title: Expression and comparative genomics of two serum response factor genes in zebrafish.
abstract: Serum response factor (SRF) is a single copy, highly conserved transcription factor that governs the expression of hundreds of genes involved with actin cytoskeletal organization, cellular growth and signaling, neuronal circuitry and muscle differentiation. Zebrafish have emerged as a facile and inexpensive vertebrate model to delineate gene expression, regulation, and function, and yet the study of SRF in this animal has been virtually unexplored. Here, we report the existence of two srf genes in zebrafish, with partially overlapping patterns of expression in 3 and 7 day old developing animals. The mammalian ortholog (srf1) encodes for a 520 amino acid protein expressed in adult vascular and visceral smooth muscle cells, cardiac and skeletal muscle, as well as neuronal cells. The second zebrafish srf gene (srf2), encoding for a presumptive protein of only 314 amino acids, is transcribed at lower levels and appears to be less widely expressed across adult tissues. Both srf genes are induced by the SRF coactivator myocardin and attenuated with a short hairpin RNA to mammalian SRF. Promoter studies with srf1 reveal conserved CArG boxes that are the targets of SRF-myocardin in embryonic zebrafish cells. These results reveal that SRF was duplicated in the zebrafish genome and that its protein expression in all three muscle cell types is highly conserved across vertebrate animals suggesting an ancient code for transcriptional regulation of genes unique to muscle cell lineages.
authors.affiliation: Department of Biological Sciences, State University of New York College at Brockport, Brockport, NY, USA.
authors.forename: Jody L
authors.initials: JL
authors.lastname: Davis
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Long
authors.forename: Mary A
authors.initials: MA
authors.lastname: Georger
authors.forename: Ian C
authors.initials: IC
authors.lastname: Scott
authors.forename: Adam
authors.initials: A
authors.lastname: Rich
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Miano
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D019143:Evolution, Molecular; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D023281:Genomics; D006801:Humans; D008969:Molecular Sequence Data; D032342:Muscle Cells / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D026362:Serum Response Factor / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics; D014161:Transduction, Genetic; D015027:Zebrafish / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism; D000099251:Myocardin
chemical_list: D004247:DNA; D017931:DNA Primers; D009687:Nuclear Proteins; D012333:RNA, Messenger; D026362:Serum Response Factor; D015534:Trans-Activators; D029961:Zebrafish Proteins; D000099251:Myocardin