Schwochow Doreen, Alameddine Asmaa, Spörndly-Nees Ellinor, Montigny Mathilde, Naboulsi Rakan, Jansson Anna, Niazi Adnan, Lindgren Gabriella
Department of Animal Biosciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Division of Gene Technology, Science of Life Laboratory, Royal Institute of Technology, Stockholm, Sweden.
BMC Genomics. 2025 Aug 18;26(1):751. doi: 10.1186/s12864-025-11814-4.
Racing without protective shoes is common in the Swedish harness racing industry, as it can enhance horses' performance on the track. Trainers typically decide whether a horse will race barefoot based on practical experience rather than objective measures. However, this practice can sometimes lead to excessive hoof wear, posing potential welfare concerns for racing horses. Gene expression differences may help reveal the underlying genetic mechanisms associated with different phenotypic traits. To explore an objective measure for assessing which horses are best suited for barefoot racing, we conducted a polyA-selected RNA-seq experiment on tissue from the growth zone at the coronary band of the hoof. This experiment compared tissues from Standardbred trotters capable of repeatedly racing barefoot without injury (n = 11) to those that could not (n = 7). By combining stringent phenotyping with racing records and trainer interviews, we aimed to elucidate the biological factors related to hoof strength in barefoot racing, focusing on differential abundant genes.
The RNA-seq analysis identified five significantly downregulated genes in horses capable of competing barefoot across consecutive races. These genes are associated with various biological processes relevant for hoof strength: ACCS, IRX2 and TRAPPAC6A contribute to enhancing the structural integrity of the hoof; MT2A regulates its metal homeostasis and SLC35F3 likely influences local vasoconstriction in the hoof. These gene findings suggest a coordinated genetic basis for structural reinforcement and physiological support of the hoof, which may be critical for sustaining performance under barefoot conditions.
Our findings suggest that the ability of Standardbred trotters to race barefoot in consecutive events is reflected in distinct gene expression patterns, underscoring a genetic basis for hoof strength. This supports further genome-wide scans aimed at identifying genetic markers for hoof durability in these horses. The focused design of our study- comparing horses that could consistently race barefoot with those that could not- enabled us to isolate a select group of genes involved in diverse aspects of hoof biology essential for quality and resilience of horse hooves. This insight could ultimately be applied to augment both the performance and wellbeing of equine athletes across disciplines.
在瑞典轻驾车赛马行业中，不穿保护蹄鞋参赛很常见，因为这可以提高马匹在赛道上的表现。训练师通常根据实际经验而非客观指标来决定一匹马是否光脚参赛。然而，这种做法有时会导致蹄过度磨损，给赛马带来潜在的福利问题。基因表达差异可能有助于揭示与不同表型特征相关的潜在遗传机制。为了探索一种客观指标来评估哪些马最适合光脚参赛，我们对蹄冠带生长区的组织进行了聚腺苷酸选择RNA测序实验。本实验将能够多次光脚参赛且无损伤的标准赛马（n = 11）的组织与不能光脚参赛的标准赛马（n = 7）的组织进行了比较。通过将严格的表型分析与比赛记录及训练师访谈相结合，我们旨在阐明与光脚赛马中蹄强度相关的生物学因素，重点关注差异丰富的基因。
RNA测序分析在能够连续光脚参赛的马匹中鉴定出五个显著下调的基因。这些基因与蹄强度相关的各种生物学过程有关：ACCS、IRX2和TRAPPAC6A有助于增强蹄的结构完整性；MT2A调节其金属稳态，SLC35F3可能影响蹄局部血管收缩。这些基因发现表明，蹄的结构强化和生理支持存在协调的遗传基础，这对于在光脚条件下维持表现可能至关重要。
我们的研究结果表明，标准赛马连续光脚参赛的能力体现在独特的基因表达模式中，强调了蹄强度的遗传基础。这支持进一步进行全基因组扫描，以确定这些马匹蹄耐久性的遗传标记。我们研究的重点设计——将能够持续光脚参赛的马与不能光脚参赛的马进行比较——使我们能够分离出一组参与蹄生物学各个方面的特定基因，这些基因对于马蹄的质量和弹性至关重要。这一见解最终可应用于提高各学科马运动员的表现和福祉。
