Understanding the regulation of overwintering diapause molecular mechanisms in Culex pipiens pallens through comparative proteomics

Chongxing Zhang,Huaiwei Wang,Lijuan Liu,Maoqing Gong,Xiaoli Huang,Peng Cheng,Gongzhen Liu,Xiuxia Guo,Dongdong Wei,Guihong Shi,Feng Miao

doi:10.1038/s41598-019-42961-w

Chongxing Zhang, Huaiwei Wang + Show 9 more

Open Access

https://doi.org/10.1038/s41598-019-42961-w

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Abstract

To reveal overwintering dormancy (diapause) mechanisms of Culex pipiens pallens (L.), global protein expression differences at three separate time points represent nondiapause, diapause preparation and overwintering diapause phases of Cx. pipiens pallens were compared using iTRAQ. Cx. pipiens pallens females accumulate more lipid droplets during diapause preparation and overwintering diapause maintenance than during the nondiapause phase. A total of 1030 proteins were identified, among which 1020 were quantified and compared. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), Domain and Clusters of Orthologous Groups (COG) analyses revealed key groups of proteins, pathways and domains differentially regulated during diapause preparation and overwintering diapause maintenance phases in this mosquito, including major shifts in energy production and conversion, fatty acid metabolism, the citrate (TCA) cycle, and the cytoskeletal reorganization pathway. Our results provide novel insight into the molecular bases of diapause in mosquitoes and corroborate previously reported diapause-associated features in invertebrates. More interestingly, the phototransduction pathway exists in Cx. pipiens pallens, in particular, actin, rather than other proteins, appears to have substantial role in diapause regulation. In addition, the differential changes in calmodulin protein expression in each stage implicate its important regulatory role of the Cx. pipiens pallens biological clock. Finally, 24 proteins were selected for verification of differential expression using a parallel reaction monitoring strategy. The findings of this study provide a unique opportunity to explore the molecular modifications underlying diapause in mosquitoes and might therefore enable the future design and development of novel genetic tools for improving management strategies in mosquitoes.

Highlights

To reveal overwintering dormancy mechanisms of Culex pipiens pallens (L.), global protein expression differences at three separate time points represent nondiapause, diapause preparation and overwintering diapause phases of Cx. pipiens pallens were compared using isobaric tags for relative and absolute quantification (iTRAQ)
The results of previous studies have increased our knowledge of the molecular regulatory mechanisms of diapause preparation, maintenance and termination, revealing several physiological themes that appear to be shared across the diapause response of multiple insect species, including shifts in metabolism[5,6,7,8], increased lipid synthesis and storage[9,10,11], upregulation of stress-response genes[12,13], hormonal regulation during diapause induction[12,14,15,16,17,18,19,20], and changes in insulin signalling[8,19,21,22,23]
All the proteins were annotated by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Domain and Subcellular Location analyses (Supplementary Table 1)