Fig. 4

Schematic representation of transcript variation in chicken NRG3. a cDNA libraries derived from Hinai-jidori were amplified using 3 different sets of primers to estimate the approximate abundance of the 5′ end transcripts by agarose gel electrophoresis. b NRG3 transcript variants are shown with the reference transcripts (highlighted). The first exon in each ISOx1 to ISOx4 transcript (Exon 1_long) is not annotated as a single independent exon in the galGal5 assembly (NC_006093.4; chr6: 3,826,268 − 3,826,962). The gray blocks depicted in variants 3, 4, 5, and 7 represent the retained introns of various lengths. Note that all transcripts with a retained intron generate a premature termination codon (PTC) in their downstream region. The PTCs and the presumed exon 1 in variants 7/8 are shown as filled circles and a dotted box, respectively