Fig. 3.

RT-PCR amplification of CNP mRNA in trout tissues. (A) CNP mRNA in blood vessels (EBA, CMA, VA and ACV) is found in the mature, fully processed form and is indicated as the smaller PCR product (product 2). Atrial CNP mRNA is also seen in the mature form (product 2), though predominantly found in an unprocessed, pre-mRNA form containing CNP intron-1 and is indicated as the larger PCR product (product 1). (B) A model was constructed to show the relative positions of CNP exon 1, intron 1 and exon 2, and the tissues where the unspliced and spliced versions are found. Arrows indicate the relative docking positions of primers used in these amplifications. (C) The sequence of the CNP intron is underlined, flanked by CNP exons 1 and 2. Consensus 5′ and 3′ splice sites are in bold.