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Nature Reviews. Genetics Jul 2017Polyploidy, or the duplication of entire genomes, has been observed in prokaryotic and eukaryotic organisms, and in somatic and germ cells. The consequences of... (Review)
Review
Polyploidy, or the duplication of entire genomes, has been observed in prokaryotic and eukaryotic organisms, and in somatic and germ cells. The consequences of polyploidization are complex and variable, and they differ greatly between systems (clonal or non-clonal) and species, but the process has often been considered to be an evolutionary 'dead end'. Here, we review the accumulating evidence that correlates polyploidization with environmental change or stress, and that has led to an increased recognition of its short-term adaptive potential. In addition, we discuss how, once polyploidy has been established, the unique retention profile of duplicated genes following whole-genome duplication might explain key longer-term evolutionary transitions and a general increase in biological complexity.
Topics: Adaptation, Biological; Animals; Biological Evolution; Humans; Phylogeny; Plants; Polyploidy
PubMed: 28502977
DOI: 10.1038/nrg.2017.26 -
Annual Review of Physiology Feb 2020In mammals, most cardiomyocytes (CMs) become polyploid (they have more than two complete sets of chromosomes). The purpose of this review is to evaluate assumptions... (Review)
Review
In mammals, most cardiomyocytes (CMs) become polyploid (they have more than two complete sets of chromosomes). The purpose of this review is to evaluate assumptions about CM ploidy that are commonly discussed, even if not experimentally demonstrated, and to highlight key issues that are still to be resolved. Topics discussed here include () technical and conceptual difficulties in defining a polyploid CM, () the candidate role of reactive oxygen as a proximal trigger for the onset of polyploidy, () the relationship between polyploidization and other aspects of CM maturation, () recent insights related to the regenerative role of the subpopulation of CMs that are not polyploid, and () speculations as to why CMs become polyploid at all. New approaches to experimentally manipulate CM ploidy may resolve some of these long-standing and fundamental questions.
Topics: Cell Proliferation; Humans; Myocardium; Myocytes, Cardiac; Polyploidy; Regeneration
PubMed: 31585517
DOI: 10.1146/annurev-physiol-021119-034618 -
Seminars in Liver Disease Nov 2023The liver's unique chromosomal variations, including polyploidy and aneuploidy, influence hepatocyte identity and function. Among the most well-studied mammalian... (Review)
Review
The liver's unique chromosomal variations, including polyploidy and aneuploidy, influence hepatocyte identity and function. Among the most well-studied mammalian polyploid cells, hepatocytes exhibit a dynamic interplay between diploid and polyploid states. The ploidy state is dynamic as hepatocytes move through the "ploidy conveyor," undergoing ploidy reversal and re-polyploidization during proliferation. Both diploid and polyploid hepatocytes actively contribute to proliferation, with diploids demonstrating an enhanced proliferative capacity. This enhanced potential positions diploid hepatocytes as primary drivers of liver proliferation in multiple contexts, including homeostasis, regeneration and repopulation, compensatory proliferation following injury, and oncogenic proliferation. This review discusses the influence of ploidy variations on cellular activity. It presents a model for ploidy-associated hepatocyte proliferation, offering a deeper understanding of liver health and disease with the potential to uncover novel treatment approaches.
Topics: Animals; Humans; Liver Regeneration; Liver; Hepatocytes; Cell Proliferation; Polyploidy; Mammals
PubMed: 37967885
DOI: 10.1055/a-2211-2144 -
Genomics, Proteomics & Bioinformatics Jun 2020Lycophytes and seed plants constitute the typical vascular plants. Lycophytes have been thought to have no paleo-polyploidization although the event is known to be...
Lycophytes and seed plants constitute the typical vascular plants. Lycophytes have been thought to have no paleo-polyploidization although the event is known to be critical for the fast expansion of seed plants. Here, genomic analyses including the homologous gene dot plot analysis detected multiple paleo-polyploidization events, with one occurring approximately 13-15 million years ago (MYA) and another about 125-142 MYA, during the evolution of the genome of Selaginella moellendorffii, a model lycophyte. In addition, comparative analysis of reconstructed ancestral genomes of lycophytes and angiosperms suggested that lycophytes were affected by more paleo-polyploidization events than seed plants. Results from the present genomic analyses indicate that paleo-polyploidization has contributed to the successful establishment of both lineages-lycophytes and seed plants-of vascular plants.
Topics: Evolution, Molecular; Genome, Plant; Genomics; Phylogeny; Polyploidy; Selaginellaceae
PubMed: 33157303
DOI: 10.1016/j.gpb.2020.10.002 -
Development (Cambridge, England) Jul 2018Polyploid cells, which contain multiple copies of the typically diploid genome, are widespread in plants and animals. Polyploidization can be developmentally programmed... (Review)
Review
Polyploid cells, which contain multiple copies of the typically diploid genome, are widespread in plants and animals. Polyploidization can be developmentally programmed or stress induced, and arises from either cell-cell fusion or a process known as endoreplication, in which cells replicate their DNA but either fail to complete cytokinesis or to progress through M phase entirely. Polyploidization offers cells several potential fitness benefits, including the ability to increase cell size and biomass production without disrupting cell and tissue structure, and allowing improved cell longevity through higher tolerance to genomic stress and apoptotic signals. Accordingly, recent studies have uncovered crucial roles for polyploidization in compensatory cell growth during tissue regeneration in the heart, liver, epidermis and intestine. Here, we review current knowledge of the molecular pathways that generate polyploidy and discuss how polyploidization is used in tissue repair and regeneration.
Topics: Animals; Cell Division; DNA Replication; Humans; Organ Specificity; Polyploidy; Regeneration; Stress, Physiological
PubMed: 30021843
DOI: 10.1242/dev.156034 -
Seminars in Cancer Biology Jun 2022Polyploidy, a cell status defined as more than two sets of genomic DNA, is a conserved strategy across species that can increase cell size and biosynthetic production,... (Review)
Review
Polyploidy, a cell status defined as more than two sets of genomic DNA, is a conserved strategy across species that can increase cell size and biosynthetic production, but the functional aspects of polyploidy are nuanced and vary across cell types. Throughout Drosophila developmental stages (embryo, larva, pupa and adult), polyploid cells are present in numerous organs and help orchestrate development while contributing to normal growth, well-being and homeostasis of the organism. Conversely, increasing evidence has shown that polyploid cells are prevalent in Drosophila tumors and play important roles in tumor growth and invasiveness. Here, we summarize the genes and pathways involved in polyploidy during normal and tumorigenic development, the mechanisms underlying polyploidization, and the functional aspects of polyploidy in development, homeostasis and tumorigenesis in the Drosophila model.
Topics: Animals; DNA; Drosophila; Homeostasis; Humans; Neoplasms; Polyploidy
PubMed: 34562587
DOI: 10.1016/j.semcancer.2021.09.011 -
Current Opinion in Plant Biology Oct 2022Recent advances in the genomics of polyploid species answer some of the long-standing questions about the role of polyploidy in crop species. Here, we summarize the... (Review)
Review
Recent advances in the genomics of polyploid species answer some of the long-standing questions about the role of polyploidy in crop species. Here, we summarize the current literature to reexamine scenarios in which polyploidy played a role both before and after domestication. The prevalence of polyploidy can help to explain environmental robustness in agroecosystems. This review also clarifies the molecular basis of some agriculturally advantageous traits of polyploid crops, including yield increments in polyploid cotton via subfunctionalization, modification of a separated sexuality to selfing in polyploid persimmon via neofunctionalization, and transition to a selfing system via nonfunctionalization combined with epistatic interaction between duplicated S-loci. The rapid progress in genomics and genetics is discussed along with how this will facilitate functional studies of understudied polyploid crop species.
Topics: Crops, Agricultural; Domestication; Genome, Plant; Genomics; Polyploidy
PubMed: 35870416
DOI: 10.1016/j.pbi.2022.102255 -
The Journal of Heredity Mar 2018Though polyploidy is an important aspect of the evolutionary genetics of both plants and animals, the development of population genetic theory of polyploids has... (Review)
Review
Though polyploidy is an important aspect of the evolutionary genetics of both plants and animals, the development of population genetic theory of polyploids has seriously lagged behind that of diploids. This is unfortunate since the analysis of polyploid genetic data-and the interpretation of the results-requires even more scrutiny than with diploid data. This is because of several polyploidy-specific complications in segregation and genotyping such as tetrasomy, double reduction, and missing dosage information. Here, we review the theoretical and statistical aspects of the population genetics of polyploids. We discuss several widely used types of inferences, including genetic diversity, Hardy-Weinberg equilibrium, population differentiation, genetic distance, and detecting population structure. For each, we point out how the statistical approach, expected result, and interpretation differ between different ploidy levels. We also discuss for each type of inference what biases may arise from the polyploid-specific complications and how these biases can be overcome. From our overview, it is clear that the statistical toolbox that is available for the analysis of genetic data is flexible and still expanding. Modern sequencing techniques will soon be able to overcome some of the current limitations to the analysis of polyploid data, though the techniques are lagging behind those available for diploids. Furthermore, the availability of more data may aggravate the biases that can arise, and increase the risk of false inferences. Therefore, simulations such as we used throughout this review are an important tool to verify the results of analyses of polyploid genetic data.
Topics: Animals; Cluster Analysis; Gene Frequency; Genetic Variation; Genetics, Population; Heterozygote; Models, Genetic; Multivariate Analysis; Polyploidy; Reproduction
PubMed: 29385510
DOI: 10.1093/jhered/esy006 -
Seminars in Cancer Biology Jun 2022Polyploid somatic cells have 'programmed' roles in normal development and stress responses. Transient polyploidy states have been observed in several tumor types at... (Review)
Review
Polyploid somatic cells have 'programmed' roles in normal development and stress responses. Transient polyploidy states have been observed in several tumor types at early stages of tumorigenesis. They can give rise to the aneuploidy state which is a common feature of human cancer cells. Similarly, to cancer development, cancer treatment can lead to transient polyploidy. Polyploid giant cells (PGCCs) in cancer are often associated with poor prognosis and disease relapse. Cancer cell senescence- a proliferation arrest accompanied by a set of characteristic markers- induced by therapy is also associated with transient polyploidy formation and cancer relapse. The question is whether therapy-induced senescence (TIS) and therapy induced polyploidy (TIP) are mechanistically or coincidentally connected. This problem needs to be solved rather urgently, because TIS appears to be more common phenomena than originally believed. Another arising question concerns reversibility of cancer cell senescence as a consequence of atypical divisions of polyploid cells. In our review we will try to answer this fundamental question by referring to published literature and to our own studies.
Topics: Carcinogenesis; Cellular Senescence; Giant Cells; Humans; Neoplasm Recurrence, Local; Polyploidy
PubMed: 33271316
DOI: 10.1016/j.semcancer.2020.11.015 -
Trends in Cell Biology Jun 2018To battle adverse internal and external conditions and maintain homeostasis, diploid organisms employ various cellular processes, such as proliferation and apoptosis. In... (Review)
Review
To battle adverse internal and external conditions and maintain homeostasis, diploid organisms employ various cellular processes, such as proliferation and apoptosis. In some tissues, an alternative mechanism, endoreplication, is employed toward similar goals. Endoreplication is an evolutionarily conserved cell cycle program during which cells replicate their genomes without division, resulting in polyploid cells. Importantly, endoreplication is reported to be indispensable for normal development and organ formation across various organisms, from fungi to humans. In recent years, more attention has been drawn to delineating its connections to wound healing and tumorigenesis. In this Review, we discuss mechanisms of endoreplication and polyploidization, their essential and positive roles in normal development and tissue homeostasis, and the relationship between polyploidy and cancer.
Topics: Cell Cycle; Cell Differentiation; Cell Division; Endoreduplication; Homeostasis; Humans; Neoplasms; Polyploidy
PubMed: 29567370
DOI: 10.1016/j.tcb.2018.02.006