DYNAMIC AND DIFFERENTIAL OCT-1 EXPRESSION DURING EARLY XENOPUS EMBRYOGENESIS - PERSISTENCE OF OCT-1 PROTEIN FOLLOWING DOWN-REGULATION OF THE RNA

As a first step towards the elucidation of the role of the transcripti on factor Oct-1 in development, we prepared a monoclonal antibody to s tudy the spatio-temporal distribution of Oct-1 protein in vivo. Here w e report differential expression of the Oct-1 gene in the Xenopus embr yo both at the RNA and the protein level. Transcripts and protein are detected in ectodermal and mesodermal cell lineages, in which the expr ession exhibits a pattern of progressive spatial restriction in the co urse of development. The Oct-1 expression as reported here is not corr elated with cell density or cell proliferation in the embryo. Our resu lts suggest a role of Oct-1 in the specification and differentiation o f neuronal and neural crest cells. In many other cells, the developmen tal decision to down regulate Oct-1 is delayed, probably due to a high stability of the protein.