Cloning, expression, and bioinformatics analysis of odorant receptor genes in Paratrioza sinica

Abstract

Purpose: Paratrioza sinica is one of the important pests on Lycium barbarum . Adults and nymphs suck in the juice of leaves and tender shoots, causing leaves to turn yellow, even tree death. It results in a decrease in the yield and quality of fruits. The odorant receptor’s receptors (ORs) genes of Paratrioza sinica were cloned and analyzed by bioinformatics methods in this study.

Method: Based on the previous transcriptome sequencing data of Paratrioza sinica , the transcript sequences of PsinOr50, PsinOr15, and PsinOrco were obtained. The CDS sequences of three odorant receptors (ORs) genes in Paratrioza sinica were cloned using rapid amplification of cDNA ends (RACE) cloning technology. The expression levels of these three genes in adult insects of different ages were determined by qRT-PCR. Physical and chemical properties, characteristics of sequences, proteins structure, and evolutionary relationships of three genes and their encoded proteins were analyzed systematically.

Result: The CDS sequences of three ORs genes in Paratrioza sinica were obtained, and their accession numbers in the NCBI database were PP556383 (PsinOr15), PP556384 (PsinOr50), and PP556385 (PsinOrco). Three genes all achieved significantly higher expression levels within 1- to 3-day-old adults of Paratrioza sinica . PsinOr15 is a hydrophilic stable protein that does not contain signal peptides but has a transmembrane domain. It is subcellularly located in the nucleus. PsinOr50 belongs to hydrophobic unstable proteins, with signal peptides and transmembrane domain, and subcellular localization in the cytoplasm. PsinOrco is a hydrophobic stable protein which does not contain signal peptides but has a transmembrane domain. It is subcellularly located in the endoplasmic reticulum. The prediction of the second and tertiary protein structure shows that the proteins encoded by the three ORs genes are mainly alpha helices and random curls. Amino acid sequence alignment revealed that they all contain four conserved amino acid sequence sites. Phylogenetic analysis showed that three ORs genes differentiated into three branches, consistent with the sequence comparison results.

Conclusion: The gene sequences and bioinformatic results of the PsinOr15, PsinOr50, and PsinOrco genes in Paratrioza sinica were obtained in this study. It provides a theoretical basis for studying the role of ORs genes and their encoded proteins in the feeding, mating, and egg laying processes of Paratrioza sinica .