Fig 7. Transcriptional effects of the dominant lethal mutant allele 18320C.

Genotypes are indicated below each histogram. Primers from exon 6d were used to monitor isoforms C, F, G and H. Transcriptional levels are normalized to sibling controls. Note that Dp2, either in one or two doses, although it rescues the dominant lethality of 18320C, denoted as DL for brevity, it does not supply the normal levels of 6d containing isoforms, 25% roughly. Also, since ♀ hdp³/hdp³; Dp2/+ and ♀ hdp³/18320C; Dp2/+ yield the same levels of these transcripts, it follows that 18320C is null for these isoforms. By extension, since 18320C is a point mutation in the white ATG site, this mutant should be also null for the rest of white TnI isoforms.