What are tailless mice? - briefly
Tailless mice are laboratory rodents that either possess a genetic mutation or have been surgically altered to lack an external tail, a characteristic that makes them valuable for specific biomedical research applications.
What are tailless mice? - in detail
Tailless mice are laboratory rodents that develop without an external tail due to a recessive mutation at the T locus. The mutation disrupts normal vertebral elongation during embryogenesis, resulting in a shortened or absent caudal vertebral column. The phenotype is stable across generations when homozygous individuals are bred, and it is commonly observed in strains such as the C57BL/6‑ta and BALB/c‑ta.
Key biological features include:
- Morphology – reduced or missing caudal vertebrae, shortened rump, and altered pelvic musculature.
- Genetics – the ta allele is inherited autosomally recessive; heterozygotes display a normal tail, while homozygotes exhibit the tailless condition.
- Development – the mutation interferes with signaling pathways (e.g., Wnt and Shh) that regulate axial skeleton formation.
- Physiology – locomotion remains largely unaffected; gait analysis shows minor adjustments in hind‑limb coordination.
- Health – no increased susceptibility to common mouse diseases, though careful monitoring of spinal integrity is recommended.
Research applications rely on the distinct anatomical trait. The absence of a tail simplifies surgical access to the lumbar region, facilitates spinal cord injury models, and provides a visual marker for genotype identification without molecular testing. Behavioral studies exploit the phenotype to examine the role of tail proprioception in balance and navigation.
Breeding protocols emphasize maintaining a homozygous colony while avoiding accidental outcrossing, which can reintroduce the wild‑type tail allele. Standard genotyping methods include PCR amplification of the T locus and phenotypic inspection of newborn pups.
In summary, tailless mice represent a genetically defined model characterized by a specific skeletal mutation, stable inheritance, and utility in neuro‑biological, developmental, and surgical research contexts.