Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via Selmi, 3, 40126 Bologna, Italy.
Integr Comp Biol. 2021 Nov 17;61(5):1699-1714. doi: 10.1093/icb/icab057.
The class Bivalvia is a highly successful and ancient taxon including ∼25,000 living species. During their long evolutionary history bivalves adapted to a wide range of physicochemical conditions, habitats, biological interactions, and feeding habits. Bivalves can have strikingly different size, and despite their apparently simple body plan, they evolved very different shell shapes, and complex anatomic structures. One of the most striking features of this class of animals is their peculiar mitochondrial biology: some bivalves have facultatively anaerobic mitochondria that allow them to survive prolonged periods of anoxia/hypoxia. Moreover, more than 100 species have now been reported showing the only known evolutionarily stable exception to the strictly maternal inheritance of mitochondria in animals, named doubly uniparental inheritance. Mitochondrial activity is fundamental to eukaryotic life, and thanks to their diversity and uncommon features, bivalves represent a great model system to expand our knowledge about mitochondrial biology, so far limited to a few species. We highlight recent works studying mitochondrial biology in bivalves at either genomic or physiological level. A link between these two approaches is still missing, and we believe that an integrated approach and collaborative relationships are the only possible ways to be successful in such endeavor.
双壳纲是一个高度成功和古老的分类群，包括约 25000 种现存物种。在它们漫长的进化历史中，双壳类动物适应了广泛的物理化学条件、栖息地、生物相互作用和摄食习性。双壳类动物的体型可以有很大的差异，尽管它们的身体结构看起来很简单，但它们进化出了非常不同的贝壳形状和复杂的解剖结构。这类动物最引人注目的特征之一是它们奇特的线粒体生物学：一些双壳类动物具有兼性厌氧的线粒体，使它们能够在长时间的缺氧/低氧环境中存活。此外，现在已经有超过 100 种物种被报道，它们表现出动物中线粒体严格母系遗传的唯一已知进化稳定例外，即双单亲遗传。线粒体的活性对真核生物的生命至关重要，由于双壳类动物的多样性和独特的特征，它们代表了一个很好的模型系统，可以扩展我们对线粒体生物学的认识，而目前对线粒体生物学的认识仅限于少数几种物种。我们强调了最近在基因组或生理水平上研究双壳类动物线粒体生物学的工作。这两种方法之间仍然存在联系，我们相信，综合方法和合作关系是在这一努力中取得成功的唯一途径。
