Drosophila mef2 expression during mesoderm development is controlled by a complex array of cis-acting regulatory modules.

The function of the Drosophila mef2 gene, a member of the MADS box supergene family of transcription factors, is critical for terminal differentiation of the three major muscle cell types, namely somatic, visceral, and cardiac. During embryogenesis, mef2 undergoes multiple phases of expression, which are characterized by initial broad mesodermal expression, followed by restricted expression in the dorsal mesoderm, specific expression in muscle progenitors, and sustained expression in the differentiated musculatures. In this study, evidence is presented that temporally and spatially specific mef2 expression is controlled by a complex array of cis-acting regulatory modules that are responsive to different genetic signals. Functional testing of approximately 12 kb of 5' flanking region of the mef2 gene showed that the initial widespread mesodermal expression is achieved through a 280-bp twist-dependent enhancer. The subsequent dorsal mesoderm-restricted mef2 expression is mediated through a 460-bp dpp-responsive regulatory module, which involves the function of the Smad4 homolog Medea and contains several binding sites for Medea and Mad. The analysis also showed that regulated mef2 expression in the caudal and trunk visceral mesoderm, which give rise to longitudinal and circular gut musculatures, respectively, is under the control of distinct enhancer elements. In addition, mef2 expression in the cardioblasts of the heart is dependent upon at least two distinct enhancers, which are active at different periods during embryogenesis. Moreover, multiple regulatory elements are differentially activated for specific expression in presumptive muscle founders, prefusion myoblasts, and differentiated muscle fibers. Taken together, the presented data suggest that specific expression of the mef2 gene in myogenic lineages in the Drosophila embryo is the result of multiple genetic inputs that act in an additive manner upon distinct enhancers in the 5' flanking region.

[1]  M. Frasch,et al.  Smad proteins act in combination with synergistic and antagonistic regulators to target Dpp responses to the Drosophila mesoderm. , 1998, Genes & development.

[2]  L. Dobens,et al.  Medea is a Drosophila Smad4 homolog that is differentially required to potentiate DPP responses. , 1998, Development.

[3]  J. Hudson,et al.  The Drosophila Medea gene is required downstream of dpp and encodes a functional homolog of human Smad4. , 1998, Development.

[4]  R. W. Padgett,et al.  The Drosophila gene Medea demonstrates the requirement for different classes of Smads in dpp signaling. , 1998, Development.

[5]  R. Schulz,et al.  The myogenic regulatory gene Mef2 is a direct target for transcriptional activation by Twist during Drosophila myogenesis. , 1998, Genes & development.

[6]  A. Nose,et al.  Regional specification of muscle progenitors in Drosophila: the role of the msh homeobox gene. , 1998, Development.

[7]  M. Frasch,et al.  Regulation of the twist target gene tinman by modular cis-regulatory elements during early mesoderm development. , 1997, Development.

[8]  Kohei Miyazono,et al.  TGF-β signalling from cell membrane to nucleus through SMAD proteins , 1997, Nature.

[9]  M. Wasser,et al.  A basic-helix-loop-helix protein expressed in precursors of Drosophila longitudinal visceral muscles , 1997, Mechanisms of Development.

[10]  M. Bate,et al.  Specific muscle identities are regulated by Krüppel during Drosophila embryogenesis. , 1997, Development.

[11]  S. M. Abmayr,et al.  Drosophila myoblast city Encodes a Conserved Protein That Is Essential for Myoblast Fusion, Dorsal Closure, and Cytoskeletal Organization , 1997, The Journal of cell biology.

[12]  A. Paululat,et al.  The Mesodermal Expression of rolling stone (rost) Is Essential for Myoblast Fusion in Drosophila and Encodes a Potential Transmembrane Protein , 1997, The Journal of cell biology.

[13]  Kirby D. Johnson,et al.  Drosophila Mad binds to DNA and directly mediates activation of vestigial by Decapentaplegic , 1997, Nature.

[14]  R. Schulz,et al.  Twist-mediated Activation of the NK-4 Homeobox Gene in the Visceral Mesoderm of Drosophila Requires Two Distinct Clusters of E-box Regulatory Elements* , 1997, The Journal of Biological Chemistry.

[15]  A. Hata,et al.  TGF-β signalling through the Smad pathway , 1997 .

[16]  C. Goodman,et al.  Genetic Analysis of Myoblast Fusion: blown fuse Is Required for Progression Beyond the Prefusion Complex , 1997, The Journal of cell biology.

[17]  S. M. Abmayr,et al.  Ectopic expression of MEF2 in the epidermis induces epidermal expression of muscle genes and abnormal muscle development in Drosophila. , 1997, Developmental biology.

[18]  R A Schulz,et al.  D‐mef2 is a target for Tinman activation during Drosophila heart development , 1997, The EMBO journal.

[19]  C. Keller,et al.  Misexpression of nautilus induces myogenesis in cardioblasts and alters the pattern of somatic muscle fibers. , 1997, Developmental biology.

[20]  P. Heitzler,et al.  ladybird, a tandem of homeobox genes that maintain late wingless expression in terminal and dorsal epidermis of the Drosophila embryo. , 1997, Development.

[21]  P. Lawrence,et al.  Segmentation and specification of the Drosophila mesoderm. , 1996, Genes & development.

[22]  B. Shilo,et al.  Heartless, a Drosophila FGF receptor homolog, is essential for cell migration and establishment of several mesodermal lineages. , 1996, Genes & development.

[23]  Stephen S. Gisselbrecht,et al.  heartless encodes a fibroblast growth factor receptor (DFR1/DFGF-R2) involved in the directional migration of early mesodermal cells in the Drosophila embryo. , 1996, Genes & development.

[24]  M. Beckerle,et al.  Two muscle-specific LIM proteins in Drosophila , 1996, The Journal of cell biology.

[25]  J. Axelrod,et al.  The wingless signaling pathway is directly involved in Drosophila heart development. , 1996, Developmental biology.

[26]  M. Bate,et al.  twist: A Myogenic Switch in Drosophila , 1996, Science.

[27]  R. Schulz,et al.  Wingless signaling induces nautilus expression in the ventral mesoderm of the Drosophila embryo. , 1996, Developmental biology.

[28]  R. Schulz,et al.  Expression of the D-MEF2 transcription in the Drosophila brain suggests a role in neuronal cell differentiation. , 1996, Oncogene.

[29]  G. Schubiger,et al.  Autonomous and nonautonomous Notch functions for embryonic muscle and epidermis development in Drosophila. , 1996, Development.

[30]  N H Brown,et al.  Anterior-posterior subdivision and the diversification of the mesoderm in Drosophila. , 1995, Development.

[31]  P. Lawrence,et al.  Segmental patterning of heart precursors in Drosophila. , 1995, Development.

[32]  R. Schulz,et al.  Regulation of muscle differentiation by the MEF2 family of MADS box transcription factors. , 1995, Developmental biology.

[33]  M. Bate,et al.  wingless is required for the formation of a subset of muscle founder cells during Drosophila embryogenesis. , 1995, Development.

[34]  M. Bate,et al.  Lethal of scute, a proneural gene, participates in the specification of muscle progenitors during Drosophila embryogenesis. , 1995, Genes & development.

[35]  R. Schulz,et al.  A series of mutations in the D-MEF2 transcription factor reveal multiple functions in larval and adult myogenesis in Drosophila. , 1995, Developmental biology.

[36]  M. Bate,et al.  Mutations in a novel gene, myoblast city, provide evidence in support of the founder cell hypothesis for Drosophila muscle development. , 1995, Development.

[37]  A. Sharrocks,et al.  The MADS-box family of transcription factors. , 1995, European journal of biochemistry.

[38]  S. M. Abmayr,et al.  Embryonic development of the larval body wall musculature of Drosophila melanogaster. , 1995, Trends in genetics : TIG.

[39]  M. Frasch,et al.  Induction of visceral and cardiac mesoderm by ectodermal Dpp in the early Drosophila embryo , 1995, Nature.

[40]  Hanh T. Nguyen,et al.  Drosophila MEF2, a transcription factor that is essential for myogenesis. , 1995, Genes & development.

[41]  M. Taylor,et al.  Drosophila MEF2 is regulated by twist and is expressed in both the primordia and differentiated cells of the embryonic somatic, visceral and heart musculature , 1995, Mechanisms of Development.

[42]  R A Schulz,et al.  Requirement of MADS domain transcription factor D-MEF2 for muscle formation in Drosophila , 1995, Science.

[43]  Michael Bate,et al.  dpp induces mesodermal gene expression in Drosophila , 1994, Nature.

[44]  M. Frasch,et al.  tinman and bagpipe: two homeo box genes that determine cell fates in the dorsal mesoderm of Drosophila. , 1993, Genes & development.

[45]  R. Bodmer.  The gene tinman is required for specification of the heart and visceral muscles in Drosophila. , 1993, Development.

[46]  N. Perrimon,et al.  Targeted gene expression as a means of altering cell fates and generating dominant phenotypes. , 1993, Development.

[47]  W. Gelbart,et al.  An activity gradient of decapentaplegic is necessary for the specification of dorsal pattern elements in the Drosophila embryo. , 1993, Development.

[48]  S. Higashijima,et al.  Two FGF-receptor homologues of Drosophila: one is expressed in mesodermal primordium in early embryos. , 1993, Development.

[49]  M. Bate,et al.  The development of Drosophila melanogaster , 1993 .

[50]  R. Steward,et al.  Dorsal-ventral polarity in the Drosophila embryo. , 1993, Current opinion in genetics & development.

[51]  John B. Thomas,et al.  apterous is a drosophila LIM domain gene required for the development of a subset of embryonic muscles , 1992, Neuron.

[52]  M. Levine,et al.  The dorsal gradient morphogen regulates stripes of rhomboid expression in the presumptive neuroectoderm of the Drosophila embryo. , 1992, Genes & development.

[53]  C. Nüsslein-Volhard,et al.  The origin of pattern and polarity in the Drosophila embryo , 1992, Cell.

[54]  A. Michelson,et al.  A role for the Drosophila neurogenic genes in mesoderm differentiation , 1991, Cell.

[55]  M. Leptin.  twist and snail as positive and negative regulators during Drosophila mesoderm development. , 1991, Genes & development.

[56]  Gerald M. Rubin,et al.  The embryonic expression patterns of zfh-1 and zfh-2, two Drosophila genes encoding novel zinc-finger homeodomain proteins , 1991, Mechanisms of Development.

[57]  M. Bate,et al.  Expression of a MyoD family member prefigures muscle pattern in Drosophila embryos. , 1990, Genes & development.

[58]  M. Frasch,et al.  A new Drosophila homeo box gene is expressed in mesodermal precursor cells of distinct muscles during embryogenesis. , 1990, Genes & development.

[59]  Y. Jan,et al.  A new homeobox-containing gene, msh-2, is transiently expressed early during mesoderm formation of Drosophila. , 1990, Development.

[60]  M. Bate,et al.  The embryonic development of larval muscles in Drosophila. , 1990, Development.

[61]  M. Leptin,et al.  Cell shape changes during gastrulation in Drosophila. , 1990, Development.

[62]  B. Thisse,et al.  Sequence of the twist gene and nuclear localization of its protein in endomesodermal cells of early Drosophila embryos. , 1988, The EMBO journal.

[63]  W. Engels,et al.  A stable genomic source of P element transposase in Drosophila melanogaster. , 1988, Genetics.

[64]  N E Baker,et al.  Molecular cloning of sequences from wingless, a segment polarity gene in Drosophila: the spatial distribution of a transcript in embryos , 1987, The EMBO journal.

[65]  M. Frasch,et al.  Characterization and localization of the even‐skipped protein of Drosophila. , 1987, The EMBO journal.

[66]  P. Simpson,et al.  Maternal-Zygotic Gene Interactions during Formation of the Dorsoventral Pattern in Drosophila Embryos. , 1983, Genetics.

[67]  G. Rubin,et al.  Genetic transformation of Drosophila with transposable element vectors. , 1982, Science.