Mechanisms of tentacle morphogenesis in the sea anemone, Nematostella vectensis. Nematostella vectensis

Evolution of the capacity to form secondary outgrowths from the principal embryonic axes was a crucial innovation that potentiated the diversification of animal body plans. Nevertheless, precisely how such outgrowths develop in early-branching metazoan species remains poorly understood. To identify genes potentially involved in tentacle initiation, outgrowth, and maintenance, we performed transcriptional profiling at three different stages of Nematostella development: late planula larvae with tentacle buds, animals with growing tentacles, and mature animals with four-tentacle polyps. At each of these three stages, the animal was bisected such that the oral tentacle portion (head) could be compared to the body column. Overall design: Tentacle buds, growing tentacles, and mature tentacles, were compared to body columns from each matching stage in duplicate, for a total of 6 samples.