Search results for "homozygosity"
showing 10 items of 42 documents
Microspore embryogenesis induced through in vitro anther culture of almond (Prunus dulcis Mill.)
2016
Anther culture is one of the most widely used methods to induce gametic embryogenesis. The aim of this investigation was to induce microspore embryogenesis in almond (Prunus dulcis Mill.), through this technique. Anthers were cultured at the vacuolated developmental stage, and seven cultivars, two culture media and two temperature treatments were assessed. Although evidence of the microspore induction was observed in all the genotypes and treatments tested (symmetrical nucleus division and multinucleated structures), calli were produced merely by anthers cultured in the medium P and the regeneration of embryos was detected only in anthers of the cultivars Filippo Ceo, Lauranne and Genco, pl…
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…
Microspore embryogenesis inCitrusand other fruit crops
2017
Conventional methods, involving several generations of selfing, are not applicable to produce homozygous lines in Citrus as well as in the other fruit crops, due to the high heterozygosity of the genomes, the long duration of the generation cycle, the large size, and, often, the self-incompatibility. For this reason, there is no different way to obtain homozygosity in this kind of plants than âgametic embryogenesisâ that allows the development of haploids (Hs, plants with gametophytic chromosome number) and doubled haploids (DHs, haploids that have undergone chromosome duplication) from heterozygous parents in a single step. Therefore, gametic embryogenesis is increasingly object of res…
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 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…
Genomic characterization of Algerian Guelmoise cattle and their genetic relationship with other North African populations inferred from SNP genotypin…
2018
International audience; Understanding between and within-breeds genetic variability is essential in the choice of conservation management decisions for threatened populations. In this study we assessed the genetic diversity of the Algerian Guelmoise cattle (GUE) by analyzing data on 24 GUE individuals genotyped for the Illumina BovineSNP50 BeadChipv2. We also provided a detailed description of the population structure of GUE using comparisons with 23 worldwide cattle populations, selected as being representative of African, South European and indicine populations, in addition to four North African populations. We show that GUE is an admixed population which has strong genetic similarity to …
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…
Genome-wide assessment of diversity and differentiation between original and modern Brown cattle populations
2020
Identifying genomic regions involved in the differences between breeds can provide information on genes that are under the influence of both artificial and natural selection. The aim of this study was to assess the genetic diversity and differentiation among four different Brown cattle populations (two original vs. two modern populations) and to characterize the distribution of runs of homozygosity (ROH) islands using the Illumina Bovine SNP50 BeadChip genotyping data. After quality control, 34 735 SNPs and 106 animals were retained for the analyses. Larger heterogeneity was highlighted for the original populations. Patterns of genetic differentiation, multidimensional scaling, and the neig…
Genome-wide homozygosity in Maremmana cattle
2017
The current availability of large numbers of single nucleotide polymorphisms (SNPs) throughout the genome makes these markers particularly suitable for the detection of patterns of genetic diversity and of genome-wide homozygosity in animal populations. The aim of this work was to estimate genetic diversity and homozygosity in the Maremmana cattle breed. We used a sample of 149 animals (males and females) geno-typed with the BovineSNP50 v2 (54K) Illumina BeadChip. After editing for call-rate >0.9 and removing SNP unassigned or on the sex chromosomes, 128 animals and 50,814 SNPs were left. We estimated the following genetic parameters: observed and expected heterozygosity (Ho and He), minor …
Genome-wide scan for runs of homozygosity identifies potential candidate genes associated with local adaptation in Valle del Belice sheep
2017
Background Because very large numbers of single nucleotide polymorphisms (SNPs) are now available throughout the genome, they are particularly suitable for the detection of genomic regions where a reduction in heterozygosity has occurred and they offer new opportunities to improve the accuracy of inbreeding (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$F$$\end{document}F) estimates. Runs of homozygosity (ROH) are contiguous lengths of homozygous segments of the genome where the two haplotypes inherited from t…