Genetics of the mimetic African butterfly Hypolimnas misippus: hindwing polymorphism

Abstract

The hindwing polymorphism in Hypolimnas misippus is autosomal but sex-limited to the female. It is characterised by three intergrading phenotypes, orange, low white (white in 1–3 intervein spaces) and high white (white in 4–8 spaces). A rare morph has variable melanic scaling, almost invariably in combination with high white. Orange and high white segregate as expected if they are allelic at the A (alcippoides) locus, A giving high white and a orange when homozygous. A postulated S locus also has two alleles, S which suppresses high white in A– genotypes (to low white or orange) and s which is a null allele. The A alleles interact with the M (misippus) locus to affect the forewing: AA/mm (f. alcippoides) has a “misippus” forewing, aa/mm is f. inaria and Aa/mm intermediate (f. immima). The dominant M allele is epistatic to A so that all M– genotypes have “misippus” forewings. Either a rare dominant gene B (black), or a third, top dominant A allele, Am, gives black scaling with high white in the otherwise orange area of the hindwing. The three or four controlling loci all segregate independently.