Unusual Rodents

Question 14

Name genus and species, and use in research.

Answer 14

Prarie vole, Microtus ochrogaster is pictured, but looks very similar to the Eastern prarie vole, M. pennsylvanicus

M. orchrogaster used to study physiology of vomeronasal organ and how chemosensory cues affect courtship, territorial marking, aggression, and reproduction. Also, M. ochrogaster is monogamous, and studies have focused on neuropeptides oxytocin and vasopressin control of pair-bonding, paternal care, maternal care, and mate-guarding.

M. pennsylvanicus is polygamous and somewhat antisocial, and is used as a contrasting species in the above studies.

Question 15

Name the genus and species and use in research.

Answer 15

Spermophilus beecheyi, California ground squirrel (LEFT).

Spermophilus elegans, Wyoming ground squirrel (RIGHT).

Hibernation studies

Cholesterol-fed ground squirrels used to study cholesterol gallstones and associated changes in gallbladder epithelium

Hepatitis B and hepatocellular carcinoma; Hepatocellular carcinoma has also developed in ground squirrels infected with ground squirrel hepatitis virus (GSHV)

Question 16

Name the genus and species, and uses in research.

Answer 16

Cynomys ludovicianus, Black-tailed prairie dog

Orthopox virology - recently developed as model for monkeypox pathogenesis & transmission

Model for biliary physiology, pathophysiology of gallstone formation. Prarie dog had accessible gall bladder which lies on ventral surface of right lobule of liver.

Also a model for antibiotic-induced diarrhea. Cefoxitin induces Clostridium dificile cecitis in this species, with a more chronic course than other such animal model species.

Question 17

Name the genus and species and use in research. Unique husbandry requirements?

Answer 17

Dipodomys spectabilis, Banner-tailed kangaroo rat

Used to study renal physiology, water conservation, disuse osteoporosis, evolutionary neuroanatomy, and marginal decompression sickness.

Do not provide ad lib water.

Require dust baths.

Very aggressive towards one another and highly territorial. They can be housed together only in extremely large areas.

Question 18

Name genus and species and use in research.

Answer 18

Neotoma floridana, Eastern wood rat

Used in behavioral and neurological studies.

A source of numerous zoonotic microorganisms:

1. murine typhus (Rickettsia typhus)
2. Brucella neotomae
3. Trypanosoma cruzi
4. Leishmania mexicana
5. Yersinia pestis
6. Lyme disease (Borrelia borgdorferi)
7. human granulocytic ehrlichiosis (Ehrlichia phagocytophila)
8. arenaviruses
9. hantavirus

Also, N. micropus contains an antihemorrhagic factor in serum against rattlesnake venom, similar to the cotton rat (Sigmodon hispidus), and opossum (Didelphis virginiana)

Question 19

Name genus and species and use in research.

Unique husbandry considerations?

Answer 19

Onychomys leucogaster, Northern grasshopper mouse

1. Behavior studies including aggression, predation, sex differences
2. Lyme disease (Borrelia borgdorgeri)
3. effect of photoperiod and melatonin on seasonal gonadal cycles
4. comparative antibody formation
5. cancer induction
6. population dynamics using DNA and mitochondrial analysis

Require dust baths, nocturnal, prone to seizures (like Mogolian gerbils) and prevalence is affected by preweaning environment.

Carnivorous

Question 20

Name genus and species and use in research.

Answer 20

Peromyscus leucopus, White-footed deer mouse.

P. leucopus and P. maniculatus readily adapt to laboratory environment. Used to study genetics, physiology, aging, cataracts, behavior.

Also used to study zoonotic diseases:

1. sin nombre and other hanatviruses
2. Lyme disease
3. vesicular stomatitis virus
4. granulocytic ehrlichia
5. babesiosis
6. trypanosomiasis
7. tularemia

Question 21

Name the genus and species and use in research.

Answer 21

Oryzomys palustris, Rice rat

1. Spontaneously develops dental disease, which is accelarted by a high sucrose diet. Used to study effects of drugs, vitamin E, and rotational stress on periodontal bone resorption.
2. effect of photoperiod on reproduction, especially melatonin and the pineal gland.
3. Robertsonian tranlocation polymorphisms exist within the species characterized by varying diploid numbers: 50, 49, 48, and 46.

Question 22

Name genus and species and use in research.

Answer 22

Zygodontomys brevicauda, Cane mouse

1. Used to study mammalian circannual reproductive cycles this is one the few tropical species which lack a reproductive response to photoperiod.
2. Evolutionary quatitative genetics
3. Viral diseases such as: arborviruses, yellow fever virus, Nariva virus (rodent parmyxovirus), Venezualian equine encephalomyelitis virus, Cocal virus (rhabdovirus),and Guanarito virus (cause of Venezuelian hemorrhagic fever - VHF)

Question 23

Name genus and species and use in research.

Answer 23

Sigmodon hispidus, Cotton rat

These human paramyxoviruses replicate well in the cotton rat:

1. respiratory syncytial virus
2. parainfluenza virus 3
3. measles

Also, cotton rats can be infected with human adenovirus, and are the only animal model of ocular adenovirus causing epidemic keratoconjunctivitis.

Used to develop gene therapy for Cystic Fibrosis with adenoviral vectors

Solitary and high dominance hierarchy, and aggressive with staff and towards one another - sometimes fighting to the death.

Prone to tail slip

Question 24

Name genus and species and use in research.

Answer 24

Mystromys albicaudatus, White-tailed rat

1. Spontaneously develop diabetes mellitus, hyperglycemia, polyuria, glycosuria, ketonuria, degenerative changes in islets. Not associated with obesity. More common in males. Models for diabetic angiopathy, and diabetic mitochondrial dysfunction.
2. Models for cutaneous leishmaniasis (Leishmania braziliensis. L, donovani, L. mexicani) including vaccine studies.
3. Model for Crimean-Congo hemorrhagic fever virus
4. Model for dental caries with infection with Streptococcus spp.
5. Chemical-induced carcinogenicity
6. Thermoregulation and digestion

Question 25

Name genus and species and use in research.

Answer 25

Mastomys natalensis, Multimammate rat

Hosts to many zoonotic diseases:

1. Yersinia pestis
2. Mycobacterium ulcerans
3. leptospirosis
4. Lassa virus
5. Crimean-Congo hemorrhagic fever virus
6. Protozoans: Leishmania spp, Plasmodium berghei, Entamoeba histolytica, Trypanosoma brucei rhodensiense
7. Nematodes: Nippostrongylus, Dipetalonema, Brugia, Litosomoides, Acanthocheilonema, Wucheria, Capillaria
8. Trematodes: Schistosoma mansoni

Also, spontaneously develops gastric carcinoma and models Zollinger Ellison syndrome, especially the role of hypergastrinemia and CCK/gastrin receptors and realtionship to histamine on tumor formation.

Question 26

Name genus and species and use in research.

Answer 26

Octodon degus, Degu

1. Precocious neonates used to study neurobiological development
2. Diurnal and used to model circadian and sleep/wake cycles.
3. Develops spontaneous diabetes mellitus with islet amyloidosis. Cytomegalovirus-induced insulinitis, alpha-cell crystals with herpes-type virus presence, guinea pig chow or fresh fruit diets are all associated with diabetes development. Diabetic degus will develop cataracts within 4 weeks.

Require dust baths

Question 27

Uses in research?

Answer 27

Graphiurus kelleni - African door mouse

Research on orthopox virus infections - specifically monkey pox