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Apparently inefficient structure of vertebrate eyes: microlens in photoreceptor cells as a possible cause

Research Project

Project/Area Number 18K19362
Research Category

Grant-in-Aid for Challenging Research (Exploratory)

Allocation TypeMulti-year Fund
Review Section Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
Research InstitutionKyoto University

Principal Investigator

Koga Akihiko  京都大学, 霊長類研究所, 教授 (80192574)

Project Period (FY) 2018-06-29 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2019: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Keywords眼 / 視細胞 / 夜行性 / ゲノム / ヘテロクロマチン / 進化 / 脊椎動物
Outline of Final Research Achievements

In photoreceptor cells of many nocturnal mammals, heterochromatin localizes to the central region of the nucleus and serves as a lens that leads to elevated night vision. This situation of the nucleus is called the nocturnal type. Photoreceptor cells of this type have hitherto been observed only in mammals. It is therefore widely believed that the nocturnal type emerged in the mammalian lineage after its divergence from reptiles. Considering that the nocturnal type is an adaptation to dark environments, it is a possible hypothesis that the nocturnal type already existed at the time point of the eye acquisition by an early vertebrate. This hypothesis is supported if the nocturnal types is found in a taxon other than mammals. Photoreceptor cells of 8 species, which belonged to reptiles, amphibians, or fishes, were examined by immunostaining experiments. One of these species was found to have photoreceptor cells that exhibited a situation close to the nocturnal type.

Academic Significance and Societal Importance of the Research Achievements

脊椎動物の眼では、光は視細胞の光受容部位に達する前に、視神経の層を通過し、さらに視細胞の核の部分を通過する。その間に情報の減衰や散逸が起こることが想像され、不合理な構造であるといえる。いったん成立した発生過程を変えられないための制約と、考えられる。しかし、夜行性型の核を現出するためには、この構造は必要である。この点を考慮すると、脊椎動物が眼を獲得した時点ではこの構造はむしろ合理的であったとの仮説が、成り立つ。得られた結果は、この仮説を積極的に支持しないとはいえ、否定するものではない。仮説をさらに追求するための足掛かりが得られたといえる。外洋の深海魚を調べることが効率的であるとの示唆である。

Report

(4 results)
  • 2020 Annual Research Report   Final Research Report ( PDF )
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (12 results)

All 2021 2020 2019 2018 Other

All Int'l Joint Research (3 results) Journal Article (4 results) (of which Int'l Joint Research: 2 results,  Peer Reviewed: 4 results,  Open Access: 2 results) Presentation (5 results) (of which Int'l Joint Research: 2 results,  Invited: 2 results)

  • [Int'l Joint Research] カセサート大学(タイ)

    • Related Report
      2019 Research-status Report
  • [Int'l Joint Research] University of Firenze(イタリア)

    • Related Report
      2018 Research-status Report
  • [Int'l Joint Research] Kasetsart University(タイ)

    • Related Report
      2018 Research-status Report
  • [Journal Article] The heterochromatin block that functions as a rod cell microlens in owl monkeys formed within a 15-Myr time span2021

    • Author(s)
      Tanabe H, Kusakabe KT, Imai H, Yokota SI, Kuraishi T, Hattori S, Kai C, *Koga A
    • Journal Title

      Genome Biology and Evolution

      Volume: 13 Issue: 3

    • DOI

      10.1093/gbe/evab021

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] The CENP-B box, a nucleotide motif involved in centromere formation, has multiple origins in New World monkeys2019

    • Author(s)
      Thongchum R、Nishihara H、Srikulnath K、Hirai H、*Koga A
    • Journal Title

      Genes & Genetic Systems

      Volume: 94 Issue: 6 Pages: 301-306

    • DOI

      10.1266/ggs.19-00042

    • NAID

      130007791988

    • ISSN
      1341-7568, 1880-5779
    • Year and Date
      2019-12-01
    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Structural variations of subterminal satellite blocks and their source mechanisms as inferred from the meiotic configurations of chimpanzee chromosome termini2019

    • Author(s)
      *Hirai H, Hirai Y, Udono T, Matsubayashi K, Tosi AJ, Koga A
    • Journal Title

      Chromosome Research

      Volume: 27 Issue: 4 Pages: 321-332

    • DOI

      10.1007/s10577-019-09615-z

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Fusion of piggyBac-like transposons and herpesviruses occurs frequently in teleosts2018

    • Author(s)
      Inoue Y, Kumagai M, Zhang X, Saga T, Wang D, Koga A, *Takeda H
    • Journal Title

      Zoological Letters

      Volume: 4 Issue: 1 Pages: 6-6

    • DOI

      10.1186/s40851-018-0089-8

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] シャム猫みたいなマントヒヒ2020

    • Author(s)
      古賀章彦・久川智恵美・吉澤未来
    • Organizer
      第36回日本;霊長類学会大会(オンライン開催)
    • Related Report
      2020 Annual Research Report
  • [Presentation] 中央アルプスの白タヌキは黒色素合成に必須の遺伝子で5個のエクソンのうちの1個が欠けている2019

    • Author(s)
      古賀章彦
    • Organizer
      日本遺伝学会第91回大会
    • Related Report
      2019 Research-status Report
  • [Presentation] Adaptation of owl monkeys to nocturnal lifestyle driven by rapid expansion of simple repeat sequence to form megasatellite DNA2018

    • Author(s)
      Koga A, Nishihara H, Stanyon R, Hirai H
    • Organizer
      Society for Molecular Biology and Evolution 2018
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] Recruitment and co-option of megasatellite DNAs coordinately facilitated adaptation of owl monkeys to nocturnal lifestyle2018

    • Author(s)
      Koga A
    • Organizer
      第41回日本分子生物学会年会
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] Dynamic role changes among three megasatellite DNAs associated with adaptation of owl monkeys to nocturnal lifestyle2018

    • Author(s)
      Koga A
    • Organizer
      会等名 2018 International Joint Conference on Genetics and Medicine
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research / Invited

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Published: 2018-07-25   Modified: 2022-01-27  

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