Disruption of murine Tenr results in teratospermia and male infertility

Gametes rely heavily on posttranscriptional control for their differentiation. Translational control, alternative splicing, and alternative processing of the 3′ end of mRNAs are all common during spermatogenesis. Tenr, which encodes a highly conserved 72-kDa protein, is expressed solely in germ cells of the testis from the mid-pachytene stage until the elongating spermatid stage. TENR contains a double-stranded RNA binding domain, is localized to the nucleus, and is phylogenetically related to a family of adenosine deaminases involved in RNA editing. We show here that targeted mutation of the Tenr gene causes male sterility. Tenr mutant males have a reduced sperm count, and Tenr−/− sperm show a decrease in motility and an increase in malformed heads. Despite their sterility, some epididymal sperm from Tenr mutants have normal morphology. The ability of Tenr mutant sperm to fertilize zona pellucida-free oocytes and to bind to, but not fertilize, zona pellucida-intact oocytes suggests that the normal-appearing sperm are not able to penetrate the zona pellucida. These data suggest that TENR plays an essential function in spermatid morphogenesis.