PP1β paralogs are required for cell shape changes required for convergent extension.

<p>A representative field of presomitic and notochordal mesoderm at the bud stage in control (A), 2MO (0.75 ng <i>ppp1cba</i> MO and 0.75 ng of <i>ppp1cbb</i> MO) embryos (B) or rescued embryos (C). The cell polarity of presomitic (D) and notochordal (E) mesodermal cells was determined by calculating the length width ratio (y-axis). The crossed bars indicate cells with the long axis length and the short axis width. The embryos are arranged such that dorsal is down and anterior is to the right. Arrows indicate cells that are actively producing bleb-like protrusions. Error bars are standard error and a * indicates a statistically significant difference from control. All calculations were made on 75 cells from 3–5 separate embryos. Statistical significance was calculated using a one-factor ANOVA with Tukey post hoc analysis and is defined as p < 0.05.