Project description:Transcriptome Analysis of Sexual Dimorphic Chinese White Wax Scale Reveals Key Differences in Developmental Programs and Transcription Factor Expression
Project description:Abstract The transformation from embryo to first instar nymph is an essential process in the insect life cycle. In order to characterize protein expression in the Ericerus pela Chavannes (Hemiptera: Coccoidea) egg, high-throughput proteomics and bioinformatics methods were used. A total of 678 peptides were identified and assigned to 358 protein groups. The proteins exhibited a wide range of molecular weight (3.50–495.12 kDa) and isoelectric points (3.50–13.1). Gene Ontology annotation showed that the majority of proteins were associated with cellular processes, metabolic processes, and response to stimulus processes. The predominant molecular functions of E. pela egg proteins included binding, catalytic activity, transporter activity, and structural molecule activity. Kyoto Encyclopedia of Genes and Genomes annotations identified 137 pathways, and most proteins were assigned to metabolism events, including many enzymes participating in energy metabolism, protein folding, sorting, and degradation. The processes and functions of the identified proteins were closely related to the physiological status of egg and embryo development. We conclude that some identified proteins are related to important egg biological characteristics, and regard them as the target proteins for future study.
Project description:Insect hormones regulate metamorphosis including that leading to sexual dimorphism. Using RNA-Seq, we discovered that the second-instar male larva (SM) of the white wax insect, Ericerus pela, have 5,968 and 8,620 differentially expressed transcripts compared with the second-instar female larva (SF) and the first-instar male larva (FM), respectively. The expression levels of genes involved in the apoptosis of old tissues and the reconstruction of new ones in the SM significantly enhanced, while the SF mainly has enhanced expression levels of anabolic genes such as chitin. We predicted that the second-instar larvae are the developmental origin of sexual dimorphic metamorphosis. Meanwhile, in the juvenile hormone (JH) metabolic pathway, CYP15A1 and JH esterase (JHE) are differentially expressed; and in the 20-hydroxyecdysone (20E) metabolic pathway, CYP307A1, CYP314A1, and CYP18A1 are differentially expressed. In the SM, the expression levels of CYP307A1 and CYP314A1 are significantly increased, whereas the expression level of CYP18A1 is significantly decreased; in the SF, the expression levels of the above genes are opposite to that of the SM. Expression trends of RNA-seq is consistent with the expression level of qRT-PCR, and seven of them are highly correlated (R ≥ 0.610) and four are moderately correlated (0.588 ≥ R ≥ 0.542).
Project description:To explore the function of small heat shock protein genes (shsps) and hsp70 in Ericerus pela, we cloned the full-length cDNA sequences of hsp21.5, hsp21.7, hsp70, and hsc70 and the genomic sequence of hsc70. Open reading frames of the four hsps were 570, 564, 1,908, and 1,962 base pairs (bp), respectively, which encode proteins with calculated molecular mass of 21.5, 21.7, 69.8, and 71.6 kDa. Amino acid sequence analysis revealed the presence of the conserved Hsp motifs in all four proteins. The genomic DNA of hsc70 had four introns. ep-hsp21.5 was orthologous and ep-hsp21.7 was species specific. Expression of all four transcripts during heat or cold stress and development was examined by quantitative real-time polymerase chain reaction. All four hsps were upregulated during heat or cold stress in female adults, indicating a correlation between the four hsps and heat or cold-stress tolerance in female adults. ep-hsp21.7 and ep-hsp70 were upregulated during heat stress in male larvae, implying a correlation between the two hsps and heat-stress tolerance in male larvae. The four ep-hsps were also upregulated during the developmental process in males, and ep-hsp21.5, ep-hsp70, and ep-hsc70 were upregulated in females, which indicates their possible role in the developmental regulation of E. pela.