Sponges have co‐evolved for millions of years alongside several types of microorganisms, which aside from participating in the animal's diet, are mostly symbionts. Since most of the genetic repertoire in the holobiont genome is provided by microbes, it is expected that the host‐associated microbiome will be at least partially heritable. Sponges can therefore acquire their symbionts in different ways. Both vertical transmission (VT) and horizontal transmission (HT) have different advantages and disadvantages in the life cycle of these invertebrates. However, a third mode of transmission, called leaky vertical transmission or mixed mode of transmission (MMT), which incorporates both VT and HT modes, has gained relevance and seems to be the most robust model. In that regard, the aim of this review is to present the evolving knowledge on these main modes of transmission of the sponge microbiome. Our conclusions lead us to suggest that MMT may be more common for all sponges, with its frequency varying across the transmission spectrum between species and the environment. This hybrid model supports the stable and specific transmission of these microbial partners and reinforces their assistance in the resilience of sponges over the years.

中文翻译：

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海绵微生物组的传播：迈向统一模型

海绵与几种微生物共同进化了数百万年，除参与动物饮食外，它们大多是共生体。由于全生命周期基因组中的大多数遗传库都是由微生物提供的，因此可以预期，与宿主相关的微生物组至少是部分可遗传的。因此，海绵可以以不同的方式获得它们的共生体。垂直传输（VT）和水平传输（HT）在这些无脊椎动物的生命周期中都有不同的优缺点。但是，第三种传输模式被称为泄漏垂直传输或混合传输模式（MMT），它既包含VT模式又包含HT模式，已经获得了相关性，并且似乎是最可靠的模型。在这方面，这篇综述的目的是介绍有关海绵微生物组这些主要传播方式的不断发展的知识。我们的结论使我们建议，MMT可能在所有海绵中更为常见，其频率在物种和环境之间的透射光谱范围内变化。这种混合模型支持这些微生物伴侣的稳定和特异性传播，并在过去的几年中增强了它们在海绵弹性方面的帮助。