Differential Expression Of Four Vision-Related Genes In The Bird Cherry-Oat Aphid, Rhopalosiphum Padi

Aphids use their visual systems to detect information about the external environment, and visual genes are likely to have a role in host plant searching and environmental adaptation. Yet, there is little understanding of the presence and expression of visual opsin genes in aphids. In this study, we cloned and identified four vision-related genes (LW-OPN, UV-OPN1, UV-OPN2, and rhodopsin) from a cosmopolitan serious cereal pest, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), and evaluated their expression patterns. Transcription of the four genes was detected at all developmental stages. The inducing conditions (short photoperiod and low temperature) significantly affected the expression of the UV-OPN1 and rhodopsin genes. The highest levels of transcription of all genes were observed in males, and the lowest in oviparae. The expression levels in wingless virginoparae were markedly lower than those in gynoparae and winged virginoparae. The starvation treatments resulted in a decline in the survivorship of adults. The mortality rates increased with increasing duration of starvation. The four genes tended to be upregulated following starvation for 24h, and their expression levels were considerably decreased after subsequent feeding. These results are of importance for further understanding the evolution and function of visual opsins in aphids.