A microarray approach identifies ANT, OS-D and takeout-like genes as differentially regulated in alate and apterous morphs of the green peach aphid Myzus persicae (Sulzer)

Aphids exhibit a complex life cycle in which their phenotypes vary in response to environmental changes. Wing polyphenism is one of the phenotypes that have not been adequately studied. We developed a cDNA microarray from the green peach aphid Myzus persicae (Sulzer), and compared mRNA samples derived from alate and apterous adults. The microarray experiment resulted in 108 significantly changing clones that represented 31 unique ESTs. Among the highest and significantly expressed clones in alate adults, seven clones showed portions of a new adenine nucleotide translocase (ANT) gene from M. persicae and four clones contained sequences of the OS-D gene. Another clone showed significant homology with the takeout (TO) and TO-like proteins described from other insects. A full-length cDNA clone of M. persicae ANT (Mp ANT) was isolated and characterized. An reverse transcription-polymerase chain reaction (RT-PCR) analysis showed significant differences in Mp ANT, OS-D and Mp takeout-like genes (Mp TOL) expression in alate compared to apterous adults. A polyclonal antibody against the beef heart mitochondrial ANT reacted with a recombinant Mp ANT expressed in Escherichia coli, as it did with aphid extracts, showing higher amounts of the expected 33 kDa band in alate adults. Spatial expression analysis showed higher Mp ANT expression in the thorax compared to head, abdomen, leg and antennae. OS-D and Mp TOL showed ubiquitous expression across the body, with OS-D being significantly higher in legs and antennae while Mp TOL being significantly higher in the head and abdomen. The possible causes for higher expression of ANT, OS-D and TOL in alates and the physiological effects on the aphid flight and dispersal are discussed.