Characterization of a fertility candidate gene Ccdc79 in meiotic germ cells

Reproductive success in livestock is essential for the economic livelihood of producers and ultimately affects the consumer cost of meat and other animal products. In many livestock production systems, poor fertility is a major factor that limits productivity. Ccdc79 was first discovered as a novel fertility candidate gene due to its high level of expression in the ovary. This study investigated the developmental expression pattern of Ccdc79 gene in embryonic and postnatal mouse testes and ovaries, and examined its cellular expression in several types of postnatal male germ cells. The expression of Ccdc79 in male was very low or absent in fetal testes. The peak expression of Ccdc79 occurred in embryonic day 14 ovary in female and postnatal day 25 testis in male. The timing of the peak expression in female coincided with onset of meiosis and high abundance of its mRNA sustained in following developing ovaries. The postnatal expression of Ccdc79 in male first appeared in day 10 and remained at high level once meiosis started. The cellular distribution study further defined that Ccdc79 was significantly enriched if not exclusively expressed in germ cells. These results laid a foundation for future comprehensive analysis of Ccdc79 function in onset and progression of meiosis in both male and female germline of livestock.