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Nature Communications Jun 2024Polyploidy, the result of whole-genome duplication (WGD), is a major driver of eukaryote evolution. Yet WGDs are hugely disruptive mutations, and we still lack a clear...
Polyploidy, the result of whole-genome duplication (WGD), is a major driver of eukaryote evolution. Yet WGDs are hugely disruptive mutations, and we still lack a clear understanding of their fitness consequences. Here, we study whether WGDs result in greater diversity of genomic structural variants (SVs) and how they influence evolutionary dynamics in a plant genus, Cochlearia (Brassicaceae). By using long-read sequencing and a graph-based pangenome, we find both negative and positive interactions between WGDs and SVs. Masking of recessive mutations due to WGDs leads to a progressive accumulation of deleterious SVs across four ploidal levels (from diploids to octoploids), likely reducing the adaptive potential of polyploid populations. However, we also discover putative benefits arising from SV accumulation, as more ploidy-specific SVs harbor signals of local adaptation in polyploids than in diploids. Together, our results suggest that SVs play diverse and contrasting roles in the evolutionary trajectories of young polyploids.
Topics: Polyploidy; Genome, Plant; Evolution, Molecular; Gene Duplication; Genomic Structural Variation; Mutation
PubMed: 38918389
DOI: 10.1038/s41467-024-49679-y -
Scientific Reports Jun 2024Haploid induction (HI) holds great promise in expediting the breeding process in onion, a biennial cross-pollinated crop. We used the CENH3-based genome elimination...
Haploid induction (HI) holds great promise in expediting the breeding process in onion, a biennial cross-pollinated crop. We used the CENH3-based genome elimination technique in producing a HI line in onion. Here, we downregulated AcCENH3 using the RNAi approach without complementation in five independent lines. Out of five events, only three could produce seeds upon selfing. The progenies showed poor seed set and segregation distortion, and we were unable to recover homozygous knockdown lines. The knockdown lines showed a decrease in accumulation of AcCENH3 transcript and protein in leaf tissue. The decrease in protein content in transgenic plants was correlated with poor seed set. When the heterozygous knockdown lines were crossed with wild-type plants, progenies showed HI by genome elimination of the parental chromosomes from AcCENH3 knockdown lines. The HI efficiency observed was between 0 and 4.63% in the three events, and it was the highest (4.63%) when E1 line was crossed with wildtype. Given the importance of doubled haploids in breeding programmes, the findings from our study are poised to significantly impact onion breeding.
Topics: Onions; RNA Interference; Plants, Genetically Modified; Haploidy; Plant Proteins; Gene Expression Regulation, Plant; Down-Regulation; Plant Breeding; Gene Knockdown Techniques
PubMed: 38914600
DOI: 10.1038/s41598-024-64432-7 -
Gene Jun 2024Products from stingless bees are rich reservoirs of microbial diversity, including yeasts with fermentative potential. Previously, two Saccharomyces cerevisiae strains,...
Products from stingless bees are rich reservoirs of microbial diversity, including yeasts with fermentative potential. Previously, two Saccharomyces cerevisiae strains, JP14 and IP9, were isolated from Jataí (Tetragonisca angustula) and Iraí (Nannotrigona testaceicornis) bees, respectively, aiming at mead production. Both strains presented great osmotic and sulfite tolerance, and ethanol production, although they have a high free amino nitrogen demand. Herein, their genomes were sequenced, assembled, and annotated, and the variants were compared to the S. cerevisiae S288c reference strain. The final assembly of IP9 and JP14 presented high N50 and BUSCO scores, and more than 6430 protein-coding genes. Additionally, nQuire predicted the ploidy of IP9 as diploid, but the results were not enough to determine the ploidy of JP14. The mitochondrial genomes of IP9 and JP14 presented the same gene content as S288c but the genes were rearranged and fragmentedin different patterns. Meanwhile, the genes with mutations of high impact (e.g., indels, gain of stop codon) for both yeasts were enriched for transmembrane transport, electron transfer, oxidoreductase, heme binding, fructose, mannose, and glucose transport, activities related to the respiratory chain and sugar metabolism. The IP9 strain presented copy number gains in genes related to sugar transport and cell morphogenesis; in JP14, genes were enriched for disaccharide metabolism and transport, response to reactive oxygen species, and polyamine transport. On the other hand, IP9 presented copy number losses related to disaccharide, thiamine, and aldehyde metabolism, while JP14 presented depletions related to disaccharide, oligosaccharide, asparagine, and aspartate metabolism. Notably, both strains presented a killer toxin gene, annotated from the assembling of unmapped reads, representing a potential mechanism for the control of other microorganisms population in the environment. Therefore, the annotated genomes of JP14 and IP9 presented a high selective pressure for sugar and nitrogen metabolism and stress response, consistent with their isolation source and fermentative properties.
PubMed: 38914244
DOI: 10.1016/j.gene.2024.148722 -
Methods in Molecular Biology (Clifton,... 2024Across eukaryotes, genome stability is essential for normal cell function, physiology, and species survival. Aberrant expression of key genes or exposure to genotoxic...
Across eukaryotes, genome stability is essential for normal cell function, physiology, and species survival. Aberrant expression of key genes or exposure to genotoxic agents can have detrimental effects on genome stability and contribute to the development of various diseases, including cancer. Chromosome instability (CIN), or ongoing changes in chromosome complements, is a frequent form of genome instability observed in cancer and is a driver of genetic and cell-to-cell heterogeneity that can be rapidly detected and quantitatively assessed using surrogate markers of CIN. For example, single cell quantitative imaging microscopy (QuantIM) can be used to simultaneously identify changes in nuclear areas and micronucleus formation. While changes in nuclear areas are often associated with large-scale changes in chromosome complements (i.e., ploidy), micronuclei are small extra-nuclear bodies found outside the primary nucleus that have previously been employed as a measure of genotoxicity of test compounds. Here, we present a facile QuantIM approach that allows for the rapid assessment and quantification of CIN associated phenotypes and genotoxicity. First, we provide protocols to optimize and execute CIN and genotoxicity assays. Secondly, we present the critical imaging settings, optimization steps, downstream statistical analyses, and data visualization strategies employed to obtain high quality and robust data. These approaches can be easily applied to assess the prevalence of CIN associated phenotypes and genotoxic stress for a myriad of experimental and clinical contexts ranging from direct tests to large-scale screens of various genetic contexts (i.e., aberrant gene expression) or chemical compounds. In summary, this QuantIM approach facilitates the identification of novel CIN genes and/or genotoxic agents that will provide greater insight into the aberrant genes and pathways underlying CIN and genotoxicity.
Topics: Chromosomal Instability; Single-Cell Analysis; Humans; DNA Damage; Microscopy; Mutagenicity Tests; Cell Nucleus; Mutagens; Micronucleus Tests
PubMed: 38913318
DOI: 10.1007/978-1-0716-3946-7_18 -
Methods in Molecular Biology (Clifton,... 2024Solid tumors and tumor-derived cell lines commonly contain highly enlarged (giant) cancer cells that enter a state of transient dormancy (active sleep) after they are...
Solid tumors and tumor-derived cell lines commonly contain highly enlarged (giant) cancer cells that enter a state of transient dormancy (active sleep) after they are formed, but retain viability, secrete growth promoting factors, and exhibit the ability to generate rapidly proliferating progeny with stem cell-like properties. Giant cells with a highly enlarged nucleus or multiple nuclei are often called polyploid giant cancer cells (PGCCs). Although PGCCs constitute only a subset of cells within a solid tumor/tumor-derived cell line, their frequency can increase markedly following exposure to ionizing radiation or chemotherapeutic drugs. In this chapter we outline a simple and yet highly sensitive cell-based assay, called single-cell MTT, that we have optimized for determining the viability and metabolic activity of PGCCs before and after exposure to anticancer agents. The assay measures the ability of individual PGCCs to convert the MTT tetrazolium salt to its water insoluble formazan metabolite. In addition to evaluating PGCCs, this assay is also a powerful tool for determining the viability and metabolic activity of cancer cells undergoing premature senescence following treatment with anticancer agents, as well as for distinguishing dead cancer cells and dying cells (e.g., exhibiting features of apoptosis, ferroptosis, etc.) that have the potential to resume proliferation through a process called anastasis.
Topics: Humans; Polyploidy; Cell Survival; Giant Cells; Cell Line, Tumor; Single-Cell Analysis; Tetrazolium Salts; Neoplasms; Antineoplastic Agents; Cell Proliferation
PubMed: 38913317
DOI: 10.1007/978-1-0716-3946-7_17 -
Methods in Molecular Biology (Clifton,... 2024Polyploid giant cancer cells (PGCCs) play a fundamental role in tumor initiation, dormancy, drug resistance, and metastasis, although the detailed biology of PGCCs...
Polyploid giant cancer cells (PGCCs) play a fundamental role in tumor initiation, dormancy, drug resistance, and metastasis, although the detailed biology of PGCCs remains poorly understood. The lack of literature on establishing a reproducible in vitro system for generating PGCCs is the leading technological obstacle to studying the biology of PGCCs. Here we provide a detailed protocol for generating stable PGCCs from Hey cancer cells and studying the PGCCs' embryonic stemness. This protocol includes (1) generating PGCCs of high purity in 2D culture by exposing Hey cells to paclitaxel, monitoring the cell cycle and amitotic budding of daughter cells from PGCCs, and collecting and studying the daughter cells; (2) inducing PGCCs to form spheroids expressing embryonic stemness markers and observing the spheroids' cleavage and blastocyst-like structure; and (3) inducing redifferentiation of PGCCs into different lineages of differentiated cells.
Topics: Humans; Polyploidy; Ovarian Neoplasms; Female; Cell Line, Tumor; Cell Differentiation; Giant Cells; Cell Culture Techniques; Neoplastic Stem Cells; Spheroids, Cellular; Paclitaxel; Cell Cycle
PubMed: 38913316
DOI: 10.1007/978-1-0716-3946-7_16 -
Frontiers in Genetics 2024ATP-BINDING CASSETTE SUBFAMILY E MEMBER (ABCE) proteins are one of the most conserved proteins across eukaryotes and archaea. Yeast and most animals possess a single...
ATP-BINDING CASSETTE SUBFAMILY E MEMBER (ABCE) proteins are one of the most conserved proteins across eukaryotes and archaea. Yeast and most animals possess a single gene encoding the critical translational factor ABCE1. In several plant species, including and , two or more gene copies have been identified, however information related to plant gene family is still missing. In this study we retrieved gene sequences of 76 plant species from public genome databases and comprehensively analyzed them with the reference to gene (). Using bioinformatic approach we assessed the conservation and phylogeny of plant ABCEs. In addition, we performed haplotype analysis of and its paralogue using genomic sequences of 1,135 ecotypes. Plant ABCE proteins showed overall high sequence conservation, sharing at least 78% of amino acid sequence identity with AtABCE2. We found that over half of the selected species have two to eight genes, suggesting that in plants genes can be classified as a low-copy gene family, rather than a single-copy gene family. The phylogenetic trees of ABCE protein sequences and the corresponding coding sequences demonstrated that and families have independently undergone lineage-specific split of the ancestral gene. Other plant species have gained gene copies through more recent duplication events. We also noticed that ploidy level but not ancient whole genome duplications experienced by a species impacts gene family size. Deeper analysis of and from 1,135 ecotypes revealed four and 35 non-synonymous SNPs, respectively. The lower natural variation in compared to is in consistence with its crucial role for plant viability. Overall, while the sequence of the ABCE protein family is highly conserved in the plant kingdom, many plants have evolved to have more than one copy of this essential translational factor.
PubMed: 38911295
DOI: 10.3389/fgene.2024.1408665 -
Scientific Data Jun 2024Synthetic hexaploid wheats (SHWs) are effective genetic resources for transferring agronomically important genes from wild relatives to common wheat (Triticum aestivum...
Synthetic hexaploid wheats (SHWs) are effective genetic resources for transferring agronomically important genes from wild relatives to common wheat (Triticum aestivum L.). Dozens of reference-quality pseudomolecule assemblies of hexaploid wheat have been generated, but none is reported for SHW-derived cultivars. Here, we generated a chromosome-scale assembly for the SHW-derived cultivar 'Chuanmai 104' based on PacBio HiFi reads and chromosome conformation capture sequencing. The total assembly size was 14.81 Gb with a contig N50 length of 58.25 Mb. A BUSCO analysis yielded a completeness score of 99.30%. In total, repetitive elements comprised 81.36% of the genome and 122,554 high-confidence protein-coding gene models were predicted. In summary, the first chromosome-level assembly for a SHW-derived cultivar presents a promising outlook for the study and utilization of SHWs in wheat improvement, which is essential to meet the global food demand.
Topics: Triticum; Chromosomes, Plant; Genome, Plant; Polyploidy
PubMed: 38909086
DOI: 10.1038/s41597-024-03527-2 -
Journal of Agricultural and Food... Jun 2024Wheat species with various ploidy levels may be different regarding their immunoreactive potential in celiac disease (CD), but a comprehensive comparison of peptide...
Wheat species with various ploidy levels may be different regarding their immunoreactive potential in celiac disease (CD), but a comprehensive comparison of peptide sequences with known epitopes is missing. Thus, we used an untargeted liquid chromatography tandem mass spectrometry method to analyze the content of peptides with CD-active epitope in the five wheat species common wheat, spelt, durum wheat, emmer, and einkorn. In total, 494 peptides with CD-active epitope were identified. Considering the average of the eight cultivars of each species, spelt contained the highest number of different peptides with CD-active epitope (193 ± 12, mean ± SD). Einkorn showed the smallest variability of peptides (63 ± 4) but higher amounts of certain peptides compared to the other species. The wheat species differ in the presence and distribution of CD-active epitopes; hence, the entirety of peptides with CD-active epitope is crucial for the assessment of their immunoreactive potential.
PubMed: 38906536
DOI: 10.1021/acs.jafc.4c02657 -
Genome Biology Jun 2024Copy number variation (CNV) is a key genetic characteristic for cancer diagnostics and can be used as a biomarker for the selection of therapeutic treatments. Using data...
BACKGROUND
Copy number variation (CNV) is a key genetic characteristic for cancer diagnostics and can be used as a biomarker for the selection of therapeutic treatments. Using data sets established in our previous study, we benchmark the performance of cancer CNV calling by six most recent and commonly used software tools on their detection accuracy, sensitivity, and reproducibility. In comparison to other orthogonal methods, such as microarray and Bionano, we also explore the consistency of CNV calling across different technologies on a challenging genome.
RESULTS
While consistent results are observed for copy gain, loss, and loss of heterozygosity (LOH) calls across sequencing centers, CNV callers, and different technologies, variation of CNV calls are mostly affected by the determination of genome ploidy. Using consensus results from six CNV callers and confirmation from three orthogonal methods, we establish a high confident CNV call set for the reference cancer cell line (HCC1395).
CONCLUSIONS
NGS technologies and current bioinformatics tools can offer reliable results for detection of copy gain, loss, and LOH. However, when working with a hyper-diploid genome, some software tools can call excessive copy gain or loss due to inaccurate assessment of genome ploidy. With performance matrices on various experimental conditions, this study raises awareness within the cancer research community for the selection of sequencing platforms, sample preparation, sequencing coverage, and the choice of CNV detection tools.
Topics: Humans; DNA Copy Number Variations; High-Throughput Nucleotide Sequencing; Software; Neoplasms; Computational Biology; Loss of Heterozygosity; Diploidy; Genome, Human; Cell Line, Tumor; Reproducibility of Results; Sequence Analysis, DNA
PubMed: 38902799
DOI: 10.1186/s13059-024-03294-8