Characterization of the response to ecdysteroid of a novel cuticle protein R&R gene in the honey bee, Apis cerana cerana

• Published in: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology Vol. 166; no. 1; pp. 73 - 80
• Main Authors: Sun, Rujiang, Zhang, Yuanying, Xu, Baohua
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.09.2013
• Subjects: 20E; AccCPR1 gene; Amino Acid Sequence; amino acids; Animals; Apis cerana; Apis cerana cerana; Apis mellifera; Bees - drug effects; Bees - genetics; binding sites; chitin; Cloning, Molecular; diet; Ecdysteroids; Ecdysterone - administration & dosage; Ecdysterone - genetics; Ecdysterone - metabolism; gene expression; Gene Expression Regulation, Developmental - drug effects; genes; honey bees; insect cuticle; insect proteins; Insect Proteins - genetics; Insect Proteins - isolation & purification; larvae; metamorphosis; Metamorphosis, Biological - genetics; Metamorphosis, Biological - physiology; molting; Molting - genetics; Molting - physiology; Open Reading Frames; Phylogeny; pupae; quantitative polymerase chain reaction; rearing; reverse transcriptase polymerase chain reaction; RT-qPCR; aa; AccCPR1 gene; ORF; E74; Ecdysteroids; CPR; Apis cerana cerana; nt; 20E; mRNA; IPCR; RT-PCR; RACE; BR-C; cDNA; RT-qPCR; ecdysteroid-regulated gene E74; open reading frame; amino acid (s); cuticle protein R&R; quantitative RT-PCR; messenger ribonucleic acid; nucleotide; DNA complementary to DNA; 20-Hydroxyecdysone; inverse polymerase chain reaction; Broad-Complex; rapid amplification of cDNA ends; reverse transcription polymerase chain reaction
• ISSN: 1096-4959; 1879-1107; 1879-1107
• DOI: 10.1016/j.cbpb.2013.07.002

Genes encoding cuticle proteins are helpful subjects to study the molecular mechanisms of insect molting and metamorphosis. In this study, we isolated and characterized a novel cuticle protein R&R gene, referred to as AccCPR1, from Apis cerana cerana. The open reading frame of AccCPR1 has a length of 573 nt and encodes a protein of 190 amino acids that contains a chitin binding region and is a typical cuticle R&R-2 protein. Five putative E74 binding sites and four BR-C binding sites were predicted in the 5′-flanking region, which suggests a potential function in molting and metamorphosis. RT-qPCR showed that AccCPR1 transcript occurred as the ecdysteroid titer decreased after reaching a peak, which suggests AccCPR1 expression requires a “pulse” regimen of ecdysteroids. This hypothesis was tested using different experimental strategies. When larvae were reared with different concentrations of 20E in their diet, the ecdysteroid peak repressed AccCPR1 expression. Exposure of the thoracic integument of the pupae in vitro to different concentration of 20E repressed AccCPR1 expression, which recovered after the removal of 20E. These results suggest that AccCPR1 is a typical cuticle R&R-2 protein that plays an important role in development, and an ecdysteroid pulse is critical for high AccCPR1 gene expression.