PP1β paralogs are required for proper zebrafish body axis elongation.

<p>(A–I) Lateral views of representative 48 hpf zebrafish embryos injected with (A) uninjected control, (B) 2.5 ng <i>ppp1cba</i> MO, (C) 2.5 ng <i>ppp1cbb</i> MO, (D) a mixture of 0.75 ng <i>ppp1cba</i> MO and 0.75 ng of <i>ppp1cbb</i> MO (2MO), (E) 200 pg of <i>ppp1cba</i> mRNA, (F) 200 pg of <i>ppp1cbb</i> mRNA (G) a partially rescued embryo injected with 100 pg <i>ppp1cba</i> mRNA and 2.5 ng of <i>ppp1cbb</i> MO (H) a partially rescued embryo injected with 100 pg <i>ppp1cbb</i> mRNA and 2.5 ng of <i>ppp1cbb</i> MO (I) a partially rescued embryo injected with 100 pg <i>ppp1cbb</i> mRNA and 0.75 ng of <i>ppp1cbb</i> and 0.75 <i>ppp1cba</i> MO (J) Quantification of the truncated body axis phenotype in morphant and mRNA injected embryos. Each injection was performed multiple times with 50 embryos used to calculate body axis length and reported as % of uninjected clutch mates. Error bars are standard error and a black * indicates a statistically significant difference from control and a # indicates a statistically significant rescue compared to the corresponding morpholino injected embryos. Statistical significance was calculated using a one-factor ANOVA with Tukey post hoc analysis and is defined as p < 0.05. (K) A western blot showing PP1β levels in zebrafish embryo lysates from control and embryos injected with two doses of morpholino cocktail (1.5 ng and 3.0 ng of total MO), individual <i>ppp1cba</i> or <i>ppp1cbb</i> (2.5 ng of either) morpholinos or a rescued embryo injected with 0.75 ng of each morpholino (1.5 ng total) and 100 pg of <i>ppp1cbb</i> mRNA. Tubulin was used as a loading control.