- Title
- Multiomics approach towards identifying plasma biomarkers for early pregnancy diagnosis in mares
- Creator
- Perera, Tharangani Rukmali Wimalarathne
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2024
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- In the realm of equine breeding, the ability to diagnose pregnancy at its earliest stage is paramount for maximizing reproductive efficiency and ensuring the timely application of management practices. The significance of this is particularly pronounced within the Australian horse industries, where breeding not only contributes substantially to the country’s GDP but also represents a cornerstone of activities ranging from racing to stock management. It is in this context that our research takes shape, aiming to uncover early pregnancy biomarkers in horses through an innovative application of omics technologies. Aims: To identify systemic changes during early equine pregnancy by employing advanced 'omics' methodologies, including proteomics, lipidomics, and metabolomics.To discover and validate potential biomarkers that can differentiate pregnant from non-pregnant mares as early as day 7 post-ovulation. To investigate and characterize the progression of pregnancy from day 7 to day 14 post-ovulation, providing deeper insights into the physiological changes that occur during this critical early stage of equine pregnancy. At the heart of our investigation is the quest to detect pregnancy as early as day 7 post-ovulation—a venture that, if successful, would revolutionize the horse breeding industry by allowing breeders to significantly reduce the interval between oestrous cycles in non-pregnant mares. This timing is critical given the unique reproductive cycle of horses, which includes phenomena such as the selective transport of embryos and a notably long preimplantation phase, posing unique challenges for early pregnancy detection. To navigate these complexities, our study has adopted a comprehensive multiomics approach, integrating proteomics, lipidomics, and metabolomics. We embarked on our journey with proteomics, examining systemic changes in the proteome of mare and identifying a suite of proteins with strong correlations to pregnancy physiology. Notably, on day 7, a pivotal time point, we identified a significant number of proteins, which we then developed into a marker cocktail for further validation. Due to proprietary considerations, we have showcased day 14 data as a representation of our methodologies and findings, which we believe captures the essence of our biomarker identification process. In the study we also identified consistent systemic changes in the pregnant mare proteome at 14 days post-ovulation, for the first time. We tentatively conclude that an immune recognition of pregnancy occurs well before implantation in this species, despite the absence of any structural integration of the conceptus with maternal tissue at this stage of gestation. Based on the overlap of viral infection-related pathways and responses across the conceptus, uterine fluid, and maternal plasma proteomes, we suspect that the conceptus uses a strategy of immune system evasion not dissimilar to that deployed by viruses and consider that this hypothesis deserves further investigation. Through the integration of blood plasma, embryo and uterine fluid proteomes, this study also identified transthyretin (TTR) and uteroglobin (SCGB1A1) as proteins of likely major functional significance in the establishment of early pregnancy in the mare. Building on the proteomic insights, we ventured into lipidomics, discovering lipid profile alterations that echoed the protein biomarkers identified at similar gestational stages. Our lipidomics analysis shed light on the lipid alterations that occur during early pregnancy, suggesting an integrated relationship between lipidomic shifts and protein markers. Through the integration of multiomics data on protein and lipids, we have identified several key biomarkers and traced the intricate molecular landscape that characterise early equine pregnancy such as complement component C6, transthyretin, and interleukin 1 receptor accessory protein, and lipids such as NAGly 11:0, Cer 18:0;O2/20:0, and HBMP 22:1_12:0_17:0. Our findings underscore the vital roles of cholesterol metabolism and the regulation of bile acid synthesis in maintaining pregnancy, while also highlighting the dynamic nature of these processes as the body prioritises the increased energy, immune remodelling and developmental demands for pregnancy maintenance. Our comprehensive analysis has led to the identification of novel biomarkers such as BA 24:1;O5, a sterol lipid that may serve as a sensitive marker for early pregnancy detection. This discovery holds promise for revolutionizing the approach to equine pregnancy diagnosis, traditionally reliant on ultrasound scan on those time points. Moreover, using platforms like IPA, Reactome, Kegg our research has revealed the critical role of calcium signaling, lipid metabolism and the WNT pathway in early pregnancy, with upregulation of proteins and lipids involved in these pathways indicating their importance in embryonic development and readiness to implantation. As we chart the metabolic profiling of equine plasma during early pregnancy, we are not only enhancing our understanding of equine reproductive physiology but also laying the groundwork for future research aimed at improving pregnancy outcomes. The observed metabolic shifts reflect the increased metabolic activity crucial for the early stages of pregnancy, underscoring the significance of metabolic flexibility for embryo development and maternal health. While challenges remain, particularly in the identification of metabolites and the need for advanced data acquisition techniques, our study has established a solid foundation for further investigation into the metabolic adaptations that underpin equine pregnancy. In conclusion, this thesis presents a pioneering exploration into the early stages of equine pregnancy, identifying systemic changes and advancing our understanding of the molecular processes involved. It offers a new lens through which to view reproductive health and gestation, setting the stage for future studies that will further elucidate the metabolic intricacies of pregnancy in horses and ultimately benefit the breeding industry through enhanced early pregnancy detection and management strategies.
- Subject
- equine early pregnancy; biomarkers; proteomics; lipidomics; metabolomics
- Identifier
- http://hdl.handle.net/1959.13/1512942
- Identifier
- uon:56684
- Rights
- Copyright 2024 Tharangani Rukmali Wimalarathne Perera
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
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| View Details Download | ATTACHMENT01 | Thesis | 7 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 271 KB | Adobe Acrobat PDF | View Details Download |