The epicardium, the outermost tissue layer that envelops all vertebrate hearts, plays a crucial role in cardiac development and regeneration and has been implicated in potential strategies for cardiac repair. The heterogenous cell population that composes the epicardium originates primarily from a transient embryonic cell cluster known as the proepicardial organ (PE). Characterized by its high cellular plasticity, the epicardium contributes to both heart development and regeneration in two critical ways: as a source of progenitor cells and as a critical signaling hub. Despite this knowledge, there are many unanswered questions in the field of epicardial biology, the resolution of which will advance the understanding of cardiac development and repair. We review current knowledge in cross-species epicardial involvement, specifically in relation to lineage specification and differentiation during cardiac development.

中文翻译：

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心脏发育中的心外膜。

心外膜是包裹所有脊椎动物心脏的最外层组织层，在心脏发育和再生中起着至关重要的作用，并且与心脏修复的潜在策略有关。构成心外膜的异质细胞群主要来源于称为心外膜前器官 (PE) 的瞬时胚胎细胞簇。心外膜以其高细胞可塑性为特征，以两种关键方式促进心脏发育和再生：作为祖细胞的来源和作为关键的信号枢纽。尽管有这些知识，但在心外膜生物学领域仍有许多悬而未决的问题，这些问题的解决将促进对心脏发育和修复的理解。我们回顾了跨物种心外膜受累的当前知识，