Within the gonad, activated, di-phosphorylated MAP kinase (MPK-1) is first detectable at the mid-pachytene stage of the meiotic prophase I. The activated form of MAP kinase disappears as germ cells pass the pachytene stage and enter the diplotene/diakinesis phase of meiotic prophase I. Activated, M.A.P kinase become detectable again in the most proximal oocyte(s) that are undergoing maturation, prior to fertilization. This proximal MAP kinase activity is induced by a cue from sperm.
Endogenous DVC1 was predominantly expressed during S and G2 phases of the cell cycle. Upon exit from mitosis, DVC1 expression was rapidly downregulated with kinetics similar to that of known APC-Cdh1 targets such as cyclin A, and reaccumulated as cells entered S phase.
In the meiotic cells of the gonad including oocytes and in the interphase cells of 200-cell embryos, DNA topoisomerase I was localized in nuclei. At the comma stage, a more narrowed concentration of DNA topoisomerase I was observed in the nucleoli of gut cells.