Tennessee Rex (T-Rex). Two curly-coated were taken in by a Chattanooga cat-lover who was sufficiently impressed by their appearance to pursue this as a new breed. In addition to their curly fur, many of the cats had a "satin" or "glitter" mutation resulting in glittering fur.
2009: Helki. Developed in California from South Sacramento feral cats with a semi-rexed coat. The silky or fleecy coat contains a mix of straight and wavy guard hairs and it appears to be a dominant mutation. the name means "touch" in the Miwok language.
2015: Australian Satin. Kim Gale discovered a litter of 4 rex satin domestic cats in Queensland Australia. The breed is being Pursued By Kim Gale, the Hair is silky with a sparkle, so far looks best on red, but other colours are being explored. Genetically it is a recessive mutation.

Dogs

Curly-coated dog breeds
- Curly-coated Retriever
- Irish Water Spaniel
- Lagotto Romagnolo
- Poodle breed group

Horse

American Bashkir Curly horse

Pig

Mangalica pig

Rabbits

A great variety exists within rex rabbits. They vary from very dense and short-haired varieties (Standard Rex) to long-and-curly-haired breeds (Astrex).

The rex rabbit was introduced in 1919 by Abbe Gillet from a spontaneous mutation. The next rex rabbit was discovered in the hutches of a breeder in Lübeck, Germany in 1926. This breed was originally called Deutsch-Kurzhaar and is due to the r2 (dek) gene. In 1927, yet another short-hair rabbit was discovered in the hutches of the French breeder Madame Du Bary, a fancier of Himalayan (ch-) rabbits. This breed was called Normannen-Kurzhaar and is due to the r3 (nok) gene. ^[7]

Of the three genetic sources of rex rabbits, the one due to the gene r1 is the most popular with fanciers and has the simple Mendelian inheritance pattern of autosomal recessive. It was not linked with any other genes known at the time although it was eventually found to be in the same linkage group as r2.^[8]

The phenotype of r1 and r2 is a completely normal coat but r1 or r2 alone produces a short coat with curly whiskers. Although the phenotypes are identical for each gene, the linkage distance was eventually worked out.^[8] The gene r3 is independent of r1 and r2 in breeding tests so they fall on different chromosomes.^[7]

The mutation associated with r1 was recently studied using modern genetic tools. A deletion of a single nucleotide was found in LIPH (lipase member H gene) of rex rabbits. In humans, this gene is associated with alopecia (hair loss phenotypes). This mutation results in a frameshift that causes the mRNA transcription machinery to sense the end of the gene prematurely. The stop codon generated by the deletion may be shortening the protein by 19 amino acids. The exact mechanism was not determined but the deletion is necessary and sufficient for the rex phenotype.^[9]

Rodents

Hamsters

Rex golden hamsters first appeared in the 1970s, characterised by curly whiskers and a curly coat; the curls in the coat are easily visible in short-coated hamsters but more difficult to see in long-coated ones.^[10]^[11]

Rex in Campbell's dwarf hamsters is not recorded as to when it first appeared. Unlike with golden hamsters, the rex coat in Campbell's dwarfs is commonly very sparse and gives a bald appearance. The whiskers are curled.^[11]

Mice

Rex mouse^[12]
Astrex mouse^[12]
Texel mouse^[13]

Rat

Rex rat ^[14]^[15]

Related Research Articles

The Bengal cat is a breed of hybrid cat created from crossing of an Asian leopard cat, with domestic cats, especially the spotted Egyptian Mau. It is then usually bred with a breed that demonstrates a friendlier personality, because after breeding a domesticated cat with a wildcat, its friendly personality may not manifest in the kitten. The breed's name derives from the leopard cat's taxonomic name.

The Cornish Rex is a breed of domestic cat. The Cornish Rex has no hair except for down hair. Most breeds of cat have three different types of hair in their coats: the outer fur or "guard hairs", a middle layer called the "awn hair"; and the down hair or undercoat, which is very fine and about 1 cm long. Cornish Rexes only have the undercoat. Occasional individuals are prone to hair loss or will develop a very thin coat or even go bald over large parts of their body. The curl in their fur is caused by a different mutation and gene than that of the Devon Rex. The breed originated in Cornwall, Great Britain.

<span class="mw-page-title-main">Selkirk Rex</span> Breed of cat

The Selkirk Rex is a breed of cat with highly curled hair.

The Sphynx cat also known as the Canadian Sphynx, is a breed of cat known for its lack of fur. Hairlessness in cats is a naturally occurring genetic mutation, and the Sphynx was developed through selective breeding of these animals, starting in the 1960s.

<span class="mw-page-title-main">Manx cat</span> Breed of cat

The Manx cat is a breed of domestic cat originating on the Isle of Man, with a mutation that shortens the tail. Many Manx have a small stub of a tail, but Manx cats are best known as being entirely tailless; this is the most distinguishing characteristic of the breed, along with elongated hind legs and a rounded head. Manx cats come in all coat colours and patterns, though all-white specimens are rare, and the coat range of the original stock was more limited. Long-haired variants are sometimes considered a separate breed, the Cymric.

The Cymric is a Canadian cat breed. Some cat registries consider the Cymric a semi-long-haired variety of the Manx breed, rather than a separate breed. Except for the length of fur, in all other respects, the two varieties are the same, and kittens of either sort may appear in the same litter. The name comes from Cymru, the indigenous Welsh name of Wales, even though the breed is not associated with Wales. The name may have been chosen to provide a "Celtic" sounding moniker for the breed. While the breed's Manx bloodline originated from the Isle of Man, the long-haired variant is claimed to have been developed by Canada. The breed is called the Longhair Manx or a similar name by some registries.

<span class="mw-page-title-main">Munchkin cat</span> Breed of cat

The Munchkin is a breed of cat characterized by its very short legs, which are caused by genetic mutation. Compared to many other cat breeds, it is a relatively new breed, documented since 1940s and officially recognized in 1991. The Munchkin is considered to be the original breed of dwarf cat.

The Devon Rex is a tall-eared, short-haired breed of cat that emerged in England during the late 1950s. The breed is known for its atypical appearance, with an oddly shaped head, large eyes, and the short and wavy coat.

The American Bobtail is an uncommon breed of domestic cat which was developed in the late 1960s. It is most notable for its stubby "bobbed" tail about one-third to one-half the length of a normal cat's tail. This is the result of a cat body type genetic mutation affecting the tail development, similar to that of a Manx cat. The breed is not related to other short-tailed breeds, such as the Cymric cat, or the Japanese Bobtail or Kurilian Bobtail, despite the similar name and physical type—the breeding programs are entirely unrelated, and the genetic mutation causing the bobbed tail are known to be different, as the mutation causing the American Bobtail's short tail is dominant; comparatively, the Japanese Bobtail, for example, has a tail mutation that is recessive.

<span class="mw-page-title-main">Fancy rat</span> Domesticated brown rat subspecies

The fancy rat is the domesticated form of Rattus norvegicus, the brown rat, and the most common species of rat kept as a pet. The name fancy rat derives from the use of the adjective fancy for a hobby, also seen in "animal fancy", a hobby involving the appreciation, promotion, or breeding of pet or domestic animals. The offspring of wild-caught specimens, having become docile after having been bred for many generations, fall under the fancy type.

Cat coat genetics determine the coloration, pattern, length, and texture of feline fur. The variations among cat coats are physical properties and should not be confused with cat breeds. A cat may display the coat of a certain breed without actually being that breed. For example, a Neva Masquerade could wear point coloration, the stereotypical coat of a Siamese.

The Cat Fanciers' Association (CFA) was established in the United States in 1906. The CFA is currently the world's largest registry of pedigreed cats. Originally headquartered in Manasquan, New Jersey, the CFA moved to Alliance, Ohio in 2010. The association's stated mission is preserving and promoting pedigreed breeds of cats while also enhancing the well-being of all cats. CFA's first licensed cat shows were held in Buffalo, New York and Detroit, Michigan in 1906. The association today has a known presence in Europe, China, and Japan along with its well-established activity in the United States and Canada.

Point coloration is animal coat coloration with a pale body and relatively darker extremities, i.e. the face, ears, feet, tail, and scrotum. It is most recognized as the coloration of Siamese and related breeds of cat, but can be found in dogs, rabbits, rats, sheep, guinea pigs and horses as well.

The Burmilla is a breed of domestic cat, that originated in the United Kingdom in 1981. It is a cross between the Chinchilla Persian and Burmese cats. In certain cat registries the breed falls under the Asian group, and is sometimes referred to as the Asian Shaded. Standards were produced in 1984, and the breed gained championship status in the United Kingdom in the 1990s.

The American Wirehair is a breed of domestic cat originating in Staten Island New York, which is characterized by its wiry fur and crinkly whiskers caused by a genetic mutation. As of 2017, though the breed is well-known, it is ranked as the most rare of the 41 Cat Fanciers' Association breeds.

The LaPerm is a breed of cat. A LaPerm's fur is curly, with the tightest curls being on the throat and on the base of the ears. LaPerms come in many colors and patterns. LaPerms generally have a very affectionate personality.

The German Rex is a breed of domestic cat.

Colours of the Syrian hamster can be described in three ways: as "self", "agouti" or "combinations". Self colours are a consistent coat colour with the same colour topcoat and undercoat. Agouti hamsters have a ticked coat, where each individual fur is banded in different colours. Agouti hamsters also have "agouti markings" which consist of dark cheek markings, a dark marking on the head, and a light underbelly. Combinations are produced when two self or agouti colours are present.

References

↑ "Frillback". AZPigeons.org. 2000. Archived from the original on 28 September 2009.
↑ "Frizzle Chicken at Poultrymad".
↑ Minvielle, Francis; Gourichon, David; Moussu, Chantal (11 March 2005). "Two new plumage mutations in the Japanese quail: "curly" feather and "rusty" plumage". BMC Genet. 6: 14. doi: 10.1186/1471-2156-6-14 . PMC 555543 . PMID 15760477.
↑ Austwick, Megan (26 October 2020). "Poodle Cat – Everything You Need To Know About This Curly Kitten". The Happy Cat Site.
↑ "Breeds". NZCF. 6 November 2007. Retrieved 18 February 2014.
↑ "Tennessee Rex- The Birth of a New Breed". Cats.com. 22 April 2017.
1 2 Castle, W. E. (1933). "Linkage interrelations of three genes for rex (short) coat in the rabbit". Proceedings of the National Academy of Sciences of the United States of America. 19 (12): 1006–1011. Bibcode:1933PNAS...19.1006C. doi: 10.1073/pnas.19.12.1006 . PMC 1086272 . PMID 16587815.
1 2 Castle, W. E.; Sawin, P. B. (1941). "Genetic linkage in the rabbit". Proceedings of the National Academy of Sciences of the United States of America. 27 (11): 519–523. Bibcode:1941PNAS...27..519C. doi: 10.1073/pnas.27.11.519 . PMC 1078373 . PMID 16588495.
↑ Diribarne, M.; Mata, X.; Chantry-Darmon, C.; Vaiman, A.; Auvinet, G.; Bouet, S.; Deretz, S.; Cribiu, E. P.; Rochambeau, H; Allain, D.; Guérin, G. (2011). "A Deletion in Exon 9 of the LIPH Gene Is Responsible for the Rex Hair Coat Phenotype in Rabbits (Oryctolagus cuniculus)". PLOS ONE. 6 (4): e19281. Bibcode:2011PLoSO...619281D. doi: 10.1371/journal.pone.0019281 . PMC 3084274 . PMID 21552526.
↑ "Rex".
1 2 Logsdail, Chris; Hovers, Kate; Logsdail, Pete (2003). Hamsterlopaedia : a complete guide to hamster care. Lydney, Gloucestershire: Ringpress. ISBN 9781860542466. OCLC 50877868.
1 2 "Varieties of Fancy Mice - AOV - Astrex".
↑ "Eva's Mouse Variety Page - Coated". Archived from the original on 28 October 2007. Retrieved 15 January 2008.
↑ "Varieties of Fancy Rat - Rex and Dumbo Varieties". NFRS.org. National Fancy Rat Society. 2011. § Rex. Archived from the original on 9 February 2017.
↑ "AFRMA Fancy Rats - Varieties". AFRMA.org. American Fancy Rat & Mouse Association. 29 September 2018. § Rex. Retrieved 29 January 2024.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[1] "Frillback". AZPigeons.org. 2000. Archived from the original on 28 September 2009.

[2] "Frizzle Chicken at Poultrymad".

[3] Minvielle, Francis; Gourichon, David; Moussu, Chantal (11 March 2005). "Two new plumage mutations in the Japanese quail: "curly" feather and "rusty" plumage". BMC Genet. 6: 14. doi: 10.1186/1471-2156-6-14 . PMC 555543 . PMID 15760477.

[4] Austwick, Megan (26 October 2020). "Poodle Cat – Everything You Need To Know About This Curly Kitten". The Happy Cat Site.

[5] "Breeds". NZCF. 6 November 2007. Retrieved 18 February 2014.

[6] "Tennessee Rex- The Birth of a New Breed". Cats.com. 22 April 2017.

[auto-7] 1 2 Castle, W. E. (1933). "Linkage interrelations of three genes for rex (short) coat in the rabbit". Proceedings of the National Academy of Sciences of the United States of America. 19 (12): 1006–1011. Bibcode:1933PNAS...19.1006C. doi: 10.1073/pnas.19.12.1006 . PMC 1086272 . PMID 16587815.

[auto1-8] 1 2 Castle, W. E.; Sawin, P. B. (1941). "Genetic linkage in the rabbit". Proceedings of the National Academy of Sciences of the United States of America. 27 (11): 519–523. Bibcode:1941PNAS...27..519C. doi: 10.1073/pnas.27.11.519 . PMC 1078373 . PMID 16588495.

[9] Diribarne, M.; Mata, X.; Chantry-Darmon, C.; Vaiman, A.; Auvinet, G.; Bouet, S.; Deretz, S.; Cribiu, E. P.; Rochambeau, H; Allain, D.; Guérin, G. (2011). "A Deletion in Exon 9 of the LIPH Gene Is Responsible for the Rex Hair Coat Phenotype in Rabbits (Oryctolagus cuniculus)". PLOS ONE. 6 (4): e19281. Bibcode:2011PLoSO...619281D. doi: 10.1371/journal.pone.0019281 . PMC 3084274 . PMID 21552526.

[10] "Rex".

[:0-11] 1 2 Logsdail, Chris; Hovers, Kate; Logsdail, Pete (2003). Hamsterlopaedia : a complete guide to hamster care. Lydney, Gloucestershire: Ringpress. ISBN 9781860542466. OCLC 50877868.

[miceandrats.com-12] 1 2 "Varieties of Fancy Mice - AOV - Astrex".

[13] "Eva's Mouse Variety Page - Coated". Archived from the original on 28 October 2007. Retrieved 15 January 2008.

[14] "Varieties of Fancy Rat - Rex and Dumbo Varieties". NFRS.org. National Fancy Rat Society. 2011. § Rex. Archived from the original on 9 February 2017.

[15] "AFRMA Fancy Rats - Varieties". AFRMA.org. American Fancy Rat & Mouse Association. 29 September 2018. § Rex. Retrieved 29 January 2024.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]