Search results for "Copy-number variation"
showing 10 items of 62 documents
A roadmap for understanding the evolutionary significance of structural genomic variation
2020
Author's accepted manuscript Structural genomic variants (SVs) take diverse forms and are ubiquitous drivers of ecological and evolutionary processes. Most studies of SVs focus on the adaptive significance of gene duplications and large inversions. Future studies should catalog SVs of all types and sizes and systematically test their evolutionary implications. We propose a roadmap and definitions for the study of SVs in ecological and evolutionary genomics. Best practices for SV detection are needed to facilitate comparisons across studies. Integrating population genomic, theoretical, and experimental approaches to SVs will more comprehensively characterize genomic variation, uncover the ad…
Karyotype variability and inter-population genomic differences in freshwater ostracods (Crustacea) showing geographical parthenogenesis
2018
Transitions from sexual to asexual reproduction are often associated with polyploidy and increased chromosomal plasticity in asexuals. We investigated chromosomes in the freshwater ostracod species Eucypris virens (Jurine, 1820), where sexual, asexual and mixed populations can be found. Our initial karyotyping of multiple populations from Europe and North Africa, both sexual and asexual, revealed a striking variability in chromosome numbers. This would suggest that chromosomal changes are likely to be accelerated in asexuals because the constraints of meiosis are removed. Hence, we employed comparative genomic hybridization (CGH) within and among sexual and asexual populations to get insigh…
Unravelling the determinants of freezing tolerance in Medicago truncatula: a first step towards improving the response of crop legumes to freezing st…
2020
International audience; Freezing is a major environmental limitation that affects biomass and seed productivity in a large number of crop species including legumes. Medicago truncatula is a model molecular‐genetic system for legume biology. A strategy to decipher freezing tolerance after a cold acclimation period in M. truncatula was developed using a quantitative genetic approach. Three main quantitative trait loci (QTL) with additive effects for freezing damage were detected on chromosomes 1, 4, and 6 using a recombinant inbred line population derived from a cross between the freezing‐tolerant accession F83005‐5 and the freezing‐sensitive accession DZA045‐5. The QTL on chromosome 6, named…
Haploinsufficiency of the Primary Familial Brain Calcification Gene SLC20A2 Mediated by Disruption of a Regulatory Element
2020
OBJECTIVE Primary familial brain calcification (PFBC) is a rare cerebral microvascular calcifying disorder with diverse neuropsychiatric expression. Five genes were reported as PFBC causative when carrying pathogenic variants. Haploinsufficiency of SLC20A2, which encodes an inorganic phosphate importer, is a major cause of autosomal-dominant PFBC. However, PFBC remains genetically unexplained in a proportion of patients, suggesting the existence of additional genes or cryptic mutations. We analyzed exome sequencing data of 71 unrelated, genetically unexplained PFBC patients with the aim to detect copy number variations that may disrupt the expression of core PFBC-causing genes. METHODS Afte…
Easy One-Step Amplification and Labeling Procedure for Copy Number Variation Detection.
2019
Abstract Background The specific characteristics of copy number variations (CNVs) require specific methods of detection and characterization. We developed the Easy One-Step Amplification and Labeling procedure for CNV detection (EOSAL-CNV), a new method based on proportional amplification and labeling of amplicons in 1 PCR. Methods We used tailed primers for specific amplification and a pair of labeling probes (only 1 labeled) for amplification and labeling of all amplicons in just 1 reaction. Products were loaded directly onto a capillary DNA sequencer for fragment sizing and quantification. Data obtained could be analyzed by Microsoft Excel spreadsheet or EOSAL-CNV analysis software. We d…
Array-based molecular karyotyping in 115 VATER/VACTERL and VATER/VACTERL-like patients identifies disease-causing copy number variations
2017
Background The acronym VATER/VACTERL refers to the rare nonrandom association of the following component features (CF): vertebral defects (V), anorectal malformations (A), cardiac defects (C), tracheoesophageal fistula with or without esophageal atresia, renal malformations (R), and limb defects (L). Patients presenting with at least three CFs are diagnosed as having VATER/VACTERL association while patients presenting with only two CFs are diagnosed as having VATER/VACTERL-like phenotypes. Recently, rare causative copy number variations (CNVs) have been identified in patients with VATER/VACTERL association and VATER/VACTERL-like phenotypes. Methods To detect further causative CNVs we perfor…
Diversification of spatiotemporal expression and copy number variation of the echinoid hbox12/pmar1/micro1 multigene family
2017
Changes occurring during evolution in the cis-regulatory landscapes of individual members of multigene families might impart diversification in their spatiotemporal expression and function. The archetypal member of the echinoid hbox12/pmar1/micro1 family is hbox12-a, a homeobox-containing gene expressed exclusively by dorsal blastomeres, where it governs the dorsal/ventral gene regulatory network during embryogenesis of the sea urchin Paracentrotus lividus. Here we describe the inventory of the hbox12/pmar1/micro1 genes in P. lividus, highlighting that gene copy number variation occurs across individual sea urchins of the same species. We show that the various hbox12/pmar1/micro1 genes grou…
Genome-wide association study between CNVs and milk production traits in Valle del Belice sheep.
2019
Copy number variation (CNV) is a major source of genomic structural variation. The aim of this study was to detect genomic CNV regions (CNVR) in Valle del Belice dairy sheep population and to identify those affecting milk production traits. The GO analysis identified possible candidate genes and pathways related to the selected traits. We identified CNVs in 416 individuals genotyped using the Illumina OvineSNP50 BeadChip array. The CNV association using a correlation-trend test model was examined with the Golden Helix SVS 8.7.0 tool. Significant CNVs were detected when their adjusted p-value was <0.01 after false discovery rate (FDR) correction. We identified 7,208 CNVs, which gave 365 C…
Evolutionary impact of copy number variation rates.
2017
[Objective]: Copy number variation is now recognized as one of the major sources of genetic variation among individuals in natural populations of any species. However, the relevance of these unexpected observations goes beyond diagnosing high diversity. [Results]: Here, it is argued that the molecular rates of copy number variation, mainly the deletion rate upon variation, determine the evolutionary road of the genome regarding size. Genetic drift will govern this process only if the efective population size is lower than the inverse of the deletion rate. Otherwise, natural selection will do.
CLOVE: classification of genomic fusions into structural variation events
2017
Background A precise understanding of structural variants (SVs) in DNA is important in the study of cancer and population diversity. Many methods have been designed to identify SVs from DNA sequencing data. However, the problem remains challenging because existing approaches suffer from low sensitivity, precision, and positional accuracy. Furthermore, many existing tools only identify breakpoints, and so not collect related breakpoints and classify them as a particular type of SV. Due to the rapidly increasing usage of high throughput sequencing technologies in this area, there is an urgent need for algorithms that can accurately classify complex genomic rearrangements (involving more than …