无性 ploidy 循环和性别的起源
1Section of Ecology and Systematics, Cornell University, Ithaca, New York 14853.
Nature
|July 21, 1994
概括
无性有机体可以进化性循环,在不同的基因组拷贝数之间交替. 这些循环减少了突变积累,在固定的 ploidy 水平上提供了优势,并可能有助于性繁殖的进化.
科学领域:
- 进化生物学是进化的生物学.
- 遗传学 是一个遗传学.
- 生殖策略 生殖策略
背景情况:
- 性繁殖涉及结合性 (结合体融合) 和半转化,创建一个交替的双胞胎和单胞胎阶段的双胞胎周期.
- 无性繁殖通常绕过 ploidy 变化,但一些无性生物体表现出 ploidy 周期.
研究的目的:
- 为了研究无性生物中 ploidy 周期的进化优势.
- 为了确定无性 ploidy 周期是否可以减少与永久 diploidy 或 polyploidy 相比的突变负载.
- 探索无性 ploidy 周期在性起源中的潜在作用.
主要方法:
- 理论建模的突变积累在不同的 ploidy 策略.
- 对无性生物的繁殖策略进行比较分析.
主要成果:
- 与永久性双倍体育或多倍体育相比,无性双倍体育周期被证明可以减少突变负载.
- 当保持每个细胞的多个基因组拷贝时,这种循环可能会演变,这始终是有利的.
结论:
- 无性聚合周期提供了一种减少突变积累的机制,提供了进化优势.
- 无性繁殖周期的进化可能通过提供先前存在的遗传减少系统来促进性繁殖的出现.
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