证据表明,在状菌根真菌中,多个基因组的进化
1Institute of Ecology, University of Lausanne, Biology Building, 1015 Lausanne, Switzerland.
Nature
|December 14, 2001
概括
古代的无性真菌挑战了进化论. 状菌根真菌通过突变积累和不频繁的重组来维持个体内的遗传多样性,进化出多基因组结构.
科学领域:
- 菌类学 菌类学是指菌类学.
- 进化生物学 进化生物学
- 遗传学 是一个遗传学.
背景情况:
- 古代无性生物挑战了解释性繁殖普遍性的进化理论.
- 树枝状菌根真菌,在4亿年前可能是无性,呈现了一个独特的案例研究.
- 这些真菌的遗传结构,每次收到数百个细胞核的后代,表明可能存在个体内遗传变异.
研究的目的:
- 为了研究个体状菌根菌的遗传结构.
- 为了确定这些真菌中是否存在基因上不同的核.
- 了解推动古代无性动物遗传变异的进化机制.
主要方法:
- 用DNA-DNA光 in situ杂交 (FISH) 来可视化和区分真菌组织中的核.
- 遗传学方法被用来分析遗传变异和推断进化过程.
- 标准的人口遗传技术的适用性被评估,并被发现是不充分的.
主要成果:
- 直接可视化证实了在单个状菌根真菌中存在着基因不同核的共存.
- 由于这些真菌的独特基因组结构,种群遗传学方法被认为不适合.
- 遗传学分析表明,个体内部的遗传变异主要来自在大多数克隆基因组中的突变积累,偶尔会出现重组.
结论:
- 树状菌根真菌具有多基因组结构,在个体内共存的基因上不同的核.
- 这些真菌的进化路径涉及突变积累和有限的重组,而不是通常在性生物体中观察到的过程.
- 这项研究为古代无性生物的生命史的演变提供了关键的见解.
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