Isolation and characterization of microsatellite loci from the Chinese white wax scale Ericerus pela Chavannes (Homopetera: Coccidae)

Arch Insect Biochem Physiol

Chen

2014

The Chinese white wax scale insect (Ericerus pela) is sexually dimorphic with holometabolous males and hemimetabolous females. Holometabolous insects were assumed to originate from hemimetabolous ancestors. Therefore, the male pupal stage is a major innovation compared with hemimetabolous female insects. Here, the protein profiles of the male pupae were obtained by high-throughput proteomics and analyzed using bioinformatics methods. A total of 1,437 peptides were identified and assigned to 677 protein groups. Most of the proteins had molecular weights below 40 kDa and isoelectric points from 4 to 7. Gene Ontology terms were assigned to 331 proteins, including metabolic process, developmental process, and cellular process. Kyoto Encyclopedia of Genes and Genomes annotations identified 142 pathways and most proteins were assigned to metabolism events. Pathways involved in cell growth and death, signal transduction, folding, and sorting and degradation were also identified. Six proteins that had undergone positive selection were classified into four groups, protein biosynthesis, protein degeneration, signal transduction, and detoxification. Many of the high-abundance proteins were enzymes involved in carbohydrate, lipid, and amino acid metabolism; signal transduction; degradation; and immunization, which indicated that metabolism, disruption, and development occurred intensely at the pupal stage. These processes are closely related to the physiological status of pupae. The results also suggested that these related proteins may be fundamental factors in the formation of pupae. This study describes pupal characterization at the molecular level and provides a basis for further physiological studies.

PROTEIN PROFILES OF CHINESE WHITE WAX SCALE, Ericerus pela, AT THE MALE PUPAL STAGE BY HIGH‐THROUGHPUT PROTEOMICS

Arch Insect Biochem Physiol

Chen

2014

Transcriptome Analysis of Sexually Dimorphic Chinese White Wax Scale Insects Reveals Key Differences in Developmental Programs and Transcription Factor Expression

Chen

Liu

et al. 2015

Sci Rep

The Chinese white wax scale insect, Ericerus pela, represents one of the most dramatic examples of sexual dimorphism in any insect species. In this study, we showed that although E. pela males display complete metamorphosis similar to holometabolous insects, the species forms the sister group to Acyrthosiphon pisum and cluster with hemimetabolous insects. The gene expression profile and Gene Ontology (GO) analyses revealed that the two sexes engaged in distinct developmental programs. In particular, female development appeared to prioritize the expression of genes related to cellular, metabolic, and developmental processes and to anatomical structure formation in nymphs. By contrast, male nymphal development is characterized by the significant down-regulation of genes involved in chitin, the respiratory system, and neurons. The wing and appendage morphogenesis, anatomical and tissue structure morphogenesis programs activated after male nymphal development. Transcription factors (that convey juvenile hormone or ecdysone signals, and Hox genes) and DNA methyltransferase were also differentially expressed between females and males. These results may indicate the roles that these differentially expressed genes play in regulating sexual dimorphism through orchestrating complex genetic programs. This differential expression was particularly prominent for processes linked to female development and wing development in males.

Transcriptome Analysis of the Chinese White Wax Scale Ericerus pela with Focus on Genes Involved in Wax Biosynthesis

Zhu

et al. 2012

PLoS ONE

BackgroundThe Chinese white wax scale, Ericerus pela Chavannes is economically significant for its role in wax production. This insect has been bred in China for over a thousand years. The wax secreted by the male scale insect during the second-instar larval stage has been widespread used in wax candle production, wax printing, engraving, Chinese medicine, and more recently in the chemical, pharmaceutical, food, and cosmetics industries. However, little is known about the mechanisms responsible for white wax biosynthesis. The characterization of its larval transcriptome may promote better understanding of wax biosynthesis.Methodology/Principal FindingsIn this study, characterization of the transcriptome of E. pela during peak wax secretion was performed using Illumina sequencing technology. Illumina sequencing produced 41,839 unigenes. These unigenes were annotated by blastx alignment against the NCBI Non-Redundant (NR), Swiss-Prot, KEGG, and COG databases. A total of 104 unigenes related to white wax biosynthesis were identified, and 15 of them were selected for quantitative real-time PCR analysis. We evaluated the variations in gene expression across different development stages, including egg, first/second instar larvae, male pupae, and male and female adults. Then we identified five genes involved in white wax biosynthesis. These genes were expressed most strongly during the second-instar larval stage of male E. pela.Conclusion/SignificanceThe transcriptome analysis of E. pela during peak wax secretion provided an overview of gene expression information at the transcriptional level and a resource for gene mining. Five genes related to white wax biosynthesis were identified.