Rat Health
Diabetes Insipidus Locus
Located on Chromosome #4Di - Wild Type Dominant.
Effect = None.
di - Diabetic Recessive.
Effect = Hypothalmic diabetes insipidus; injection with vasopressin helps normalize.
Veterinarian Resources; Stock and Strain List http://www.nih.gov/od/ors/dirs/vrp/s&slst.htm#ratinbred.
Jerker Locus
Located on Chromosome #5, near Brown Je - Wild Type Dominant.Effect = None.
je - Jerker Recessive.
Effect = Affected rats act similar to shaker-walter deaf mutants and are neuroepithelial degeneratively deaf. Linked to B (brown).
Veterinarian Resources; G. E. Truett, J. A. Walker and J. W. Brock A rat homolog of the mouse deafness mutant jerker (je) Journal: Mammalian Genome Volume: 7 Pages: 356-358 Year: 1996
Gruneberg's Lethal
Linked to Tyr (aka: c) on chromosome #1. Lg - Wild Type Dominant.Effect = None.
lg - Gruneberg's Lethal Recessive.
Effect = Lethal, found to be linked to Tyr (aka: c) on chromosome #1. Homozygotes appear normal at birth but growth is retarded, with the head looking abnormally large in compairson to the body. Those that live long enough for the teeth to emerge have malocussion. Most are hunchbacked. All affected individuals have deformed rib cages. In normal baby rats, applying slight pressure to the ribcage with the fingers will result in the noticing of some "give". In "lg" homozygotes however, the ribcage is thick and doesnt give even when considerable pressure is applied. Because of this, the lungs are restricted and respiration must be done abdominally rather than in the chest. Because they can not breathe from the chest, they also can not sneeze so the nose becomes clogged with nesting debris- forcing the animal to breathe exclusively through its mouth... making nursing extreemly difficult if not impossible to do. Their abnormal breathing often produces a sharp noise which may sound "metallic".
Homozygotes have emphysema. Additionally the heart situated directly between the ribs and the lungs, rather than partially enveloped by the ribs as in a normal rat. Dilated lungs apply pressure to the lungs themselves and to the heart. Parts of the lungs may collapse. The heart often has hemorraging which fill's the lungs with blood. The nails become dark with pooling blood. Most die by the second week of life, a very few survive up to a month. Causes of death vary but tend to follow one of the following scenarios:
Veterinarian Resources; Robinson, Roy. Genetics of the Norway Rat. Pergamun Press 1965. pg 231.
H. Gruneberg. The linkage relations of a new lethal gene in rat ( rattus norvegicus). Genetics Vol 24 pg 732-741. yr:1939
Microphthalmia Locus
This locus' Chromosomal location is: 4q34-q41 Mitf - Wild Type Dominant.Effect = None.
Mitf(pw) - Micropthalmia pink eyed white.
Effect = Small pink eyes, White fur colour, and bones problems (osteosclerosis). Teeth may be missing, small or easily broken, and also erupt later than do their non-affected siblings. Most animals reach adult age, but only males are fertile. Females are steril.
Veterinarian Resources; Moutier R, Ostrowski K, Lamendin H. Microphthalmia: a new recessive mutation in the Norway rat. J Hered 1989 Jan-Feb;80(1):76-8
Opdecamp, K., et al., The rat microphtalmia-associated transcription factor gene (Mitf) maps at 4q34-q41 and is mutaded in the mib rats. Mammalian Genome 9:617-621 (1998)
Mitf(ew) - Micropthalmia eyeless white.
Effect = Like Mitf(pw) but eyes are totally missing.
Osteopetrosis Locus
Op - Wild Type Dominant.Effect = None.
op - Osteopetrosis autosomal recessive.
Effect = Characterized by significant increase in skeletal mass and shorter and broader bones especially in the region of the epiphyseal plate. Dependig on severity, the young rats may exhibit failure to thrive, anemia, increased susceptibility to infection, an enlarged head/hydrocephalus, optic atrophy, facial paresis. Severely affected individuals may die young but some can live through adulthood.
Veterinarian Resources; Stock and Strain List http://www.nih.gov/od/ors/dirs/vrp/s&slst.htm#ratinbred.
Quiverer Locus
Qv - Wild Type Dominant.Effect = None.
qv - Quiverer Recessive.
Effect = Tremors affecting lateral movement, generally of short magnitude, then repeated at frequent intervals; both sexes fertile;
Veterinarian Resources; Stock and Strain List http://www.nih.gov/od/ors/dirs/vrp/s&slst.htm#ratinbred.
Reeler Locus
Chromosomal location is: 4 q11.2 Rl - Wild Type Dominant.Effect = None.
rl - Reeler
Veterinarian Resources; Y. Matsuda, T. Takahara, M. Kusakabe and Y. Hayashizaki Comparative mapping of the reeler gene on human chromosome 7q22, rat chromosome 4q11.2, and mouse chromosome 5 A3-B1 Mammalian GenomeVolume: 7 Pages: 468-469 Year: 1996
Shiverer Locus
Shi - Wild Type Dominant.Effect = None.
shi - Wild Type Recessive.
Effect = Tremors of varying degree of severity beginning at the head and travelling back to the tail in waves, some so severe it affect's the ability of the individual to walk. Homozygous males are fertile, but homozygous females are infertile.
Veterinarian Resources; Stock and Strain List. http://www.nih.gov/od/ors/dirs/vrp/s&slst.htm#ratinbred.
Spastic Locus
Sp - Wild Type Dominant.Effect = None.
sp(cr) - Spastic Crawler Recessive.
Effect = Trembling evident by 2 weeks of age, rear legs paralyzed by 3 weeks; Incapable of normal movement because of neuromuscular disorder, animals fall on their sides holding limbs out in a rigid position with arched backs; no survivors beyond 4 weeks.
Veterinarian Resources; Stock and Strain List http://www.nih.gov/od/ors/dirs/vrp/s&slst.htm#ratinbred.
Trembler Locus
Tl - Wild Type Dominant.Effect = None.
tl - Trembler Recessive.
Effect = Characterized by uncooridinated movement of fore and hind limbs begining at about 3 weeks of age and progresses until death about 5-7 weeks of age.
Veterinarian Resources; Stock and Strain List http://www.nih.gov/od/ors/dirs/vrp/s&slst.htm#ratinbred.
Tremor Locus
Tr - Wild Type Dominant.Effect = None.
tr - Tremor Recessive.
Effect = Causes epilepsy (whole body tremors), bent overhairs, bent whiskers, and spongiform encephalopathy of the central nervous system. Affected rats are Steril.
Veterinarian Resources; Serikawa T, Yamada J Epileptic seizures in rats homozygous for two mutations, zitter and tremor. . J Hered 1986 Nov-Dec;77(6):441-4
Turning
Tur - Turning DominantEffect = Gene with incomplete penetrance. Affected rats turn in circles as if chasing after their tails. Behavior begins to show around 4 to 5 weeks of age and is agitated by sound or vibration. Turning is more pronounced in younger rats rather than older rats.
Veterinarian Resources; Yamazaki K, Mikami T, Kawaguchi A, Kuwabara M, Nozaki Y, Hosokawa S, Tagaya O, Katoh H, Yamamoto N, Wakabayashi T. A new mutant rat with turning behavior (Tur). Journal of Heredity 1995 Jul-Aug;86(4):311-4
tur - Wild Type Recessive.
Effect = None.
Zitter Locus
Located on Chromosome #3 Zi - Wild Type Dominant.Effect = None.
zi- Zitter Recessive.
Effect = Causes epilepsy (whole body tremors), bent overhairs, bent whiskers, and spongiform encephalopathy of the central nervous system.
Veterinarian Resources; Yamada T, Mori M, Hamada S, Serikawa T, Yamada J Assignment of tremulous body mutant gene zitter (zi) to linkage group IV of the rat (Rattus norvegicus). J Hered 1989 Sep-Oct;80(5):383-6
Serikawa T, Yamada J Epileptic seizures in rats homozygous for two mutations, zitter and tremor. J Hered 1986 Nov-Dec;77(6):441-4
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