Mechanisms for creating neomorphs in acquisition, loss, and convergence

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H02446
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 44020:Developmental biology-related
• Research Institution: Tohoku University
• Principal Investigator: Tamura Koji 東北大学, 生命科学研究科, 教授 (70261550)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 収斂 / 獲得 / 新奇形質 / 共有派生形質 / 発生 / 進化

Outline of Final Research Achievements

The aim of this project was to demonstrate the concept that "morphogenetic mechanisms specific to a group of animals, in which common trans-regulatory sequences act, give rise to synapomorphy" in the evolutional process of acquisition, loss and convergence. Focusing on birds for which a wide range of embryos and whole genome sequences are available (as our own systems), a method was used in which candidate sequences and genes were narrowed down using a combination of comparative genome analysis and RNAseq. Functional analyses using multiple avian embryos and other vertebrate embryos was performed. We obtained and analyzed the trans-regulatory sequences and their neighboring genes that may have led the convergent web formation in birds. We also studied fish and proposed a novel hypothesis on the acquisition of a novel trait, fin, in vertebrates.

Free Research Field

動物発生学

Academic Significance and Societal Importance of the Research Achievements

「特徴的な共有派生形質」「豊富なゲノム配列情報」「形態形成メカニズム解析系」が必要となる学術研究分野において、本研究では全ゲノム配列が解読されている種数が脊椎動物の中で最も多い動物群である「鳥類綱」を主に用いた。鳥類は、飛翔に特化した形態を固有に進化させているなど、特徴的な形質を多数もっており、本研究ではニワトリ胚に加え、複数種の鳥類胚を用いることで独自性の高い成果をもたらした。
本研究目的が達成されることで新しい概念が実証でき、それ自体意義が高い。さらに、固有かつ共通のゲノム配列と遺伝子発現解析から候補配列を絞り込み、胚を用いて候補遺伝子と配列の機能解析を行う、という方法論が構築できた。