Effects of microinjection with zebrafish pgrmc1 antisense morpholino oligonucleotides on plasma membrane expression of mPRa (A) and DHP induction of OM (B). (A) Western blot analysis of Pgrmc1, mPRα and actin expression on ovarian membranes of zebrafish oocytes after microinjection of zebrafish pgrmc1 antisense morpholino oligonucleotides (PG-As), and non-targeting control morpholino oligonucleotides (NC). (B) Vitellogenic follicle-enclosed oocytes with diameters of 450–500 μm were injected with 1 nl of the oligonucleotides (< 1% of oocyte volume) and incubated with 10nM DHP in the in vitro OM bioassay. OM was assessed by GVBD (disappearance of germinal vesicle). The experiment was repeated two times and the results pooled. The total number of oocytes in each treatment group were: vehicle −30, DHP −14, DHP + PG-As −29, and DHP + NC −16. All data represent means ± S.E.M. Results were analyzed by one-way ANOVA followed by the Bonferroni test. Significant differences between the paired groups of microinjection with Pgrmc1 antisense (PG-As) versus Pgrmc1 non-targeting controls (NC) were tested by Student’s t-test. Different letters denote significant differences between the treatments groups (p < 0.05) in the post hoc Bonferroni test.