Fig. 7. Dyn3 transcripts are differentially regulated during neuronal development. (A) Isolated hippocampal neurons: primers flanking a 30-nucleotide spliced insert in Dyn3 were used in RT-PCR reactions to assess the relative levels of Dyn3aaa and Dyn3baa in maturing cultured neurons at each age as labeled (`DIV' means `days in vitro'). The Dyn3aaa product is 370 bp, whereas the Dyn3baa product is 400 bp. The PCR product at 430 bp is an RT-PCR artefact representing a heteroduplex of strands from each spliceoform. GAPDH RT-PCR demonstrates the use of equal amounts of template in each reaction. MW, molecular weight markers; Br, brain; –con, negative control. (B) Identical RT-PCR reactions were prepared using template derived from whole rat hippocampus at various developmental stages as listed above (P, postnatal day). GAPDH RT-PCR provides evidence for equal transcript copy number in the loading of template for each reaction. (C) RT-PCR using the cultured neuron template set and primers designed to exhibit total levels of all Dyn3 transcripts. (D) RT-PCR using the whole hippocampi template set and primers designed to exhibit total levels of all Dyn3 transcripts.