De novo characterization of Phenacoccus solenopsis transcriptome and analysis of gene expression profiling during development and hormone biosynthesis

Abstract

The cotton mealybug Phenacoccus solenopsis is a devastating pest of cotton causing tremendous loss in the yield of crops each year. Widespread physiological and biological studies on P. solenopsis have been carried out, but the lack of genetic information has constrained our understanding of the molecular mechanisms behind its growth and development. To understand and characterize the different developmental stages, RNA-Seq platform was used to execute de-novo transcriptome assembly and differential gene expression profiling for the eggs, first, second, third instar and adult female stages. About 182.67 million reads were assembled into 93,781 unigenes with an average length of 871.4 bp and an N50 length of 1899 bp. These unigenes sequences were annotated and classified by performing NCBI non-redundant (Nr) database, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Groups (COG), Gene ontology (GO), the Swiss-Prot protein database (Swiss-Prot), and nearest related organism Acyrthosiphon pisum (pea aphid) database. To get more information regarding the process of metamorphosis, we performed a pairwise comparison of four developmental stages and obtained 29,415 differentially expressed genes. Some of the differentially expressed genes were associated with functional protein synthesis, anti-microbial protection, development and hormone biosynthesis. Functional pathway enrichment analysis of differentially expressed genes showed the positive correlation with specific physiological activities of each stage, and these results were confirmed by qRT-PCR experiments. This study gives a valuable genomics resource of P. solenopsis covering all its developmental stages and will promote future studies on biological processes at the molecular level.

Reconstruction of insect hormone pathways in an aquatic firefly, Sclerotia aquatilis (Coleoptera: Lampyridae), using RNA-seq

“…5 and 6). These stage-specific expression profiles observed for the ecdysteroid- and JH-related genes were also observed in the transcriptome study of the mealy bug, Phenacoccus solenopsis (Arya et al, 2018).…”

“…However, Nvd was not able to be identified in either the S. aquatilis transcriptome obtained in the present study or that for any of the other three firefly species that have been sequenced (Wang et al, 2017). Likewise, in the transcriptome study of the mealybug, P. solenopsis , no putative Nvd homolog was identified (Arya et al, 2018). The nvd gene was originally identify in B. mori (Niwa et al, 2004; Yoshiyama et al, 2006).…”

Sex-specific expression profiles of ecdysteroid biosynthesis and ecdysone response genes in extreme sexual dimorphism of the mealybug Planococcus kraunhiae (Kuwana)

“…Expression of ecdysteroid biosynthetic genes and ecdysone response genes were previously assessed in another mealybug, Phenacoccus solenopsis, by a transcriptome analysis but was limited to a few developmental stages [39]. Here we present, for the first time, a detailed developmental expression pattern of ecdysteroid biosynthesis and ecdysone response genes, highlighting the major differences in gene expression between male and female development in the mealybug Planococcus kraunhiae.…”

Potential targets for controlling Bactrocera dorsalis using cuticle‐ and hormone‐related genes revealed by a developmental transcriptome analysis

“…With the rapid development of sequencing technology, high‐throughput sequencing techniques have been used widely in functional investigations of genes related to insect growth and development. In recent years, developmental transcriptomes have been reported in several insect species, including Cyrtotrachelus buqueti , Chrysomya megacephala , Trichopria drosophilae , Dendrolimus punctatus , Bombyx mori , Phenacoccus solenopsis and B. dorsalis …”

“…Fortunately, the use of next‐generation transcriptome sequencing can provide more genetic information related to developmental and other metabolic processes involved in metamorphosis. This accurate, rapid and sensitive method has been used to explore the molecular mechanisms of adaptive evolution involved in insect physiology, morphology, development and behavior …”