Transcription and Induction Profiles of Three Novel P450 Genes in Liposcelis bostrychophila (Psocoptera: Liposcelididae)

Abstract

The cDNAs of three novel P450 genes, CYP4CB1, CYP4CC1, and CYP4CD1 (GenBank accessions EU979550, EU979549, and EU979551, respectively), were sequenced and characterized from the psocid Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae). CYP4CB1, CYP4CC1, and CYP4CD1 contain open reading frames of 1533, 1512, and 1536 nucleotides that encode 511,504, and 512 amino acid residues, respectively. The putative proteins of CYP4CB1, CYP4CC1, and CYP4CD1 show predicted molecular mass of 59.65, 58.87, and 59.71 kDa, with a theoretical isoelectric point of 6.59, 8.80, and 8.84, respectively. The N-terminal transmembrane domain was only found in CYP4CB1 suggested it is a typical microsomal P450. Phylogenetic analysis showed a close relationship of CYP4CB1, CYP4CC1, and CYP4CD1 with CYP4AW1, CYP4L4, and CYP4E2. Quantitative real-time reverse transcriptase-polymerase chain reaction indicated that these three genes were expressed at all tested developmental stages. In addition, the highest expression occurred in the adult stage, which suggested that these three P450 genes may play important roles in adulthood. The transcripts of CYP4CB1 and CYP4CC1 in adult psocids could be induced to the highest level at 36 and 24 h after the exposure to deltamethrin and paraoxon-methyl (50% lethal concentration [LC50]), respectively, whereas CYP4CD1 remained unchanged. CYP4CD1 transcripts, however, increased rapidly at 8 h after aldicarb (LC50) induction and reached the peak at 36 h. The induction profiles of the three P450 genes suggested that CYP4CB1 and CYP4CC1 are possibly associated with deltamethrin and paraoxonmethyl metabolism in psocids, whereas CYP4CD1 is probably involved in aldicarb metabolism. However, our assumption needs to be further verified by recombinant protein expression of these proteins as well as RNA interference of these genes.

CHARACTERIZATION AND EXPRESSION PROFILES OF FIVE POSSIBLE CYTOCHROME P450 GENES FROM Liposcelis entomophila (ENDERLEIN) (PSOCOPTERA: LIPOSCELIDIDAE)

“…The obverse is that different CYP P450s can be differentially influenced by the same insecticide (Huang et al., ). Our results on mRNA expression showed most of the expression level of CYP P450s changed at 12 or 24 h postexposure, which is consistent with the previous studies, such as CYP4CB1 , CYP4CC1 , and CYP4CD1 in Liposcelis bostrychophila (Jiang et al., ). Thus, the five CYP P450 genes are not uniformly responsive to the same insecticides in terms of level change and responding time, reflecting the complexity of induction response.…”

“…Therefore, we still lack sufficient evidence to imply that the upregulated CYP P450 genes reported here contribute to deltamethrin and malathion metabolism in psocids. The result is consistent with expression levels of CYP4CB1 , CYP4CC1 , and CYP4CD1 in Liposcelis bostrychophila (Jiang et al., ). Our interpretation is that individual CYP P450 genes can be regulated by various insecticides and this can result in different levels of expressions.…”

“…To analyze the sequence homology and phylogenetic relationships, 35 CYP P450s from Pediculus humanus humanus and five from Liposcelis bostrychophila (Jiang et al., , ; Wei et al., ) were download from GenBank and aligned with the five L. entomophila genes to generate the phylogenetic tree (Fig. A).…”

“…Exploring the induced transcription profiles of insect cytochromes P450 may facilitate understanding how insects adapt to the environment and reveal their expression regulation mechanisms. In our previous studies, we investigated the transcription response of cytochromes P450 to insecticides in another psocid, Liposcelis bostrychophila (Jiang et al., , ). The present study extends our work on cytochromes P450 in L. entomophila .…”

Characterization of Esterase Genes Involving Malathion Detoxification and Establishment of an RNA Interference Method in Liposcelis bostrychophila

“…Like other insects, multiple resistance mechanisms in Liposcelis psocids have been reported (Wei et al, 2014). Metabolic resistance (e.g., P450s, GSTs) (Jiang et al, 2012;Jing et al, 2017) and target-site insensitivity (e.g., nicotinic acetylcholine receptor, acetylcholinesterase) (Tang et al, 2009;Wu et al, 2010) are the two main mechanisms involved in the development of insecticide resistance in psocids. In L. bostrychohila, the detoxifying enzymes in insecticide resistance have been widely studied from synergist bioassays to molecular level.…”