Comparative evolutionary study on C. elegans and the sister species

• Project/Area Number: 16H04722
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Genome biology
• Research Institution: University of Miyazaki
• Principal Investigator: Kikuchi Taisei 宮崎大学, 医学部, 准教授 (20353659)
• Co-Investigator(Kenkyū-buntansha): 神崎 菜摘 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (70435585) ; 杉本 亜砂子 東北大学, 生命科学研究科, 教授 (80281715)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥16,120,000 (Direct Cost: ¥12,400,000、Indirect Cost: ¥3,720,000); Fiscal Year 2018: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000); Fiscal Year 2017: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2016: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
• Keywords: シーエレガンス / モデル生物 / 姉妹種 / ゲノム進化 / 線虫 / トランスポゾン / 比較ゲノム / 最近縁種 / C. elegans / C elegans / 種分化

Outline of Final Research Achievements

A sister species of the model organism Caenorhabditis elegans has long been sought for use in comparative analyses that would enable deep evolutionary. We discovered the first sibling species of C. elegans, C. inopinata, which was isolated from fig syconia in Okinawa. We investigate the morphology, developmental processes and behaviour of C. inopinata, which differ significantly from those of C. elegans. We assembled the 123-Mb C. inopinata genome into six nuclear chromosomes and revealed unique characteristics, such as highly expanded transposable elements and massive gene losses in chemoreceptor gene families. We have developed genetic and molecular techniques for C. inopinata; thus C. inopinata provides an exciting new platform for comparative evolutionary studies.

Academic Significance and Societal Importance of the Research Achievements

線虫C. elegansはその培養や観察の容易さなどから、生物学、医学、薬学研究等で幅広く利用されているモデル生物であり、生物学において重大な数々の発見がなされてきた。このC. elegansのモデル生物としての「最大の弱点」は姉妹種が見つかっておらず、比較進化学的視点からの解析が難しいことであった。我々は沖縄県石垣島のイチジク（オオバイヌビワ）からC. elegansの姉妹種を発見し、C. inopinataと名付けた。本線虫において我々が構築した高品質なゲノムと遺伝学解析ツールにより、本線虫とC.elegansはこれまでにない最高の比較生物学解析プラットフォームとなりうる。

Research Products

• [Journal Article] Biology and genome of a newly discovered sibling species of Caenorhabditis elegans (2018)
  • Author(s): Kanzaki N, Tsai IJ, Tanaka R, Hunt VL, Liu D, Tsuyama K, Maeda Y, Namai S, Kumagai R, Tracey A, Holroyd N, Doyle SR, Woodruff GC, Murase K, Kitazume H, Chai C, Akagi A, Panda O, Ke HM, Schroeder FC, Wang J, Berriman M, Sternberg PW, Sugimoto A, Kikuchi T.
  • Journal Title: Nature Communications Volume: 9 Issue: 1 Pages: 3216-3216
  • DOI: 10.1038/s41467-018-05712-5
  • Peer Reviewed / Open Access / Int'l Joint Research