Core RNAi machinery and gene knockdown in the emerald ash borer (Agrilus planipennis)

Chaoyang Zhao; Miguel A Alvarez Gonzales; Therese M Poland; Omprakash Mittapalli

doi:10.1016/j.jinsphys.2014.12.002

Core RNAi machinery and gene knockdown in the emerald ash borer (Agrilus planipennis)

J Insect Physiol. 2015 Jan:72:70-78. doi: 10.1016/j.jinsphys.2014.12.002. Epub 2014 Dec 23.

Authors

Chaoyang Zhao¹, Miguel A Alvarez Gonzales¹, Therese M Poland², Omprakash Mittapalli³

Affiliations

¹ Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA.
² U.S. Forest Service, Northern Research Station, East Lansing, MI 48823, USA.
³ Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA. Electronic address: [email protected].

PMID: 25541004
DOI: 10.1016/j.jinsphys.2014.12.002

Abstract

The RNA interference (RNAi) technology has been widely used in insect functional genomics research and provides an alternative approach for insect pest management. To understand whether the emerald ash borer (Agrilus planipennis), an invasive and destructive coleopteran insect pest of ash tree (Fraxinus spp.), possesses a strong RNAi machinery that is capable of degrading target mRNA as a response to exogenous double-stranded RNA (dsRNA) induction, we identified three RNAi pathway core component genes, Dicer-2, Argonaute-2 and R2D2, from the A. planipennis genome sequence. Characterization of these core components revealed that they contain conserved domains essential for the proteins to function in the RNAi pathway. Phylogenetic analyses showed that they are closely related to homologs derived from other coleopteran species. We also delivered the dsRNA fragment of AplaScrB-2, a β-fructofuranosidase-encoding gene horizontally acquired by A. planipennis as we reported previously, into A. planipennis adults through microinjection. Quantitative real-time PCR analysis on the dsRNA-treated beetles demonstrated a significantly decreased gene expression level of AplaScrB-2 appearing on day 2 and lasting until at least day 6. This study is the first record of RNAi applied in A. planipennis.

Keywords: Agrilus planipennis; Argonaute-2; Dicer-2; R2D2; RNA interference; ScrB.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Coleoptera / enzymology
Coleoptera / genetics*
Gene Expression
Gene Knockdown Techniques
Insect Proteins / genetics
Insect Proteins / metabolism
Microinjections
Phylogeny
RNA Interference*
RNA, Double-Stranded / genetics
RNA, Messenger / metabolism
beta-Fructofuranosidase / genetics

Substances

Insect Proteins
RNA, Double-Stranded
RNA, Messenger
beta-Fructofuranosidase