Color mouse
Color mice ( Mus musculus f. Domestica) are mammals ( Mammalia ) from the order of rodents ( Rodentia ). They are the domesticated form of the house mouse ( Mus musculus ). The most important European wild subspecies of the house mouse are the western house house mouse ( Mus musculus domesticus ) and the northern field house mouse ( Mus musculus musculus ). The cultivated forms of domesticated mice, which are zoologically referred to as Mus musculus forma domestica , are derived from Mus musculus domesticus .
Color mice are offered as pets for permanent keeping and in terraristics also as food animals for feeding snakes and other exotic domestic and zoo animals ( reptiles ). They have also been one of the most important model organisms in European animal research since the mid-19th century .
origin
The direct ancestors of color mice are the usually gray-brown house mice. Breeders derived various forms of appearance with different coat colors, coat variants and sizes from them. If free-range mice are successfully kept in cages for several generations and repeatedly mated with one another, it is to be expected that individual cubs will be born with a purely white or purely black coat after around ten generations. Color mice are mostly unable to survive in the wild and are dependent on human care ( commensalism ).
White mice are usually albino forms, which means that as a result of a mutation, the production of skin pigments ( melanins ) has completely failed, which is why these animals also have unpigmented and - due to the blood supply to the eye - red eyes. White mice are already known from ancient Crete . They were considered sacred and good luck charms. Sometimes dozens were kept in special temples and cared for at state expense.
Based on some images on bowls and clay pots of ancient Egypt , it is known that mice were kept there 4000 years ago. The Egyptians ascribed them supernatural powers.
In China , so-called dance mice have been known since around the Late Bronze Age. Dancing mice, white mice, and color mice have been bred in Japan since about the 18th century. From there the first such mice made their way to America and finally to Europe . Today dance mice are considered torture breeding in Germany .
The god Apollo was revered for centuries in Sicily , Greece and Asia Minor as the mouse god named Smintheus , and real mice were used to question the gods. In the middle of the 19th century, the British were primarily concerned with the selection of colors and drawings of mice. It is believed that the first British mice came with Portuguese navigators from Japan rather than Greece.
At the end of the 19th century the first association (National Mouse Club - NMC) was established in England, which dealt with the breeding, exhibition and awarding of color mice. Since 2004 there has also been an association in Germany dedicated to breed breeding and the exhibition of colored mice, the German Mice Breed Association Muroidea eV (DMRM).
behavior
Like many rodents , color mice also show an alternation of activity and rest phase ( polyphasic ) several times a day . They are very good at climbing, jumping high, and will fit through any holes their head can fit through; the rest of the body is extremely malleable. The tail is used as a "rudder" to maintain balance. It can also be used as a "suspension line".
Color mice are social animals. The parent species lives in groups. In the case of pure female groups, there are hardly any battles for ranking . Keeping males is more difficult. If there are several males in a group, regardless of the degree of relationship of the animals with the onset of sexual maturity, fights can occur which, regardless of the size of the holding area, can end with bite wounds or fatal. After castration , male mice largely abandon their aggressive behavior because of the reduced production of sex hormones and can then be kept together with castrated males or females.
Color mice are omnivores . In addition to plant-based food, they also feed on insects . They communicate by means of sounds in the ultrasound range , which is imperceptible to humans.
Reproduction and Life Expectancy
Color mice show a high fertility rate (FTR), regardless of the space available. Females can be recognized by the vaginal opening in the back of the lower abdomen. In females, the distance between anus and genital opening is also significantly smaller than in males, which can also be recognized by their externally clearly visible testicles.
The sexual maturity of female color mice depends on various factors such as genetic disposition, the state of development, length of day and ambient temperature. In the literature, the information varies between 28 and 56 days after birth. Male color mice become sexually mature at 28 to 35 days.
Color mice have a year-round sexual cycle that is stimulated by male urine and a regular 12-hour light / dark rhythm. The litter size of vital females is between three and twelve young animals, sometimes even more. Smaller litters can indicate that the mother is old (more than six months) or that the parents are beginning to have inbreeding depression , but they also occur occasionally in completely vital females. The ability to reproduce ends at the age of approx. 8 months after 4 to 6 litters. Females that are not related to each other also help each other in rearing young and thus increase the reproductive success.
17 to 24 days after fertilization , the still naked, deaf and blind boys ( nestlings ) are born. A few hours after giving birth, the female is ready to conceive again. If the female covered while it is still suckling, delayed usually the preimplantation period until the uterine lining has regenerated, and therefore the gestation period of seven to fourteen days.
Three days after birth, the boys' fur begins to grow , so that you can gradually see the first marks and coat colors. After about ten days the fur is completely developed. After almost two weeks, the eyes open and the young animals leave the nest to explore the area for the first time. From this point on, the dams no longer show any feeding behavior . In addition, the young begin to eat independently, but are still suckled until they are 21 to 30 days old. Young animals need six to eight weeks of contact with their mother for undisturbed development of their social behavior.
The life expectancy of color mice is usually around 1.5 to 2 years, but individual animals can also get considerably older. Tumors are a common cause of death .
Use in biomedical research
For research purposes, color mice ("laboratory mice") are bred as inbred strains, each with different genotypic properties. So the tribe "NMRI" is particularly suitable for behavioral tests (the acronym stands for its origin from the Naval Medical Research Institute ), other tribes tend to earlier tumor formation and are therefore used in cancer research. The effects of infections on fertility , embryonic development or Alzheimer's dementia , for example , can be researched with other strains .
Well-known strains are, for example, “C57BL / 6”, “ NOD ” and nude mouse ( naked mouse ). Since the early 1980s it has been possible to genetically modify mice in such a way that new genes are introduced (so-called transgenic mice) or genes are switched off in the whole mouse or in individual tissues (“ knockout mouse ” or conditionally gene-deficient mouse ). Such genetically modified mouse strains are used extensively to research the function and significance of genes.
It is estimated that knockout mouse strains have currently been generated for about a third of all known genes.
For the generation of the first knockout mouse and their subsequent work, Martin Evans , Mario Capecchi and Oliver Smithies were awarded the 2007 Nobel Prize in Physiology or Medicine .
However, mice are not equally suitable for all research topics: the activation of genes after inflammation , for example, follows a different pattern in mice than in humans.
See also
Web links
- Model organism mouse. On: mpg.de , last viewed on June 16, 23010.
- Veterinary Association for Animal Welfare eV: Mice. Leaflet for pet owners, status: October 2013.
- Deutscher Tierschutzbund eV: My color mice
- Color mice in: A heart for animals. Retrieved June 27, 2015
- Color mouse info Information portal to avoid posture errors in color mouse keeping
- Biomaus project Advice on the appropriate keeping of food mice
Individual evidence
- ↑ Stefanie Weber: Sonographic pregnancy diagnosis in the multi-teat mouse (Mastomys coucha) Univ.-Diss., Munich 2014 (Faculty of Veterinary Medicine)
- ↑ Ultrasound chants: Mice men learn new songs Der Spiegel, October 11, 2012. Accessed June 28, 2015.
- ↑ Stefanie Weber: Sonographic pregnancy diagnosis in the multi-teat mouse (Mastomys coucha) Univ.-Diss., Munich 2014 (Faculty of Veterinary Medicine)
- ↑ Mice men bewitch with their fragrance Vetmeduni Vienna, Thieme-Verlag
- ^ University of Kentucky : Mouse Reproduction ( Memento July 2, 2016 in the Internet Archive ) Reproductive life, p. 2
- ↑ Silke Mateika: Influence of different genetic backgrounds on the pathology of the small intestine after oral infection with Yersinia enterocolitica in the mouse Univ.-Diss. FU Berlin 2007
- ↑ Silke Mateika: Influence of different genetic backgrounds on the pathology of the small intestine after oral infection with Yersinia enterocolitica in the mouse Univ.-Diss. FU Berlin 2007, pp. 19-67
- ^ Mouse projects of the Department of Molecular Developmental Biology at the University of Bonn
- ↑ Stephan Röskam: In vivo behavior models for neurodegenerative diseases ( Memento from March 4, 2016 in the Internet Archive ) AG Neurological Therapy Research , University of Marburg
- ↑ Information from the Nobel Foundation on the 2007 award ceremony for Martin Evans, Mario Capecchi and Oliver Smithies (English)
- ↑ Junhee Seok et al .: Genomic responses in mouse models poorly mimic human inflammatory diseases. In: PNAS . Volume 110, No. 9, 2013, pp. 3507-3512, doi: 10.1073 / pnas.1222878110