Molecular cloning and preliminary function study of iron responsive element binding protein 1 gene from cypermethrin-resistant Culex pipiens pallens

Background: insecticide resistance jeopardizes the control of mosquito populations and mosquito-borne disease control,which creates a major public health concern. two-dimensional electrophoresis identified one protein segment with high sequence homology to part of aedes aegypti iron-responsive element binding protein (ire-bp). method. rt-pcr and race (rapid amplification of cdna end) were used to clone a cdna encoding full length ire-bp 1. real-time quantitative rt-pcr was used to evaluate the transcriptional level changes in the cr-ire strain aedes aegypti compared to the susceptible strain of cx. pipiens pallens. the expression profile of the gene was established in the mosquito life cycle. methyl tritiated thymidine (3h-tdr) was used to observe the cypermethrin resistance changes in c6/36 cells containing the stably transfected ire-bp 1 gene of cx. pipiens pallens. results: the complete sequence of iron responsive element binding protein 1 (ire-bp 1) has been cloned from the cypermethrin-resistant strain of culex pipiens pallens (cr-ire strain). quantitative rt-pcr analysis indicated that the ire-bp 1 transcription level was 6.7 times higher in the cr-ire strain than in the susceptible strain of 4th instar larvae. the ire-bp 1 expression was also found to be consistently higher throughout the life cycle of the cr-ire strain. a protein of predicted size 109.4 kda has been detected by western blotting in ire-bp 1-transfected mosquito c6/36 cells. these ire-bp 1-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by 3h-tdr incorporation. conclusion: ire-bp 1 is expressed at higher levels in the cr-ire strain,and may confer some insecticide resistance in cx. pipiens pallens. © 2011tan et al; licensee biomed central ltd.