Ccdc79 is preferentially expressed during meiotic prophase in mice. RT-PCR was used to measure expression of Ccdc79, S9 (a “house-keeping” gene), Sycp3 (a meiosis marker), Mvh (a germ cell marker), and Xist (a somatic cell marker in females) (A) RT-PCR analysis of testes collected at the indicated ages. Expression of Ccdc79 is noticeably up-regulated as the first wave of germ cells enters meiosis after 7 days post-partum (dpp). (B) RT-PCR analysis of ovaries collected from foetuses at the indicated times post fertilization. Expression of Ccdc79 is strongly up-regulated as female germ cells enter meiosis between 12.5 and 14.5 days post coitum (dpc). (C) RT-PCR analysis of testis and somatic tissues. cDNA was prepared from four RNA mixtures that contained RNA from adult testis and from somatic tissues in different ratios. (1) Somatic tissue mix: 1 μg of total RNA made up by mixing 59 ng of total RNA from 17 somatic tissues (see Material and Methods). (2) Testis: 59 ng total RNA from adult testis. (3) Somatic + testis mix: 1 μg of total RNA made up by mixing 59 ng total RNA from testis with 941 ng of somatic tissue mix. (4) Somatic + 5x testis: 1 μg of total RNA made up by mixing 295 ng total RNA from testis with 705 ng of somatic tissue mix. (5) noRT control with somatic + testis mix. Ccdc79 specific PCR-products could be amplified only from templates that contained testis cDNA. (D) RT-PCR analysis of mixed ovarian cells, ovarian somatic cells and germ cells that were separated by fluorescence-activated cell sorting from ovaries of 16.5 dpc foetuses (see Materials and Methods). Purity of cell populations was assessed by RT-PCR specific for Xist, Sycp3, and Mvh marker genes. Ccdc79 expression is restricted to germ cells in the ovary.