Distribution of p58 during ascidian embryonic development.

<p>(A) Immunoblot using NN18 antibody on <i>Phallusia mammillata</i> extracts prepared at the indicated stages of development; hr: hours after fertilization. (B) Examples of <i>Phallusia</i> embryos stained with NN18; egg: an equatorial view (top) or surface view (bottom) of the same unfertilized egg; 16 cell: 2 different embryos with 4 posterior cells (B5.1 and B5.2 pairs) labeled. Gastrula: posterior muscle territory is labeled. Tailbud and tadpole tail: individual mononucleate muscle cells are distinguishable. Scale bars are 20 microns in all panels.