title: Bombyx E75 isoforms display stage- and tissue-specific responses to 20-hydroxyecdysone.
abstract: Resulted from alternative splicing of the 5' exons, the nuclear receptor gene E75 in the silkworm, Bombyx mori, processes three mRNA isoforms, BmE75A, BmE75B and BmE75C. From the early 5(th) larval instar to the prepupal stages, BmE75A mRNA and protein levels in the prothoracic glands display developmental profiles similar to ecdysteroid titer. In the fat body, mRNA levels but not protein levels of all three BmE75 isoforms correlate with ecdysteroid titer; moreover, proteins of all three BmE75 isoforms disappear at the prepupal stages, and a modified BmE75 protein with smaller molecular weight and cytoplasm localization occurs. At the early 5(th) larval instar stage, treatment of the prothoracic glands and fat body with 20-hydroxyecdysone (20E) and/or cycloheximide (CHX) revealed that BmE75A is 20E primary-responsive at both mRNA and protein levels, while BmE75B and BmE75C exhibit various responses to 20E. At the early wandering stage, RNAi-mediated reduction of gene expression of the 20E nuclear receptor complex, EcR-USP, significantly decreased mRNA and protein levels of all three BmE75 isoforms in both tissues. In conclusion, BmE75 isoforms display stage- and tissue-specific responses to 20E at both mRNA and protein levels; moreover, they are regulated by other unknown factors at the protein level.
authors.affiliation: 1] Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Sciences, South China Agricultural University, Guangzhou, 510642, China [2] Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Li
authors.affiliation: 1] Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Sciences, South China Agricultural University, Guangzhou, 510642, China [2] Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Enen
authors.initials: E
authors.lastname: Guo
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Muktadir S
authors.initials: MS
authors.lastname: Hossain
authors.affiliation: The Sericultural and Agri-Food Research Institute of the Guangdong Academy of Agricultural Sciences, Guangzhou 510610, China.
authors.forename: Qingrong
authors.initials: Q
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Sciences, South China Agricultural University, Guangzhou, 510642, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Tian
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Sciences, South China Agricultural University, Guangzhou, 510642, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Deng
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
mesh_terms: D000818:Animals; D012831:Bombyx / Q000378:metabolism*; D026461:Ecdysteroids / Q000378:metabolism; D004441:Ecdysterone / Q000378:metabolism*; D005091:Exons / Q000235:genetics; D005216:Fat Body / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D019476:Insect Proteins / Q000378:metabolism*; D007605:Juvenile Hormones / Q000378:metabolism; D007814:Larva / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism*; D034622:RNA Interference / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism
chemical_list: D026461:Ecdysteroids; D019476:Insect Proteins; D007605:Juvenile Hormones; D020033:Protein Isoforms; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D004441:Ecdysterone