Hamsters (other than Syrian)

Question 116

What characteristics of the Chinese hamster make it an appealing research subject?

Answer 116

Small size

Polyestrous cycle

Short gestation period (20.5d)

Low chromosome number

Question 117

What tissue/cell line from this animal is used extensively in biomedical research as a source of cell lines?

Answer 117

Chinese hamser ovary (CHO) cells are used for cell culture experiments to obtain heterologous protein products.

Question 118

T/F Chinese hamsters are more radioresistant than Syrian hamsters.

Answer 118

True

Question 119

Name three areas of research in which this Chinese hamsters are used.

Answer 119

1. Radiobiology
2. Diabetes mellitus - spontaneous hereditary DM with similarities to human disease
3. Cancer research - susceptible to induction of esophageal and stomach cancer

Question 120

How many chromosomes does the Chinese hamster have?

Answer 120

2N = 22

Question 121

What organs in the Chinese hamster are relatively large compared to the Syrian hamster?

Answer 121

Testicles, brain, and spleen

Question 122

How is sexual maturity indicated in female Chinese hamsters?

Answer 122

Vaginal opening with mucus-like material frequently secreted at the beginning of estrus.

Question 123

What is the length of the estrous cycle in Chinese hamsters?

Answer 123

4 days

Question 124

What environmental factor may increase the number of runts in litters of Chinese hamsters?

Answer 124

Temperature > 82F

Question 125

T/F: Chinese hamsters are highly susceptible to demodecosis.

T/F: Chinese hamsters are more susceptible to Tyzzer’s disease.

Answer 125

False - Chinese hamsters have low susceptibility to demodicosis

True - Chinese hamsters are more susceptible to Tyzzer’s disease

Question 126

For which type of diabetes mellitus is the Chinese hamster a good model?

What are the genetics of the disease?

Answer 126

Type I (insulin-dependent) DM & it is genetically recessive

Disease is associated with degranulation of the beta cells resulting in a primary defect in the biosynthesis of insulin.

Question 127

T/F: Chinese hamsters have a high incidence of spontaneous neoplasia.

Answer 127

False

Question 128

Why was the Armenian hamster originally chosen as a laboratory research animal?

Answer 128

Because of it’s susceptibility to mutagenic and carcinogenic agents

Also important for studying meiosis due to unique semisynchronous meiotic progression beginning at day 15.

Question 129

T/F: Like the Syrian hamster, the Armenian hamster is highly susceptible to oncogenic viruses.

Answer 129

True

Question 130

What is unique about Armenian hamster spleen cells with respect to hybridoma formation?

Answer 130

They can form stable hybridomas with mouse myeloma cell lines.

Question 131

What is the diploid chromosome number of Armenian hamsters?

Answer 131

2N = 22

Question 132

How does amyloidosis differ in the Armenian hamster compared to that in the Syrian hamster?

Answer 132

Expression of spontaneous amyloidosis differs in gender-specific AP expression and susceptibility to AA amyloidosis compared to Syrian

Question 133

The European hamster (Cricetus cricetus) is susceptible to N-diethylnitrosamine, with subsequent development of ___________tumors.

Answer 133

Respiratory

Question 134

The European hamster has been found more suitable than the Syrian hamster for what type of studies?

Answer 134

Highly concentrated & prolonged smoke-inhalation studies

Question 135

What is the diploid chromosome number of the European hamster?

Answer 135

2N = 22

Question 136

What is the lifespan of the European hamster?

Answer 136

34 months for female

31 months for male

Reports of 6-10 years

Question 137

T/F: The European hamster breeds year-round.

Answer 137

False: sexual activity is not observed in the winter months, during which time females and males are very aggressive towards each other.

Question 138

T/F: The European hamster is a true hibernator.

Answer 138

True

Question 139

In which sex is there a higher incidence of spontaneous tumors in European hamsters?

Answer 139

Male

Question 140

Which sex develops intraperitoneal cysts more frequently?

Answer 140

Female

Question 141

Name two species of Djungarian hamsters.

Answer 141

• Phodopus cambelli* (Russian dwarf or striped hairy-footed hamster)
• Phodopus sungorus* (Siberian dwarf)

Question 142

Name two unique features of the hair coat in these hamsters (Djungairan).

Answer 142

1. The feet and tail are covered with fur
2. Under natural light some of these animals turn white in the winter.

Question 143

What is the diploid chromosome number is this genus?

Answer 143

2N = 28

Question 144

These hamsters have a low/high incidence of neoplasia?

Answer 144

HIGH - unlike the other hamsters

Question 145

In what areas of research are Djungarian hamsters used?

Answer 145

Viral oncogensis - SV40, Rous sarcoma virus, human adenovirus-12

Behavior & reproductive biology

Studies of the pineal gland and melatonin secretion in mediating the effects of photoperiod

Question 146

What is unique about the Djungarian hamster reproduction cycle?

Answer 146

Most compressed reproductive cycle of any eutherian mammal

They can mate on the day of parturition and deliver the second litter, while weaning the first, within a 36-day time period

Question 147

T/F: Female Djungarian hamsters are nonaggressive.

Answer 147

True

Question 148

T/F: Dwarf hamsters are true hibernators.

Answer 148

False - these hamsters are unique in that they do not hibernate even when exposed to very low temperatures.

Question 149

Female Russian dwarf hamsters prevented from breeding may develop what disease condition?

Answer 149

Cystic ovaries