Molecular basis for acquisition of de novo sensory circuit

2010 Fiscal Year Final Research Report

• Project/Area Number: 21790189
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: General anatomy (including Histology/Embryology)
• Research Institution: Jichi Medical University
• Principal Investigator: YAJIMA Hiroshi Jichi Medical University, 医学部, 講師 (10433583)
• Project Period (FY): 2009 – 2010
• Keywords: 発生 / 分化 / 神経堤細胞 / 脊髄神経節 / 感覚神経 / 一次知覚神経 / Six遺伝子

Research Abstract

In the trunk of adult vertebrates, dorsal root ganglia (DRG) convey a variety of sensory modalities to the nervous system. However, during fish and amphibian development, intramedullary sensory neurons, Rohon-Beard (RB) cells, are responsible for juvenile mechanosensation and functionally substituted by DRG. In Xenopus RB cells, Six1 appears just before the switching. Forced expression of Six1 in Xenopus early embryo reduced the number of RB cells but induced premature extramedullary sensory neurogenesis. Genetic elimination of both Six1 and Six4 in mouse caused the emergence of RB-like cells within spinal cord. Since Six1 is expressed from the beginning of mouse DRG development, the heterochronic shift of the expressions of Six1 might be a key step in the evolution of vertebrate primary sensory system in the trunk.

Research Products

• [Journal Article] Six family genes control the proliferation and differentiation of muscle satellite cells. (2010)
  • Author(s): Yajima H., Motohashi N., Ono Y., Sato S., Ikeda K., Masuda S., Yada E., Kanesaki H., Miyagoe-Suzuki Y., Takeda S., Kawakami K.
  • Journal Title: Experimental Cell Research 316(17) Pages: 2932-2944
  • Peer Reviewed
• [Journal Article] Conserved expression of mouse Six1 in the pre-placodal region (PPR) and identification of an enhancer for the rostral PPR. (2010)
  • Author(s): Sato S., Ikeda K., Shioi G., Ochi H., Ogino H., Yajima H., Kawakami K.
  • Journal Title: Developmental Biology 344(1) Pages: 158-171
  • Peer Reviewed
• [Presentation] 脊索動物体幹部一次知覚神経発生・進化におけるSix遺伝子の役割 (2010)
  • Author(s): 矢嶋浩, 鈴木誠, 越智陽城, 池田啓子, 佐藤滋, 荻野肇, 上野直人, 川上潔
  • Organizer: 第81回日本動物学会年会,1E1500
  • Place of Presentation: 東京大学教養学部
  • Year and Date: 2010-09-25
• [Presentation] Developmental switch from Rohon-Beard cells to dorsal root ganglia in Xenopus (2010)
  • Author(s): 矢嶋浩, 鈴木誠, 越智陽城, 池田啓子, 佐藤滋, 荻野肇, 上野直人, 川上潔
  • Organizer: 日本発生生物学会第43回大会,P-089
  • Place of Presentation: 国立京都国際会館
  • Year and Date: 2010-06-21
• [Presentation] The key regulator in the evolution of trunk primary sensory neurons (2009)
  • Author(s): 矢嶋浩, 鈴木誠, 池田啓子, 佐藤滋, 上野直人, 川上潔
  • Organizer: The 18th CDB Meeting, Common Themes and New Concepts in Sensory Formation, P30
  • Place of Presentation: 理化学研究所・発生再生科学総合研究センター
  • Year and Date: 20090413-20090415
• [Presentation] Key regulator for the transition from intra-to extra-spinal sensory neurons in the craniates (2009)
  • Author(s): 矢嶋浩, 鈴木誠, 池田啓子, 佐藤滋, 上野直人, 川上潔
  • Organizer: Neuroscience 2009, B93 225.18
  • Place of Presentation: McCormick Place convention center (米国・シカゴ)
  • Year and Date: 2009-10-18
• [Presentation] Formation of the extraspinal sensory cells in the craniates (2009)
  • Author(s): 矢嶋浩, 鈴木誠, 池田啓子, 佐藤滋, 上野直人, 川上潔
  • Organizer: 日本発生生物学会第42回大会,P-003C
  • Place of Presentation: 朱鷺メッセ・新潟コンベンションセンター
  • Year and Date: 2009-05-30