Biology and Physiology of

Laboratory Rodents

Bersényi, Andrásassistant professor

bersenyi.andras@univet.hu

12th February, 2018

Landrace

Lab animal: animals specially bred for use in experiments

in facilities approved and registered by the authority - BIOMODELS

LAB ANIMALS in EU(EC, 2010)

fishfrogsbirdsruminantspigsrabbitsrodentshamstersguinea pigsratsmice

Mouse (M. musculus)

Taxonomy

Grandorder: Glires

Order: Rodentia (&Lagomorpha)

Suborder: Myomorpha

Family: Muridae

Genus & Species:

Mus house mouse (M. musculus)

Biology

I. Large Surface Area(20 g: 36 cm2)

Cold

Non-shivering thermogenesis

(thermoneutral zone: 30±0.5oC)

Heat

Non-true endotherm

(newborns!)

Ears vascularization

Conclusion: housing (20-25oC!), drinking water, bedding material

NO sweat glands; limited panting and

salivation shock!

II. Fast Heart and RespiratoryFrequency

(300-800/min.; 100-200/min.)

High erythrocyte count (9-10x1012/l),haemoglobin, blood O2 capacity,alveolar O2 pressure

Bohr-effect

III. Urinary System

Number of glomeruli, filtering surface,

volume of urine (4300 mOsm/l vs human

1160 mOsm/l)

Henle-loops, vasa recta

IV. Pheromones

Lee-Boot-, Whitten-, Bruce-effect

Mice in Research

BALB/cC57BL/6

Mice in Research

• Gerontology: short lifespan

• Genetics: high reproductive potential

(pregnancy: 19-21 days vs rat: 21-23 days)

• Oncology: tumor incidence &

histocompatibility

• Virology: susceptibility

• Toxicology

• Radiobiology: response & economics

Rat (R. norvegicus)

Taxonomy

Class: Glires

Order: Rodentia

Suborder: Myomorpha

Family: Muridae

Genus & Species:Rattus Norwegian rat (R. norvegicus)

Biology

NO gall bladder & tonsils

Heat loss: sweat glands, tail vessels,

saliva on body

(mice: ear vessels)

Rats in Research

Wistar Sprague Dawley Long-Evans

Rats in Research

• Nutrition

• Toxicology

• Behaviour (stress)

• Inherited Diseases:

diabetes insipidus:

Brattleboro

Rats in Research

• Inherited Diseases:

retinal degeneration, microophtalmia,

epilepsy, deafness, obesity:

Zucker Diabetic Fatty (fa/fa)

Syrian/Golden Hamsters

(M. auratus)Chinese/striped back hamster (Cricetus griseus)

Taxonomy

Suborder: Myomorpha

Family: Cricetidae

Genus & Species:

Mesocricetus golden hamster (M. auratus)

History

Allepo, Syria (1930)

Biology

• black spot/sebaceous gland (males!)

I. Prolificacy(6 litters/year, 4-10 pups/litter)

inherited diseases

II. Freedom from SpontaneousDiseases

susceptibility to induced agents:influenza,

Creutzfeldt-Jakob disease

III. Anatomy & Physiology• Hibernation (2-3 days sleep + 12 hrs wakefulness):

hypotermia

• Cheek Pouch: transplantation

• Dentition: caries-inhibiting agents

• Respiratory Tract: chronic bronchitis

IV. Rapid Development(pregnancy: 15-17 days)

teratology

Other• pancreatic & renal tumor (+dog)

Chinese hamster

• Radiology

• Chromosomes (2n=22 vs 44):

in vivo cytogenetics

Gerbil (M. unguiculatus)

Taxonomy

Suborder: Myomorpha

Family: Cricetidae

Genus & Species:

Meriones Mongolian gerbil (M. unguiculatus)

Biology

• sebaceous glands (males!)

• short erythrocyte lifespan:

reticulocytes, basophil RBCs

• desert origin:

(thermoneutral zone (0-35oC vs mice),

water requirement, urine excretion)

• free of spontaneous diseases

• neurological research:

idiopathic epilepsy

• cholesterol metabolism:

obesity

atherosclerosis

Gerbils in Research

Guinea Pig (C. porcellus)

short-haired/English

roug-haired/Abyssinian (Ethiopian)

long-haired/Peruvian &

hairless

Taxonomy

Suborder: Hystricomorpha

Family: Caviidae

Genus & Species:

Cavia guinea pig (C. porcellus)

Biology

• 1 pair of nipples; fingers: 4/3

• Biorhythm: appr. 20 hours activity and

appr. 10 min. sleeping

• Coprophagy

- caecotrophy(rabbit; guinea pig; rat!)

• Kurloff cells (3-4%):

Foetus protection

Guinea Pigs in Research

• Scorbutus (L-gulonolactone oxidase)

• Easy to immunize: TBC, diphtheria,

leptospirosis, brucellosis

• Otology research (tympanic bullae)

Thank you for

your attention!

Experimental animals Lab animals

Landrace

YorkshireGöttingen

Directive (2010/63/EU): live non-human vertebrate animals, including:

independently feeding larval forms, and foetal forms of mammals

as from the last third of their normal development; live cephalopods

Experimental animal: vertebrate specimen used or to be used in

experiments

Lab animal: animals specially bred for use in experiments

in facilities approved and registered by the authority

Anatomy

Physiology

Behaviour