Project description:The absence of meiosis and sex are expected to lead to mutation accumulation in asexual (apomictic) plants. We have performed a double-validated analysis of copy number variation (CNV) on 10 biological replicates each of diploid sexual and diploid apomictic Boechera using a high-density (>700K) custom microarray, in order to compare mutation accumulation in the form of CNV between the transcribing regions of their genomes. The Boechera genome demonstrated higher levels of depleted compared to enriched CNV, irrespective of reproductive mode. Genome-wide patterns of CNV revealed four divergent lineages, three of which were characterized by both sexual and apomictic genotypes. Hence genome-wide CNV is reflective of at least 3 independent origins (i.e. expression) of apomixis from different sexual genetic backgrounds. CNV distributions for different families of transposable elements (TEs) were lineage specific, and a trend for enrichment in LINE/L1 and LTR/Copia elements in lineage 3 apomicts is consistent with sex and meiosis being mechanisms for purging genomic parasites. We hypothesize that significant overrepresentation of specific gene ontology classes (e.g. pollen-pistil interaction) in apomicts implies that gene enrichment could be an adaptive mechanism for genome stability in diploid apomicts by providing a polyploid-like system for buffering the effects of deleterious mutations.
Project description:The 16p11.2 is the most common copy number variant (CNV) associated with Autism Spectrum Disorder (ASD). We used patient-derived cerebral organoids to investigate neurodevelopmental pathways dysregulated by dosage changes of 16p11.2 CNV. To investigate molecular dysregulation in DEL and DUP organoids, we carried out RNA sequencing and Tandem Mass Tag mass spectrometry (TMT-MS) on 1-month and 3-month organoids from the same samples. In proteomic analyses, we quantified a total of 6126 proteins in 1-month and 5481 proteins in 3-month organoids, with 13 and 11 proteins from within 16p11.2 CNV, respectively. Transcriptomic and proteomic profiling of organoids identifies the key drivers of functional effect by 16p11.2 CNV during neocortical development.
Project description:Copy number variations (CNVs) are abundant, possibly variable among populations, and can confer various phenotypic variations such as risk to complex disease. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes that originated from single sperm, and have advantages as materials over conventional diploid cells in detecting CNVs by hybridization, because greater S/N ratios are expected, and overlapping CNV segments are independently detected without being bothered by possible heterozygous situations. Overall occupancy of CNV segments per haploid found here was at a level similar to previous reports. Approximately a half of our polymorphic CNV regions have not been described in the previous report for Asians, but the frequencies of most of these new CNV regions were low. The limited number of examined samples is likely to be the reason that they have escaped detection in the previous report. Many common CNV regions are resolvable to clusters of CNV segmets (that is, CNV events) on the basis of mutual overlap of the segments. The similarity of haplotype backgrounds surrounding different CNV events within the same CNV regions suggests that ancestral recurrences of CNV events were predominantly haplotype preferential.
Project description:Copy number variations (CNVs) are abundant, possibly variable among populations, and can confer various phenotypic variations such as risk to complex disease. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes that originated from single sperm, and have advantages as materials over conventional diploid cells in detecting CNVs by hybridization, because greater S/N ratios are expected, and overlapping CNV segments are independently detected without being bothered by possible heterozygous situations. Overall occupancy of CNV segments per haploid found here was at a level similar to previous reports. Approximately a half of our polymorphic CNV regions have not been described in the previous report for Asians, but the frequencies of most of these new CNV regions were low. The limited number of examined samples is likely to be the reason that they have escaped detection in the previous report. Many common CNV regions are resolvable to clusters of CNV segmets (that is, CNV events) on the basis of mutual overlap of the segments. The similarity of haplotype backgrounds surrounding different CNV events within the same CNV regions suggests that ancestral recurrences of CNV events were predominantly haplotype preferential.
Project description:The genomic DNA sample of hPGES were compared to UCSC Human genome19 by CNV data. The data confirmed that the human parthenogenetic haploid ESCs sustained normal genome integrity
Project description:Trypanosoma cruzi is a protozoan parasite and the etiologic agent of Chagas disease, an important public health problem in Latin America. T. cruzi is diploid, almost exclusively asexual, and displays an extraordinarily diverse population structure both genetically and phenotypically. Yet, to date the genotypic diversity of T. cruzi and its relationship, if any, to biological diversity have not been studied at the whole genome level. In this study, we used whole genome oligonucleotide tiling arrays to compare gene content in biologically disparate T. cruzi strains by comparative genomic hybridization (CGH). We observed that T. cruzi strains display widespread and focal copy number variations (CNV) and a substantially greater level of diversity than can be adequately defined by the current genetic typing methods. As expected, CNV were particularly frequent in gene family-rich regions containing mucins and trans-sialidases but were also evident in core genes. Gene groups that showed little variation in copy numbers among the strains tested included those encoding protein kinases and ribosomal proteins, suggesting these loci were less permissive to CNV. Moreover, frequent variation in chromosome copy numbers were observed, and chromosome-specific CNV signatures were shared by genetically divergent T. cruzi strains, suggesting a greater degree of chromosome exchange than previously thought.
Project description:Immunoglobulin A Nephropathy (IgAN) is a complex multifactorial disease whose genetic bases remain unknown. Distinct linkage and genome-wide association studies in both familial and sporadic IgAN suggest that there is a strong genetic component in IgAN. In this context, an intriguing role could be ascribed to copy number variants (CNVs) that have been recognized as an important source of genetic variation in humans. Here, we performed a whole-genome screening of CNVs in IgAN patients, their healthy relatives and healthy subjects (HS). A total of 217 individuals consisting of 51 IgAN cases and 166 healthy relatives were included in the initial screening. The high-throughput analysis of structural genetic variations, to find concordant aberrations across classes of samples, identified 178 IgAN-specific aberrations, specifically 114 loss and 64 gain. Several CNVs overlapped with regions evidenced by previous genome-wide genetic studies. Moreover, we found that IgAN patients characterized by deteriorated renal function carried low copy numbers of a CNV in chromosome 3 (chr3_loss:52031010-52260722). This CNV contained the TLR9 gene whose expression significantly correlated with the loss aberration in patients with progressive renal damage. Conversely, IgAN patients with normal renal function had no chr3_loss:52031010-52260722 and the TLR9 mRNA was expressed at the same level as in HS, still maintaining a strong correlation with the CNV. In conclusion, here we performed the first genome-wide CNV study in IgAN identifying some structural variants specific to IgAN patients and providing a collection of new candidate genes and loci that could help to dissect the complex genomic setting of the disease. Moreover, we identified a specific CNV, spanning the TLR9 gene, which could explain the disease severity in IgAN patients.