Search results for "ASSOCIATION"
showing 10 items of 1747 documents
Association study between beta-defensin gene polymorphisms and mastitis resistance in Valle del Belice dairy sheep breed
2016
Abstract Mastitis is generally caused by bacteria, and it is the most common disease in livestock species. Defensins are peptides with a broad spectrum of antimicrobial activity and β-defensin genes have been studied in several livestock species due to their important role in the innate immune response. The aim of this study was to establish an association between polymorphisms in the β-defensin 1 and 2 genes and mastitis resistance in the Valle del Belice dairy sheep. Data consisted of 1855 and 2804 observations for case and control group, respectively. Six single nucleotide polymorphisms and seven haplotypes were selected for association studies with mastitis. In particular, polymorphism …
Genetics and pathophysiology of granulomatosis with polyangiitis (GPA) and its main autoantigen proteinase 3.
2016
Granulomatosis with polyangiitis (GPA) is a severe autoimmune disease and one of the small vessel anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides. Although its etiology and pathophysiology are still widely unknown, it is accepted that infections, environmental factors, epigenetic modifications, and a genetic predisposition provide the basis for this systemic disorder. GPA typically evolves into two phases: an initial phase characterized by ear, nose and throat (ENT) manifestations, such as chronic sinusitis and otitis, ulceration of the oral cavity and pharynx, as well as pulmonary nodules and a severe generalized phase, defined by the occurrence of rapidly progressive g…
RBFOX1, encoding a splicing regulator, is a candidate gene for aggressive behavior
2020
The RBFOX1 gene (or A2BP1) encodes a splicing factor important for neuronal development that has been related to autism spectrum disorder and other neurodevelopmental phenotypes. Evidence from complementary sources suggests that this gene contributes to aggressive behavior. Suggestive associations with RBFOX1 have been identified in genome-wide association studies (GWAS) of anger, conduct disorder, and aggressive behavior. Nominal association signals in RBFOX1 were also found in an epigenome-wide association study (EWAS) of aggressive behavior. Also, variants in this gene affect temporal lobe volume, a brain area that is altered in several aggression-related phenotypes. In animals, this gen…
Novel and known signals of selection for fat deposition in domestic sheep breeds from Africa and Eurasia
2018
International audience; Genomic regions subjected to selection frequently show signatures such as within-population reduced nucleotide diversity and outlier values of differentiation among differentially selected populations. In this study, we analyzed 50K SNP genotype data of 373 animals belonging to 23 sheep breeds of different geographic origins using the Rsb (extended haplotype homozygosity) and FST statistical approaches, to identify loci associated with the fat-tail phenotype. We also checked if these putative selection signatures overlapped with regions of high-homozygosity (ROH). The analyses identified novel signals and confirmed the presence of selection signature in genomic regio…
Genome-wide association mapping for milk fat composition and fine mapping of a QTL for de novo synthesis of milk fatty acids on bovine chromosome 13
2017
Background Bovine milk is widely regarded as a nutritious food source for humans, although the effects of individual fatty acids on human health is a subject of debate. Based on the assumption that genomic selection offers potential to improve milk fat composition, there is strong interest to understand more about the genetic factors that influence the biosynthesis of bovine milk and the molecular mechanisms that regulate milk fat synthesis and secretion. For this reason, the work reported here aimed at identifying genetic variants that affect milk fatty acid composition in Norwegian Red cattle. Milk fatty acid composition was predicted from the nation-wide recording scheme using Fourier tr…
Fine mapping of a QTL on bovine chromosome 6 using imputed full sequence data suggests a key role for the group-specific component (GC) gene in clini…
2016
Background Clinical mastitis is an inflammation of the mammary gland and causes significant costs to dairy production. It is unfavourably genetically correlated to milk production, and, thus, knowledge of the mechanisms that underlie these traits would be valuable to improve both of them simultaneously through breeding. A quantitative trait locus (QTL) that affects both clinical mastitis and milk production has recently been fine-mapped to around 89 Mb on bovine chromosome 6 (BTA6), but identification of the gene that underlies this QTL was not possible due to the strong linkage disequilibrium between single nucleotide polymorphisms (SNPs) within this region. Our aim was to identify the gen…
Genome-Wide Association Study Identifies New Candidate Markers for Somatic Cells Score in a Local Dairy Sheep
2021
In the Mediterranean basin countries, the dairy sheep production is usually based on local breeds, which are very well-adapted to their production systems and environments and can indeed guarantee income, employment, and economic viability in areas where production alternatives are scarce or non-existent. Mastitis is still one of the greatest problems affecting commercial milk production. However, genetic evaluation of mastitis is particularly difficult because of its low heritability and the categorical nature of the trait. The aim of this study was to identify genomic regions putatively associated with somatic cells count (SCC) in the local economically important Valle del Belice sheep br…
Genome-wide association studies for milk production traits in Valle del Belice sheep using repeated measures
2019
Genome-wide association studies (GWASes) have become a powerful tool for identifying genomic regions associated with important traits in livestock. Milk production traits in dairy sheep are measured at different time points during their life span. Using phenotypic data generated from longitudinal traits could improve the power of association studies but until now have received less attention in GWASes as a methodology and has not been implemented. The aim of this study was to carry out a GWAS for milk production traits in Valle del Belice sheep using repeated measures. After quality control, 469 ewes and 37 228 SNPs were retained for the analysis, and phenotypic data included 5586 test-day …
The Sensory Neocortex and Associative Memory
2016
Most behaviors in mammals are directly or indirectly guided by prior experience and therefore depend on the ability of our brains to form memories. The ability to form an association between an initially possibly neutral sensory stimulus and its behavioral relevance is essential for our ability to navigate in a changing environment. The formation of a memory is a complex process involving many areas of the brain. In this chapter we review classic and recent work that has shed light on the specific contribution of sensory cortical areas to the formation of associative memories. We discuss synaptic and circuit mechanisms that mediate plastic adaptations of functional properties in individual …
Principal components analysis: theory and application to gene expression data analysis
2018
Advances in computational power have enabled research to generate significant amounts of data related to complex biological problems. Consequently, applying appropriate data analysis techniques has become paramount to tackle this complexity. However, theoretical understanding of statistical methods is necessary to ensure that the correct method is used and that sound inferences are made based on the analysis. In this article, we elaborate on the theory behind principal components analysis (PCA), which has become a favoured multivariate statistical tool in the field of omics-data analysis. We discuss the necessary prerequisites and steps to produce statistically valid results and provide gui…