Posters

Summarizing these data we hypothesized that Hippo signaling can be involved in regulation of the oocyte selection during the first wave of oocyte death.We compared the mRNA expression levels of the main participants of the Hippo cascade in mammals (mst1/2, lats1/2, yap) between the developmental stages (E14,5 -18,5) of Mus musculus embryos by qRT-PCR.It turned out that the expression level of the main kinases (mst1/2 and lats1/2) increased at the E16,5 stage, but decreased at 17,5.The ovarian cyst break-down takes place during these late stages of development, so the rise of the kinases' expression can be connected with this process.The immunocytochemical staining of the embryonic ovaries for LATS1/2 and YAP showed that these proteins were mainly localized in the somatic cells of the ovary.The cyst break-down occurs with the direct involvement of somatic (future follicular) cells, that are necessary for the primordial follicles' formation.So the condition of the somatic cells around the oocytes can be the factor of oocyte selection.Understanding of this process can help to find out the ways of ovarian reserve restoration and maintainance in the females of reproductive age.