性别决定机制和性染色体的演化
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摘要
性别决定机制和性染色体的演化一直是演化生物学的核心领域.因为性别决定过程发生在早期发育阶段,而性染色体的基因调控通常又牵涉非编码RNA和表观遗传学修饰,因此这一领域又经常与发育生物学和分子生物学成为交叉热点.本文将从性别的重要性、起源、决定方式,以及性染色体演化的一般模式等方面进行阐述,总结了已经发现并报道的性别决定基因,并介绍了性染色体在没有同源重组的条件下如何演化的群体遗传模型.至今仍只有少数动植物的性别决定基因被发现,却已经显示出了超出生物学家预期的多态性.未来的研究方向将集中在鉴定更多的动植物的上游性别决定基因和其下游的性别决定通路上.新的基因组研究技术和基因敲除手段将为这一方向发展新的合适的模式生物,并最终解答为何不同的生物需要演化出如此繁多的性别决定方式,以及它们之间是如何相互转化的等基本生物学问题.
The evolution of sex determination mechanisms and sex chromosomes has always been a central research topic in evolutionary biology.Because the sex determination process occurs during the early stage of development,and the regulation of sex-linked genes often involves non-coding RNAs and epigenetic modifications,this topic is an interdisciplinary hotspot with developmental biology and molecular biology.This review elaborates on the importance and origin of sex,numerous ways of sex determination,and the mechanisms of sex chromosome evolution.We will summarize the reported sex-determining genes and introduce the population genetic models under which the sex chromosomes evolve without homologous recombination.To date,only a few sex-determining genes have been discovered,but they have already exhibited a great diversity beyond biologists' expectation.Future research directions will focus on identifying more upstream sex-determining genes for plants and animals and their downstream sexdetermining pathways.New genome research and gene knockout techniques will develop other appropriate model organisms in this area,and to ultimately address the basic biological questions that why different organisms need to evolve such a great variety of sexdetermining ways and how they transit to each other.
The evolution of sex determination mechanisms and sex chromosomes has always been a central research topic in evolutionary biology.Because the sex determination process occurs during the early stage of development,and the regulation of sex-linked genes often involves non-coding RNAs and epigenetic modifications,this topic is an interdisciplinary hotspot with developmental biology and molecular biology.This review elaborates on the importance and origin of sex,numerous ways of sex determination,and the mechanisms of sex chromosome evolution.We will summarize the reported sex-determining genes and introduce the population genetic models under which the sex chromosomes evolve without homologous recombination.To date,only a few sex-determining genes have been discovered,but they have already exhibited a great diversity beyond biologists' expectation.Future research directions will focus on identifying more upstream sex-determining genes for plants and animals and their downstream sexdetermining pathways.New genome research and gene knockout techniques will develop other appropriate model organisms in this area,and to ultimately address the basic biological questions that why different organisms need to evolve such a great variety of sexdetermining ways and how they transit to each other.
引文
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