双方の神経線索の収束進化

José M Martín-Durán¹, Kevin Pang¹, Aina Børve¹

¹Sars International Centre for Marine Molecular Biology, University of Bergen, Thørmohlensgate 55, 5006 Bergen, Norway.

Nature

|December 14, 2017

まとめ

神経系の進化の歴史は議論されている. この研究は,神経系特性の独立した進化を示唆する,多様な双方向性における神経線索に保存された分子パターンを発見しなかった.

科学分野:

動物学
発達生物学
進化生物学

背景:

中央腹部神経線は,祖先のバイラテリアの特徴であると仮定されています.
脊椎動物,ハエ,アネリドの類似の背中分子パターンは,この仮説を支持する.
多様な双方の神経解剖学におけるこれらのパターンの保存は不明である.

研究の目的:

脊髄神経の保存を調査する
祖先のバイラテリアとして保存された中央腹部神経コードの仮説を再評価する.

主な方法:

Xenacoelomorpha,Rotifera,Nemertea,Brachiopoda,およびAnnelidaの代表者の神経解剖学と分子パターンを研究した.
背中神経のパターンの保存を評価した.

主要な成果:

研究されたどの種の神経線索にも,保存された背中部分子地域化は見つかりませんでした.
この保存の欠如は,脊椎動物やハエに似た幹神経解剖を持つアネリドOwenia fusiformisでも観察されました.
背中神経構造と幹神経構造の類似性は独立して進化したようです

結論:

分子パターンは双方の神経線で普遍的に保たれているわけではありません.
祖先のビラテリアの特徴として,中央腹部神経線が凝縮された神経系という仮説は,保存された分子パターンによって支持されていません.
背中部と幹部の神経解剖は,おそらく独立して進化した.

さらに関連する動画

05:36

Dissection and Lateral Mounting of Zebrafish Embryos: Analysis of Spinal Cord Development

Published on: February 28, 2014

14.4K

09:38

Embryo Microinjection and Electroporation in the Chordate Ciona intestinalis

Published on: October 16, 2016

16.7K

関連する概念動画

01:54

Convergent Evolution

33.1K

Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.

33.1K

01:30

Neurulation

46.4K

Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the...

46.4K

01:54

The Spinal Cord

32.0K

The spinal cord is the body’s major nerve tract of the central nervous system, communicating afferent sensory information from the periphery to the brain and efferent motor information from the brain to the body. The human spinal cord extends from the hole at the base of the skull, or foramen magnum, to the level of the first or second lumbar vertebra.

32.0K

01:23

Spinal Nerves: Anatomy

9.2K

Spinal nerves are pivotal conduits in the nervous system, bridging the central nervous system (CNS) with the peripheral nervous system (PNS). These nerves enable a complex communication network between the brain, spinal cord, and the rest of the body, facilitating sensory input, motor output, and autonomic functions.
There are 31 bilateral pairs of spinal nerves, each emerging from the spinal cord through the intervertebral foramina—openings between adjacent vertebrae. These nerves are...

9.2K

01:26

Spinal Cord

2.0K

The spinal cord, a critical component of the central nervous system, extends from the base of the brainstem to the lumbar region of the vertebral column. It is essential for maintaining physical stability and facilitating communication between the brain and peripheral parts of the body.

2.0K

01:15

Spinal Cord: Gross Anatomy

6.0K

The spinal cord resides within the protective confines of the vertebral column. It is the main pathway for information traveling between the brain and the body. It plays a fundamental role in nearly all bodily functions, from simple reflexes to complex motor movements. The spinal cord begins at the medulla oblongata at the base of the brainstem and extends downward, terminating at the conus medullaris near the first and second lumbar vertebrae. The spinal cord's length in adults is...