Waved 1-like (wa1l), a new mutation causing a curly coat

Louise Dionne, Richard Samples, Patricia Ward-Bailey, Kenneth R. Johnson, and Muriel T. Davisson

Source of Support: This research was supported by NIH/NCRR grant RR01183 to the Mouse Mutant Resource (M.T. Davisson, PI) and Cancer Center Core Grant CA34196.

Mutation (allele) symbol: wa1l

Mutation (allele) name: waved 1-like

Gene symbol: wa1l

Strain of origin: B6;129P2 Seletm1Hyn-Ap3b1pe-14J/J

Current strain name: B6;129 P2-wa1l/J

Stock #:008048 (view JAX® Mice Data Sheet for additional information including Price and Supply Information)  Note: As of October 21, 2008, available as DNA only from the Jackson Laboratory DNA  Resource.

Phenotype categories: skin and hair

Abstract

A new mutation that causes affected mice to have a wavy coat (See Photo) has been identified and has been mapped to Chromosome 6 in the same region as the previously described waved 1 (Tgfawa1) mutation. A direct test for allelism was not performed because the waved 1 mutation is only available as cryopreserved embryos.

Origin and Description

Mice carrying the new spontaneous recessive wa1l mutation were discovered in a research colony of B6;129P2Seletm1Hyn-Ap3b1pe-14J/J mice at the Jackson Laboratory. Like Tgfawa1 mutant mice, the wavy hair of mice affected with the wa1l mutation is recognized as soon as their first coat of hair comes in (See Photo). The original Tgfawa1 mutant mice have curly vibrissae, misaligned hair follicles, reduced body weight and eye defects that are not seen in the wa1l mutant mice. The B6;129P2-wa1l/J colony is maintained by homozygous and heterozygous sibling matings. Mice homozygous for the wa1l mutation were backcrossed to C57BL/6J mice to eliminate the Sele targeted mutation from the background strain.

Genetic Analysis

Using our standard mapping protocols B6;129P2-wa1l/J mice were mated to CAST/Ei mice. The affected progeny from these matings were then intercrossed and they produced 27 affected F2 progeny of which 21 were used for linkage analysis. This mutation was mapped distal to D6Mit3 (BLAT sequence 78.56 Mb), proximal to D6Mit100 (NCBI 36 position 92.0 Mb), and non-recombinant with D6Mit29 (NCBI 36 position 86.7 Mb). The original Tgfawa1 mutation is mapped at the NCBI 36 position 86.1 Mb.

Pathology

A pathological screen of one homozygous mutant was performed at three weeks of age and no gross abnormalities were observed. A pelt pad and plucked hair samples were taken from 2 homozygous mutant mice at three weeks of age. The results showed the pelt pad to be normal and all hair types are wavy (See Photo).

Hearing was normal as assessed by auditory brainstem response (ABR) testing of two homozygous mutants and one heterozygous mouse at twenty-six days of age.

The eyes of five homozygous mutants and two heterozygous mice at 4 weeks of age were examined with an opthalamscope and were determined to be normal. Electroretinogram testing (ERG) on a homozygous mutant at 24 weeks of age was normal.

Discussion

Based on phenotype and chromosome position, this new mutation may be a remutation to Tgfawa1, however this was not  confirmed by a direct test for allelism.

Acknowledgements

The authors wish to thank Richard Samples for discovering the mouse, Norm Hawes and Ron Hurd for the eye examination and EKG, and Coleen Marden for her excellent technical assistance.