Hoxc13 mutant mice lack external hair

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Hox genes typically exhibit colinear spatial and temporal expression patterns.
• Hoxc13, a member of paralogous group 13, is expected to follow this colinear expression.
• Initial expression of Hoxc13 is observed in embryonic nails and tail.

Purpose of the Study:

• To investigate the role of Hoxc13 in mammalian development.
• To characterize the developmental defects associated with Hoxc13 mutations.
• To explore the potential function of Hoxc13 in appendage development.

Main Methods:

• Gene targeting was employed to create mice with mutant Hoxc13 alleles.
• Expression patterns of Hoxc13 were analyzed in various embryonic and adult tissues.
• Phenotypic analysis of homozygous mutant mice was conducted to identify developmental defects.

Main Results:

• Hoxc13 expression was observed in hair follicles, vibrissae, tongue filiform papillae, and nails, challenging strict spatial colinearity.
• Homozygous Hoxc13 mutant mice displayed defects in all observed expression domains.
• The most prominent phenotype was brittle hair leading to alopecia (hairless mice).

Conclusions:

• Hoxc13 plays a crucial role in the development of hair, nails, and filiform papillae.
• The observed expression pattern suggests Hoxc13 has been co-opted for a common developmental function across these appendages.
• Mutations in Hoxc13 lead to significant defects in hair and nail formation.