类似眼睛的眼球是由不同的内共生获得的组件构成的.
Gregory S Gavelis1, Shiho Hayakawa2, Richard A White3
1Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Nature
|July 2, 2015
概括
恐龙状体的眼睛,或状体,是由现有的线粒体和塑体构成的复杂结构,挑战了多细胞性和先进的生物特征之间的联系. 这项研究揭示了这些单细胞有机体如何形成复杂的视觉系统.
科学领域:
- 细胞生物学 细胞生物学
- 进化生物学 进化生物学
- 微生物学 微生物学
背景情况:
- 多细胞性通常与动物眼睛等复杂结构有关.
- 单细胞真核生物Dinoflagellates拥有"ocelloid",一种类似眼睛的有机体.
- 由于研究这些生物体的挑战,形体的起源和功能仍然不太清楚.
研究的目的:
- 为了阐明恐龙鞭状虫的结构组成和进化起源.
- 研究细胞下细胞器官如何在单细胞生物中形成复杂的视觉结构.
主要方法:
- 电子显微镜和断层扫描以可视化眼形超结构.
- 分离器官基因组学和单细胞基因组学用于分析遗传组件.
- 对有机细胞的起源和功能进行比较分析.
主要成果:
- 眼球体是由先前存在的有机细胞组装成的嵌合体结构.
- 一个类似角膜的层是由线粒体形成的.
- 一个视网膜体由解体塑体组成,起源于古代红藻内共生.
结论:
- 形体表明,复杂的解剖结构可以通过组装现有的有机体在单细胞生物中产生.
- 像线粒体和塑体这样的有机体可以作为结构复杂性的基石,超出它们的代谢作用.
- 这挑战了多细胞性是复杂生物特征的严格先决条件的概念.
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