All
  • All
  • Insight
  • Research Services
  • Preclinical CRO
  • Animal Resource Bank
CN
中文 English
Latest News

Latest News

Focusing on cutting-edge technologies and research advancements,
sharing Aniphe BioLab’s achievements in scientific innovation, Professional insights
and practical experience in the fields of laboratory animals and preclinical research.

Mouse Classroom | Do nude mice really have no fur? How should you choose between OB and DB strains?

The long-awaited “Mouse Classroom” is back! In this installment, we’ve gathered several common questions from our community and provided detailed answers.

 

BALB/C nude mice

Nude mice do, in fact, have some hair; they are not completely hairless (there is a specific strain of hairless mice). Sparse hair grows on the head and neck of nude mice, and as the animals age, sparse hair also appears on other parts of the trunk. Once these hairs penetrate the epidermis, their shafts become severely distorted and often break off before reaching their full length.

Long hair: At 4 weeks, long hair begins to grow (reaching its peak), shedding starts at 5 weeks, and by 6 weeks the fur has been completely shed. By 7 weeks, male mice begin to regrow their coat (at this stage, the fur is difficult to shed).

Why doesn’t it grow fur? Due to the loss of Foxn1 gene function, the hair shafts lack keratin—whose expression is regulated by Foxn1—and become extremely fragile. As a result, the vast majority of hair shafts fail to penetrate the epidermis properly and instead remain twisted and coiled within the dilated infundibulum of the hair follicle. Compared with normally haired littermates, these mice exhibit no difference in the number or function of their hair follicles; both groups are capable of generating normal hair roots and hair shafts. However, because their hair follicles are functionally impaired, the animals appear hairless.

 

B6-OB/OB mice

This mouse strain is on a C57BL/6 background. The ob/ob mouse is a spontaneously mutant obese strain, whose phenotype results from a homozygous mutation in the Lep gene—commonly referred to as the OB gene—which encodes leptin, leading to an increase in both the number and size of adipocytes.

Obesity phenotypes begin to emerge around 4 weeks of age; following dietary intake, these mice exhibit transient hyperglycemia, impaired glucose tolerance, and elevated plasma insulin levels, with body weights reaching up to three times that of wild-type mice.

Mice with a homozygous genotype may simultaneously exhibit traits such as reduced metabolism, hypothermia, decreased fertility, impaired wound healing, and elevated secretion of pituitary and adrenal hormones.

Breeding: Homozygous mice cannot reproduce naturally and must be bred by mating heterozygous individuals.

Blood glucose: It was slightly higher than the control group before 12 weeks, after which it returned to normal, indicating an early‑stage hyperglycemia model.

Application areas:

1. Screen therapeutic agents for diabetes, and model type 2 diabetes as well as obesity in stages I and II.

2. Investigate the signaling pathways of “leptin”;

3. Reproductive physiology research.

 

 

BKS-DB/DB mice

The db/db mouse is a spontaneous type 2 diabetes model, whose pathogenesis stems from a homozygous mutation in the leptin receptor gene (Obese Gene Receptor, OB‑R, also known as the Diabetes Gene, db), encoded by Leprdb. This mutation is accompanied by peripheral neuropathy and cardiomyopathy and may lead to hypothalamic dysfunction.

This mouse exhibits delayed wound healing, increased metabolic efficiency, reduced uterine and ovarian weights in females, and decreased estrogen secretion.

Phenotypes become apparent around three weeks of age, with body weights reaching up to three times that of wild-type control mice. By more than eight weeks, male mice exhibit genital atrophy; consequently, homozygous males are sterile.

Mice of this strain typically do not survive beyond 10 months, with most succumbing to ketosis.

Breeding: Homozygous mice cannot reproduce naturally and must be bred by mating heterozygous individuals.

Blood glucose: From 5 to 9 weeks of age, blood glucose levels in mice rise rapidly; after 9 weeks, they reach a critical threshold. In the later stages, the mice exhibit phenotypes associated with diabetes complications, such as weight loss, and there is substantial inter‑individual variation in body weight at the same age.

Application areas:

1. Research on type 2 diabetes and stage III obesity;

2. Research on endocrine deficiencies;

3. Metabolic studies;

4. Research in reproductive biology.

 

 

That concludes this episode of Mouse Classroom.

For more engaging, interesting, and professional research consulting, look no further than Aniphe BioLab.

PREVIOUS:

Literature Review | Could There Be New Hope for Osteoarthritis Treatment? Biodegradable HMBP Enzyme Shows Great Potential!

NEXT:

Practical Guide | How to Randomize Animals into Groups? How Many Animals per Group? How Should Animals Be Assigned?