DOI QR코드

DOI QR Code

Expression of Hr-Erf Gene during Ascidian Embryogenesis

  • Kim, Jung Eun (Department of Marine Molecular Biotechnology, Gangneung-Wonju National University) ;
  • Lee, Won Young (Department of Marine Molecular Biotechnology, Gangneung-Wonju National University) ;
  • Kim, Gil Jung (Department of Marine Molecular Biotechnology, Gangneung-Wonju National University)
  • Received : 2013.11.23
  • Accepted : 2013.12.14
  • Published : 2013.12.31

Abstract

FGF9/16/20 signaling pathway specify the developmental fates of notochord, mesenchyme, and neural cells in ascidian embryos. Although a conserved Ras/MEK/Erk/Ets pathway is known to be involved in this signaling, the detailed mechanisms of regulation of FGF signaling pathway have remained largely elusive. In this study, we have isolated Hr-Erf, an ascidian orthologue of vertebrate Erf, to elucidate interactions of transcription factors involved in FGF signaling of the ascidian embryo. The Hr-Erf cDNA encompassed 3110 nucleotides including sequence encoded a predicted polypeptide of 760 amino acids. The polypeptide had the Ets DNA-binding domain in its N-terminal region. In adult animals, Hr-Erf mRNA was predominantly detected in muscle, and at lower levels in ganglion, gills, gonad, hepatopancreas, and stomach by quantitative real-time PCR (QPCR) method. During embryogenesis, Hr-Erf mRNA was detected from eggs to early developmental stage embryos, whereas the transcript levels were decreased after neurula stage. Similar to the QPCR results, maternal transcripts of Hr-Erf was detected in the fertilized eggs by whole-mount in situ hybridization. Maternal mRNA of Hr-Erf was gradually lost from the neurula stage. Zygotic expression of Hr-Erf started in most blastomeres at the 8-cell stage. At gastrula stage, Hr-Erf was specifically expressed in the precursor cells of brain and mesenchyme. When MEK inhibitor was treated, embryos resulted in loss of Hr-Erf expression in mesenchyme cells, and in excess of Hr-Erf in a-line neural cells. These results suggest that zygotic Hr-Erf products are involved in specification of mesenchyme and neural cells.

Keywords

References

  1. Bartel FO, Higuchi T, Spyropoulos DD (2000) Mouse models in the study of the Ets family of transcription factors. Oncogene 19:6443-6454. https://doi.org/10.1038/sj.onc.1204038
  2. Bertrand V, Hudson C, Caillol D, Popovici C, Lemaire P (2003) Neural tissue in ascidian embryos is induced by FGF9/16/20, acting via a combination of maternal GATA and Ets transcription factors. Cell 115:615-627. https://doi.org/10.1016/S0092-8674(03)00928-0
  3. Imai KS, Satoh N, Satou Y (2002) Early embryonic expression of FGF4/6/9 gene and its role in the induction of mesenchyme and notochord in Ciona savignyi embryos. Development 129:1729-1738.
  4. Inazawa T, Okamura Y, Takahashi K (1998) Basic fibroblast growth factor induction of neuronal ion channel expression in ascidian ectodermal blastomeres. J Physiol 511:347- 359. https://doi.org/10.1111/j.1469-7793.1998.347bh.x
  5. Kawashima T, Kawashima S, Kanehisa M, Nishida H, Makabe KW (2000) MAGEST: Maboya gene expression patterns and sequence tags. Nucleic Acids Res 1:133-135.
  6. Kim GJ, Nishida H (2001) Role of the FGF and MEK signaling pathway in the ascidian embryo. Dev Growth Differ 5:521-533.
  7. Kim GJ, Yamada A, Nishida H (2000) An FGF signal from endoderm and localized factors in the posteriorvegetal egg cytoplasm pattern the mesodermal tissues in the ascidian embryo. Development 127:2853-2862.
  8. Kumano G, Yamaguchi S, Nishida H (2006) Overlapping expression of FoxA and Zic confers responsiveness to FGF signaling to specify notochord in ascidian embryos. Dev Biol 300:770-784. https://doi.org/10.1016/j.ydbio.2006.07.033
  9. Lee WY, Ham HS, Kim GJ (2011) Expression of Wee1 gene in the ascidian, Halocynthia roretzi embryo. Dev Reprod 15:1-7.
  10. Le Gallic L, Sgouras D, Beal G Jr, Mavrothalassitis G (1999) Transcriptional repressor ERF is a Ras/mitogenactivated protein kinase target that regulates cellular proliferation. Mol Cell Biol 19:4121-4133.
  11. Mavrothalassitis G, Ghysdael J (2000) Proteins of the ETS family with transcriptional repressor activity. Oncogene 19:6524-6532. https://doi.org/10.1038/sj.onc.1204045
  12. Miya T, Morita K, Suzuki A, Ueno N, Satoh N (1997) Functional analysis of an ascidian homologue of vertebrate Bmp-2/Bmp-4 suggests its role in the inhibition of neural fate specification. Development 24:5149-5159.
  13. Miya T, Nishida H (2003) An Ets transcription factor, HrEts, is target of FGF signaling and involved in induction of notochord, mesenchyme, and brain in ascidian embryos. Dev Biol 261:25-38. https://doi.org/10.1016/S0012-1606(03)00246-X
  14. Nakatani Y, Yasuo H, Satoh N, Nishida H (1996) Basic fibroblast growth factor induces notochord formation and the expression of As-T, a Brachyury homolog, during ascidian embryogenesis. Development 122:2023- 2031.
  15. Oikawa T, Yamada T (2003) Molecular biology of the Ets family of transcription factor. Gene 303:11-34. https://doi.org/10.1016/S0378-1119(02)01156-3
  16. Papadaki C, Alexiou M, Cecena G, Verykokakis M, Bilitou A, Cross JC, Oshima RG, Mavrothalassitis G (2007) Transcriptional repressor erf determines extraembryonic ectoderm differentiation. Mol Cell Biol 27: 5201-5213. https://doi.org/10.1128/MCB.02237-06
  17. Rizzo F, Fernandez-Serra M, Squarzoni P, Archimandritis A, Arnone MI (2006) Identification and developmental expression of the Ets gene family in the sea urchin (Strongylocentrotus purpuratus). Dev Biol 300:35-48. https://doi.org/10.1016/j.ydbio.2006.08.012
  18. Saitou N, Nei M (1987) The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4:406-425.
  19. Sgouras DN, Athanasiou MA, Beal GJ Jr, Fisher RJ, Blair DG, Mavrothalassitis G (1995) ERF: an ETS domain protein with strong transcriptional repressor activity, can suppress ets-associated tumorigenesis and is regulated by phosphorylation during cell cycle and mitogenic stimulation. EMBO J 14:4781-4793.
  20. Tootle TL, Rebay I (2005) Post-translational modifications influence transcription factor activity: a view from the ETS superfamily. Bioessays 27:285-298. https://doi.org/10.1002/bies.20198
  21. Twigg SR, Vorgia E, McGowan SJ, Peraki I, Fenwick AL, Sharma VP, Allegra M, Zaragkoulias A, Sadighi Akha E, Knight SJ, Lord H, Lester T, Izatt L, Lampe AK, Mohammed SN, Stewart FJ, Verloes A, Wilson LC, Healy C, Sharpe PT, Hammond P, Hughes J, Taylor S, Johnson D, Wall SA, Mavrothalassitis G, Wilkie AO (2013) Reduced dosage of ERF causes complex craniosynostosis in human and mice and links ERK1/2 signaling to regulation of osteogenesis. Nat Genet 45:308-313. https://doi.org/10.1038/ng.2539
  22. Yordy JS, Muise-Helmericks RC (2000) Signal transduction and the Ets family of transcription factors. Oncogene 19:6503-6513. https://doi.org/10.1038/sj.onc.1204036