Fish gut microbial assemblages play a crucial role in the growth rate, metabolism, and immunity of the host. We hypothesized that the gut microbiota of rainbow trout was correlated with breeding program based genetic selection for muscle yield. To test this hypothesis, fecal samples from 19 fish representing an F2 high-muscle genetic line (ARS-FY-H) and 20 fish representing an F1 low-muscle yield genetic line (ARS-FY-L) were chosen for microbiota profiling using the 16S rRNA gene. Significant differences in microbial assemblages between these two genetic lines might represent the effect of host genetic selection in structuring the gut microbiota of the host. Tukey’s transformed inverse Simpson indices indicated that high muscle yield genetic line (ARS-FY-H) samples have higher microbial diversity compared to those of the low muscle yield genetic line (ARS-FY-L) (LMM, χ2(1) =14.11, p < 0.05). The fecal samples showed statistically distinct structure in microbial assemblages between the genetic lines (F1,36 = 4.7, p < 0.05, R2 = 11.9%). Functional profiling of bacterial operational taxonomic units predicted characteristic functional capabilities of the microbial communities in the high (ARS-FY-H) and low (ARS-FY-L) muscle yield genetic line samples. The significant differences of the microbial assemblages between high (ARS-FY-H) and low (ARS-FY-L) muscle yield genetic lines indicate a possible effect of genetic selection on the microbial diversity of the host. The functional composition of taxa demonstrates a correlation between bacteria and improving the muscle accretion in the host, probably, by producing various metabolites and enzymes that might aid in digestion. Further research is required to elucidate the mechanisms involved in shaping the microbial community through host genetic selection.

中文翻译：

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与遗传选择相关的独特微生物组合，用于虹鳟鱼高肌肉产量和低肌肉产量

鱼肠微生物群在宿主的生长速度，新陈代谢和免疫力中起着至关重要的作用。我们假设虹鳟鱼的肠道菌群与基于繁殖程序的肌肉产量遗传选择相关。为了检验这一假设，选择了代表F2高肌肉遗传系（ARS-FY-H）的19条鱼和代表F1低肌肉产量遗传系（ARS-FY-L）的20条鱼的粪便样本，以进行微生物群分析，方法是16S rRNA基因。这两个遗传系之间微生物组合的显着差异可能代表宿主遗传选择在构建宿主肠道菌群中的作用。Tukey变换的Simpson逆指数表明，高肌肉产量遗传系（ARS-FY-H）样品比低肌肉产量遗传系（ARS-FY-L）具有更高的微生物多样性（LMM，χ2（1）= 14.11 ，p ＜0.05）。粪便样品在遗传系之间的微生物组合中显示出统计学上不同的结构（F1,36 = 4.7，p <0.05，R2 = 11.9％）。细菌操作分类单位的功能分析预测了高产量（ARS-FY-H）和低产量（ARS-FY-L）肌肉产量遗传系样品中微生物群落的特征功能。高（ARS-FY-H）和低（ARS-FY-L）肌肉产量基因系之间微生物组合的显着差异表明遗传选择对宿主微生物多样性的可能影响。分类单元的功能组成可能通过产生可能有助于消化的各种代谢物和酶，证明细菌与宿主肌肉发达之间的相关性。需要进一步的研究来阐明通过宿主基因选择来塑造微生物群落的机制。