Ultrastructure Of Human Embryonic Germ Cells And Expression Of Cytokines In Culture System Of Human Embryonic Germ Cells

Objective: The concentrations of LIF, SCF and bFGF in the culture medium of cells were determined and microstructure of primordial germ cells (PGCs) and ultrastructure of human embryonic germ cells (EG cells) were observed so as to explore a perfect culture system in vitro.Methods: ELISA was used to determine concentrations of LIF, SCF and bFGF in the culture medium of cells on the third day and ninth day. Sections of an embryo were prepare and observed. Human embryonic germ cells were cultured and were observed. Enough cells were collected to prepare ultrathin sections and the morphology was studied by transmission electron microscopy.Results: The concentration of LIF in the culture medium of cells on theninth day (55.25±6.51 pg/ml) were higher than that on the third day(46.56±0.89 pg/ml) (P<0.05). The concentration of SCF on the ninth day(90.39±3.98pg/ml) were obviously higher than that on the third day(78.47±2.03pg/ml) (P<0.01). The concentration of bFGF on the ninth day(26.06±1.73pg/ml) were obviously higher than that on the third day (22.13±L08) (PO.01). PGCs were large and round cells with large, excentric nuclei and visible nucleoli. EG cells had a large nuclear-cytoplasmic ratio and few of organelles and the cytoplasm contained abundant glycogen particles and occasional lipid droplets. Embryo fibroblast contained abundant rough endoplasmic reticulums, free ribosome and Golgi complexs.Conclusions: The ultrastructure of EG cells originated from PGCs are consistent with that of undifferentiated cell. Using endogenous fibroblasts as the feeder layer, enough cytokines can be secreted to favour the survival and proliferation of EG cells in vitro and to prevent the differentiation of them.