西班牙巴塞罗那大学Cristian Cañestro及其课题组报道了心咽的解构和祖先被膜的固着。这一研究成果发表在2021年11月17日出版的国际学术期刊《自然》上。
研究人员发现尾海鞘动物经历了与心咽基因和亚功能相关大量祖基因的丧失，这导致被囊类心咽基因调控网络的两个原始模块“解构”。在海鞘中，这些模块与早期和晚期多能性有关，这决定了第一和第二心场以及虹吸肌谱系细胞的命运决定。研究表明，心咽基因调控网络的解构涉及虹吸肌的退化缺失，这支撑祖被囊类动物具有成年无柄海鞘样生活方式的进化理论。
与这种情况一致，研究还发现，这种解构有助于加速心脏形成，并促进尾海鞘动物心脏重塑为开放式层状结构以适应进化。这在海鞘动物过渡到完全浮游生活方式的过程中发挥食品过滤功能。
据了解，脊索动物进化的核心问题是成年海鞘固着的起源，以及附肢完全自由的生活方式是否是被囊类动物的原始或衍生条件。根据“新心脏换新头”假说，了解心咽基因调控网络的进化是理解脊索动物生活方式进化的关键。
附：英文原文
Title: Cardiopharyngeal deconstruction and ancestral tunicate sessility
Author: Ferrndez-Roldn, Alfonso, Fabreg-Torrus, Marc, Snchez-Serna, Gaspar, Duran-Bello, Enya, Joaqun-Llus, Mart, Bujosa, Paula, Plana-Carmona, Marcos, Garcia-Fernndez, Jordi, Albalat, Ricard, Caestro, Cristian
Issue&Volume: 2021-11-17
Abstract: A central question in chordate evolution is the origin of sessility in adult ascidians, and whether the appendicularian complete free-living style represents a primitive or derived condition among tunicates1. According to the ‘a new heart for a new head’ hypothesis, the evolution of the cardiopharyngeal gene regulatory network appears as a pivotal aspect to understand the evolution of the lifestyles of chordates2,3,4. Here we show that appendicularians experienced massive ancestral losses of cardiopharyngeal genes and subfunctions, leading to the ‘deconstruction’ of two ancestral modules of the tunicate cardiopharyngeal gene regulatory network. In ascidians, these modules are related to early and late multipotency, which is involved in lineage cell-fate determination towards the first and second heart fields and siphon muscles. Our work shows that the deconstruction of the cardiopharyngeal gene regulatory network involved the regressive loss of the siphon muscle, supporting an evolutionary scenario in which ancestral tunicates had a sessile ascidian-like adult lifestyle. In agreement with this scenario, our findings also suggest that this deconstruction contributed to the acceleration of cardiogenesis and the redesign of the heart into an open-wide laminar structure in appendicularians as evolutionary adaptations during their transition to a complete pelagic free-living style upon the innovation of the food-filtering house5.
DOI: 10.1038/s41586-021-04041-w
Source: https://www.nature.com/articles/s41586-021-04041-w
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
