Slow expanders invade by forming dented fronts in microbial colonies.
Slow expanders invade by forming dented fronts in microbial colonies.
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DOI：
10.1073/pnas.2108653119
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发表时间：
2022-01-04
影响因子：
11.1
通讯作者：
Korolev KS
中科院分区：
文献类型：
--
作者：
Lee H;Gore J;Korolev KS
生物体永远不会停止进化，因此在生命科学的所有分支中，预测和控制进化都有很大的兴趣。最基本的问题是，在给定的环境中，一个性状应该增加还是减少。对于生物反应器中的生长速度或肿瘤的扩张速度等性状来说，答案似乎微不足道。然而，有人认为，在进化过程中，这些特征可能会减少，而不是增加。在这里，我们报告了一个突变体，它在竞争中战胜了祖先，尽管在隔离时扩张速度较慢。为了解释这一观察结果，我们开发并验证了一种理论，该理论描述了具有不同扩张速率和任意竞争相互作用的生物体之间的空间竞争。大多数生物都在太空中生长，无论它们是在宿主组织中传播的病毒还是在新大陆上定居的入侵物种。进化通常在空间增长过程中选择更高的扩张速率，但有人认为，在某些条件下，较慢的扩张者可以接管。在这里，我们报告这样的人口动态的实验观察。我们表明，突变体生长缓慢，但在隔离赢得竞争，不仅当这两种类型是混杂的，而且当它们在空间上分离成部门。后者被认为是不可能的，因为以前的研究只关注扩张速度介导的全球竞争，而忽略了部门边界的局部竞争。然而，地方竞争可以提高部门边界的任何一种速度，从而改变扩张动态。我们开发了一个理论，该理论考虑了本地和全球竞争，并描述了所有可能的行业形状。特别是，该理论预测，一个速度较慢但更具竞争力的突变体在接管扩张前沿时会形成一个凹陷的V形扇区。这样的扇区确实在实验中观察到了，它们的形状与理论定量吻合。在模拟中，我们进一步探讨了几种机制，可以提供缓慢的扩张与本地的竞争优势，并表明他们都很好地描述了我们的理论。总之，我们的研究结果揭示了以前未探索的空间竞争的结果，并建立了一个通用的框架，以了解不断扩大的人口的进化和生态动态。
Living organisms never cease to evolve, so there is a significant interest in predicting and controlling evolution in all branches of life sciences. The most basic question is whether a trait should increase or decrease in a given environment. The answer seems to be trivial for traits such as the growth rate in a bioreactor or the expansion rate of a tumor. Yet, it has been suggested that such traits can decrease, rather than increase, during evolution. Here, we report a mutant that outcompeted the ancestor despite having a slower expansion velocity when in isolation. To explain this observation, we developed and validated a theory that describes spatial competition between organisms with different expansion rates and arbitrary competitive interactions. Most organisms grow in space, whether they are viruses spreading within a host tissue or invasive species colonizing a new continent. Evolution typically selects for higher expansion rates during spatial growth, but it has been suggested that slower expanders can take over under certain conditions. Here, we report an experimental observation of such population dynamics. We demonstrate that mutants that grow slower in isolation nevertheless win in competition, not only when the two types are intermixed, but also when they are spatially segregated into sectors. The latter was thought to be impossible because previous studies focused exclusively on the global competitions mediated by expansion velocities, but overlooked the local competitions at sector boundaries. Local competition, however, can enhance the velocity of either type at the sector boundary and thus alter expansion dynamics. We developed a theory that accounts for both local and global competitions and describes all possible sector shapes. In particular, the theory predicted that a slower on its own, but more competitive, mutant forms a dented V-shaped sector as it takes over the expansion front. Such sectors were indeed observed experimentally, and their shapes matched quantitatively with the theory. In simulations, we further explored several mechanisms that could provide slow expanders with a local competitive advantage and showed that they are all well-described by our theory. Taken together, our results shed light on previously unexplored outcomes of spatial competition and establish a universal framework to understand evolutionary and ecological dynamics in expanding populations.
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影响因子：
64.8
作者：
Abraham, ER
通讯作者：
Abraham, ER
影响因子：
2.4
作者：
Bauer, Marianne;Frey, Erwin
通讯作者：
Frey, Erwin
影响因子：
2.4
作者：
Benichou, O.;Calvez, V.;Voituriez, R.
通讯作者：
Voituriez, R.
DOI：
10.1073/pnas.0710150104
发表时间：
2007-12-11
影响因子：
11.1
作者：
Hallatschek, Oskar;Hersen, Pascal;Nelson, David R.
通讯作者：
Nelson, David R.
影响因子：
64.8
作者：
Cremer, Jonas;Honda, Tomoya;Hwa, Terence
通讯作者：
Hwa, Terence