Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Département Adaptations du Vivant (AVIV), Muséum National d'Histoire Naturelle, CNRS, Paris, Cedex 05, France.
Structure et instabilité des génomes (STRING UMR 7196 CNRS / INSERM U1154), Département Adaptations du Vivant (AVIV), Muséum National d'Histoire Naturelle, Paris, Cedex 05, France.
Biol Cell. 2020 Jun;112(6):173-185. doi: 10.1111/boc.202000006. Epub 2020 Apr 7.
Gregarines, a polyphyletic group of apicomplexan parasites infecting mostly non-vertebrates hosts, remains poorly known at taxonomic, phylogenetic and genomic levels. However, it represents an essential group for understanding evolutionary history and adaptive capacities of apicomplexan parasites to the remarkable diversity of their hosts. Because they have a mostly extracellular lifestyle, gregarines have developed other cellular developmental forms and host-parasite interactions, compared with their much better studied apicomplexan cousins, intracellular parasites of vertebrates (Hemosporidia, Coccidia, Cryptosporidia). This review highlights the promises offered by the molecular exploration of gregarines, that have been until now left on the side of the road of the comparative -omic exploration of apicomplexan parasites. Elucidating molecular bases for both their ultrastructural, functional and behavioural similarities and differences, compared with those of the typical apicomplexan models, is expected to provide entirely novel clues on the adaptive capacities developed by Apicomplexa over evolution. A challenge remains to identify which gregarines should be explored in priority, as recent metadata from open and host-associated environments have confirmed how underestimated is our current view on true gregarine biodiversity. It is now time to turn to gregarines to widen the currently highly skewed view we have of adaptive mechanisms developed by Apicomplexa.
疟原虫，一个多系的顶复门寄生虫，感染大多数非脊椎动物宿主，在分类学、系统发育和基因组水平上仍然知之甚少。然而，它是了解顶复门寄生虫进化历史和适应宿主多样性的重要群体。由于它们主要生活在细胞外，与在脊椎动物（血孢子虫、球虫、隐孢子虫）中研究得更好的内寄生顶复门寄生虫相比，疟原虫具有其他细胞发育形式和宿主-寄生虫相互作用。这篇综述强调了分子探索疟原虫所带来的前景，迄今为止，疟原虫在顶复门寄生虫的比较 - 组学探索中被忽视了。阐明它们与典型顶复门模型在超微结构、功能和行为上的相似和不同的分子基础，预计将为顶复门在进化过程中发展的适应能力提供全新的线索。目前仍面临的挑战是确定应该优先探索哪些疟原虫，因为来自开放和宿主相关环境的最新元数据证实了我们目前对真正的疟原虫生物多样性的看法是多么低估。现在是时候转向疟原虫，以扩大我们目前对顶复门寄生虫开发的适应机制的高度偏颇的看法了。
