Spawning induction, development and culturing of the solitary ascidianPolycarpa mytiligera, an emerging model for regeneration studies
Spawning induction, development and culturing of the solitary ascidianPolycarpa mytiligera, an emerging model for regeneration studies
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DOI：
10.1186/s12983-020-00365-x
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发表时间：
2020-06-11
影响因子：
2.8
通讯作者：
Shenkar, Noa
中科院分区：
文献类型：
--
作者：
Gordon, Tal;Roth, Lachan;Shenkar, Noa
研究背景海鞘（Ascidians）是脊椎动物的近亲，是研究脊索动物进化的重要模式动物。孤生海鞘Polycarpa mytiligera在孤生脊索动物中具有独特的再生能力，为再生研究提供了一个新的模式。了解其生殖发育和建立陆基养殖方法是利用该物种进行实验研究的关键。因此，在野外和实验室中研究了其繁殖周期，产卵行为和发育过程，并开发了在开放和封闭水域系统中培养的方法。结果田间调查显示，P.贻贝的自然补充期从夏季（6月）开始，到冬季（12月）海水温度下降时结束。实验室实验表明，低温（21摄氏度）对其受精和发育有负面影响。虽然自发产卵事件只发生在6月至12月之间，我们能够诱导产卵控制条件下，全年通过逐步改变环境条件。在人工海水和天然海水养殖条件下，海鞘都经历了产卵、幼体发育和变态过程，其发育过程与其它卵生海鞘相似，幼体在孵化后12 h左右开始附着和变态，3 d后进入幼鱼期。结论在人工饲养条件下，可以全年诱导出糠虾产卵，不受自然繁殖季节的影响。P. Mytiligera作为再生研究的模式系统，结合本文提供的详细发育数据和培养方法，将有助于未来解决发育和进化问题的研究，并促进该物种作为实验研究的适用模式系统的使用。
Background Ascidians (phylum Chordata, class Ascidiacea) represent the closest living invertebrate relatives of the vertebrates and constitute an important model for studying the evolution of chordate development. The solitary ascidianPolycarpa mytiligeraexhibits a robust regeneration ability, unique among solitary chordates, thus offering a promising new model for regeneration studies. Understanding its reproductive development and establishing land-based culturing methods is pivotal for utilizing this species for experimental studies. Its reproduction cycle, spawning behavior, and developmental processes were therefore studied in both the field and the lab, and methods were developed for its culture in both open and closed water systems. Results Field surveys revealed thatP. mytiligera'snatural recruitment period starts in summer (June) and ends in winter (December) when seawater temperature decreases. Laboratory experiments revealed that low temperature (21 degrees C) has a negative effect on its fertilization and development. Although spontaneous spawning events occur only between June and December, we were able to induce spawning under controlled conditions year-round by means of gradual changes in the environmental conditions. Spawning events, followed by larval development and metamorphosis, took place in ascidians maintained in either artificial or natural seawater facilities.P. mytiligera's fast developmental process indicated its resemblance to other oviparous species, with the larvae initiating settlement and metamorphosis at about 12 h post-hatching, and reaching the juvenile stage 3 days later. Conclusions Polycarpa mytiligeracan be induced to spawn in captivity year-round, independent of the natural reproduction season. The significant advantages ofP. mytiligeraas a model system for regenerative studies, combined with the detailed developmental data and culturing methods presented here, will contribute to future research addressing developmental and evolutionary questions, and promote the use of this species as an applicable model system for experimental studies.