Chinese Hamster Flashcards
Genus, species, and common name of Chinese hamster.
Cricetulus griseus. Striped-back hamster.
Why was the Chinese hamster chosen for research?
Small size, polyestrous cycle, short gestation period, and low chromosome number.
How is the Chinese hamster used today?
Use of animal in research overshadowed by use of cell lines derived from ovarian cells. Chinese hamster ovary (CHO) cells used exclusively for cell culturing experiments to obtain heterologous protein products. Synthesize an array of recombinant therapeutic proteins utilized clinically for the treatment of human diseases.
What diseases/conditions are the Chinese hamster susceptible to?
Number of infectious agents including bacteria, mycobacteria, protozoa, diphtheria, rabies, influenza, and equine encephalitis. Spontaneous hereditary diabetes mellitus. Susceptibility to experimental induction of stomach and esophageal cancer by oral diethylnitrosamine.
How does the size of the Chinese hamster compare to the mouse?
Comparable. Similar style of caging is adequate.
Does the Chinese hamster possess an immunologically privileged cheek pouch?
Yes
What is the chromosome number of the Chinese hamster? What chromosome number is maintained in cell culture? Why is this important?
2n = 22. Autosomes and sex chromosomes can be readily differentiated. Constant diploidly maintained in cell culture provides system for assessment of agents with known or suspect mutagenic and carcinogenic properties.
How much do adult Chinese hamsters weigh?
39-46g.
What is the average lifespan of a Chinese hamster/
2.5-3.0 years.
What are unique characteristics of the Chinese compared to the Syrian hamster?
Adult males have very large testes, spleen and brain are relatively larger.
What dietary and water needs do Chinese hamsters have?
No unique dietary needs. 11-12 mL/100g body weight water requirement.
Early attempts to breed Chinese hamsters in the lab were unsuccessful until what?
A reversed illumination schedule was used.
Sexual maturity is indicated by what? What typically occurs at the beginning of estrus?
Vaginal opening. Mucus-like, creamy material secreted at beginning of estrus.
Describe the Chinese hamster estrous cycle.
Four phases, with distinct behavioral characteristics associated with vaginal orifice changes. Routine exam of vulva can assist with determining estrus and optimal breeding time.
Describe progesterone levels in the Chinese hamster. How does this differ from the Syrian hamster?
Sig. different during estrus cycle and pregnancy. 4-day estrous cycle, with max synthesis on day 3. Differs from Syrian in which low levels are found on day 3 of Syrian hamster cycle.
When are Chinese hamsters weaned? Sexually mature? How long is gestation? Average litter size?
Weaned at 21-25 days. Sexually mature at 8-12 weeks with 20.5 day gestation and average litter size of 4.5-5.
Why was hand mating originally used for breeding purposes of Chinese hamsters? How has this changed?
Females can become very aggressive immediately following mating and kill the male. Selective monogamous breeding with docile females with high fecundity found to be successful. Chinese hamsters can be mated in groups.
What can infertility in young female hamsters be due to?
Excess growth of hair around vulva, preventing penile penetration.
How is pregnancy indicated in Chinese hamsters?
Closed vagina with dry, pale, and scaly perineal tissue at day 4 following mating.
Describe progesterone levels during pregnancy in Chinese hamsters.
Progesterone increases in peripheral blood through day 12, stabilizes through day 18, peaks on day 19, and drops dramatically prior to parturition.
Why might dystocia occur in Chinese hamsters? What can be done?
Fetal wedging in proximal portion of vagina during parturition attempts. Fetuses can be saved by surgical removal.
Describe the development of Chinese hamster pups.
Newborn animals have front incisors. Body hair at 3-4 days of age, with complete coverage at 7 days. Eyes and ears open within 10-14 days. Testicles descend at about 30 days.
What occurs as pups approach sexual maturity?
Aggressive females may fight until dominance is established.
