Hox complex modification underlying the evolution of echinoderms

• Project/Area Number: 24570235
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Developmental biology
• Research Institution: Kanazawa University
• Principal Investigator: YAMAGUCHI MASAAKI 金沢大学, 自然システム学系, 教授 (60182458)
• Co-Investigator(Renkei-kenkyūsha): WADA Hiroshi 筑波大学, 生命環境科学研究科, 教授 (60303806)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2014: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2012: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 棘皮動物 / ボディープラン / 進化 / ヨツアナカシパン / Hox遺伝子 / 前後軸 / ボディプラン / in toto co-option / sea urchin / Peronella japonica / adult rudiment / Hox complex / body plan

Outline of Final Research Achievements

Echinoderms are a curious group of deuterostomes that forms a clade with hemichordates but has a pentameral body plan. In contrast to hemichordateswith an organized Hox cluster, a sea urchin has a Hox cluster with an atypical organization. We report a comprehensive examination of hox expression in a sand dollar. Nine hox genes are expressed in the adult rudiment, which are classified into two groups: one with linear expression in coeloms and another with radial expression around the adult mouth. The linear genes may endow the mesentery with axial information to direct postmetamorphic transformation of the digestive tract, whereas the radial genes developmentally correlate with the morphological novelties of echinoderms and/or sea urchins. Recruitment of the radial genes appears to be accompanied by the loss of axial roles. This in toto co-option of the hox genes provides insight into the molecular mechanisms underlying the evolution of echinoderms from a bilateral ancestor.

Research Products

• [Journal Article] Early stalked stages in ontogeny of the living isocrinid sea lily Metacrinus rotundus (2015)
  • Author(s): Amemiya, S., Omori, A., Tsurugaya, T., Hibino, T., Yamaguchi, M., Kuraishi, R., Kiyomoto, M., and Minokawa, T.
  • Journal Title: Acta Zoologica Volume: in press Issue: 1 Pages: 1-15
  • DOI: 10.1111/azo.12109
  • Peer Reviewed / Open Access
• [Journal Article] Development of ciliary bands in larvae of the living isocrinoid sea lily Metacrinus rotundus. (2014)
  • Author(s): Amemiya, S., Hibino, T., Nakano, H., Yamaguchi, M., Kuraishi, R., and Kiyomoto, M.
  • Journal Title: Acta Zoologica Volume: in press Issue: 1 Pages: 36-43
  • DOI: 10.1111/azo.12049
  • Peer Reviewed / Open Access
• [Journal Article] Hox expression in the direct-type developing sand dollar Peronella japonica. (2014)
  • Author(s): Tsuchimoto, J. and Yamaguchi, M.
  • Journal Title: Developmental Dynamics Volume: in press Issue: 8 Pages: 1020-1029
  • DOI: 10.1002/dvdy.24135
  • Peer Reviewed
• [Journal Article] Larval mesenchyme cell specification in the primitive echinoid occurs independently of the double-negative gate (2014)
  • Author(s): Yamazaki, A., Kidachi, Y., Yamaguchi, M., and Minokawa, T.
  • Journal Title: Development Volume: 141 Issue: 13 Pages: 2669-2679
  • DOI: 10.1242/dev.104331
  • Peer Reviewed
• [Journal Article] Development of the swimming acorn worm Glandiceps hacksi: similarity to holothroids. (2014)
  • Author(s): Urata, M, Iwasaki, S., Ohtsuka, S., and Yamaguchi, M.
  • Journal Title: Evolution & Development Volume: 16 Issue: 3 Pages: 149-154
  • DOI: 10.1111/ede.12075
  • Peer Reviewed
• [Presentation] ヨツアナカシパン成体原基形成における胚葉間相互作用の解析 (2014)
  • Author(s): 新美伊代、山口正晃
  • Organizer: 日本動物学会中部支部大会
  • Place of Presentation: ホテルのときんぷら
  • Year and Date: 2014-11-23
• [Presentation] ウニ胚におけるデルマタン硫酸エピメラーゼの発現と機能解析
  • Author(s): 丹後麻衣、香川弘恵、山口正晃
  • Organizer: 日本動物学会第８４回大会
  • Place of Presentation: 岡山大学
  • Invited