title: Homeodomain Protein Scr Regulates the Transcription of Genes Involved in Juvenile Hormone Biosynthesis in the Silkworm.
abstract: The silkworm Dominant trimolting (Moltinism, M³) mutant undergoes three larval molts and exhibits precocious metamorphosis. In this study, we found that compared with the wild-type (WT) that undergoes four larval molts, both the juvenile hormone (JH) concentration and the expression of the JH-responsive gene Krüppel homolog 1 (Kr-h1) began to be greater in the second instar of the M³ mutant. A positional cloning analysis revealed that only the homeodomain transcription factor gene Sex combs reduced (Scr) is located in the genomic region that is tightly linked to the M³ locus. The expression level of the Scr gene in the brain-corpora cardiaca-corpora allata (Br-CC-CA) complex, which controls the synthesis of JH, was very low in the final larval instar of both the M³ and WT larvae, and exhibited a positive correlation with JH titer changes. Importantly, luciferase reporter analysis and electrophoretic mobility shift assay (EMSA) demonstrated that the Scr protein could promote the transcription of genes involved in JH biosynthesis by directly binding to the cis-regulatory elements (CREs) of homeodomain protein on their promoters. These results conclude that the homeodomain protein Scr is transcriptionally involved in the regulation of JH biosynthesis in the silkworm.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. keven190@sina.com.
authors.forename: Meng
authors.initials: M
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. mlliuchun@163.com.
authors.forename: Chun
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. theppone@163.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. wenliang20081103@126.com.
authors.forename: Wenliang
authors.initials: W
authors.lastname: Qian
authors.affiliation: The Sericultural Research Institute, Jiangsu University of Science and Technology, Jiangsu 212018, China. qianheying123@163.com.|The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Jiangsu 212018, China. qianheying123@163.com.
authors.forename: Heying
authors.initials: H
authors.lastname: Qian
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. tianling@sibs.ac.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. ljr1994@email.swu.edu.cn.
authors.forename: Jiarui
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. dai_dandan91@163.com.
authors.forename: Dandan
authors.initials: D
authors.lastname: Dai
authors.affiliation: The Sericultural Research Institute, Jiangsu University of Science and Technology, Jiangsu 212018, China. srixay@126.com.|The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Jiangsu 212018, China. srixay@126.com.
authors.forename: Anying
authors.initials: A
authors.lastname: Xu
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. shengli@sippe.ac.cn.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. xiaqy@swu.edu.cn.
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. chengdj@swu.edu.cn.
authors.forename: Daojun
authors.initials: D
authors.lastname: Cheng
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D005786:Gene Expression Regulation; D007605:Juvenile Hormones / Q000096:biosynthesis*; D009154:Mutation; D010641:Phenotype; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D040641:Quantitative Trait Loci; D014158:Transcription, Genetic; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D007605:Juvenile Hormones; D019061:src-Family Kinases
keywords: biosynthesis; juvenile hormone; sex combs reduced; silkworm; transcriptional regulation