Differential expression of BMP inhibitors gremlin and noggin in Hydra suggests distinct roles during budding and patterning of tentacles.

Background: Mechanisms regulating BMP and Wnt pathways and their interactions are not well studied in Hydra.

Results: We report identification of BMP inhibitor gremlin, comparison of its expression with that of noggin and possible antagonism between Wnt and BMP signaling in Hydra. Gremlin is expressed in body column with high levels in budding region and in early buds.