Introduction

Ruminants play a pivotal role in our society by transforming non-consumable substances from industrial by-products and plant fibers into valuable resources such as meat and milk. This remarkable conversion ability is primarily attributed to the rumen microbiota, which is influenced by various factors, including diet, climate, and geographical location. In recent years, increasing research has shown that host factors (breed, genetic variation, etc.) also play vital roles in shaping rumen microbial composition and function in cattle.

Objective

This study aims to provide a theoretical basis and an opportunity for further investigating the regulation of lactation traits in dairy cows through host genetics and the interaction with the rumen microbiota.

Method

To investigate the interactions between host genotype, rumen microbiota, and animal phenotype, we curated and analyzed the dairy herd improvement (DHI) data, single nucleotide polymorphisms (SNPs) genotypes, and 16S rumen microbiota data from 1,169 Holstein dairy cows. Heritability and microbiability estimation, along with genome-wide association studies (GWAS) were performed to identify candidate microorganisms and host genetic loci.

Result

We identified thirty-one heritable taxa, whose functions were predominantly enriched in carbohydrate metabolism and energy metabolism. The genome-wide association study revealed that nine heritable bacteria were significantly associated with forty-three SNPs. Functional genes located within or near these SNPs were primarily associated with rumen epithelial development. Additionally, these nine heritable bacteria were primarily annotated as complex polysaccharide degraders and butyrate producers, such as Fibrobacter sp900143055 and Pseudoruminococcus massiliensis, which showed significant associations with milk yield and milk fat percentage. Compared to previous studies, we newly discovered the existence of a high heritability of Olsenella umbonate, Butyrivibrio hungatei, among others.

中文翻译：

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奶牛瘤胃微生物组中特定功能群的宿主遗传调控：对泌乳性状的影响

 介绍

反刍动物通过将工业副产品和植物纤维中的非消耗性物质转化为肉类和牛奶等有价值的资源，在我们的社会中发挥着关键作用。这种非凡的转化能力主要归因于瘤胃微生物群，它受多种因素的影响，包括饮食、气候和地理位置。近年来，越来越多的研究表明，宿主因素（品种、遗传变异等）在塑造牛瘤胃微生物组成和功能方面也起着至关重要的作用。

 目的

本研究旨在为通过宿主遗传学和与瘤胃微生物群的相互作用进一步研究奶牛泌乳性状的调控提供理论依据和机会。

 方法

为了研究宿主基因型、瘤胃微生物群和动物表型之间的相互作用，我们整理并分析了 1,169 头荷斯坦奶牛的奶牛群改良 （DHI） 数据、单核苷酸多态性 （SNP） 基因型和 16S 瘤胃微生物群数据。进行遗传力和微生物能力估计以及全基因组关联研究 （GWAS） 以确定候选微生物和宿主遗传位点。

 结果

我们确定了 31 个可遗传的分类群，其功能主要富含碳水化合物代谢和能量代谢。全基因组关联研究表明，9 个可遗传细菌与 43 个 SNP 显著相关。位于这些 SNP 内部或附近的功能基因主要与瘤胃上皮发育相关。此外，这 9 种可遗传细菌主要被注释为复杂的多糖降解剂和丁酸盐生产者，例如 Fibrobacter sp900143055 和 Pseudoruminococcus massiliensis，它们与产奶率和乳脂百分比呈显著关联。与以前的研究相比，我们新发现 Olsenella umbonate、Butyrivibrio hungatei 等存在高遗传性。