Genetic influence of a STAU2 frameshift mutation and RELN regulatory elements on performance in Icelandic horses.
Abstract: Selection for performance in horse breeding benefits from precise genetic insights at a molecular level, but knowledge remains limited. This study used whole-genome sequences of 39 elite and non-elite Icelandic horses to identify candidate causal variants linked to previously identified haplotypes in the STAU2 and RELN genes affecting pace and other gaits. A frameshift variant in linkage disequilibrium with the previously identified haplotypes in the STAU2 gene (r2 = 0.85) was identified within a predicted STAU2 transcript. This variant alters the amino acid sequence and introduces a premature stop codon but does not appear harmful or disease-causing and is potentially unique to equine biology. A large portion of the RELN haplotype overlapped with an H3K27me3 modification mark, suggesting a regulatory role of this region. Despite the small sample size, the RELN haplotype's effects were validated for tölt, trot, and canter/gallop. Additionally, the RELN haplotype significantly influenced the age at which horses were presented for breeding field tests, indicating a potential role of the region in precocity and trainability. Functional experiments are needed to further investigate the regions' influences on biological processes and their potential impact on horse performance.
© 2025. The Author(s).
Publication Date: 2025-04-04 PubMed ID: 40185812PubMed Central: PMC11971302DOI: 10.1038/s41598-025-95593-8Google Scholar: Lookup
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Summary
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This research investigated the genetic factors affecting performance in Icelandic horses. It found a mutation in the STAU2 gene as well as regulatory elements in the RELN gene which could influence not only the horse’s gait, but also the age at which they are presented for breeding.
Genetic Analysis of Icelandic Horses
- The study used whole-genome sequences from 39 Icelandic horses, both elite and non-elite, in order to uncover genetic variants potentially affecting their performance.
- The research focused on variants linked to previously identified haplotypes in the STAU2 and RELN genes. Haplotypes are groups of genes that inherited together from a single parent.
- The focus on these specific genes was due to their previously identified effect on the pace and other gaits of the horses.
Discovery of a STAU2 Frameshift Mutation
- The researchers identified a frameshift variant in the STAU2 gene. A “frameshift” mutation is one where the addition or removal of DNA bases changes a gene’s reading frame. Essentially, the way the gene is read and interpreted is shifted, resulting in a different output.
- This specific variant resulted in a premature stop codon — the signal to stop protein synthesis. However, it did not appear to cause any harmful or disease conditions and is thought to be unique to equine biology.
Regulatory Role of the RELN Gene
- The study also found an expansive portion of the RELN haplotype overlapping with a mark known as H3K27me3. This mark is known to play a role in modifying the genetic activity, suggesting a potential regulatory role of the RELN gene in horse performance.
- Even though the sample size was small, the effects of this haplotype were validated for three different types of gait in horses: tölt, trot, and canter/gallop.
Influence on Breeding and Trainability
- The RELN haplotype was also found to influence the age at which horses are presented for breeding field tests, suggesting a potential role of this region in early maturity and trainability.
- This discovery points a potential way of genetically determining an optimal breeding timeline, but further experiments are needed for confirmation.
Conclusion and Future Research
- While the study contributes valuable genetic insight into equine performance, additional research is needed to investigate the biological processes involved and understand how these genetic variants might be applied to horse breeding and training strategies.
Cite This Article
APA
Sigurðardóttir H, Eriksson S, Niazi A, Rhodin M, Albertsdóttir E, Kristjansson T, Lindgren G.
(2025).
Genetic influence of a STAU2 frameshift mutation and RELN regulatory elements on performance in Icelandic horses.
Sci Rep, 15(1), 11641.
https://doi.org/10.1038/s41598-025-95593-8 Publication
Researcher Affiliations
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, SE-75007, Sweden. heidrun.sigurdardottir@slu.se.
- Faculty of Agricultural Sciences, Agricultural University of Iceland, Hvanneyri, Borgarbyggð, IS-311, Iceland. heidrun.sigurdardottir@slu.se.
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, SE-75007, Sweden.
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, SE-75007, Sweden.
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, SE-75007, Sweden.
- Independent Researcher, Kópavogur, IS-203, Iceland.
- Faculty of Agricultural Sciences, Agricultural University of Iceland, Hvanneyri, Borgarbyggð, IS-311, Iceland.
- The Icelandic Agricultural Advisory Centre, Höfðabakka 9, Reykjavik, IS-110, Iceland.
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, SE-75007, Sweden.
- Center for Animal Breeding and Genetics, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 30, Leuven, BE-3001, Belgium.
MeSH Terms
- Animals
- Horses / genetics
- Frameshift Mutation
- Haplotypes
- RNA-Binding Proteins / genetics
- Linkage Disequilibrium
- Breeding
- Regulatory Sequences, Nucleic Acid
- Iceland
Conflict of Interest Statement
Declaration. Competing interests: The authors declare competing interests concerning the commercial applications of the current study. GL is a co-inventor of a patent application concerning commercial testing of the DMRT3 mutation. The stated patent does not restrict research applications of the method. Other authors declare no potential conflict of interest. .
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