Integrative and Systems Biology Group, Department of Abiotic Stress, Institute for Cellular and Molecular Biology of Plants (IBMCP) from the Spanish National Research Council (CSIC), Polytechnic University of Valencia (UPV), 46022 Valencia, Spain.
Department of Genetics, Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Ireland.
Int J Mol Sci. 2021 Nov 14;22(22):12293. doi: 10.3390/ijms222212293.
The cell central metabolism has been shaped throughout evolutionary times when facing challenges from the availability of resources. In the budding yeast, , a set of duplicated genes originating from an ancestral whole-genome and several coetaneous small-scale duplication events drive energy transfer through glucose metabolism as the main carbon source either by fermentation or respiration. These duplicates (~a third of the genome) have been dated back to approximately 100 MY, allowing for enough evolutionary time to diverge in both sequence and function. Gene duplication has been proposed as a molecular mechanism of biological innovation, maintaining balance between mutational robustness and evolvability of the system. However, some questions concerning the molecular mechanisms behind duplicated genes transcriptional plasticity and functional divergence remain unresolved. In this work we challenged to the use of lactic acid/lactate as the sole carbon source and performed a small adaptive laboratory evolution to this non-fermentative carbon source, determining phenotypic and transcriptomic changes. We observed growth adaptation to acidic stress, by reduction of growth rate and increase in biomass production, while the transcriptomic response was mainly driven by repression of the whole-genome duplicates, those implied in glycolysis and overexpression of ROS response. The contribution of several duplicated pairs to this carbon source switch and acidic stress is also discussed.
细胞中心代谢在进化过程中一直受到资源可用性的挑战，因此发生了改变。在出芽酵母中，一组来自祖先全基因组的复制基因和几个同时发生的小规模复制事件，通过葡萄糖代谢来驱动能量转移，作为主要的碳源，无论是通过发酵还是呼吸。这些副本（约占基因组的三分之一）可以追溯到大约 100 百万年前，这为它们在序列和功能上的分化提供了足够的进化时间。基因复制被认为是生物创新的一种分子机制，在系统的突变稳健性和可进化性之间保持平衡。然而，关于复制基因转录可塑性和功能分化背后的分子机制的一些问题仍未解决。在这项工作中，我们对使用乳酸/乳酸作为唯一的碳源提出了挑战，并对这种非发酵碳源进行了小规模的适应性实验室进化，以确定表型和转录组的变化。我们观察到了对酸性胁迫的生长适应，表现为生长速度降低和生物量增加，而转录组的反应主要是由整个基因组副本的抑制驱动的，这些副本与糖酵解有关，同时还过表达了对 ROS 的反应。还讨论了几个复制对在这种碳源转换和酸性胁迫中的贡献。
