Search results for "BeadChip"
showing 9 items of 9 documents
Genome structure in Sicilian cattle breeds
2014
Genomic technologies provide background information concerning genome structure in domestic animals. The aim of this work was to investigate the genetic structure and the patterns of linkage disequilibrium (LD) in two Sicilian local cattle breeds, Cinisara and Modicana. Genotypes from animals of Italian Holstein breed were also used to investigate the relationship among breeds. Structure software was used to analyze the genetic structure and assign the individuals to each cluster. The genetic relationship between individuals was estimated by Principal Components Analysis (PCA) of genetic distance. A standard descriptive LD parameter (r2) was obtained between adjacent SNPs and for all pairwi…
Genome-wide detection of signatures of selection in three Valdostana cattle populations
2020
International audience; The Valdostana is a local dual purpose cattle breed developed in Italy. Three populations are recognized within this breed, based on coat colour, production level, morphology and temperament: Valdostana Red Pied (VPR), Valdostana Black Pied (VPN) and Valdostana Chestnut (VCA). Here, we investigated putative genomic regions under selection among these three populations using the Bovine 50K SNP array by combining three different statistical methods based either on allele frequencies (F-ST) or extended haplotype homozygosity (iHS and Rsb). In total, 8, 5 and 8 chromosomes harbouring 13, 13 and 16 genomic regions potentially under selection were identified by at least tw…
Combined approaches to identify genomic regions involved in phenotypic differentiation between low divergent breeds: Application in Sardinian sheep p…
2019
Selective breeding has led to modifications in the genome of many livestock breeds. In this study, we identified the genomic regions that may explain some of the phenotypic differences between two closely related breeds from Sardinia. A total of 44 animals, 20 Sardinian Ancestral Black (SAB) and 24 Sardinian White (SW), were genotyped using the Illumina Ovine 50K array. A total of 68, 38 and 15 significant markers were identified using the case–control genome-wide association study (GWAS), the Bayesian population differentiation analysis (FST) and the Rsb metric, respectively. Comparisons among the approaches revealed a total of 22 overlapping markers between GWAS and FST and one marker bet…
Genome wide linkage disequilibrium and genetic structure in Sicilian dairy sheep breeds
2014
Background The recent availability of sheep genome-wide SNP panels allows providing background information concerning genome structure in domestic animals. The aim of this work was to investigate the patterns of linkage disequilibrium (LD), the genetic diversity and population structure in Valle del Belice, Comisana, and Pinzirita dairy sheep breeds using the Illumina Ovine SNP50K Genotyping array. Results Average r2 between adjacent SNPs across all chromosomes was 0.155 ± 0.204 for Valle del Belice, 0.156 ± 0.208 for Comisana, and 0.128 ± 0.188 for Pinzirita breeds, and some variations in LD value across chromosomes were observed, in particular for Valle del Belice and Comisana breeds. Ave…
Genome-wide identification of runs of homozygosity islands and associated genes in local dairy cattle breeds
2018
Runs of homozygosity (ROH) are widely used as predictors of whole-genome inbreeding levels in cattle. They identify regions that have an unfavorable effect on a phenotype when homozygous, but also identify the genes associated with traits of economic interest present in these regions. Here, the distribution of ROH islands and enriched genes within these regions in four dairy cattle breeds were investigated. Cinisara (71), Modicana (72), Reggiana (168) and Italian Holstein (96) individuals were genotyped using the 50K v2 Illumina BeadChip. The genomic regions most commonly associated with ROHs were identified by selecting the top 1% of the single nucleotide polymorphisms (SNPs) most commonly…
LINKAGE DISEQUILIBRIUM AND GENETIC DIVERSITY IN TWO SICILIAN CATTLE BREEDS ASSESSED BY BOVINE SNP CHIP
2013
The Modicana (MOD) and Cinisara (CIN) are two Sicilian cattle breeds farmed in extensive systems and their economic importance lies on the traditional making of two typical ‘pasta filata’ cheeses. The aim of this study was to explore the genetic structure and the extent of Linkage Disequilibrium (LD) of MOD and CIN cattle breeds. A total of 144 animals were genotyped, using the Bovine SNP50K v2 BeadChip. The squared correlation coefficient between two loci (r2) was used as a measure of LD. Principal components analysis (PCA), molecular inbreeding (F) and Bayesian clustering algorithm (Pritchard et al., 2000) were used to explore the relationship between individuals and populations. The r2 r…
Linkage disequilibrium and genetic diversity estimation in three Sicilian autochthonous dairy sheep breeds
2014
Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. In the present study, we used the OvineSNP50K BeadChip to characterize LD, identify haplotype blocks and to analyze genetic diversity in the Valle del Belice (VDB), Comisana (COM) and Pinzirita (PIN) dairy sheep breeds. LD between adjacent SNPs and for all pairwise combinations of SNPs on each chromosome was measured using r2. Haplotype blocks were estimated using D’ based method. Genetic diversity and Principal Component Analysis (PCA) were calculated using PLINK. Small differences in average LD value for adjace…
Application of molecular markers to investigate genetic diversity in Sicilian livestock
2014
La diversità genetica delle specie e razze di interesse zootecnico, rappresenta un’importante risorsa in tutti i sistemi di allevamento . Per lo studio della diversità genetica, nel corso dei decenni sono stati sviluppati diversi metodi che si basano su informazioni del pedigree o su dati molecolari (microsatelliti e SNPs, Single Nucleotide Polymorphisms). Con l’aumento della disponibilità di marcatori molecolari per la maggior parte delle specie di interesse zootecnico, e con lo sviluppo di sofisticate tecniche analitiche, sta crescendo la capacità di caratterizzare la variabilità genetica delle razze. Inoltre, ad oggi, poche sono le informazioni sulla diversità genetica delle razze e dell…
Genome-wide detection of copy-number variations in local cattle breeds
2019
The aim of the present study was to identify copy-number variations (CNVs) in Cinisara (CIN) and Modicana (MOD) cattle breeds on the basis of signal intensity (logR ratio) and B allele frequency of each marker, using Illumina’s BovineSNP50K Genotyping BeadChip. The CNVs were detected with the PennCNV and SVS 8.7.0 software and were aggregated into CNV regions (CNVRs). PennCNV identified 487 CNVs in CIN that aggregated into 86 CNVRs, and 424 CNVs in MOD that aggregated into 81 CNVRs. SVS identified a total of 207 CNVs in CIN that aggregated into 39 CNVRs, and 181 CNVs in MOD that aggregated into 41 CNVRs. The CNVRs identified with the two softwares contained 29 common CNVRs in CIN and 17 co…