PDF(Pubmed)
Abstract：
Duplication is a major route for the emergence of new gene functions. However, the emergence of new gene functions via this route may be reduced in prokaryotes, as redundant genes are often rapidly purged. In lineages with compact, streamlined genomes, it thus appears challenging for novel function to emerge via duplication and divergence. A further pressure contributing to gene loss occurs under Black Queen dynamics, as cheaters that lose the capacity to produce a public good can instead acquire it from neighbouring producers. We propose that Black Queen dynamics can favour the emergence of new function because, under an emerging Black Queen dynamic, there is high gene redundancy spread across a community of interacting cells. Using computational modelling, we demonstrate that new gene functions can emerge under Black Queen dynamics. This result holds even if there is deletion bias due to low duplication rates and selection against redundant gene copies resulting from the high cost associated with carrying a locus. However, when the public good production costs are high, Black Queen dynamics impede the fixation of new functions. Our results expand the mechanisms by which new gene functions can emerge in prokaryotic systems.
摘要：
复制是新基因功能出现的主要途径。然而,通过这种途径出现的新基因功能可能会在原核生物中减少，因为多余的基因经常被迅速清除。在紧凑的谱系中，精简的基因组，因此，通过重复和分歧出现新功能似乎具有挑战性。在黑皇后动力学下，导致基因丢失的进一步压力发生，因为那些失去生产公共物品能力的骗子可以从邻近的生产者那里获得它。我们认为BlackQueen动力学可以促进新功能的出现，因为在新兴的BlackQueen动力学下，基因冗余很高，分布在相互作用细胞的社区中。使用计算建模，我们证明了在黑皇后动力学下可以出现新的基因功能。即使由于低复制率和由于与携带基因座相关的高成本导致的针对冗余基因拷贝的选择而存在缺失偏差,该结果仍然成立。然而,当公共物品生产成本很高时，黑皇后动力学阻碍了新功能的固定。我们的结果扩展了原核系统中出现新基因功能的机制。
