Splice variants of PAC₁ receptor during early neural development of rats

The specific pituitary adenylate cyclase-activating polypeptide (PACAP) receptor, PAC₁-R, consists of at least seven isoforms, and they are differentially coupled to signal transduction pathways by alternative splicing. We have found that the major splice variants of the PAC₁ receptor seen during development are the short splice isoform, PAC₁-R-s (which does not contain either the 'hip' or 'hop' cassette), and another form, PAC₁-R- hop (which contains the 'hop' cassette). We also have applied an innovative molecular histochemical technique, in situ reverse transcription-polymerase chain reaction (RT-PCR), and determined that these two splice isoforms are colocalized in the neuroepithelia from the primitive streak stage. (C) 2000 Elsevier Science Inc.