Asymmetry of viscera and their positions in the body

2023 Fiscal Year Final Research Report

• Project/Area Number: 17K07410
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Developmental biology
• Research Institution: Kobe University
• Principal Investigator: HONDA Hisao 神戸大学, 医学研究科, 非常勤講師 (10289118)
• Project Period (FY): 2017-04-01 – 2024-03-31
• Keywords: 初期心臓 / 数理的細胞モデル / vertex dynamics / コンピュータ・シミュレーション / convergent extension / キラリティー

Outline of Final Research Achievements

A mathematical model was used to elucidate the mechanism of cardiac loop formation in the early stage of development. The research progressed by first considering cell division in localized regions as the cause of tube looping, but this did not lead to a satisfactory solution, and then by considering convergent-extension. Convergent-extension is the process by which collective cells rearrange themselves to converge in one direction and elongate in a direction perpendicular to that direction.
Based on a report of experiments in which cardiomyocytes in the early chick embryo heart contracted strongly only at the boundary of a special direction (anisotropic contraction), we constructed a mathematical model of convergent extension and showed that a heart tube made of cells elongated in an oblique direction. When the top and bottom ends of the tube were fixed, buckling occurred near the center and the tube twisted.

Free Research Field

Theoretical biology

Academic Significance and Societal Importance of the Research Achievements

生物体の形はDNA情報に基づいてつくられるがその道筋は謎であった。DNA情報が種々のタンパク質をつくり、タンパク質がシグナル伝達や力の生成を行う事が知られるようになり、これにより細胞が持つ能力の由来は理解されるようになった。この細胞が集まった集団の形については数理モデル、たとえばvertex dynamicsを使って理解できる。こうして生物学の主要な問題であるDNAから形への道筋は見当がつくようになった。心臓のねじれ形成解明により道筋の実例が示せた。
心臓の先天的奇形は深刻な疾患であるがその発生のメカニズムについては不明なことが多い。心臓のねじれ形成の理解はこの解明に役立つと考えられる。