title: Enhancer activity of Helitron in sericin-1 gene promoter from Bombyx mori.
abstract: Sericin is a kind of water-soluble protein expressed specifically in the middle silk gland of Bombyx mori. When the sericin-1 gene promoter was cloned and a transgenic vector was constructed to express a foreign protein, a specific Helitron, Bmhel-8, was identified in the sericin-1 gene promoter sequence in some genotypes of Bombyx mori and Bombyx mandarina. Given that the Bmhel-8 Helitron transposon was present only in some genotypes, it could be the source of allelic variation in the sericin-1 promoter. The length of the sericin-1 promoter sequence is approximately 1063 or 643 bp. The larger size of the sequence or allele is ascribed to the presence of Bmhel-8. Silkworm genotypes can be homozygous for either the shorter or larger promoter sequence or heterozygous, containing both alleles. Bmhel-8 in the sericin-1 promoter exhibits enhancer activity, as demonstrated by a dual-luciferase reporter system in BmE cell lines. Furthermore, Bmhel-8 displays enhancer activity in a sericin-1 promoter-driven gene expression system but does not regulate the tissue-specific expression of sericin-1.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.|College of Forestry & Life Science, Chongqing University of Arts & Sciences, Yongchuan, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.
authors.forename: Jun-Hong
authors.initials: JH
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.|College of Forestry & Life Science, Chongqing University of Arts & Sciences, Yongchuan, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zou
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.
authors.forename: Min-Jin
authors.initials: MJ
authors.lastname: Han
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.|Laboratory of Animal Biology, Chongqing Normal University, Chongqing, China.
authors.forename: Ze-Yang
authors.initials: ZY
authors.lastname: Zhou
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D012831:Bombyx / Q000235:genetics*; D002460:Cell Line; D004251:DNA Transposable Elements; D019476:Insect Proteins / Q000235:genetics; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D047030:Sericins / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D019476:Insect Proteins; D047030:Sericins
keywords: Bmhel-8; enhancer; promoter; regulation; sericin-1