The lanceolate hair (lah) mutation, later identified as an allele of the desmoglein 4 (Dsg4) gene (Kljuic et al. 2003), was discovered during inbreeding of progeny of a chemically mutagenized mouse. 8-week old male mice of a stock homozygous for seven recessive mutations (a, Tyrp1b, p, Tyrc-ch, Ednrbs, Myo5ad and Bmp5se)(Russell 1951) were treated with ethylnitrosourea and bred to BALB/cByJ females. Several independent lines were established from these crosses by more than 10 generations of sister-brother inbreeding. Mice with alopecia were found during development of one of these lines, and a subline segregating for Dsg4lah was established by crossing homozygous males with their heterozygous sisters. After 20 generations of such inbreeding, this line became the segregating inbred strain LAH. The congenic strain CByJ.LAH-Dsg4lah was created by crossing LAH and BALB/cByJ mice, then backcrossing Dsg4lah carriers, identified by progeny testing, to BALB/cByJ mice for 4 additional generations (to N5) in the laboratory of Dr. Xavier Montagutelli at Unite de Genetique des Mammiferes, Institut Pasteur, Paris (Montagutelli et al. 1996; Montagutelli, personal communication, 1999). The strain was imported to The Jackson Laboratory by Dr. John P. Sundbergin 1996; upon their arrival, Dsg4lah/Dsg4lah males were crossed to female BALB/cByJ mice. Dr. Sundberg donated offspring of the first-generation progeny of these crosses to the Mouse Mutant Resource. After initial crosses of pairs that may have been siblings or half siblings, the strain was maintained by sister-brother inbreeding. Embryos were preserved from crosses of heterozygous females and homozygous males.
