spermatogonial stem cell (ssc) technologies provide multiple opportunities for research in the field of biotechnology and regenerative medicine. the therapeutic use of embryonic stem cells (escs) is restricted due to severe ethical and immunological concerns. therefore, we need a new pluripotent cell type. despite well-known role of germ cells in the gametogenesis, some facts apparently show th...

The aim of our study was to examine the influence of short-term (6h) hyperthermia (41.5 °C and 42.5 °C) on the developmental capacity of preimplantation rabbit embryos in vitro. Rabbit embryos were isolated from superovulated and inseminated rabbit females after slaughter by flushing from oviducts of 19 hpc. The embryos were cultured in k-DMEM medium with the addition of 10 % fetal calf serum. ...

In mice and humans, a normal offspring can be obtained by injecting a single spermatozoon into an oocyte, the process called intracytoplasmic sperm injection (ICSI). When three or more mouse spermatozoa with intact acrosomes were injected into individual mouse oocytes, an increasing proportion of oocytes became deformed and lysed. Oocytes did not deform and lyse when acrosome-less spermatozoa w...

Survival of the chick depends upon the transfer of maternal IgG from the egg yolk into the fetal circulation. Radiolabeled chicken IgG binds specifically to both fixed and unfixed yolk sac tissue from day 7 or 8 of embryogenesis through at least day 18. This binding is saturable, Fc-specific, pH-dependent, and reversible. Chicken Fc fragments and some heterologous IgGs compete with IgG binding,...