Comparative profiling of microRNAs in the winged and wingless English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae)

Authors: LI, XIANGRUI - Chinese Academy Of Agricultural Sciences; ZHANG, FANGMEI - Chinese Academy Of Agricultural Sciences; Coates, Brad; ZHANG, YUNHUI - Chinese Academy Of Agricultural Sciences; ZHOU, XUGUO - University Of Kentucky; CHENG, DENGFA - Chinese Academy Of Agricultural Sciences

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2016
Publication Date: 10/20/2016
Citation: Li, X., Zhang, F., Coates, B.S., Zhang, Y., Zhou, X., Cheng, D. 2016. Comparative profiling of microRNAs in the winged and wingless English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae). Scientific Reports. 6:35668. doi: 10.1038/srep35668.

Interpretive Summary: Aphids are a group if insects that cause direct feeding damage to several crops by sucking on plant juices, and in doing so transmit a variety of plant pathogens that affect plant health. Due to sucking feeding habits, aphids tend to be wingless and stationary on a plant, but as their numbers increase the development of progeny in the subsequent generation tends to change towards a higher proportion of winged individuals. This physical change in direct response to the environment is highly unique, and a key factor influencing the spread of aphids to un-infested crop plants. In order to study this phenomenon, an ARS scientist in collaboration with university collaborators determined that a mechanism of RNA degradation is involved in the control of differences in gene expression between winged and wingless aphids. Furthermore, the genes likely degraded by the mechanism were previously known to be involved in metamorphosis and embryonic development of wings. These data are important for the understanding of how insects have adapted the genetic means by which to rapidly respond to shifts in the environment, as well as knowledge that could potentially lead to tactics used to limit aphid movement and associated damage within the agroecosystem.

Technical Abstract: English green aphid, Sitobion avenae (F.), show a classic polyphenic wing dimorphism among isogenic adults that is an intriguing model for the study of morphological plasticity in response to the environment. Short non-coding microRNA (miRNA) molecules regulate gene expression by post-transcriptional RNA silencing, and affect developmental and physiological processes, including the wing development in insects. Here, the potential role of miRNAs in S. avenae wing development was investigated between apterous alate (winged) and wingless S. avenae adults. High-throughput sequencing of S. avenae small RNA libraries identified a total of 340 unique 20 to 23 bp miRNAs, of which 168 were annotated to the known sequences in miRBase, while 177 were potential S. avenae-specific miRNAs. The putative targets of these miRNAs and pathways analysis were carried out using Gene Ontology and KEGG analyses. The expression profiles of 9 miRNAs (7 conserved and 2 novel miRNAs) were evaluated between the two wing morphs of S. avenae adults using real-time quantitative PCR (qRT-PCR). The results showed that the expression of 5 miRNAs showed higher expression in winged adult than that of wingless adult. Additionally, the expression of 8 out of 9 candidate miRNAs were significantly different between two wing morphs (P<0.05), suggesting that these miRNAs may play a role in aphid wing development. Inventory of miRNAs in S. avenae and assess their expression profiles in two wing morphs lay the foundation for the mechanistic understanding of miRNA-mediated gene regulation on the wing development.