Figure 2. Partial nucleic acid sequence of the IIS6 segment of the Heliothis virescens sodium channel. The region indicated by the arrow is where the L1029H mutation occurs. Leucine is encoded by CTT and Histidine is encoded by CAT. Examples of the three genotypes are shown; A) Luecine homozygote (CTT/CTT); B) Histidine homozygote (CAT/CAT); and C) Leu/His heterozygote (CTT/CAT).