PDF(Pubmed)
Abstract：
Convergent evolution is central in the origins of multicellularity. Identifying the basis for convergent multicellular evolution is challenging because of the diverse evolutionary origins and environments involved. Haploid Kluyveromyces lactis populations evolve multicellularity during selection for increased settling in liquid media. Strong genomic and phenotypic convergence is observed between K. lactis and previously selected S. cerevisiae populations under similar selection, despite their >100-million-year divergence. We find K. lactis multicellularity is conferred by mutations in genes ACE2 or AIM44, with ACE2 being predominant. They are a subset of the six genes involved in the S. cerevisiae multicellularity. Both ACE2 and AIM44 regulate cell division, indicating that the genetic convergence is likely due to conserved cellular replication mechanisms. Complex population dynamics involving multiple ACE2/AIM44 genotypes are found in most K. lactis lineages. The results show common ancestry and natural selection shape convergence while chance and contingency determine the degree of divergence.
摘要：
趋同进化是多细胞起源的核心。由于涉及不同的进化起源和环境，因此确定融合多细胞进化的基础具有挑战性。单倍体乳酸克鲁维酵母种群在选择过程中进化出多细胞性，以增加在液体培养基中的沉降。在相似的选择下，在K.lactis和先前选择的酿酒酵母种群之间观察到强烈的基因组和表型趋同。尽管他们超过1亿年的分歧。我们发现K.lactis多细胞性是由基因ACE2或AIM44中的突变赋予的，其中ACE2是主要的。它们是酿酒酵母多细胞性涉及的六个基因的子集。ACE2和AIM44都调节细胞分裂，表明遗传趋同可能是由于保守的细胞复制机制。涉及多种ACE2/AIM44基因型的复杂种群动态在大多数乳酸克雷伯菌谱系中发现。结果表明，共同祖先和自然选择形状趋同，而机会和偶然性决定了分歧的程度。
