Caracul-like 4, a dominant mutation resembling Krt2-6g<Ca> (caracul) and mapping to the same chromosomal location.
Richard M Samples, Patricia F. Ward-Bailey, Leah Rae Donahue, Roderick T. Bronson and Muriel T. Davisson
Source of Support: This research was supported by grants RR01183 to the Mouse Mutant Resource (M.T. Davisson, PI) and Cancer Core Grant CA34196.
Mutation (allele) symbol: Cal4
Mutation (allele) name: caracul-like 4
Gene symbol: Cal4
Strain of origin: C57BL/6J
Current strain name: C57BL/6J- Cal4/J
Stock #:005123 (Available as DNA only from the Jackson Laboratory DNA Resource)
Phenotype categories: HairAbstract
A spontaneous, dominant, curly coat mutation resembling Krt2-6g <Ca> (caracul) (MGD) has been discovered and named caracul-like 4 (Cal4). This mutation maps to Chromosome 15 in the same region as Krt2-6g <Ca>. Cal4 may be a remutation to Krt2-6g<Ca> however a direct test for allelism was not performed.
Origin and Description
This spontaneous mutation was discovered in a production colony (Annex-10) at the Jackson Laboratory on Nov. 28, 2001 by Karen Hammond. Mice carrying the Cal4 mutation are easily recognizable at 3 weeks of age by their very curly coat and kinked vibrissae. With age, the coat of mutant mice straightens slightly but appears to be rubbed the wrong way, while the vibrissae are kinked to a lesser degree.
Genetic Analysis
To determine the mode of inheritance an affected female was mated to an unrelated normal C57BL/6J male. In 4 litters produced, 11 progeny were affected and 9 were normal thus proving the mutation to be dominant.
Cal4 maps between D15Mit76 and D15Mit16 and is non-recombinant with D15Mit44 and D15Mit263 in 21 animals typed. Our placement of these markers and of Ca agree with the Ensembl Build 32 placement, with D15Mit76 at 96.9 Mb, D15Mit44 at 101.0 Mb, D15Mit263 at 101.3 Mb, Ca at 103.9 and D15Mit16 at 105Mb.
Pathology
Our standard pathology screen revealed no lesions in major organs other than skin. The skin of a 7-week old Cal4/+ mutant mouse had aberrant large hair follicles (possibly guard hair follicles) that may have been prohibitive to hair growth; a 7-week old +/+ control had no skin lesions. Hair samples taken from a 3-week old Cal4/+ mouse displayed occasional dysplastic hair follicles, while the hair from a control littermate was normal.
ABR (auditory brainstem response) testing revealed no significant hearing loss in 1 +/Cal4 mutant and 1 +/+ control tested at 5 weeks of age.Discussion
Based on the phenotype and chromosomal location of Cal4, it is likely to be a remutation to Krt2-6g<Ca>.
Acknowledgements
The authors wish to thank Karen Hammond for discovery of the mutant, and Coleen Marden for excellent technical assistance.
References
Mouse Genome Database (MGD) Mouse Genome Informatics Project, The Jackson Laboratory, Bar Harbor, Maine. World Wide Web
(URL:http://www.informatics.jax.org)
MGSC19.32.2., Mouse Genome Sequencing Consortium
