This is the first in vivo mammalian model of katanin p80 dysfunction, and it presents with a phenotype reminiscent of a commonly observed clinical phenotype of male infertility characterized by low sperm counts, poor motility and abnormal sperm morphology (referred to as oligoasthenoteratospermia or OAT). The gene discussed is KATNB1; the disease is thyroid gland oncocytic adenoma.