title: Characterization of the sterol carrier protein-x/sterol carrier protein-2 gene in the cotton bollworm, Helicoverpa armigera.
abstract: Cholesterol is a membrane component and the precursor of ecdysteroids in insects, but insects cannot synthesize cholesterol de novo. Therefore, cholesterol uptake and transportation during the feeding larval stages are critical processes in insects. The sterol carrier protein-2 domain (SCP-2) in sterol carrier proteins-x (SCP-x) has been speculated to be involved in intracellular cholesterol transfer and metabolism in vertebrates. However, a direct association between SCP-x gene expression, cholesterol absorption and development in lepidopteran insects is poorly understood. We identified the Helicoverpa armigera sterol carrier protein-x/2 (HaSCP-x/2) gene from the larval midgut cDNAs. The HaSCP-x/2 gene is well conserved during evolution and relatively divergent in heterogenetic species. Transcripts of HaSCP-x/2 were detected by qRT-PCR at the highest level in the midgut of H. armigera during the larval stages. Expression knockdown of HaSCP-x/2 transcripts via dsRNA interference resulted in delayed larval development and decreased adult fecundity. Sterol carrier protein-2 inhibitors were lethal to young larvae and decreased fertility in adults emerged from treated elder larvae in H. armigera. The results taken together suggest that HaSCPx/2 gene is important for normal development and fertility in H. armigera.
authors.affiliation: College of Life Sciences, Central China Normal University, 100 Luoyu Road, Wuhan, Hubei 430079, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.forename: Haihao
authors.initials: H
authors.lastname: Ma
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Kaiyu
authors.initials: K
authors.lastname: Liu
authors.forename: Jianxin
authors.initials: J
authors.lastname: Peng
authors.forename: Que
authors.initials: Q
authors.lastname: Lan
authors.forename: Huazu
authors.initials: H
authors.lastname: Hong
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D005260:Female; D005298:Fertility; D015870:Gene Expression; D019476:Insect Proteins / Q000235:genetics*; D007814:Larva / Q000254:growth & development; D009036:Moths / Q000235:genetics* / Q000254:growth & development; D052287:Oviparity; D034622:RNA Interference; D017422:Sequence Analysis, DNA
chemical_list: D002352:Carrier Proteins; D019476:Insect Proteins; C072087:sterol carrier proteins