title: Differences in the effects of treatment of uncompacted and compacted mouse embryos with phorbol esters on pre- and postimplantation development.
abstract: Differences are described in the effects of treatment of preimplantation mouse embryos with low levels (0.01-1 nM) of phorbol myristate acetate (PMA), during three different periods of a 48-h culture from the 2-cell stage, on pre- and postimplantation development. Treatment of embryos with PMA for 48 h (first group) or 24 h (second group) from the 2-cell stage caused premature cavitation (prior to the 16-cell stage) and it also reduced the size and alkaline phosphatase (ALPase) activity of inner cell masses (ICMs), as well as the numbers of cells in blastocysts, in a dose-dependent manner. Treatment of early morulae with PMA for 24 h (third group) did not have the above mentioned effects on embryos but inhibited the formation and subsequent enlargement of the blastocoel. The blastocysts that were allowed to develop in the three treatment groups were examined for postimplantation development. Implantation was unaffected in all groups. The survival rate after implantation was low in the first and second groups but relatively high in the third group. The results indicate that an embryo exposed to PMA for 24 h from the 2-cell stage forms a premature blastocoel, and, in such an embryo, quantitative and qualitative differentiation into the ICM is blocked but qualitative differentiation into trophectoderm is uninhibited. Consequently, the embryo can implant but does not survive for a long time. When embryos were exposed to PMA for 24 h from the early morula stage, the formation and enlargement of the blastocoel were inhibited even though the treatment had a minimal effect on other developmental events.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anatomy, Mie University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohsugi
authors.forename: H
authors.initials: H
authors.lastname: Yamamura
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001755:Blastocyst / Q000187:drug effects / Q000201:enzymology; D002448:Cell Adhesion / Q000187:drug effects; D002970:Cleavage Stage, Ovum / Q000187:drug effects* / Q000648:ultrastructure; D003433:Crosses, Genetic; D010064:Embryo Implantation / Q000502:physiology; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development / Q000187:drug effects*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D005326:Fetal Proteins / Q000032:analysis; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H / Q000196:embryology; D008810:Mice, Inbred C57BL / Q000196:embryology; D008813:Mice, Inbred ICR; D009028:Morula / Q000187:drug effects; D010703:Phorbol Esters / Q000494:pharmacology; D011493:Protein Kinase C / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; D005326:Fetal Proteins; D010703:Phorbol Esters; C008876:phorbol-12,13-didecanoate; D011493:Protein Kinase C; D000469:Alkaline Phosphatase; D013755:Tetradecanoylphorbol Acetate