ESA-SRB-AOTA 2019

Cep76 is a centriole-related gene with an essential role in sperm development (#211)

Brendan J Houston 1 , Liina Nagirnaja 2 , Don Conrad 2 , Moira K O'Bryan 1
  1. Monash University, Clayton, VIC, Australia
  2. Oregon National Primate Research Center, Hillsboro, Oregon, USA

Male infertility is a common disease that affects approximately 7% of men in the Western world and its aetiology is unknown in the majority of cases. It is, however, estimated that at least 50% of male infertility cases are genetic in origin. To identify novel male infertility mutations, we performed whole exome sequencing on infertile men. In one man, we have identified a homozygous SNP mutation in the centriole-related protein gene CEP76.  Although CEP76 has been implicated in the prevention of over-duplication of centrioles in cell lines, its role in germ cells and male fertility is largely unknown. In order to define this role, we generated a knockout mouse model for Cep76. Cep76 knockout males mate normally, but are sterile, due to a combination of sperm structural defects within the sperm head and tail, and an almost complete absence of sperm motility. Knockout sperm exhibit minimal twitching motility and are unable to manifest forward progressive motility (p < 0.0001). Approximately 40% of the sperm also contain head shape defects (p < 0.0001), and on average the sperm tail length is 15% shorter than their wild-type counterparts (p < 0.001). These data indicate an essential role of CEP76 in the processes of sperm head shaping and tail formation during spermiogenesis. Collectively these data strongly support that CEP76 is an essential regulator of male fertility in humans and mice.