Vasa mRNA is enriched in the posterior enterocoel (PE) of the sea stars Asterina miniata and Asterias forbesii. (A) In A. miniata, vasa mRNA accumulates uniformly through blastula formation, is enriched in the vegetal region of the gastrula, and then accumulates selectively in the PE (arrow) of the larva. (B) In A. forbesii, vasa mRNA is enriched at the vegetal region of the early gastrula, at the tip of the archenteron in the gastrula, and in both the coelomic pouches and PE (arrow) of the larva. Scale bars are 20 μm.