Genomic organization and expression pattern of cytochrome P450 genes in the wolf spider Pardosa pseudoannulata

Miniature Inverted-Repeat Transposable Elements (MITEs) in the Two Lepidopteran Genomes of Helicoverpa armigera and Helicoverpa zea

Simple Summary

Miniature inverted-repeat transposable elements (MITEs) are non-autonomous transposable elements that play important roles in genome organization and evolution. Helicoverpa armigera and Helicoverpa zea shows a high number of reported cases of insecticide resistance worldwide, having evolved resistance against pyrethroids, organophosphates, carbamates, organochlorines, and recently to macrocyclic lactone spinosad and several Bacillus thuringiensis toxins. In the present study, we conducted a genome screening of MITEs in the H. armigera and H. zea genomes using bioinformatics approaches, and the results revealed a total of 3570 and 7405 MITE sequences in the H. armigera and H. zea genomes, respectively. Among these MITEs, we highlighted eleven MITE insertions in the H. armigera defensome genes and only one MITE insertion in those of H. zea.

Abstract

Miniature inverted-repeat transposable elements MITEs are ubiquitous, non-autonomous class II transposable elements. The moths, Helicoverpa armigera and Helicoverpa zea, are recognized as the two most serious pest species within the genus. Moreover, these pests have the ability to develop insecticide resistance. In the present study, we conducted a genome-wide analysis of MITEs present in H. armigera and H. zea genomes using the bioinformatics tool, MITE tracker. Overall, 3570 and 7405 MITE sequences were identified in H. armigera and H. zea genomes, respectively. Comparative analysis of identified MITE sequences in the two genomes led to the identification of 18 families, comprising 140 MITE members in H. armigera and 161 MITE members in H. zea. Based on target site duplication (TSD) sequences, the identified families were classified into three superfamilies (PIF/harbinger, Tc1/mariner and CACTA). Copy numbers varied from 6 to 469 for each MITE family. Finally, the analysis of MITE insertion sites in defensome genes showed intronic insertions of 11 MITEs in the cytochrome P450, ATP-binding cassette transporter (ABC) and esterase genes in H. armigera whereas for H. zea, only one MITE was retrieved in the ABC-C2 gene. These insertions could thus be involved in the insecticide resistance observed in these pests.

Identification and Characterization of CYP6 Family Genes from the Oriental Fruit Moth (Grapholita molesta) and Their Responses to Insecticides

Simple Summary

Eight CYP6 family genes were identified in Grapholita molesta (Busck). The expression of individual gene members differed between the developmental stages and insect tissues. High expression was found in third/fourth-instar larvae and in the midgut and Malpighian tubules. The response patterns of the genes exhibited diverse response patterns to the three representative insecticides were diverse.

Abstract

Cytochrome P450 (CYP) monooxygenases comprise a superfamily of proteins that detoxify xenobiotics and plant secondary metabolites in insects. The CYP6 family is unique to the class Insecta, and its members participate in the metabolism of exogenous substances. In this study, we sequenced and characterized the full-length cDNAs of eight CYP6 family genes from Grapholita molesta (Busck), a global pest of pome fruits. P450 genes with the exception of CYP6AN35, which was most highly expressed in adults, consistently showed high expression in third- or fourth-instar larvae. The analysis of different tissues of adults showed that most of these genes were predominantly expressed in the midgut, Malpighian tubules, and/or fat body. The expression of these eight CYP6 genes was differentially affected by three representative insecticides: malathion (organophosphate), deltamethrin (pyrethroid), and chlorantraniliprole (carbamate). All eight CYP6 genes responded to malathion treatment. Only three CYP6 genes were highly expressed in deltamethrin-treated individuals. Chlorantraniliprole treatment exerted weak effects on gene expression. Interestingly, CYP6AN35 was a highly expression level in the adult head and its expression was induced by all three insecticides. CYP6AN35 may be a key gene in the metabolism of insecticides. This study provides a fundamental understanding of the functions of the CYP6 gene family in insecticide metabolism in G. molesta.