Molecular characterization, expression analysis and RNAi knock-down of elongation factor 1α and 1γ from Nilaparvata lugens and its yeast-like symbiont.
In the present paper, four cDNAs encoding the alpha and gamma subunits of elongation factor 1 (EF-1) were cloned and sequenced from Nilaparvata lugens, named NlEF-1α, NlEF-1γ, and its yeast-like symbiont (YLS), named YsEF-1α and YsEF-1γ, respectively. Comparisons with sequences from other species indicated a greater conservation for EF-1α than for EF-1γ. NlEF-1α has two identical copies. The deduced amino acid sequence homology of NlEF-1α and NlEF-1γ is 96 and 64%, respectively, compared with Homalodisca vitripennis and Locusta migratoria. The deduced amino acid sequence homology of YsEF-1α and YsEF-1γ is 96 and 74%, respectively, compared with Metarhizium anisopliae and Ophiocordyceps sinensis. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis revealed that the expression level of NlEF-1α and NlEF-1γ mRNA in hemolymph, ovary, fat body and salivary glands were higher than the midgut and leg tissue. YsEF-1α and YsEF-1γ was highly expressed in fat body. The expression level of NlEF-1α was higher than that of NlEF-1γ. Through RNA interference (RNAi) of the two genes, the mortality of nymph reached 92.2% at the 11th day after treatment and the ovarian development was severely hindered. The RT-qPCR analysis verified the correlation between mortality, sterility and the down-regulation of the target genes. The expression and synthesis of vitellogenin (Vg) protein in insects injected with NlEF-1α and NlEF-1γ double-stranded RNA (dsRNA) was significantly lower than control groups. Attempts to knockdown the YsEF-1 genes in the YLS was unsuccessful. However, the phenotype of N. lugens injected with YsEF-1α dsRNA was the same as that injected with NlEF-1α dsRNA, possibly due to the high similarity (up to 71.9%) in the nucleotide sequences between NlEF-1α and YsEF-1α. We demonstrated that partial silencing of NlEF-1α and NlEF-1γ genes caused lethal and sterility effect on N. lugens. NlEF-1γ shares low identity with that of other insects and therefore it could be a potential target for RNAi-based pest management.
State Key Laboratory of Rice Biology,China National Rice Research Institute,Tiyuchang Road 359, Hangzhou, Zhejiang, 310006,People's Republic of China.
W X
WX
Wang
College of Biological and Environmental Engineering,Zhejiang University of Technology,Chaowang Road,Hangzhou,Zhejiang, 310014,People's Republic of China.
T H
TH
Zhu
State Key Laboratory of Rice Biology,China National Rice Research Institute,Tiyuchang Road 359, Hangzhou, Zhejiang, 310006,People's Republic of China.
K L
KL
Li
State Key Laboratory of Rice Biology,China National Rice Research Institute,Tiyuchang Road 359, Hangzhou, Zhejiang, 310006,People's Republic of China.
L F
LF
Chen
State Key Laboratory of Rice Biology,China National Rice Research Institute,Tiyuchang Road 359, Hangzhou, Zhejiang, 310006,People's Republic of China.
F X
FX
Lai
State Key Laboratory of Rice Biology,China National Rice Research Institute,Tiyuchang Road 359, Hangzhou, Zhejiang, 310006,People's Republic of China.
Q
Q
Fu
D000818:Animals; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005260:Female; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006430:Hemiptera / Q000235:genetics / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008297:Male; D009758:Nymph / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D009928:Organ Specificity; D020648:Peptide Elongation Factor 1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013559:Symbiosis; D015003:Yeasts / Q000235:genetics / Q000502:physiology*
D018076:DNA, Complementary; D005656:Fungal Proteins; D019476:Insect Proteins; D020648:Peptide Elongation Factor 1

               Nilaparvata lugens
            ; RNAi; elongation factor 1 alpha; elongation factor 1 gamma; yeast-like symbionts