CnOtx, a Member of the Otx Gene Family, Has a Role in Cell Movement in Hydra

Abstract

Otx genes have been identified in a variety of organisms and are commonly associated with the patterning of anterior structures. In some vertebrates, Otx genes are also expressed in the prechordal mesoderm, where they may have a role in cell movement. Here we report the characterization of CnOtx, an Otx gene in hydra, thereby providing evidence that Otx genes appeared early in metazoan evolution. CnOtx is expressed at high levels in developing buds and aggregates, where it appears to have a role in the cell movements that are involved in the formation of new axes. Further, the gene is expressed at a low level throughout the body column of hydra. This latter pattern may reflect a role for CnOtx in specifying tissue as competent to be anterior, although the gene does not have a direct role in the formation of the head.

Hym-301, a novel peptide, regulates the number of tentacles formed in hydra

“…The expression patterns of a number of genes also illustrates this sudden change. Cnotx (Smith et al, 1999) andCnox-3 (Bode, 2001), the hydra orthologues of Otx and labial/Hox-1 are expressed in epithelial cells of the tentacle zone, but cease expression at the tentacle zone/tentacle border. Conversely, TS-19, a cell surface antigen (Bode et al, 1988), an annexin gene (Schlaepfer et al, 1992), HMP1 a metalloprotease (Yan et al, 1995) and HTK (Steele et al, 1996) are expressed immediately as the epithelial cells cross the tentacle/tentacle zone border and subsequently all along the tentacles.…”

Formation of the head organizer in hydra involves the canonical Wnt pathway

“…Animals were fed three times per week, and maintained in hydra medium as described previously (Smith et al, 1999).…”

Primary body axes of vertebrates: Generation of a near‐Cartesian coordinate system and the role of Spemann‐type organizer

“…The opening of the gastric column represents the blastopore as indicated by the Brachyury and Wnt expression (Technau and Bode, 1999;Hobmayer et al, 2000). The Otx expression in the body column of hydra (Smith et al, 1999) suggests that this part is equivalent to the fore-and midbrain. An Aristalessrelated gene is expressed in hydra at the tentacle zone (Smith et al, 2000) and in Xenopus in the telen-and diencephalon (Miura et al, 1997).…”