一个基于遗传学的转录组年龄指数反映了遗传学分歧模式.
Tomislav Domazet-Lošo1, Diethard Tautz
1Max-Planck-Institut für Evolutionsbiologie, August-Thienemannstrasse 2, 24306 Plön, Germany. tdomazet@irb.hr
Nature
|December 15, 2010
概括
类型阶段是胚胎发育中的保存阶段,标志着各种物种中古老基因的表达. 这项研究揭示了这一阶段的分子特征,显示了从到线虫的基因进化中保存的模式.
科学领域:
- 发展生物学 发展生物学
- 进化生物学 进化生物学
- 基因组学就是基因组学.
背景情况:
- 类型阶段 (phylotypic stage) 是一个在发育过程中在类内物种之间高度相似的时期,在历史上与回顾进化历史有联系.
- 虽然以前人们认为它反映了祖先的特征,但现在人们理解类型阶段是受限制的发育调节和基因相互作用的阶段.
- 以前的研究表明,在类型阶段的基因进化速度较慢,但明确的分子特征仍然难以捉摸.
研究的目的:
- 通过分析整个本体发生的基因表达的进化年龄来确定类型阶段的分子特征.
- 研究模型生物中的基因表达模式,进化年龄和发育阶段之间的关系.
- 为了确定观察到的模式是否在不同的动物类中保持.
主要方法:
- 基因表达谱与特定阶段的基因表达数据分析相结合.
- 开发一个累积索引来量化不同本体遗传阶段的转录组的进化年龄.
- 对斑马鱼,和线虫的基因表达数据进行比较分析.
主要成果:
- 斑马鱼的类型阶段表现出最古老的一组表达的基因,与 evolution. hourglass 演化模型一致.
- 早期和晚期发育阶段表达更年轻的基因组,而生殖活跃的动物显示最年轻的转录组与性别特异性差异.
- 老龄化的动物表现出老基因表达的增加.
- 交叉基因组比较证实,一个古老的转录组是基因型阶段的特征,年轻的基因与其他阶段的基因学分歧相关.
结论:
- 类型阶段在分子层面上是由进化保存的较古老基因的表达所定义的.
- 沙时钟发展模型由基因表达模式支持,在类型阶段保留了基因组,并在早期/晚期发育和繁殖过程中表达了新型基因.
- 这些发现为了解各种动物血统的发育约束和进化分歧提供了一个保存的分子框架.
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