title: Activation at the germinal vesicle stage of starfish oocytes produces parthenogenetic development through the failure of polar body extrusion.
abstract: Starfish oocytes can be fertilized after germinal vesicle breakdown (GVBD) and artificial parthenogenesis can be induced by activating the oocytes after GVBD (post-GVBD activation). In the present study, parthenogenotes were obtained by the activation of immature oocytes with caffeine before treatment with 1-methyladenine (1-MeAde) to induce oocyte maturation. Most of the caffeine-treated eggs developed as tetraploids, as parthenogenotes produced by the post-GVBD activation. The parthengenotes were derived only from eggs that failed to extrude polar bodies, mostly from eggs failing to extrude a second polar body. Eggs derived from immature oocytes activated by A23187, treated with 1-MeAde and post-treated with cytochalasin B failed to extrude polar bodies, and eventually developed into parthenogenetic embryos. These results indicate that the present parthenogenesis mechanism shares the same characteristics as that achieved by post-GVBD activation in the suppression of polar body formation as a key means for successful starfish parthenogenesis.
authors.affiliation: Biological Laboratory, Hitotsubashi University, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Washitani-Nemoto
authors.forename: S
authors.initials: S
authors.lastname: Nemoto
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D005260:Female; D007476:Ionophores / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D010312:Parthenogenesis / Q000187:drug effects / Q000235:genetics; D011123:Polyploidy; D013215:Starfish / Q000196:embryology* / Q000235:genetics / Q000502:physiology
chemical_list: D007476:Ionophores; D000001:Calcimycin; D003571:Cytochalasin B; D002110:Caffeine; C008407:1-methyladenine; D000225:Adenine