Ithaca College

M.C. Caillaud and J. Losey. 2010. Genetics of colour polymorphism in the pea aphid Acyrthosiphon pisum. Journal of Insect Science, 10, 82. View the PDF here.

ABSTRACT:

The genetic basis of color polymorphism is explored in the pea aphid, Acyrthosiphon pisum(Harris) (Homoptera: Sternorrhyncha), in which two color morphs have been described (pink orgreen). Laboratory crosses and a Mendelian genetic analysis reveal that color polymorphism in pea aphids is determined by a single biallelic locus, which we name colorama, with alleles P and p, pink being dominant to green. The putative genotypes are Pp or PP for pink morphs, and pp for green morphs. This locus is shown to be autosomal. Last, there was no evidence of influence of the direction of the cross on color inheritance, thus showing that cytoplasmic effects and/or maternally-inherited symbionts play no role in the inheritance of color polymorphism in pea aphids. The existence of a simple genetic determinism for color polymorphism in a system in which genetic investigation is possible may facilitate investigations on the physiological and molecular mechanisms of genetically-based color morph variation, and the establishment of a link between this locus and fitness in a range of ecological conditions.