Unravelling the hybrid vigor in domestic equids: the effect of hybridization on bone shape variation and covariation.
Abstract: Hybridization has been widely practiced in plant and animal breeding as a means to enhance the quality and fitness of the organisms. In domestic equids, this hybrid vigor takes the form of improved physical and physiological characteristics, notably for strength or endurance. Because the offspring of horse and donkey is generally sterile, this widely recognized vigor is expressed in the first generation (F1). However, in the absence of recombination between the two parental genomes, F1 hybrids can be expected to be phenotypically intermediate between their parents which could potentially restrict the possibilities of an increase in overall fitness. In this study, we examine the morphology of the main limb bones of domestic horses, donkeys and their hybrids to investigate the phenotypic impact of hybridization on the locomotor system. We explore bone shape variation and covariation to gain insights into the morphological and functional expressions of the hybrid vigor commonly described in domestic equids. Our data reveal the occurrence of transgressive effects on several bones in the F1 generation. The patterns of morphological integration further demonstrate that the developmental processes producing covariation are not disrupted by hybridization, contrary to functional ones. These results suggest that an increase in overall fitness could be related to more flexibility in shape change in hybrids, except for the main forelimb long bones of which the morphology is strongly driven by muscle interactions. More broadly, this study illustrates the interest of investigating not only bone shape variation but also underlying processes, in order to contribute to better understanding how developmental and functional mechanisms are affected by hybridization.
Publication Date: 2019-10-15 PubMed ID: 31615394PubMed Central: PMC6794909DOI: 10.1186/s12862-019-1520-2Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research investigates the impact of hybridization – the creation of hybrid offspring from horse and donkey parents – on the bone structure and overall fitness of the offspring. It proposes the theory that hybridization may not only result in intermediate physical traits between the two parents, but also introduce new shape variations in the bones, potentially contributing to increased fitness.
Aim and Methodology
- The main aim of the research was to understand the effects of hybridization on the bone morphology of domestic equids, focusing on the locomotor system.
- This was done by analyzing the variation in bone shapes and covariation—how the shapes of different bones relate to each other—in horses, donkeys, and their hybrid offspring.
Findings
- The results showed that hybridization resulted in transgressive effects on several bones in the first generation (F1) hybrids. Transgressive effects refer to the hybrid having traits that exceed the range of variation observed in both parent species.
- Importantly, the morphology of the forelimb long bones, which is largely influenced by muscle interactions, was not disrupted by these transgressive effects.
Morphological Integration
- The patterns of morphological integration showed that hybridization does not disrupt the developmental processes that lead to covariation, contradicting to some extent the assumption that hybridization generally disrupts functional mechanisms.
- This interesting finding suggests that an increase in overall fitness in hybrid equids might be related to greater flexibility in shape changes, a result of undisturbed bone development processes.
Conclusion and Implications
- The findings suggest that hybridization in equids not only produces intermediate traits but can also introduce flexibility in shape changes that potentially contribute to the overall fitness of the hybrid.
- This has implications for understanding and advancing animal breeding methods, potentially leading to stronger, more robust hybrid breeds.
- Furthermore, the study highlights the worth of investigating both bone shape variation and the underlying processes involved, in gaining a better understanding of how hybridization can influence developmental and functional mechanisms.
Cite This Article
APA
(2019).
Unravelling the hybrid vigor in domestic equids: the effect of hybridization on bone shape variation and covariation.
BMC Evol Biol, 19(1), 188.
https://doi.org/10.1186/s12862-019-1520-2 Publication
Researcher Affiliations
MeSH Terms
- Animals
- Animals, Domestic / genetics
- Bone and Bones / anatomy & histology
- Breeding
- Horses / genetics
- Hybrid Vigor / genetics
- Hybridization, Genetic
- Least-Squares Analysis
- Models, Theoretical
- Principal Component Analysis
- Sample Size
Conflict of Interest Statement
The authors declare that they have no competing interests.
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