Search results for " Homozygosity"
showing 10 items of 34 documents
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…
Genome-wide analysis in endangered populations: a case study in Barbaresca sheep
2017
Analysis of genomic data is becoming increasingly common in the livestock industry and the findings have been an invaluable resource for effective management of breeding programs in small and endangered populations. In this paper, with the goal of highlighting the potential of genomic analysis for small and endangered populations, genome-wide levels of linkage disequilibrium, measured as the squared correlation coefficient of allele frequencies at a pair of loci, effective population size, runs of homozygosity (ROH) and genetic diversity parameters, were estimated in Barbaresca sheep using Illumina OvineSNP50K array data. Moreover, the breed's genetic structure and its relationship with oth…
Signatures of selection in the genome of Swedish warmblood horses selected for sport performance
2019
Abstract Background A growing demand for improved physical skills and mental attitude in modern sport horses has led to strong selection for performance in many warmblood studbooks. The aim of this study was to detect genomic regions with low diversity, and therefore potentially under selection, in Swedish Warmblood horses (SWB) by analysing high-density SNP data. To investigate if such signatures could be the result of selection for equestrian sport performance, we compared our SWB SNP data with those from Exmoor ponies, a horse breed not selected for sport performance traits. Results The genomic scan for homozygous regions identified long runs of homozygosity (ROH) shared by more than 85%…
Early embryo achievement through isolated microspore culture in citrus clementina hort. Ex tan., cvs. 'Monreal Rosso' and 'nules'
2015
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Genome‐wide survey on three local horse populations with a focus on runs of homozygosity pattern
2022
Purosangue Orientale Siciliano, Sanfratellano and Siciliano represent the Sicilian equine genetic resource. This study aimed to investigate the genetic diversity, population structure and the pattern of autozygosity of Sicilian horse populations using genome-wide single-nucleotide polymorphism (SNP) data generated with the Illumina Equine SNP70 array. The genotyping data of 17 European and Middle East populations were also included in the study. The patterns of genetic differentiation, model-based clustering and Neighbour-Net showed the expected positioning of Sicilian populations within the wide analysed framework and the close connections between the Purosangue Orientale Siciliano and the…
Gametic embryogenesis through isolated microspore culture in mandarin (Citrus reticulata Blanco), Mandarino Tardivo Di Ciaculli: effect of meta-Topol…
2016
Haploid technology, allowing the single-step development of complete homozygous genotypes from heterozygous plants through gametic embryogenesis, has already an enormous impact on breeding programs of many important crops. Microspore embryogenesis can be carried out through in vitro culture of anther or isolated microspore. Experiments have been carried out via isolated microspore culture in Citrus reticulata (Blanco), Mandarino Tardivo di Ciaculli, investigating the influence of two culture media, of two plant growth regulator types and of two temperature treatments applied before the culture or just after the culture. After ten months of culture, for all the media tested, different struct…
Genome-wide scan for Runs of Homozygosity in Valle del Belice sheep
2017
The current availability of very large numbers of single nucleotide polymorphisms (SNPs) throughout the genome makes these markers particularly suitable for the detection of genomic regions where a reduction in heterozygosity occurred and offers new opportunities to improve the accuracy of inbreeding (F) estimates. Runs of homozygosity (ROH) are contiguous lengths of homozygous segments of the genome where the two haplotypes inherited from the parents are identical. Here, we investigated the occurrence and the distribution of ROH in medium-density SNP genotypes (~ 50 000) in order to characterize autozygosity in 512 individuals of Valle del Belice sheep and identify the regions of the genom…
Genome-wide analyses reveal population structure and identify candidate genes associated with tail fatness in local sheep from a semi-arid area.
2021
Abstract Under a climate change perspective, the genetic make-up of local livestock breeds showing adaptive traits should be explored and preserved as a priority. We used genotype data from the ovine 50 k Illumina BeadChip for assessing breed autozygosity based on runs of homozygosity (ROH) and fine-scale genetic structure and for detecting genomic regions under selection in 63 Tunisian sheep samples. The average genomic inbreeding coefficients based on ROH were estimated at 0.017, 0.021, and 0.024 for Barbarine (BAR, n = 26), Noire de Thibar (NDT, n = 23), and Queue fine de l'Ouest (QFO, n = 14) breeds, respectively. The genomic relationships among individuals based on identity by state (I…
Runs of homozygosity in the Italian goat breeds: impact of management practices in low-input systems
2021
Abstract Background Climate and farming systems, several of which are considered as low-input agricultural systems, vary between goat populations from Northern and Southern Italy and have led to different management practices. These processes have impacted genome shaping in terms of inbreeding and regions under selection and resulted in differences between the northern and southern populations. Both inbreeding and signatures of selection can be pinpointed by the analysis of runs of homozygosity (ROH), which provides useful information to assist the management of this species in different rural areas. Results We analyzed the ROH distribution and inbreeding (FROH) in 902 goats from the Italia…
Ploidy manipulation for genetic improvement in some Mediterranean fruit crops
2017
Plant breeding is focused on selection of new genotypes with improved traits. Conventional methods based on hybridization and those based on biotechnology (somatic hybridization, genetic transformation, ploidy manipulation, etc.) are used to create novel genetic variations. Biotechnology provides powerful tools for plant breeding, for instance, haploid technology allows achievement of homozygous lines from heterozygous parents in one step, which reduces significantly the time required by conventional methods. Concerning woody species, characterized by self-incompatibility, long juvenile period and high degree of heterozygosity, this technique is the only way to get homozygous lines. Haploid…