Type and distribution of induced mutations discovered in seven amplicons. Orange boxes correspond to exons, lines to introns. Homology to proteins in the BLOCKS database  is indicated by the green boxes above gmppck4 and gmrhg4b. The other amplicons did not contain regions of BLOCKS homology. Arrowheads indicate approximate position of missense changes, upside down arrowheads indicate silent changes, asterisks indicate nonsense mutations, boxes indicate deletions. Hollow arrowheads = A population; red = B population; gray = C population; black = D population. The number of mutations discovered in each amplicon per population is indicated on the right.