Cellular Innovation of the Cyanobacterial Heterocyst by the Adaptive Loss of Plasticity
Cellular Innovation of the Cyanobacterial Heterocyst by the Adaptive Loss of Plasticity
复制标题
蓝藻异形体通过可塑性适应性丧失的细胞创新
DOI：
10.1016/j.cub.2019.11.056
复制
发表时间：
2019
期刊：
影响因子：
9.2
通讯作者：
T. Bauersachs
中科院分区：
文献类型：
--
作者：
Scott R. Miller;R. Longley;Patrick R. Hutchins;T. Bauersachs
细胞创新是生物多样化的核心，但其潜在机制仍然知之甚少[1]。新的细胞性状的一个潜在来源是环境诱导的表型变异，或表型可塑性。可塑性第一假说[2-4]提出，自然选择可以改善祖先的可塑性表型，以产生局部适应性性状，但可塑性对适应性进化的作用仍不清楚[5-10]。在这里，我们表明，一种结构新颖的形式的异形胞，专门的固氮细胞的多细胞蓝藻Fischerella thermalis，已经演变了多次从祖先的可塑性发育变化过程中适应高温。异形胞糖脂（HG）提供了一个细胞外气体扩散屏障，保护氧敏感性固氮酶[11，12]，蓝细菌通常表现出HG组合物的温度诱导的可塑性，调节异形胞渗透性[13，14]。相比之下，高温专家f. thermalisconstitutively过量生产糖脂异构体与高温的水平达不到塑料菌株。这导致在一个较低的渗透性的异形胞，这是有利的，在高温下，但在低温下的固氮活性和健身有害。我们的研究说明了一种新的细胞表型的起源是如何通过遗传同化和适应性改进的塑料性状可以是生物多样性的来源，并有助于生态专业化。
Cellular innovation is central to biological diversification, yet its underlying mechanisms remain poorly understood [1]. One potential source of new cellular traits is environmentally induced phenotypic variation, or phenotypic plasticity. The plasticity-first hypothesis [2–4] proposes that natural selection can improve upon an ancestrally plastic phenotype to produce a locally adaptive trait, but the role of plasticity for adaptive evolution is still unclear [5–10]. Here, we show that a structurally novel form of the heterocyst, the specialized nitrogen-fixing cell of the multicellular cyanobacteriumFischerella thermalis, has evolved multiple times from ancestrally plastic developmental variation during adaptation to high temperature. Heterocyst glycolipids (HGs) provide an extracellular gas diffusion barrier that protects oxygen-sensitive nitrogenase [11, 12], and cyanobacteria typically exhibit temperature-induced plasticity in HG composition that modulates heterocyst permeability [13, 14]. By contrast, high-temperature specialists ofF. thermalisconstitutively overproduce glycolipid isomers associated with high temperature to levels unattained by plastic strains. This results in a less-permeable heterocyst, which is advantageous at high temperature but deleterious at low temperature for both nitrogen fixation activity and fitness. Our study illustrates how the origin of a novel cellular phenotype by the genetic assimilation and adaptive refinement of a plastic trait can be a source of biological diversity and contribute to ecological specialization.
影响因子：
8.8
作者：
Poisot T;Bever JD;Nemri A;Thrall PH;Hochberg ME
通讯作者：
Hochberg ME
影响因子：
16.8
作者：
Levis, Nicholas A.;Isdaner, Andrew J.;Pfennig, David W.
通讯作者：
Pfennig, David W.
影响因子：
3.7
作者：
Bauersachs T;Talbot HM;Sidgwick F;Sivonen K;Schwark L
通讯作者：
Schwark L