title: A Genome-Wide Identification and Analysis of the Basic Helix-Loop-Helix Transcription Factors in Brown Planthopper, Nilaparvata lugens.
abstract: The basic helix-loop-helix (bHLH) transcription factors in insects play essential roles in multiple developmental processes including neurogenesis, sterol metabolism, circadian rhythms, organogenesis and formation of olfactory sensory neurons. The identification and function analysis of bHLH family members of the most destructive insect pest of rice,Nilaparvata lugens, may provide novel tools for pest management. Here, a genome-wide survey forbHLHsequences identified 60bHLHsequences (NlbHLHs) encoded in the draft genome ofN. lugens. Phylogenetic analysis of the bHLH domains successfully classified these genes into 40bHLHfamilies in group A (25), B (14), C (10), D (1), E (8) and F (2). The number ofNlbHLHswith introns is higher than many other insect species, and the average intron length is shorter than those ofAcyrthosiphon pisum. High number of ortholog families ofNlbHLHswas found suggesting functional conversation for these proteins. Compared to other insect species studied,N. lugenshas the highest number of bHLH members. Furthermore, gene duplication events ofSREBP,Kn(col),Tap,Delilah,Sim,AtoandCrpwere found inN. lugens. In addition, a putative full set ofNlbHLHgenes is defined and compared with another insect species. Thus, our classification of theseNlbHLHmembers provides a platform for further investigations of bHLH protein functions in the regulation ofN. lugens, and of insects in general.
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. wanpinjun@caas.cn.
authors.forename: Pin-Jun
authors.initials: PJ
authors.lastname: Wan
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. yuansanyue@163.com.
authors.forename: San-Yue
authors.initials: SY
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. weixwang74@126.com.
authors.forename: Wei-Xia
authors.initials: WX
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. 2014102079@njau.edu.cn.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. laifengxiang@caas.cn.
authors.forename: Feng-Xiang
authors.initials: FX
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. fuqiang@caas.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
keywords: Nilaparvata lugens; basic helix-loop-helix; ortholog family; phylogenetic analysis