The deer mouse (Peromyscus maniculatus) and congeneric species are the most common native North American mammal. They range from Alaska to Central America and occur in many natural habitats. Because of their abundance, these mice constitute a major component of nearctic terrestrial ecosystems. Laboratory stock of both wild-type and genetically variant Peromyscus are used for investigations in which laboratory-based studies can be interfaced with those of natural populations. Deer mice differ distinctly from laboratory house mice (Mus domesticus) and rats (Rattus norvegicus) and are not closely related to these species.
The Peromyscus Genetic Stock Center (PGSC) was established in 1985 to provide a reliable source of these animals and related materials to the national scientific and educational communities. The Stock Center currently keeps seven species of Peromyscus and more than 35 distinctive mutant and other genetically defined stocks, primarily of the deer mouse. The Stock Center also supplies biological materials from Peromyscus including fresh, frozen and preserved tissues. The Stock Center functions as a clearing house for information regarding this genus by sponsoring an internet database, maintaining a reference collection of reprints, standardizing the genetic nomenclature for the genus and publishing a semi-annual Peromyscus Newsletter.
Deer mice can be maintained using standard laboratory mouse methodology. A maximum of six animals can be housed in a 7" X 10" plastic cage. Feed and water are presented ad libitum. Nutritionally complete commercial laboratory rodent feed is advised. Do not use rabbit or guinea pig feed. Supplements of fresh vegetables, raisins, sunflower seed, etc., are unnecessary, and may be detrimental. Peromyscus are reasonably cold tolerant, but ambient temperature should never exceed 33oC. Optimum temperature is 22-25oC.
Laboratory stocks are sexually mature by 55 days of age. The estrous cycle is five days. Gestation is 23 days, except in lactating females where it is delayed by 4-6 days to 28 or 30 days. Breeding is optimized when animals are continuously retained in breeding pairs. The females enter postpartum estrus about 12 hours after delivery and re-mate. Thus, serial litters are born at 28-30 day intervals. About 80% of the pairs are productive within 3 months. There may be a lag in breeding during midwinter under natural lighting.
Peromyscus are bred in mated pairs. Matings are established with young vigorous sexually mature (3-6 months) animals. A 16:8 hour light/dark cycle is maintained. Each mating is assigned an individual identification consisting of a number with a letter prefix. The basic numbering system has been in place since the colony was founded in 1962, and follows many of the conventions of other rodent colonies.
Each mating is checked daily for newborn or obvious pregnancy. Copulatory plugs are inconspicuous in Peromyscus and are not a reliable indication of mating. When a new litter is born, the date and number born are indicated on the mating record card and also on the cage tag. The weaned young are removed from the mating cages at 25-35 days of age, depending on species, ear marked and placed in storage cages separated by sex.
From the Greek "pero" = "boots"
"mys" meaning "mouse"
The "Mouse With Boots", referring to the white feet.
Most species have potential life spans of 4 - 5 years. White-footed mice live up to eight years, therefore have been used as a gerontological model to contrast with house mouse which has a 2 - 3 year life span. In nature, few Peromyscus survive longer than six months.
Mice of the genus Peromyscus range in adult size from 15g (oldfield mouse) to 150g (Thomas' deermouse).
Seeds and berries constitute about 75% of the diet and about 25% is other animal material. A few are more insectivorous.
Feed and water are presented ad libitum. Nutritionally complete commercial laboratory rodent feed is advised. Do not use rabbit or guinea pig feed. Supplements of fresh vegetables, raisins, sunflower seed, etc., are unnecessary, and may be detrimental.
Weanling deer mice are identified by ear punch. Only the last two digits of an animal number is marked. Numbering Chart