Publications by authors named "MacHugh D"

Nonadditive genetic effects pose significant challenges to traditional genomic selection methods for quantitative traits. Machine learning approaches, particularly kernel-based methods, offer promising solutions to overcome these limitations. In this study, we developed a novel machine learning method, KPRR, which integrated a polynomial kernel into ridge regression to effectively capture nonadditive genetic effects.

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  • - Bos taurus and Bos indicus cattle diverged over 150,000 years ago, leading to significant genomic differences and complex genetic mixing in African and Southern European cattle populations over the millennia.
  • - Using software tools MOSAIC and ELAI, researchers analyzed the ancestry of hybrid African and Southern European cattle and found common genomic regions indicating retained or introgressed ancestry from various lineages, demonstrating the effectiveness of both methodologies.
  • - The study highlighted that certain genomic regions relate to important biological functions, particularly in diseases like bovine tuberculosis and trypanosomiasis, showing how retained African taurine ancestry may help cattle manage severe anaemia, improving livestock resilience in sub-Saharan Africa.
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  • - The PhoPR system acts as a crucial regulator in Mycobacterium tuberculosis, with a notable difference in the PhoR protein between M. tuberculosis and M. bovis due to a specific genetic substitution.
  • - Previous studies on M. bovis PhoPR have yielded mixed results regarding its functionality, prompting the authors to investigate this further by creating a mutant strain.
  • - Their experiments revealed that the M. bovis ΔphoPR mutant displayed reduced growth and significant changes in gene expression, particularly in lipid metabolism, emphasizing the role of the PhoPR system in regulating gene expression within the Mycobacterium tuberculosis complex.
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  • Over 3000 years, Tibetan cattle on the Qinghai-Xizang Plateau have adapted to harsh conditions like low oxygen, UV radiation, and extreme cold, but the genetic basis of this adaptation is not fully understood.
  • Analysis of 258 cattle from various breeds shows Tibetan cattle have genetic lineages from both East Asian and South Asian ancestors, with specific genes linked to body size and energy use identified as crucial for their adaptation.
  • The study also found evidence of yak genes introgressing into Tibetan cattle genomes, which contribute to their ability to cope with high altitude challenges, such as hypoxia and cold.
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  • Canine demodicosis is a common skin disease caused by an overgrowth of Demodex mites, with complex factors like T-cell exhaustion and immune responses potentially playing a role in its development.
  • The study employed mass spectrometry and pathway analysis to reveal that endoplasmic reticulum (ER) stress activates signaling pathways linked to immune regulation, particularly affecting Toll-like receptors and promoting M2 macrophage development.
  • Findings demonstrated that the interaction between Demodex mites and the immune system creates an immunosuppressive environment that facilitates the mites' proliferation, highlighting significant molecular changes in affected dogs.
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Criollo cattle, the descendants of animals brought by Iberian colonists to the Americas, have been the subject of natural and human-mediated selection in novel tropical agroecological zones for centuries. Consequently, these breeds have evolved distinct characteristics such as resistance to diseases and exceptional heat tolerance. In addition to European taurine () ancestry, it has been proposed that gene flow from African taurine and Asian indicine () cattle has shaped the ancestry of Criollo cattle.

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During the oestrous cycle, the bovine endometrium undergoes morphological and functional changes, which are regulated by alterations in the levels of oestrogen and progesterone and consequent changes in gene expression. To clarify these changes before and after oestrus, RNA-seq was used to profile the transcriptome of oestrus-synchronized beef heifers. Endometrial samples were collected from 29 animals, which were slaughtered in six groups beginning 12 h after the withdrawal of intravaginal progesterone releasing devices until seven days post-oestrus onset (luteal phase).

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  • Mycobacterium tuberculosis and Mycobacterium bovis are closely related pathogens that both cause tuberculosis but in humans and cattle, respectively, with similar disease mechanisms.
  • A multi-omics approach was used to analyze the immune response in different macrophage types after infection, allowing for a deeper understanding of how these pathogens interact with their hosts.
  • The study identified 32 genes linked to disease resistance, highlighting important pathways involved in the immune response, particularly the NF-κB signaling pathway, which plays a crucial role in the formation of granulomas in response to infection.
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Bovine tuberculosis (bTB), caused by infection with , continues to cause significant issues for the global agriculture industry as well as for human health. An incomplete understanding of the host immune response contributes to the challenges of control and eradication of this zoonotic disease. In this study, high-throughput bulk RNA sequencing (RNA-seq) was used to characterise differential gene expression in γδ T cells - a subgroup of T cells that bridge innate and adaptive immunity and have known anti-mycobacterial response mechanisms.

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  • Adipose-derived stem cells (ADSCs) from sheep with fat tails show strong potential for use in therapeutic research and tissue engineering due to their ability to differentiate into various cell types.
  • The study successfully isolated ADSCs from sheep, demonstrating high self-renewal and strong capabilities in adipogenic differentiation while identifying key transcription factors that regulate this process.
  • Comparative transcriptome analysis reveals these sheep ADSCs have enhanced metabolic ability and identifies novel genes involved in adipogenesis, offering valuable insights for cellular transplantation therapy and fat metabolism studies.
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Behavioural plasticity enables horses entering an exercise training programme to adapt with reduced stress. We characterised SNPs associated with behaviour in yearling Thoroughbred horses using genomics analyses for two phenotypes: (1) handler-assessed coping with early training events [coping] (n = 96); and (2) variation in salivary cortisol concentration at the first backing event [cortisol] (n = 34). Using RNA-seq derived gene expression data for amygdala and hippocampus tissues from n = 2 Thoroughbred stallions, we refined the SNPs to those with functional relevance to behaviour by cross-referencing to the 500 most highly expressed genes in each tissue.

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The proportion of the genome containing runs of homozygosity (ROH) affects production traits in livestock populations. In European and Australasian Thoroughbreds inbreeding, quantified using ROH (F ), is associated with the probability of ever racing. Here, we measured F using 333 K SNP genotypes from 768 Thoroughbred horses born in North America to evaluate the effect of inbreeding on racing traits in that region.

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Background: Thousands of years of natural and artificial selection since the domestication of the horse has shaped the distinctive genomes of Chinese Mongolian horse populations. Consequently, genomic signatures of selection can provide insights into the human-mediated selection history of specific traits and evolutionary adaptation to diverse environments. Here, we used genome-wide SNPs from five distinct Chinese Mongolian horse populations to identify genomic regions under selection for the population-specific traits, gait, black coat colour, and hoof quality.

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Selection for system-wide morphological, physiological, and metabolic adaptations has led to extreme athletic phenotypes among geographically diverse horse breeds. Here, we identify genes contributing to exercise adaptation in racehorses by applying genomics approaches for racing performance, an end-point athletic phenotype. Using an integrative genomics strategy to first combine population genomics results with skeletal muscle exercise and training transcriptomic data, followed by whole-genome resequencing of Asian horses, we identify protein-coding variants in genes of interest in galloping racehorse breeds (Arabian, Mongolian and Thoroughbred).

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Objectives: Improved bovine tuberculosis (bTB) diagnostics with higher sensitivity and specificity are urgently required. A better understanding of the peripheral blood transcriptional response of Mycobacterium bovis-infected animals after bovine purified protein derivative (PPD-b) stimulation of whole blood-an important component of current bTB diagnostics-will provide new information for development of better diagnostics.

Methods: RNA sequencing (RNA-seq) was used to study the peripheral blood transcriptome after stimulation with PPD-b across four time points (-1 wk pre-infection, and +1 wk, +2 wk, and +10 wk post-infection) from a 14-week M.

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  • * All African cattle have taurine mitochondrial DNA, even those with significant zebu ancestry, indicating historical human influence through the importation of zebu bulls from South Asia.
  • * Research shows mitonuclear coevolution in hybrid African cattle, revealing increased taurine ancestry in nuclear genes linked to mitochondria, suggesting incompatibility between the taurine mitochondria and zebu nuclei.
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Small effective population sizes and active inbreeding can lead to inbreeding depression due to deleterious recessive mutations exposed in the homozygous state. The Thoroughbred racehorse has low levels of population genetic diversity, but the effects of genomic inbreeding in the population are unknown. Here, we quantified inbreeding based on runs of homozygosity (ROH) using 297 K SNP genotypes from 6128 horses born in Europe and Australia, of which 13.

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Fat-tail sheep exhibit a unique trait whereby substantial adipose tissue accumulates in the tail, a phenotype that is advantageous in many agroecological environments. In this study, we conducted histological assays, transcriptome analysis and functional assays to examine morphogenesis, characterize gene expression, and elucidate mechanisms that regulate fat tail development. We obtained the microstructure of tail before and after fat deposition, and demonstrated that measurable fat deposition occurred by the 80-day embryo (E80) stage, earlier than other tissues.

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Infection with the zoonotic trematode , common in many regions with a temperate climate, leads to delayed growth and loss of productivity in cattle, while infection in sheep can have more severe effects, potentially leading to death. Previous transcriptomic analyses revealed upregulation of , cell death and Toll-like receptor signalling, T-cell activation, and inhibition of nitric oxide production in macrophages in response to infection. However, the differences between ovine and bovine responses have not yet been explored.

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Bovine tuberculosis, caused by infection with members of the complex, particularly , is a major endemic disease affecting cattle populations worldwide, despite the implementation of stringent surveillance and control programs in many countries. The development of high-throughput functional genomics technologies, including RNA sequencing, has enabled detailed analysis of the host transcriptome to infection, particularly at the macrophage and peripheral blood level. In the present study, we have analysed the transcriptome of bovine whole peripheral blood samples collected at -1 week pre-infection and +1, +2, +6, +10, and +12 weeks post-infection time points.

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is a trematode parasite responsible for major economic losses in livestock production, and is also a food-borne zoonotic agent in developing rural regions. For years, the immunoregulatory mechanisms employed by the parasite have hampered efforts to develop a successful vaccine candidate. Given that a comprehensive understanding of the immune response to infection is needed, we investigated the gene expression changes in ovine hepatic lymph nodes after experimental infection with .

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Background: Bovine TB (bTB), caused by infection with Mycobacterium bovis, is a major endemic disease affecting global cattle production. The key innate immune cell that first encounters the pathogen is the alveolar macrophage, previously shown to be substantially reprogrammed during intracellular infection by the pathogen. Here we use differential expression, and correlation- and interaction-based network approaches to analyse the host response to infection with M.

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Background: Mastitis in dairy cows caused by is a major problem hindering economic growth in dairy farms worldwide. It is difficult to prevent or eliminate due to its asymptomatic nature and long persistence of infection. Although transcriptomic responses of bovine mammary gland cells to pathogens that cause mastitis have been studied, the common responses of peripheral blood leukocytes to infection across two consecutive generations of dairy cattle have not been investigated.

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Bovine tuberculosis is caused by infection with , which can also cause disease in a range of other mammals, including humans. Alveolar macrophages are the key immune effector cells that first encounter and how the macrophage epigenome responds to mycobacterial pathogens is currently not well understood. Here, we have used chromatin immunoprecipitation sequencing (ChIP-seq), RNA-seq and miRNA-seq to examine the effect of infection on the bovine alveolar macrophage (bAM) epigenome.

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Thoroughbred horse racing is a global sport with major hubs in Europe, North America, Australasia and Japan. Regional preferences for certain traits have resulted in phenotypic variation that may result from adaptation to the local racing ecosystem. Here, we test the hypothesis that genes selected for regional phenotypic variation may be identified by analysis of selection signatures in pan-genomic SNP genotype data.

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