SPINK5 Gene Influences Dairy Cattle Rumen Microbiota

A recent study involving 603 lactating Holstein cows across five farms has identified the SPINK5 gene as a significant factor in regulating rumen microbiota and fermentation processes. The research, published in npj Biofilms and Microbiomes, highlights how host genetics contribute to variations in rumen microbial communities.

The study integrated genomic data with rumen microbiome and fermentation parameters. Genetic clustering was found to significantly influence the structure and diversity of the microbial community in the rumen. Researchers identified 54 heritable microbial taxa and noted that moderate short-chain fatty acid (SCFA) concentrations were linked to high connectivity within microbial networks.

A genome-wide association analysis pinpointed a hotspot on chromosome 7 associated with butyrate and propionate concentrations. This analysis prioritized SPINK5 as the strongest candidate gene. The SPINK5 gene was specifically expressed in the stratified squamous epithelium of the rumen, playing a role in epithelial keratinization and barrier permeability.

Further experimentation showed that knocking down SPINK5 increased the expression of keratinization-related genes and enhanced the properties of the epithelial barrier. Conversely, overexpression of SPINK5 resulted in increased epithelial permeability. This suggests a novel mechanism by which SPINK5 variants regulate the rumen microecology through the epithelial barrier-SCFA homeostasis axis.

The findings present actionable markers for microbiome-targeted genomic selection, which could potentially enhance fermentation efficiency, mitigate methane emissions, and improve overall dairy performance. This research was supported by the National Key Research and Development Program of China and the Fundamental Research Funds for the Central Universities.