Multimammate Rats/Mice Flashcards
Where are multimammate native to?
South Africa, probably one of most widely distributed and abundant rodents in Africa
Where does the common name arise from?
High number of mammary glands - Usually 8 to 12 pairs, but can be as many as 18.
What species are most commonly used in research? How do they differ?
Mastomys natalensis and M. coucha.
Morphologically identical and overlap in their habitats. Differ in chromosome number, biochemical traits, and sperm morphology
In which habitats are MMRs found?
Throughout much of sub-Saharan Africa, chiefly in association with people. Do not occupy large towns, probably due to competition with Rattus.
What are MMRs used for in research?
M. natalensis is natural host of hemorrhagic fever agent Lassa virus. Also studied on spread of Mopeia virus, an arenavirus related to Lassa virus that is non-pathogenic to humans.
M. coucha is natural host of bubonic plague.
What gastric research do MMRs contribute to?
M. natalensis spontaneously develop gastric carcinoid and serve as a model for Zollinger Ellison syndrome.
Describe endogenous papillomaviruses in MMRs.
M. natalensis has endogenous papillomavirus MnPV which causes cutaneous tumors on activation.
M. coucha has McPV2 that produces anogenital condylomas.
What is the richest source of nerve growth factor?
M. natalensis submaxillary salivary gland.
Describe the prostate and gallbladder in M. natalensis.
Both sexes have a prostate, no gallbladder, like rats.
How long does the MMR live?
3 years
Describe reproduction in MMRs.
Sexually mature at 55-75 days. 6-8 day estrous cycle. Breed year round with postpartuirent estrus. Gestation of 23 days with 6-12 pups. Pups weaned at 19-21 days.
What is unique about housing of MMRs in captivity?
Aggressive in the lab. Will attempt to dispose of waste in captivity by pushing it through a hole in the cage.
What are important considerations for feeding MMRs in captivity?
In wild, will eat nearly everything humans do. M. coucha has narrow range for protein, with depressed reproduction at protein higher and lower than 10-15%.
What neoplastic disease is common in aged MMRs? What is it associated with?
Lymphoepithelial thymoma in animals over 2. Associated with myositis, atrophy of skeletal muscles, and myocarditis.
What degenerative change is common in aged MMRs?
Osteoarthritis. Degenerative joint disease.
What autoimmune conditions are found in MMRs?
Autoimmune thyroiditis and membranous/membranoproliferative glomerulonephritis
A high incidence of what intestinal condition is seen in MMRs?
Duodenitis and duodenal ulcers.
