title: Medaka vasa gene has an exonic enhancer for germline expression.
abstract: Enhancers are DNA sequences that enhance gene transcription in a position- and orientation-independent manner. Many enhancers controlling somatic gene expression have been described. Enhancers controlling germline expression have remained rare. Here we report the identification of V35 as a first exonic germline enhancer in vertebrates. V35 constitutes the first 35bp of exon 1 of the medaka vasa gene. V35 is required for vasa promoter function and sufficient to increase transcriptional activity of a heterologous promoter by ~13 fold in either forward or reverse orientation. V35 contains CAGCAGCACGAG for two paired E box-like motifs. Upon incubation with nuclear extract from spermatogonial cells, V35 formed three DNA-protein complexes. We show that complex formation is inhibited partially by oligos containing an E box or E box-like motif but completely by V35 and oligos that contain overlapped E box and E box-like motifs. Most importantly, V35 is sufficient to drive transgene expression in germ cells of developing embryos. These results establish V35 as the first exonic germline enhancer in a lower vertebrate, and provide evidence for the importance of exonic sequences in controlling germ gene expression.
authors.affiliation: Key Laboratory of Exploration & Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
authors.forename: Mingyou
authors.initials: M
authors.lastname: Li
authors.affiliation: School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Huazhong Normal University, Wuhan 430079, China.
authors.forename: Haobing
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore; Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education , Southwest University, Chongqing 400715, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wei
authors.affiliation: Key Laboratory of Exploration & Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
authors.forename: Junling
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Exploration & Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China. Electronic address: dbshyh@nus.edu.sg.
authors.forename: Yunhan
authors.initials: Y
authors.lastname: Hong
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D005091:Exons; D029941:Fish Proteins / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D009990:Oryzias / Q000196:embryology / Q000235:genetics*; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014162:Transfection; D019076:Transgenes
chemical_list: D029941:Fish Proteins; D053487:DEAD-box RNA Helicases
keywords: Exonic enhancer; Gene transcription; Germline; V35; Vasa