The Selkirk Rex is a breed of cat with highly curled hair.
23-777: The Selkirk Rex is distinct from all other Rex breeds. Unlike the Devon Rex and Cornish Rex , the hair is of normal length and not partly missing. There are longhair and shorthair varieties. It differs from the LaPerm in that the Selkirk Rex coat is plusher and thicker. While the LaPerm gene is a simple dominant, the Selkirk gene (Se) acts as an incomplete dominant ; incompletely dominant allele pairs produce three possible genotypes and phenotypes : heterozygous cats (Sese) may have
46-565: A few million base pairs generally cannot be seen on a karyogram. Autosomal genetic disorders can arise due to a number of causes, some of the most common being nondisjunction in parental germ cells or Mendelian inheritance of deleterious alleles from parents. Autosomal genetic disorders which exhibit Mendelian inheritance can be inherited either in an autosomal dominant or recessive fashion. These disorders manifest in and are passed on by either sex with equal frequency. Autosomal dominant disorders are often present in both parent and child, as
69-558: A fuller coat that is preferred in the show ring, while homozygous cats (SeSe) may have a tighter curl and less coat volume. The Selkirk Rex originated in Montana , USA in 1987, with a litter born to a rescued cat. The only unusually coated kitten in the litter was ultimately placed with breeder Jeri Newman, who named her Miss DiPesto (after a curly-haired character in the TV series Moonlighting played by Allyce Beasley ). This foundation cat
92-455: A result of unbalanced translocations during meiosis. Deletions of part of a chromosome cause partial monosomies, while duplications can cause partial trisomies. If the duplication or deletion is large enough, it can be discovered by analyzing a karyogram of the individual. Autosomal translocations can be responsible for a number of diseases, ranging from cancer to schizophrenia . Unlike single gene disorders, diseases caused by aneuploidy are
115-420: A retrospective study of cases of the disease. The Devon Rex is predisposed to congenital hypotrichosis and Malassezia dermatitis . Autosomal An autosome is any chromosome that is not a sex chromosome . The members of an autosome pair in a diploid cell have the same morphology , unlike those in allosomal ( sex chromosome ) pairs, which may have different structures. The DNA in autosomes
138-414: A single copy of an autosome (known as a monosomy) is nearly always incompatible with life, though very rarely some monosomies can survive past birth. Having three copies of an autosome (known as a trisomy) is far more compatible with life, however. A common example is Down syndrome , which is caused by possessing three copies of chromosome 21 instead of the usual two. Partial aneuploidy can also occur as
161-514: A type of dye (most commonly, Giemsa ). These chromosomes are typically viewed as karyograms for easy comparison. Clinical geneticists can compare the karyogram of an individual to a reference karyogram to discover the cytogenetic basis of certain phenotypes . For example, the karyogram of someone with Patau Syndrome would show that they possess three copies of chromosome 13 . Karyograms and staining techniques can only detect large-scale disruptions to chromosomes—chromosomal aberrations smaller than
184-718: Is a large and solidly built breed, similar to a British Shorthair . The coat is very soft and has a woolly look and feel with loose, unstructured curls. The head is round, with large rounded eyes, medium-sized ears, and a distinct muzzle, whose length is equal to half its width. An extreme break, like that of a Persian, is a disqualifiable fault. American Shorthairs , Persians , Himalayans , Exotic Shorthairs , and British Shorthairs have been used as outcrosses to develop this breed. The American Shorthair has now been discontinued as an outcross, except in The International Cat Association (TICA). The breed
207-648: 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. Beryl Cox came across a novel curly-coated kitten in Buckfastleigh , Devon in 1960 whom she decided to name Kirlee . Originally, Cox believed the cat's gene to be related to the Cornish Rex which led to her breeding Kirlee with Cornish Rexes. However, when
230-740: Is collectively known as atDNA or auDNA . For example, humans have a diploid genome that usually contains 22 pairs of autosomes and one allosome pair (46 chromosomes total). The autosome pairs are labeled with numbers (1–22 in humans) roughly in order of their sizes in base pairs, while allosomes are labelled with their letters. By contrast, the allosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. Unusual combinations XYY , XXY , XXX , XXXX , XXXXX or XXYY , among other irregular combinations, are known to occur and usually cause developmental abnormalities. Autosomes still contain sexual determination genes even though they are not sex chromosomes. For example,
253-476: Is found in some Devon Rexes. It is caused by a genetic variant known as COLQ and it appears anytime from 3 to 23 weeks of age. Typically, there is a chance that the myopathy in the cats might stabilize, however, most of the time, the condition worsens and the Devon rex cats die from laryngospasm , after obstructing their larynx with food. The Devon Rex was found to be predisposed to feline atopic dermatitis in
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#1732797212769276-564: The SRY gene on the Y chromosome encodes the transcription factor TDF and is vital for male sex determination during development. TDF functions by activating the SOX9 gene on chromosome 17 , so mutations of the SOX9 gene can cause humans with an ordinary Y chromosome to develop as females. All human autosomes have been identified and mapped by extracting the chromosomes from a cell arrested in metaphase or prometaphase and then staining them with
299-601: The breed. In the UK, all Selkirk Rex registered with the Governing Council of the Cat Fancy (GCCF) for breeding are genetically tested for Polycystic Kidney Disease or are from two genetically tested parents. The Selkirk Rex is defined by an autosomal dominant woolly rexoid hair (ADWH) abnormality that is characterized by tightly curled hair shafts. A splice variant in the gene KRT71 was found to be associated with
322-471: The brow curving to a flat skull. The eyes are large, set wide, and oval-shaped. Devon Rexes may have any eye colour. The ears are large and set wide apart with rounded tips. The coat is short dense and soft and curls inwards a little giving it a waved or rippled effect. Some areas of the body such as the neck may lack enough fur for the wave/ripple effect. The whiskers and eyebrows are crinkled and twisted. Devon Rexes may come in any colour. Hereditary myopathy
345-446: The child needs to inherit only one copy of the deleterious allele to manifest the disease. Autosomal recessive diseases, however, require two copies of the deleterious allele for the disease to manifest. Because it is possible to possess one copy of a deleterious allele without presenting a disease phenotype, two phenotypically normal parents can have a child with the disease if both parents are carriers (also known as heterozygotes ) for
368-482: The chocolate and lilac series. This breed has an extremely dense coat and high propensity for shedding. Unlike other Rex breeds with reduced amounts of hair, the Selkirk Rex is not recommended for those who might be allergic to cat allergens . The temperament of the Selkirk Rex reflects that of the breeds used in its development. They have a lot of the laid-back, reserved qualities of the British Shorthair,
391-413: The condition. Autosomal aneuploidy can also result in disease conditions. Aneuploidy of autosomes is not well tolerated and usually results in miscarriage of the developing fetus. Fetuses with aneuploidy of gene-rich chromosomes—such as chromosome 1 —never survive to term, and fetuses with aneuploidy of gene-poor chromosomes—such as chromosome 21 — are still miscarried over 23% of the time. Possessing
414-539: The cuddly nature of the Persian, and the playfulness of the Exotic Shorthair. There are no known health problems specific to the Selkirk Rex breed. They are a robust breed. Breeding towards proper head structure is necessary to prevent kinking of the tear ducts , resulting in tear run down the front of the face, or muzzle creases that can result in dermatitis on the face. Like other Rex breeds, irritation of
437-533: The curly coat phenotype . KRT71 is a crucial gene for keratinization of the hair follicle. An allele of this gene is also responsible for the hairless (hr) Sphynx and the Devon Rex (re) hair. Three mutations in KRT71 have now been identified in cats, forming the allelic series, KRT71SADRE > KRT71+ > KRT71re > KRT71hr, where SADRE is the suggested locus designation for the Selkirk autosomal dominant rex 21 allele . Devon Rex The Devon Rex
460-532: The inside of the ear by curly fur can occur, increasing the production of ear wax. Homozygous cats (with two copies of the dominant Selkirk Rex gene) may have a tendency towards excessive greasiness of the coat, requiring increased frequency of bathing. Other health problems may be inherited from the outcross breeds used, including polycystic kidney disease from Persians and hypertrophic cardiomyopathy from British Shorthairs. Responsible breeders screen their breeding cats for these diseases to minimize their impact on
483-409: The queen gave birth the kittens all had straight coats, which led to the discovery that Kirlee had a different mutation than Cornish Rexes. Following this Cox began a breeding program to try and preserve Kirlee's unique mutation. The Devon Rex is a very short haired breed with a medium build and a unique head type which gives the breed a 'pixie-like' appearance. The head is short with a broad wedge and
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#1732797212769506-606: Was accepted by The International Cat Association in 1992, the American Cat Fanciers Association in 1998, and the Cat Fanciers' Association in 2000. In Cat Fanciers' Association (CFA) and in Australia, all outcrosses are scheduled to be discontinued in 2015. The breed is accepted in all colors, including the pointed, sepia, and mink varieties of albinism; bicolors; cinnamon; silver/smoke; and
529-470: Was bred to a black Persian tomcat, producing three Selkirk Rex and three straight-haired kittens. This demonstrated that the gene had an autosomal dominant mode of inheritance. All Selkirk Rex trace their ancestry back to the cat Miss DiPesto. Jeri Newman named the breed after her stepfather, "Selkirk," making this the first (and currently only) breed of cat to be named after an actual person. The breed has been developed in two coat lengths, long and short. It
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