Role of the transmembrane potential in preimplantation mammalian embryos
In this work the transmembrane potential (Vmem) has been measured in oocytes and mice embryos during all preimplantation period of development by means of the patch-clamp method in whole-cell configuration. It is established that at an oocyte stage the Vmem value is at the level of -13,2 ± 1,54 mV. Transition to a one-celle stage, after fertilization, is characterized by depolarization of membrane potential therefore its value authentically increases to -9,4 ± 1,07 mV. The subsequent stages of division crushing of an embryo are followed by gradual hyperpolarization (Vmem = -10,8 ± 1,03 mV for the two-cell and Vmem = -13,7 ± 1,61 mV for the four-cell stages), and reach the minimum value at a 8-cell embryo (-22,9 ± 1,63 mV). Upon transition to a multicells, at a stage of a morula and a blastocyst, repeated depolarization is observed, Vmem values were -18,1 ±1,17 mV and -10,3 ± 0,9 mV respectively. Thus, processes of fertilization and primary differentiation of cages at a stage of a blastocyst are defined points in preimplantation development, characterized by depolarization of a membrane charge. The obtained data allow to speak about an important role of transmembrane potential in early embryo development of mammals, and with his help it will be possible to operate processes of proliferation and a differentiation not only at the level of an embryo, but also the whole organism.