Ci-IPF1, the pancreatic homeodomain transcription factor, is expressed in neural cells of Ciona intestinalis larva

We describe the cloning and the expression pattern of insulin promoter fact or 1 in the ascidian Ciona intestinalis (Ci-IPF1). Northern blot analysis s howed that transcripts appeared at the late tailbud stage and increased at the larval stage. We have raised a specific antibody against the Ci-IPF1-GS T fusion protein to determine the spatial expression of this gene. The prot ein is immunodetected at the larval stage in the sensory vesicle, in the vi sceral ganglion and in the mesenchymal cells. Our results support the hypot hesis that IPF1/IDX1 might have extrapancreatic functions during animal dev elopment, particularly in neural cells. (C) 2001 Elsevier Science Ireland L td. All rights reserved.