Laboratory rat

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(Redirected from
Sprague-Dawley rat
)

albino
laboratory rat with its red eyes and white fur is an iconic model organism for scientific research in a variety of fields

Laboratory rats or lab rats are

biomedical science.[1]

Origins of rat breeding

Rat-baiting

In 18th-century

Rattus norvegicus) ran rampant and this infestation fueled the industry of rat-catching. Rat-catchers would not only make money by trapping the rodents, but also by selling them for food or, more commonly, for rat-baiting
.

Rat-baiting was a popular sport, which involved filling a pit with rats and timing how long it took for a

domesticated for purely scientific reasons.[2]

Hooded

In

albino rat strains collected from all parts of the world carried out by a team led by Takashi Kuramoto at Kyoto University in 2012 showed that the albinos descended from hooded rats and all the albinos descended from a single ancestor.[3] As there is evidence that the hooded rat was known as the "Japanese rat" in the early 20th century, Kuramoto concluded that one or more Japanese hooded rats might have been brought to Europe or the Americas and an albino rat that emerged as a product of the breeding of these hooded rats was the common ancestor of all the albino laboratory rats in use today.[3]

Use in research

Dissection

The rat found early use in

William Ernest Castle at the Bussey Institute of Harvard University until it closed in 1994. Rats have long been used in cancer research; for instance at the Crocker Institute for Cancer Research.[7]

Morris water navigation test

The historical importance of this species to scientific research is reflected by the amount of

euthanized or, in some cases, become pets
.

Deprivation of REM sleep using the flowerpot technique

Rodentia) in many ways: they are calmer and significantly less likely to bite, they can tolerate greater crowding, they breed earlier and produce more offspring, and their brains, livers, kidneys, adrenal glands, and hearts
are smaller.

Scientists have bred many

Sprague Dawley, Fischer 344,[8] Holtzman albino strains, Long–Evans, and Lister black hooded rats. Inbred strains
are also available, but are not as commonly used as inbred mice.

Much of the

sequenced.[9] In October 2003, researchers succeeded in cloning two laboratory rats by nuclear transfer. This was the first in a series of developments that have begun to make rats tractable as genetic research subjects, although they still lag behind mice, which lend themselves better to the embryonic stem cell techniques typically used for genetic manipulation. Many investigators who wish to trace observations on behavior and physiology to underlying genes
regard aspects of these in rats as more relevant to humans and easier to observe than in mice, giving impetus to the development of genetic research techniques applicable to rats.

Traversing complex terrain under the influence of electrode inputs to its brain

A 1972 study compared

testicular tumors occurred in the rats from a single supplier. The researchers found that the incidence of tumors in Sprague Dawleys from different suppliers varied as much from each other as from the other strains of rats. The authors of the study "stressed the need for extreme caution in evaluation of carcinogenicity studies conducted at different laboratories and/or on rats from different sources."[10]

During food rationing due to World War II, British biologists had eaten laboratory rats, creamed.[11][12][13][14][15][16]

Scientists have also spent time studying the thermoregulation of the rat's tail in research. The rat's tail works as a variable heat exchanger. The tail's blood flow allows for thermoregulation to take place because it is under control of sympathetic vasoconstrictor nerves.[17] Vasodilation occurs when the tail temperature increases, causing heat loss. Vasoconstriction occurs when the tail temperature decreases allowing heat to be conserved. Thermoregulation in the rat tail has been used to study metabolism.[18]

Stocks and strains

A "

outbred" populations are used when identical genotypes are unnecessary or a population with genetic variation is required, and these rats are usually referred to as "stocks" rather than "strains".[19][20]

Wistar rat

Wistar rat

The Wistar rat is an outbred albino rat. This breed was developed at the Wistar Institute in 1906 for use in biological and medical research, and is notably the first rat developed to serve as a model organism at a time when laboratories primarily used the house mouse (Mus musculus). More than half of all laboratory rat strains are descended from the original colony established by physiologist Henry Herbert Donaldson, scientific administrator Milton J. Greenman, and genetic researcher/embryologist Helen Dean King.[21][22][23]

The Wistar rat is currently one of the most popular rats used for laboratory research. It is characterized by its wide head, long ears, and a tail length that is always less than its body length. The Sprague Dawley and Long–Evans were developed from Wistars. Wistars are more active than others like Sprague Dawleys. The

Lewis
are other well-known stocks developed from Wistars.

Long–Evans rat

The Long–Evans rat is an outbred rat developed by Long and Evans in 1915 by crossbreeding several Wistar females with a wild gray male. Long-Evans rats are white with a black hood, or occasionally white with a brown hood. They are utilized as a multipurpose model organism, frequently in behavioral research, especially in alcohol research. Long-Evans consume alcohol in a much higher rate compared to other strains, thus require less time for these behavioral studies.[citation needed]

Sprague Dawley rat

Sprague Dawley rat

The Sprague Dawley is an outbred, multipurpose breed of

albino rat used extensively in medical and nutritional research.[24][25][26][27] Its main advantage is its calmness and ease of handling.[28] This breed of rat was first produced by the Sprague Dawley farms (later to become the Sprague Dawley Animal Company) in Madison, Wisconsin, in 1925. The name was originally hyphenated, although the brand styling today (Sprague Dawley, the trademark used by Envigo) is not. The average litter size of the Sprague Dawley rat is 11.0.[29]

These rats typically have a longer tail in proportion to their body length than Wistars. They were used in the

RoundUp was claimed to increase the occurrence of tumor in these rats. However, since these rats are known to grow tumors at a high (and very variable) rate, the study was considered flawed in design and its findings unsubstantiated.[30]

Biobreeding rat

The biobreeding rat (a.k.a. the biobreeding diabetes-prone rat or BBDP rat) is an inbred strain that spontaneously develops autoimmune type 1 diabetes. Like NOD mice, biobreeding rats are used as an animal model for Type 1 diabetes. The strain re-capitulates many of the features of human type 1 diabetes and has contributed greatly to the research of T1DM pathogenesis.[31]

Brattleboro rat

The Brattleboro rat is a strain that was developed by

Dartmouth Medical School. It has a naturally occurring genetic mutation that makes specimens unable to produce the hormone vasopressin
, which helps control kidney function. The rats were being raised for laboratory use by Henry Schroeder and technician Tim Vinton, who noticed that the litter of 17 drank and urinated excessively.

Hairless rat

Hairless laboratory rats provide researchers with valuable data regarding compromised immune systems and genetic kidney diseases. It is estimated that there are over 25 genes that cause

recessive hairlessness in laboratory rats.[32]
The more common ones are denoted as rnu (Rowett nude), fz (fuzzy), and shn (shorn).

A Rowett nude rat
  • Rowett nude rats, first identified in 1953 in Scotland, have no thymus. The lack of this organ severely compromises their immune system, with infections of the respiratory tract and eyes increasing the most dramatically.[33]
  • Fuzzy rats were identified in 1976 in a Pennsylvania lab. The leading cause of death among fz/fz rats is ultimately a progressive kidney failure that begins around the age of 1 year.[34]
  • Shorn rats were bred from Sprague Dawley rats in Connecticut in 1998.[35] They also suffer from severe kidney problems.

Lewis rat

The Lewis rat was developed by Margaret Lewis from Wistar stock in the early 1950s. Characteristics include albino coloring, docile behavior, and low fertility.[36] The Lewis rat suffers from several spontaneous pathologies: first, they can suffer from high incidences of neoplasms, with the rat's lifespan mainly determined by this. The most common are adenomas of the pituitary and adenomas/adenocarcinomas of the adrenal cortex in both sexes, mammary gland tumors and endometrial carcinomas in females, and C-cell adenomas/adenocarcinomas of the thyroid gland and tumors of the haemopoietic system in males. Second, Lewis rats are prone to develop a spontaneous transplantable lymphatic leukaemia. Lastly, when in advanced age, they sometimes develop spontaneous glomerular sclerosis.[36]

Research applications include transplantation research, induced arthritis and inflammation, experimental allergic encephalitis, and STZ-induced diabetes.[37][36]

Royal College of Surgeons rat

A Royal College of Surgeons rat undergoing visual acuity testing

The Royal College of Surgeons rat (or RCS rat) is the first known animal with inherited retinal degeneration. Although the genetic defect was not known for many years, it was identified in the year 2000 as a mutation in the gene MERTK. This mutation results in defective retinal pigment epithelium phagocytosis of photoreceptor outer segments.[38]

Shaking rat Kawasaki

The shaking rat Kawasaki (SRK) is an

RELN (reelin) gene.[39] This results in the lowered expression of reelin protein, essential for proper cortex lamination and cerebellum development. Its phenotype is similar to the widely researched reeler mouse. Shaking rat Kawasaki was first described in 1988.[40]
This and the Lewis rat are well-known stocks developed from Wistar rats.

Zucker rat

Zucker rat

The Zucker rat was bred to be a genetic model for research on obesity and hypertension. They are named after Lois M. Zucker and Theodore F. Zucker, pioneer researchers in the study of the genetics of obesity. There are two types of Zucker rat: a lean Zucker rat, denoted as the dominant trait (Fa/Fa) or (Fa/fa); and the characteristically obese (or fatty) Zucker rat or Zucker diabetic fatty rat (ZDF rat), which is actually a recessive trait (fa/fa) of the leptin receptor, capable of weighing up to 1 kilogram (2.2 lb) — more than twice the average weight.[41][42][43]

Obese Zucker rats have high levels of

hyperphagic nature and excessive hunger; however, food intake does not fully explain the hyperlipidemia or overall body composition.[42][44]

Knockout rats

A knockout rat (also spelled knock out or knock-out) is a

Knock Out Rat Consortium (KORC). Knockout rat disease models for Parkinson's disease, Alzheimer's disease, hypertension, and diabetes, using zinc-finger nuclease technology, are being commercialized by SAGE Labs
.

See also

References

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  2. ^ .
  3. ^ a b Kuramoto, Takashi (November 2012). "Origin of Albino Laboratory Rats". Bio Resource Newsletter. National Institute of Genetics. Retrieved 20 December 2013.
  4. ^ John B. Watson (1903) "Psychical development of the white rat", Ph.D. University of Chicago
  5. PMID 11615648
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  6. ^ Long, J. A.; Evans H. M. (1922). The oestrous cycle in the rat and its associated phenomena. University of California Press.
  7. .
  8. ^ "43rd Annual Pathology of Laboratory Animals Course". Archived from the original on 16 August 2000. Retrieved 15 September 2008.
  9. Ensembl
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  19. ^ International Committee on Standardized Genetic Nomenclature for Mice / Rat Genome and Nomenclature Committee (January 2016). "Rules and Guidelines for Nomenclature of Mouse and Rat Strains". Mouse Genome Informatics. Jackson Laboratory. Retrieved 5 December 2018.
  20. ^ "Outbred Stocks". 15 February 2019.
  21. ^ Clause, B. T. (February 1998). "The Wistar Institute Archives: Rats (Not Mice) and History". Mendel Newsletter. Archived from the original on 16 December 2006.
  22. ^ "The Wistar Institute: History". The Wistar Institute. 2007. Archived from the original on 17 October 2008. Retrieved 9 November 2008.
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  28. ^ "Online Medical Dictionary". 12 December 1998. Archived from the original on 2 December 2008. Retrieved 15 December 2007.
  29. ^ "Sprague Dawley Outbred Rat". Harlan Laboratories. Archived from the original on 26 October 2012. Retrieved 25 October 2012.
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  36. ^ a b c "Research Animal Models". CRiver.com. Charles River Laboratories. 2021. Archived from the original on 24 May 2013.
  37. ^ "Lewis Rat". CRiver.com. Charles River Laboratories. Retrieved 7 June 2021.
  38. ^ D'Cruz, P. M.; Yasumura, D.; Weir, J.; Matthes, M. T.; Abderrahim, H.; LaVail, M. M.; Vollrath, D. (March 2000). "Mutation of the receptor tyrosine kinase gene Mertk in the retinal dystrophic RCS rat".
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  42. ^ a b Davis, Amy J. (January 1997). "The Heart of a Zucker". Research PennState. 18 (1). Archived from the original on 22 May 2002. Retrieved 6 December 2008.
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Further reading

External links