Alternative splicing generates diversity of VD1/RPD2α peptides in the central nervous system ofLymnaea stagnalis

1. Two giant peptidergic neurons, VD1 and RPD2, of the visceral ganglion and right parietal ganglion ofLymnaea stagnalis, respectively, play an important role in the modulation of complex physiological and behavioral adjustments that occur as a result of changes in O2 availability. 2. By cDNA cloning, we have identified two types of VD1/RPD2 transcripts expressed in VD1 and RPD2. In addition, these transcripts are also expressed in other neurons. 3. Both transcripts encode distinct yet related VD1/RPD2 preprohormones that may be cleaved to yield distinct but overlapping sets of neuropeptides. 4. Using the polymerase chain reaction technique, we could show the existence of additional splice variants. 5. Analysis of the organization of the VD1/RPD2 gene indicates that theα peptide coding region is interrupted by a number of introns. 6. We concluded that the mRNA segment encoding theα peptide domain of the VD1/RPD2 preprohormones is alternatively spliced, thus generating differentα peptides.