Homozygous mutants of this strain have a smaller body size and abnormal development of the inner ear leading to unbalanced gait and deafness.Read More +
Homozygotes have a fail-to-thrive phenotype such that they have a smaller body size and unbalanced gait detectable at 10 days of age. Those that survive to 2 months of age can generally live up to 18 months. The inner ear has extensive hypoplasia of the membranous labyrinth, a rudimentary tectorial membrane, and enlarged scala vestibuli and severe hearing loss or complete deafness are found at 19 days of age both by failed response to sounds and auditory brainstem response analysis. Homozygotes also fail to orient in water.
The hml mutation arose spontaneously in the CByJ.Cg-Foxn1nu/J colony at The Jackson Laboratory in 1995 and was backcrossed onto the C57BL/6J background via backcross-intercross. In 2007 sperm was cryopreserved from heterozygous males at backcross generation N10.