Effects of cell morphology and attachment to a surface on the hydrodynamic performance of unicellular choanoflagellates
Effects of cell morphology and attachment to a surface on the hydrodynamic performance of unicellular choanoflagellates
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DOI：
10.1098/rsif.2018.0736
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发表时间：
2019-01-01
影响因子：
3.9
通讯作者：
Fauci, Lisa
中科院分区：
文献类型：
--
作者：
Hoa Nguyen;Koehl, M. A. R.;Fauci, Lisa
领鞭毛虫是水生生态系统中重要的细菌捕食者，与动物关系密切，是研究动物从原生动物进化的模式系统。Salpingoeca rosetta具有复杂的生活史，具有不同的形态类型，有些是单细胞的，有些是多细胞的。本文利用计算流体力学方法研究了不同单细胞阶段的S.罗塞塔：游泳细胞，具有围绕单个鞭毛的捕获猎物的微绒毛环;附着在表面的囊细胞;以及具有细长身体、长鞭毛和短环的散布阶段细胞。我们发现，较长的鞭毛增加游泳速度，较长的微绒毛降低速度和细胞形状只影响速度时，衣领是非常短的。携带猎物的水进入项圈捕获区的流量是大于无柄细胞游泳，但这种优势随着项圈的大小而减小。茎长对无柄细胞的通量影响不大。我们发现，忽略衣领，早期的模型已经做了，高估流量和大大高估的好处，以喂养性能的游泳与被重视，和一个较长的柄附着细胞。
Choanoflagellates, eukaryotes that are important predators on bacteria in aquatic ecosystems, are closely related to animals and are used as a model system to study the evolution of animals from protozoan ancestors. The choanoflagellate Salpingoeca rosetta has a complex life cycle with different morphotypes, some unicellular and some multicellular. Here we use computational fluid dynamics to study the hydrodynamics of swimming and feeding by different unicellular stages of S. rosetta: a swimming cell with a collar of prey-capturing microvilli surrounding a single flagellum, a thecate cell attached to a surface and a dispersal-stage cell with a slender body, long flagellum and short collar. We show that a longer flagellum increases swimming speed, longer microvilli reduce speed and cell shape only affects speed when the collar is very short. The flux of prey-carrying water into the collar capture zone is greater for swimming than sessile cells, but this advantage decreases with collar size. Stalk length has little effect on flux for sessile cells. We show that ignoring the collar, as earlier models have done, overestimates flux and greatly overestimates the benefit to feeding performance of swimming versus being attached, and of a longer stalk for attached cells.