title: Si-CSP9 regulates the integument and moulting process of larvae in the red imported fire ant, Solenopsis invicta.
abstract: Chemosensory proteins (CSPs) have been predicted to be involved in development; however, direct evidence for their involvement is lacking, and genetic basis is largely unknown. To determine the function of the chemosensory protein 9 (Si-CSP9) gene in Solenopsis invicta, we used RNA interference to silence Si-CSP9 in 3rd-instar larvae. The 3rd-instar larvae failed to shed their cuticle after being fed Si-CSP9-directed siRNA, and expression profiling of RNAi-treated and untreated control larvae showed that 375 genes were differentially expressed. Pathway enrichment analysis revealed that 4 pathways associated with larval development were significantly enriched. Blast analysis revealed that one fatty acid amide hydrolase (FAAH) gene was up-regulated and 4 fatty acid synthase (FAT) genes and one protein kinase DC2 gene (PKA) were down-regulated in the enriched pathways. Significantly higher expression of these genes was found in 4th-instar larvae, and Pearson correlation analysis of the expression patterns revealed significant relationships among Si-CSP9, PKA, FAAH, and FAT1-4. Moreover, we confirmed that expression levels of Si-CSP9, FAAH, and FAT1-4 were significantly reduced and that the development of 3rd-instar larvae was halted with PKA silencing. These results suggest that Si-CSP9 and PKA may be involved in the network that contributes to development of 3rd-instar larvae.
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, Guangdong, People's Republic China.
authors.forename: Daifeng
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, Guangdong, People's Republic China.
authors.forename: Yongyue
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, Guangdong, People's Republic China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zeng
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, Guangdong, People's Republic China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Liang
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, Guangdong, People's Republic China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: He
mesh_terms: D000581:Amidohydrolases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001000:Ants / Q000254:growth & development / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D064429:Fatty Acid Synthases / Q000378:metabolism; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034582:Integumentary System / Q000502:physiology*; D007814:Larva / Q000378:metabolism; D008018:Life Cycle Stages; D018978:Molting / Q000502:physiology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism*; D059467:Transcriptome; D015854:Up-Regulation; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D017868:Cyclic AMP-Dependent Protein Kinases; D064429:Fatty Acid Synthases; D019476:Insect Proteins; D034741:RNA, Small Interfering; D000099252:Fatty Acid Amide Hydrolases