Two pea aphid genotypes responded differently to crowded conditions in a peer-reviewed laboratory experiment. Winged offspring predominated in one; pale, wingless aphids appeared in the other. Both altered forms had fewer offspring than their counterparts, with a reproductive difference also appearing in the following generation. Comparisons of selected genes associated the contrasting forms with different activity patterns.
Two pea aphid genotypes followed different developmental routes under crowding in a peer-reviewed laboratory study. Offspring of the N116 genotype commonly grew wings. In N127, wing formation remained rare, while red aphids gave rise to pale individuals without wings. The two genotypes came from the vicinity of Slough in the United Kingdom.[1]
Within each genotype, offspring were less numerous in the altered form than its wingless or red counterpart. A difference in reproduction was also present among descendants growing outside crowded conditions. Researchers compared selected genes associated with development, flight and metabolism. Activity of wing-related genes was especially pronounced in winged N116 aphids, while other gene-activity differences accompanied both crowding-associated forms.[1]
Chemical marks on DNA differed significantly in four candidate genes. Across the examined regions, these differences did not correlate significantly with gene activity. The samples varied in developmental history and exposure as well as body form, so those influences remained intertwined. Maternal effects or other molecular processes may contribute to the reproductive difference in descendants; the study examined selected genetic regions rather than a complete genome.[1]
