Polyploid

This page has been archived and polyploid no longer updated.

Polyploidy has been hypothesized to be both an evolutionary dead-end and a source for evolutionary innovation and species diversification. Although polyploid organisms, especially plants, abound, the apparent nonrandom long-term establishment of genome duplications suggests a link with environmental conditions. Whole-genome duplications seem to correlate with periods of extinction or global change, while polyploids often thrive in harsh or disturbed environments. Evidence is also accumulating that biotic interactions, for instance, with pathogens or mutualists, affect polyploids differently than nonpolyploids. Here, we review recent findings and insights on the effect of both abiotic and biotic stress on polyploids versus nonpolyploids and propose that stress response in general is an important and even determining factor in the establishment and success of polyploidy.

Polyploid

Federal government websites often end in. The site is secure. Polyploidy, which results from whole-genome duplication, is a fundamental complement to vertical copying. Both organismal and cell polyploidy can emerge via premature cell cycle exit or via cell-cell fusion, the latter giving rise to polyploid hybrid organisms and epigenetic hybrids of somatic cells. Polyploidy-related increase in biological plasticity, adaptation, and stress resistance manifests in evolution, development, regeneration, aging, oncogenesis, and cardiovascular diseases. Despite the prevalence in nature and importance for medicine, agri- and aquaculture, biological processes and epigenetic mechanisms underlying these fundamental features largely remain unknown. The evolutionarily conserved features of polyploidy include activation of transcription, response to stress, DNA damage and hypoxia, and induction of programs of morphogenesis, unicellularity, and longevity, suggesting that these common features confer adaptive plasticity, viability, and stress resistance to polyploid cells and organisms. By increasing cell viability, polyploidization can provide survival under stressful conditions where diploid cells cannot survive. However, in somatic cells it occurs at the expense of specific function, thus promoting developmental programming of adult cardiovascular diseases and increasing the risk of cancer. Notably, genes arising via evolutionary polyploidization are heavily involved in cancer and other diseases. Ploidy-related changes of gene expression presumably originate from chromatin modifications and the derepression of bivalent genes. The provided evidence elucidates the role of polyploidy in evolution, development, aging, and carcinogenesis, and may contribute to the development of new strategies for promoting regeneration and preventing cardiovascular diseases and cancer.

The mechanism regulating pairing in Polyploid timopheevii. The involvement of genomic duplication in the regulation of developmental programs, life expectancy, and adaptation to stress indicates the importance of polyploid in the physiological and pathological processes, which affect postnatal morphogenesis and adaptation including developmental programming of widespread diseases, polyploid, tissue regeneration, and carcinogenesis.

Federal government websites often end in. The site is secure. Most, if not all, green plant Virdiplantae species including angiosperms and ferns are polyploids themselves or have ancient polyploid or whole genome duplication signatures in their genomes. Polyploids are not only restricted to our major crop species such as wheat, maize, potato and the brassicas, but also occur frequently in wild species and natural habitats. Polyploidy has thus been viewed as a major driver in evolution, and its influence on genome and chromosome evolution has been at the centre of many investigations.

Cells and their owners are polyploid if they contain more than two haploid n sets of chromosomes; that is, their chromosome number is some multiple of n greater than the 2n content of diploid cells. For example, triploid 3n and tetraploid cell 4n cells are polyploid. Polyploidy is very common in plants, especially in angiosperms. Species of coffee plant with 22, 44, 66, and 88 chromosomes are known. This suggests that the ancestral condition was a plant with a haploid n number of 11 and a diploid 2n number of 22, from which evolved the different polyploid descendants.

Polyploid

Federal government websites often end in. The site is secure. Despite the wide-reaching importance of polyploidy, communication across disciplinary boundaries to identify common themes at different scales has been almost non-existent. However, a critical need remains to understand commonalities that derive from shared polyploid cellular processes across organismal diversity, levels of biological organization, and fields of inquiry — from biodiversity and biocomplexity to medicine and agriculture. Here, we review the current understanding of polyploidy at the organismal and sub-organismal levels, identify shared research themes and elements, and propose new directions to integrate research on polyploidy toward confronting interdisciplinary grand challenges of the 21 st century. Polyploidy whole-genome duplication; WGD, see glossary , defined as having three or more sets of chromosomes, influences organisms in all clades of eukaryotic life and all levels of biological organization, from genes to cells to entire ecosystems Fig. The intersection of these axes of biodiversity and biological scale offers new opportunity for insight and research innovation. Yet, polyploidy remains underexplored in many contexts, and its roles and impact in biological processes and across phylogeny are unclear.

Reels rockstars

Notably, in response to various biotic interactions that involve penetration of the plant tissue, endoreduplication results in the upregulation of some host genes that normally regulate cell cycle and cellular hypertrophy, suggesting that the involved effectors are generic reactions to cell stress Smant et al. Plant J 82 : — Asymmetrical changes of gene expression, small RNAs and chromatin in two resynthesized wheat allotetraploids. Cytogenetic relationships within the Maghrebian clade of Festuca subgen. Chromosoma , 31— Cell Sci. The circumstances and the extent to which polyploidy might confer a selective advantage under stressful conditions, however, as well as the mechanisms underlying the responses to stress-related phenomena, might differ greatly and clearly need further study Fox et al. Kimmel G. Prieto, P. Conclusions Polyploidy is widespread in whole organisms and individual cells of multicellular tissues. Nat Rev Genet 18 : — Lineage-specific rediploidization is a mechanism to explain time-lags between genome duplication and evolutionary diversification. Or Browse Visually. Forrester, C N.

Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer.

Crow, J. Another advantage conferred by gene redundancy is the ability to diversify gene function over time. Bibcode : NatCo.. Figure 2. The main contradiction of multicellularity stems from its evolutionary origin, as it is between the cellular and organismal levels [ 12 ]. Cell Biol. Desplats P. Pathways Leading to Polyploidy There are several routes leading to the formation of a polyploid individual. Nature Reviews Genetics 6 , link to article. Nucleic Acids Res. Scitable Chat. DNA Research. The incentive for depoliploidization is stress, associated with starvation or aging [ ]. Doyle JJ Phylogenetic perspectives on the origins of nodulation. Plant Cell 12 ,