Genetics of Color Polymorphism in the Pea Aphid,Acyrthosiphon pisum

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 or green). 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.

Characterization and analysis of a de novo transcriptome from the pygmy grasshopper Tetrix japonica

“…T. japonica is a good organism for investigating body colour and the evolution of colour pathways and functions. In other species, colour polymorphisms are caused by variation at single or a few loci (Caillaud & Losey 2010). Body coloration in insects is primarily a result of melanin, hormone, ommochromes and pteridines (Croucher et al 2013;Nie et al 2014).…”

Differential accumulation of energy by the colour morphs of the pea aphid Acyrthosiphon pisum (Hemiptera: Aphididae) mirrors their ecological adaptations

“…Pea aphids occur in two colour morphs, red and green (Weisser & Braendle, 2001). Laboratory crosses between red and green morphs suggest that body colour determination in pea aphids is genetically based, with the morphs remaining distinct throughout the vegetative season because the aphids reproduce parthenogenetically (Losey et al, 1997;Caillaud & Losey, 2010). However, some environmental factors (such as symbiotic microorganisms) are also thought to affect aphid body colour (Tsuchida et al, 2010).…”

Genomic and Cytogenetic Localization of the Carotenoid Genes in the Aphid Genome

“…Aphids shows a range of colour polymorphisms, especially green and red (sometimes referred as pink), which influences their susceptibility to natural enemies [Caillaud and Losey, 2010]. According to literature data, aphid colour is based on the amount and type of the synthesized carotenoids which is due to genes that appear to have a fungal origin, but have been integrated and duplicated into the aphid genome [Jenkins et al, 1999;Moran and Jarvik, 2010].…”