Gut microbiomes play an essential role in host survival and local adaptation and thus can facilitate the invasion of host species. Biological invasions have been shown to be linked to the genetic properties of alien host species. It is thus plausible that the holobiont, the host, and its associated microbiome act as an entity to drive invasion success. The bighead carp and silver carp (bigheaded carps), invasive species that exhibit extensive hybridization in the Mississippi River Basin (MRB), provided a unique model to test the holobiont hypothesis of invasion. Here, we investigated the microbiomes of foreguts and hindguts in bigheaded carps and their reciprocal hybrids reared in aquaculture ponds using 16S amplicons and the associated gene prediction. We found an admixed pattern in the gut microbiome community in bigheaded carp hybrids. The hybrid gut microbiomes showed special characteristics such as relatively high alpha diversity in the foregut, an increasing dissimilarity between foreguts and hindguts, and a remarkable proportion of genes coding for putative enzymes related to their digestion of main food resources (Cyanobacteria, cellulose, and chitin). The pond‐reared hybrids had advantageous features in genes coding for putative enzymes related to their diet. The above results collectively suggested that the gut microbiomes of hybrids could be beneficial to their local adaptation (e.g., food resource utilization), which might have facilitated their invasion in the MRB. The gut microbial findings, along with the intrinsic genomic features likely associated with life‐history traits revealed in our recent study, provide preliminary evidence supporting the holobiont hypothesis of invasion.

中文翻译：

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鳙鱼和杂交鱼的肠道微生物组为入侵提供了见解：全基因组视角


肠道微生物组在宿主生存和局部适应中发挥着重要作用，因此可以促进宿主物种的入侵。生物入侵已被证明与外来宿主物种的遗传特性有关。因此，全生物、宿主及其相关微生物组作为一个实体来驱动入侵成功是合理的。鳙鱼和鲢鱼这两种入侵物种在密西西比河流域（MRB）表现出广泛的杂交，为检验全生物入侵假说提供了一个独特的模型。在这里，我们使用 16S 扩增子研究了水产养殖池塘中饲养的鳙鱼及其互杂种的前肠和后肠微生物组以及相关基因预测。我们在鳙鱼杂交种的肠道微生物群落中发现了混合模式。混合肠道微生物组表现出特殊的特征，例如前肠中相对较高的α多样性、前肠和后肠之间的差异越来越大，以及编码与主要食物资源（蓝藻、纤维素和几丁质）消化相关的推定酶的基因的显着比例）。池塘饲养的杂交品种在编码与其饮食相关的推定酶的基因方面具有优势特征。上述结果共同表明，杂交种的肠道微生物群可能有利于它们的局部适应（例如食物资源利用），这可能促进它们入侵 MRB。肠道微生物的发现，以及我们最近的研究中揭示的可能与生活史特征相关的内在基因组特征，提供了支持全生物入侵假说的初步证据。