Development of baboon preimplantation embryos to post-implantation stages in vitro.
Development of baboon preimplantation embryos to post-implantation stages in vitro.
复制标题
狒狒植入前胚胎在体外发育至植入后阶段。
作者：
C. Pope;V. Z. Pope;L. R. Beck
Preimplantation baboon embryos were recovered nonsurgically and cultured in vitro to postimplantation stages. Most embryos (61/69) were cultured in CMRL-1066 medium supplemented with glutamine (1 mM), pyruvate (0.37 mM) and antibiotics; plus 20% heat-inactivated human cord serum (1-ICS) or fetal calf serum (FCS). Embryos were cultured in microtiter plate wells containing approximately 250 �zl of medium in a gas atmosphere of 5% 02, 5% CO2 and 90% N2, at 37#{176}C and 100% relative humidity. Initially, embryos were cultured in CMRL medium plus 20% FCS until after hatching occurred (4/14), at which time FCS was replaced with HCS. When medium contained 1-ICS which had been heat inactivated and filtered prior to freeze storage, 12 of 35 embryos developed to the expanded blastocyst stage and hatched from the zona pellucida. Seven of 12 (56%) embryos hatched when medium contained unfiltered UCS which was heat inactivated after thawing. Hatching occurred after 4 to 7 days in culture following recovery at the 8-cell to morula stage and blastocysts hatched on the second day after recovery. Hatching occurred rapidly, i.e., the zona pellucida was completely evacuated within 2 to 4 h after hatching had started. Most blastocysts underwent further expansion and attached to the culture dish within 5 days after hatching. Coincident with attachment, a second cell layer was formed around the inner periphery of the blastocyst cavity, and trophoblast outgrowth was initiated 1 to 3 days after attachment. In 12/20 embryos, the primary yolk sac greatly increased in diameter, and a structure identified as the embryonic disc was observed in 7 of 12 embryos. The interval from recovery to maximal post-attachment development ranged from 10 to 16 days, depending upon the stage of development at recovery: and up to a 7- to 8-fold increase in size was achieved. These post-attachment embryos correspond in size and morphological appearance to 11- to 12-day (Stage Vc-VI) human and rhesus monkey embryos after fixation.
