两腔心脏的进化,有心房和心室,在氘代造口(脊椎动物)和一些原虫(无脊椎动物)中都改善了心脏功能。尽管研究已经检查了这两个腔室的独特结构和功能,分子比较很少,仅限于脊椎动物。这里,我们专注于软体动物的两腔原虫心脏,提供可以更好地理解心脏进化的数据。具体来说,我们询问软体动物心脏的心房和心室在分子水平上是否不同。要做到这一点,我们研究了两个非常不同的物种,巨大的非洲陆地蜗牛(Lissachatinafulica)和相对较小的蜗牛,水生扇贝(Mizuhopectenyessoensis),假设如果它们表现出共性,这些相似性可能会反映出整个门的相似性。我们发现,尽管这两个物种的心脏在组织学上有所不同,它们的心脏基因功能富集相似,正如转录组学分析所揭示的。此外,每个物种的心房和心室都有不同的基因功能簇,表明软体动物心腔的进化分化。最后,探索脊椎动物和无脊椎动物两腔心之间的关系,我们将我们的转录组数据与斑马鱼发表的数据进行了比较,一个经过充分研究的脊椎动物模型,有一个两腔的心脏。我们的分析表明软体动物和斑马鱼的心室基因功能相似,表明在无脊椎动物和脊椎动物中,心室被分化以实现相同的功能。作为第一个关于原生质体的研究,我们的发现提供了关于两腔心脏是如何产生的初步见解,包括对其在原虫和氘气孔中的发生的可能理解。
■在线版本包含补充材料,可在10.1007/s42995-023-00202-0获得。
The evolution of a two-chambered heart, with an
atrium and a ventricle, has improved heart function in both deuterostomes (vertebrates) and some protostomes (invertebrates). Although studies have examined the unique structure and function of these two chambers, molecular comparisons are few and limited to vertebrates. Here, we focus on the two-chambered protostome heart of the mollusks, offering data that may provide a better understanding of heart evolution. Specifically, we asked if the
atrium and ventricle differ at the molecular level in the mollusk heart. To do so, we examined two very different species, the giant African land snail (Lissachatina fulica) and the relatively small, aquatic yesso scallop (Mizuhopecten yessoensis), with the assumption that if they exhibited commonality these similarities would likely reflect those across the phylum. We found that, although the hearts of these two species differed histologically, their cardiac gene function enrichments were similar, as revealed by transcriptomic analysis. Furthermore, the
atrium and ventricle in each species had distinct gene function clusters, suggesting an evolutionary differentiation of cardiac chambers in mollusks. Finally, to explore the relationship between vertebrate and invertebrate two-chambered hearts, we compared our transcriptomic data with published data from the zebrafish, a well-studied vertebrate model with a two-chambered heart. Our analysis indicated a functional similarity of ventricular genes between the mollusks and the zebrafish, suggesting that the ventricle was differentiated to achieve the same functions in invertebrates and vertebrates. As the first such study on protostomes, our findings offered initial insights into how the two-chambered heart arose, including a possible understanding of its occurrence in both protostomes and deuterostomes.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s42995-023-00202-0.