Alternating selection for dispersal and multicellularity favors regulated life cycles
Alternating selection for dispersal and multicellularity favors regulated life cycles
复制标题
DOI：
10.1101/2022.10.14.512267
复制
发表时间：
2023-03
期刊：
影响因子：
9.2
通讯作者：
Julien Barrere;P. Nanda;A. Murray
中科院分区：
文献类型：
--
作者：
Julien Barrere;P. Nanda;A. Murray
复杂多细胞生物的进化为增加形态多样性和组织新奇开辟了道路。这种转变涉及三个过程：细胞保持相互附着以形成群体，这些群体内的细胞分化以执行不同的任务，并且群体进化出新的生殖策略1 -5。最近的实验确定了选择压力和突变，可以驱动简单的多细胞和细胞分化的出现6 -11，但生命周期的进化，特别是简单的多细胞形式如何繁殖一直研究不足。产生单细胞和多细胞群体之间有规律交替的选择压力和机制仍然不清楚12。为了探索调节简单多细胞生命周期的因素，我们检测了一组芽殖酵母S。ae12，13.我们发现，所有这些菌株都可以作为多细胞簇存在，这是一种受交配型基因座控制并受营养环境强烈影响的表型。受这种变化的启发，我们在多细胞实验室菌株中设计了诱导型分散，并证明了当环境在有利于细胞间合作（低蔗糖浓度）和分散（由乳液产生的斑块环境）之间交替时，受调节的生命周期比组成性单细胞或组成性多细胞生命周期具有优势。我们的研究结果表明，母细胞和子细胞的分离是在野生菌株的选择，并受其遗传组成和他们遇到的环境和资源可用性的交替模式可能发挥了作用，在生命周期的演变。视觉摘要
The evolution of complex multicellularity opened paths to increased morphological diversity and organizational novelty. This transition involved three processes: cells remained attached to one another to form groups, cells within these groups differentiated to perform different tasks, and the groups evolved new reproductive strategies1–5. Recent experiments identified selective pressures and mutations that can drive the emergence of simple multicellularity and cell differentiation6–11 but the evolution of life cycles, in particular, how simple multicellular forms reproduce has been understudied. The selective pressure and mechanisms that produced a regular alternation between single cells and multicellular collectives are still unclear12. To probe the factors regulating simple multicellular life cycles, we examined a collection of wild isolates of the budding yeast, S. cerevisiae12,13. We found that all these strains can exist as multicellular clusters, a phenotype that is controlled by the mating type locus and strongly influenced by the nutritional environment. Inspired by this variation, we engineered inducible dispersal in a multicellular laboratory strain and demonstrated that a regulated life cycle has an advantage over constitutively single-celled or constitutively multicellular life cycles when the environment alternates between favoring intercellular cooperation (a low sucrose concentration) and dispersal (a patchy environment generated by emulsion). Our results suggest that the separation of mother and daughter cells is under selection in wild isolates and is regulated by their genetic composition and the environments they encounter and that alternating patterns of resource availability may have played a role in the evolution of life cycles. Visual abstract