Meander tail: a recessive mutant located in chromosome 4 of the mouse

Area of Science:

• Genetics and Developmental Biology
• Mammalian Genetics
• Mutant Phenotyping

Background:

• A variable kinked-tail mutation was identified in a mouse stock in 1974.
• The mutation, termed meander tail (mea), was characterized as completely recessive.

Purpose of the Study:

• To investigate the phenotypic effects of the meander tail (mea) mutation in mice.
• To determine the genetic linkage of the mea mutation within the mouse genome.

Main Methods:

• Analysis of 8 alizarin-stained skeletons from affected mice.
• Phenotypic observation of vertebral structure and neurological deficits.
• Linkage analysis to map the mea gene on mouse chromosome 4.

Main Results:

• Observed variable degrees of ankylosis and fusion in tail vertebrae, with occasional involvement of other vertebrae.
• Extreme cases showed a reduced number of tail vertebrae.
• Affected mice over 2 weeks old commonly displayed unsteadiness and, less frequently, hind limb paralysis, suggesting pleiotropic effects.
• Linkage tests placed the mea mutant near the brown (b) locus on chromosome 4, within the Ps-Pt segment.

Conclusions:

• The meander tail (mea) mutation in mice results in significant vertebral abnormalities, primarily affecting the tail.
• Pleiotropic effects include motor coordination deficits and potential hind limb paralysis.
• The mea gene is located on mouse chromosome 4, providing a new marker for genetic mapping studies.