Mice homozygous for this Huntingtin Associated Protein (HAP1)-deficient allele have neurodegeneration in areas of the hypothalamus that control feeding behavior, resulting in decreased feeding behavior, dehydration, hypoactivity, and death between two and 15 days after birth. No protein expression from the targeted gene is observed in brain tissue from homozygous mice. Hypothalamus tissue from HAP1-deficient homozygotes exhibit reduced levels of gamma-aminobutyric acid-A (GABAA; a neurotransmitter associated with feeding) and tropomyosin-related kinase A receptor tyrosine kinase (TrkA; a nerve growth factor receptor associated with neurite outgrowth). Heterozygous mice are viable and fertile with no abnormalities in HAP1 expression levels, life span, behavior, and body weight. These huntingtin-associated protein-1 (HAP1) mutant mice may be useful in studying the hypothalamic neurodegeneration and loss of body weight in Huntingon's disease (HD), neurotransmitters, microtubule-dependent transporters, intracellular trafficking, receptor tyrosine kinase and neurite function, and feeding.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. These mice were originally published on a mixed Black Swiss and 129S6/SvEvTac genetic background. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.
