We demonstrate that Katnal1 is expressed in testicular Sertoli cells from 15.5 dpc onwards, co-localises with SC microtubules in vivo, and that loss of function leads to male-specific infertility through disruption of microtubule dynamics and premature exfoliation of post-meiotic germ cells from the seminiferous epithelium. Here, KATNAL1 is linked to Infertility.