Open AccessScreening of olfactory genes related to blood-feeding behaviors in Culex pipiens quinquefasciatus and Culex pipiens molestus by transcriptome analysis
Author(s) -
Zhenyu Gu,
Heting Gao,
Qiaojiang Yang,
Meng Ni,
Man-jin Li,
Dan Xing,
Tongyan Zhao,
Teng Zhao,
Chunxiao Li
Publication year - 2022
Publication title -
plos neglected tropical diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.99
H-Index - 135
eISSN - 1935-2735
pISSN - 1935-2727
DOI - 10.1371/journal.pntd.0010204
Subject(s) - biology , culex quinquefasciatus , transcriptome , gene , culex , culex pipiens , olfactory system , zoology , genetics , gene expression , ecology , larva , aedes aegypti , neuroscience
Background Culex pipiens quinquefasciatus Say ( Cx . quinquefasciatus ) and Culex pipiens form molestus Forskal ( Cx . molestus ) in the Culex pipiens complex group show considerable differences in host seeking, blood feeding, mating behavior and in vector competence. Blood-feeding mosquito behaviors are closely related to their olfactory gene expression and olfactory gene repertoire composition. Comparing olfactory genes between these two subspecies with significantly different blood-feeding behaviors can support further research on the molecular mechanism of the Culex pipiens complex olfactory sensory system, providing a new approach for determining candidate attractant or repellent compounds. Methods Non-blood-feeding (NBF) and post-blood-feeding (PBF) olfactory system transcriptomes of the two subspecies were sequenced, and the biological functions of their differentially expressed genes were described by bioinformatics analysis. A quantitative polymerase chain reaction (qPCR) was applied to validate the RNA-seq data. The roles of particular olfactory receptors in Cx . quinquefasciatus blood-feeding behaviors were evaluated by RNAi. Results Five, 7, 24, and 3 Cx . quinquefasciatus -specific OBPs, Cx . molestus -specific OBPs, Cx . quinquefasciatus -specific ORs and Cx . molestus -specific ORs were identified, respectively. The majority of selected ORs were consistent with the predicted transcriptome sequencing results after qRT-PCR validation. OR5 was expressed only in Cx . quinquefasciatus , and OR65 was the only gene upregulated after blood feeding in Cx . molestus . The blood-feeding rates of the OR5 and OR78 dsRNA groups were significantly lower (4.3%±3.1% and 13.3%±11.5%) than those of the enhanced green fluorescence protein (EGFP) group (64.5%±8.7%). Conclusion Most OBPs and ORs were expressed in both subspecies but showed divergence in expression level. OR5 and OR65 might be species-specific expressed genes that regulate the olfactory behaviors of Cx . quinquefasciatus and Cx . molestus , respectively. The RNA interference of OR5 and OR78 could inhibit the blood-feeding behavior of Cx . quinquefasciatus , providing new targets for screening effective repellent compounds to control mosquito-borne diseases effectively and efficiently.