Molecular Cloning and Sequence Analysis of Four New cDNA Fragments of Cytochrome P450 from Liposcelis bostrychophila Badonnel ( Psocoptera: Liposcelididae)

摘要

P450 enzymes are an important metabolic system involved in the metabolism of a phenomenal number of endogenous and exogenous compounds. In China, Liposcelis bostrychophila is a dominant species in stored products and the resistance to PH3 has been a severe problem. In order to reveal whether P450 enzymes were involved in the resistance to PH3 or not and the molecular mechanism of resistance, four different P450 cDNA fragments （243 bp) were cloned from the susceptible strain of L. bostryehophila, according to the RT-PCR strategy with a pair of degenerate primers designed on the basis of the heme-binding region of CYP6 family. The putative conserved domains of P450 were found in fragments 1,2 and 4,by the Blast search in GenBank database. It was the first time that P450 genes had been cloned from L. bostrychophila, which verified the existence of P450 enzymes in L. bostrychophila. The homologous alignment by ClustalX （Ver. 1.81) indicated that the fragments 1,2 and 4 shared higher identities of deduced amino acid sequences with certain known members of CYP6 family(42%-67%,42%-56% and 41%-66%, respectively), while fragment 3 showed lower identities(38%-56%). And the result was further tested by the phylogeny analysis by MEGA (Ver. 3.1) utilizing the UPGMA（unweighted pair group method with arithmetic mean).