Expression of a gene encoding a Gata transcription factor during embryogenesis of the starfish Asterina miniata.

The sea urchin zinc finger transcription factor SpGatae is a major activator of endomesoderm-specific regulatory genes. We have cloned the ortholog of this gene, AmGatae, from a distantly related echinoderm, the starfish Asterina miniata. Expression of AmGatae is first detected in a ring around the vegetal pole of the blastula. During gastrulation, transcripts are detected surrounding the blastopore, in the posterior archenteron and more faintly in the anterior mesoderm of the archenteron. In early bipinnaria larva, expression is localized to the midgut and hindgut and to the developing coelomic pouches. These observations show that despite differences in the early specification processes of the endomesoderm in starfish and sea urchins, gatae factors are expressed very similarly in these two taxa.