Spadafora Corrado
Institute of Translational Pharmacology, National Research Council (CNR), Rome, Italy.
Prog Biophys Mol Biol. 2023 Mar;178:57-69. doi: 10.1016/j.pbiomolbio.2023.01.005. Epub 2023 Jan 30.
An increasing body of data are revealing key roles of epigenetics in evolutionary processes. The scope of this manuscript is to assemble in a coherent frame experimental evidence supporting a role of epigenetic factors and networks, active during embryogenesis, in orchestrating variation-inducing phenomena underlying evolution, seen as a global process. This process unfolds over two crucial levels: i) a flow of RNA-based information - predominantly small regulatory RNAs released from somatic cells exposed to environmental stimuli - taken up by spermatozoa and delivered to oocytes at fertilization and ii) the highly permissive and variation-prone environments offered by zygotes and totipotent early embryos. Totipotent embryos provide a variety of biological tools favouring the emergence of evolutionarily significant phenotypic novelties driven by RNA information. Under this light, neither random genomic mutations, nor the sieving role of natural selection are required, as the sperm-delivered RNA cargo conveys specific information and acts as "phenotypic-inducer" of defined environmentally acquired traits.
越来越多的数据揭示了表观遗传学在进化过程中的关键作用。本手稿的范围是将支持表观遗传因子和网络在胚胎发育过程中发挥作用的实验证据整合到一个连贯的框架中，这些因子和网络在协调进化背后的变异诱导现象方面发挥作用，进化被视为一个全局过程。这个过程在两个关键层面展开：i）基于RNA的信息流——主要是从暴露于环境刺激的体细胞释放的小调节RNA——被精子摄取并在受精时传递给卵母细胞；ii）合子和全能早期胚胎提供的高度宽松且易于发生变异的环境。全能胚胎提供了各种生物学工具，有利于由RNA信息驱动的具有进化意义的表型新奇性的出现。在这种情况下，既不需要随机的基因组突变，也不需要自然选择的筛选作用，因为精子传递的RNA货物传达了特定信息，并作为特定环境获得性状的“表型诱导剂”。
