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Blake-Mahmud J, Sessa EB, Visger CJ, Watkins JE. Polyploidy and environmental stress response: a comparative study of fern gametophytes. THE NEW PHYTOLOGIST 2024. [PMID: 39044655 DOI: 10.1111/nph.19969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/24/2024] [Indexed: 07/25/2024]
Abstract
Climate change is rapidly altering natural habitats and generating complex patterns of environmental stress. Ferns are major components of many forest understories and, given their independent gametophyte generation, may experience unique pressures in emerging temperature and drought regimes. Polyploidy is widespread in ferns and may provide a selective advantage in these rapidly changing environments. This work aimed to understand whether the gametophytes of allopolyploid ferns respond differently to climate-related physiological stress than their diploid parents. The experimental approach involved a multifactorial design with 27 treatment combinations including exposure to multiple levels of drought and temperature over three treatment durations, with recovery measured at multiple timepoints. We measured Chl fluorescence from over 2000 gametophytes to evaluate stress avoidance and tolerance in diploid and polyploid species. Polyploids generally showed a greater ability to avoid and/or tolerate a range of stress conditions compared with their diploid counterparts, suggesting that polyploidy may confer enhanced flexibility and resilience under climate stress. Overall, these results suggest that polyploidy may provide some resilience to climate change in mixed ploidy populations. However, all species remain susceptible to the impacts of extreme drought and heat stress.
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Affiliation(s)
| | - Emily B Sessa
- William & Lynda Steere Herbarium, New York Botanical Garden, Bronx, NY, 10458, USA
| | - Clayton J Visger
- Department of Biological Sciences, California State University, Sacramento, CA, 95819, USA
| | - James E Watkins
- Department of Biology, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
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2
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Pungaršek Š, Frajman B. Influence of polyploidy on morphology and distribution of the Cypress Spurge (Euphorbia cyparissias, Euphorbiaceae). PLANT BIOLOGY (STUTTGART, GERMANY) 2024. [PMID: 38979801 DOI: 10.1111/plb.13685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/26/2024] [Indexed: 07/10/2024]
Abstract
Polyploidy can cause differences in phenotypic and physiological traits among different cytotypes of the same species. Polyploids may have larger organs or occupy different ecological niches than their diploid counterparts, therefore they are hypothesized to have larger distributions or prosper in stressful environments, such as higher elevations. The Cypress spurge (Euphorbia cyparissias L.; Euphorbiaceae) is a widespread European heteroploid species including di- (2x), tetra- (4x) and hexaploid (6x) cytotypes. We tested the hypotheses that polyploids are more widespread and more abundant at higher elevations and have larger organs than their diploid ancestors in the case of E. cyparissias. We also analysed whether genome downsizing had occurred after polyploidisation. We conducted a comprehensive geographic sampling of 617 populations of E. cyparissias throughout Europe. We estimated their relative genome size using flow cytometry and inferred ploidy level of each population. We scored 13 morphological traits of vegetative and seed characters and performed statistical analyses. The study indicates that polyploidisation facilitated colonisation of new areas in E. cyparissias, where the tetraploids are most widespread, whereas the diploids are limited to putative Pleistocene refugia, mostly in southern Europe. On the other hand, the three ploidies do not differ in their elevational distribution. Although some quantitative morphological traits exhibited an increasing trend with increasing ploidy, most traits did not differ significantly among the three ploidies, and there was no overall phenotypic differentiation among them. Given that individuals of different ploidies thrive in similar habitats across the same elevations, we suggest that ecological segregation following polyploidisation is a more important trigger for morphological differentiation than polyploidisation itself in autopolyploid plants. The study demonstrates that polyploidisation can be crucial for the colonisation of new areas and for range expansion, but it does not necessarily influence elevational distribution nor confer a different phenotype.
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Affiliation(s)
- Š Pungaršek
- Department of Botany, University of Innsbruck, Innsbruck, Austria
- Slovenian Museum of Natural History, Ljubljana, Slovenia
| | - B Frajman
- Department of Botany, University of Innsbruck, Innsbruck, Austria
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3
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Othmani A, Hamza H, Kadri K, Sellemi A, Leus L, Werbrouck SPO. The Promising Potential of Triploidy in Date Palm ( Phoenix dactylifera L.) Breeding. PLANTS (BASEL, SWITZERLAND) 2024; 13:815. [PMID: 38592841 PMCID: PMC10975707 DOI: 10.3390/plants13060815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/28/2024] [Accepted: 03/07/2024] [Indexed: 04/11/2024]
Abstract
Date palms are a vital part of oasis ecosystems and are an important source of income in arid and semi-arid areas. Crossbreeding is limited due to the long juvenile stage of date palms and their dioecious nature. The aim of this study was to create triploid date palms to obtain larger and seedless fruits and to increase resilience to abiotic stresses. A tetraploid date palm mutant was crossed with a diploid male palm, yielding hundreds of seeds suspected of containing triploid embryos. Six years after planting, four palms with confirmed triploidy reached maturity. They are phenotypically distinct from diploids, with a thicker rachis, thinner spines, wider and longer midleaf spines, and a longer apical spine. They were classified as sterile bisexual, sterile male and fertile female. One of the latter produced very tasty dates with a very small seed, which is promising for the marketability and profitability of date palm fruits. This first report on triploid date palms provides a way in which to make a significant leap forward in date palm breeding. Given the vigor and fruit quality of female triploid date palms, compared to their diploid counterparts, they will be the target of breeding programs and may spearhead new oases.
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Affiliation(s)
- Ahmed Othmani
- Laboratory for In Vitro Tissue Culture, Regional Centre for Research in Oasis Agriculture, Tozeur Km1, Degueche 2260, Tunisia; (A.O.); (A.S.)
- LR21AGR03-Production and Protection for Sustainable Horticulture (2-PHD), Regional Research Centre on Horticulture and Organic Agriculture Chott Mariem, University of Sousse, Sousse 4042, Tunisia
| | - Hammadi Hamza
- Arid and Oasis Cropping Laboratory, Institute of Arid Lands, Medenine 4119, Tunisia;
| | - Karim Kadri
- Biotechnology and Genetic Resources Laboratory, Regional Centre for Research in Oasis Agriculture, BO 62, Degueche 2260, Tunisia;
- Laboratory of Biotechnology Applied to Agriculture, National Institute for Agronomic Research of Tunis, University of Carthage Tunis, Ariana 2049, Tunisia
| | - Amel Sellemi
- Laboratory for In Vitro Tissue Culture, Regional Centre for Research in Oasis Agriculture, Tozeur Km1, Degueche 2260, Tunisia; (A.O.); (A.S.)
| | - Leen Leus
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Caritasstraat 39, 9090 Melle, Belgium;
| | - Stefaan P. O. Werbrouck
- Department of Plant & Crops, Faculty of Bioscience Engineering, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium
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4
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Xia F, Li B, Song K, Wang Y, Hou Z, Li H, Zhang X, Li F, Yang L. Polyploid Genome Assembly Provides Insights into Morphological Development and Ascorbic Acid Accumulation of Sauropus androgynus. Int J Mol Sci 2023; 25:300. [PMID: 38203470 PMCID: PMC10778994 DOI: 10.3390/ijms25010300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Sauropus androgynus (S. androgynus) (2n = 4x = 52) is one of the most popular functional leafy vegetables in South and Southeast Asia. With its rich nutritional and pharmaceutical values, it has traditionally had widespread use for dietary and herbal purposes. Here, the genome of S. androgynus was sequenced and assembled, revealing a genome size of 1.55 Gb with 26 pseudo-chromosomes. Phylogenetic analysis traced back the divergence of Sauropus from Phyllanthus to approximately 29.67 million years ago (Mya). Genome analysis revealed that S. androgynus polyploidized around 20.51 Mya and shared a γ event about 132.95 Mya. Gene function analysis suggested that the expansion of pathways related to phloem development, lignin biosynthesis, and photosynthesis tended to result in the morphological differences among species within the Phyllanthaceae family, characterized by varying ploidy levels. The high accumulation of ascorbic acid in S. androgynus was attributed to the high expression of genes associated with the L-galactose pathway and recycling pathway. Moreover, the expanded gene families of S. androgynus exhibited multiple biochemical pathways associated with its comprehensive pharmacological activity, geographic adaptation and distinctive pleasurable flavor. Altogether, our findings represent a crucial genomic asset for S. androgynus, casting light on the intricate ploidy within the Phyllanthaceae family.
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Affiliation(s)
- Fagang Xia
- Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (F.X.); (Y.W.)
- Key Laboratory of Biological Breeding for Fujian and Taiwan Crops, Ministry of Agriculture and Rural Affairs, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Bin Li
- Agricultural Big-Data Research Center, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China; (B.L.); (K.S.); (H.L.); (X.Z.)
| | - Kangkang Song
- Agricultural Big-Data Research Center, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China; (B.L.); (K.S.); (H.L.); (X.Z.)
| | - Yankun Wang
- Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (F.X.); (Y.W.)
- Key Laboratory of Biological Breeding for Fujian and Taiwan Crops, Ministry of Agriculture and Rural Affairs, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhuangwei Hou
- Guangdong Provincial Key Laboratory of Plant Molecular Breeding, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China;
| | - Haozhen Li
- Agricultural Big-Data Research Center, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China; (B.L.); (K.S.); (H.L.); (X.Z.)
| | - Xiaohua Zhang
- Agricultural Big-Data Research Center, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China; (B.L.); (K.S.); (H.L.); (X.Z.)
| | - Fangping Li
- Guangdong Provincial Key Laboratory of Plant Molecular Breeding, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China;
| | - Long Yang
- Agricultural Big-Data Research Center, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China; (B.L.); (K.S.); (H.L.); (X.Z.)
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5
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Yan X, Chen X, Li Y, Li Y, Wang F, Zhang J, Ning G, Bao M. The Abundant and Unique Transcripts and Alternative Splicing of the Artificially Autododecaploid London Plane ( Platanus × acerifolia). Int J Mol Sci 2023; 24:14486. [PMID: 37833935 PMCID: PMC10572260 DOI: 10.3390/ijms241914486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/14/2023] [Accepted: 09/16/2023] [Indexed: 10/15/2023] Open
Abstract
Transcription and alternative splicing (AS) are now appreciated in plants, but few studies have examined the effects of changing ploidy on transcription and AS. In this study, we showed that artificially autododecaploid plants of London plane (Platanus × acerifolia (Aiton) Willd) had few flowers relative to their hexaploid progenitors. Transcriptome analysis based on full-length Oxford Nanopore Technologies (ONTs) and next-generation sequencing (NGS) revealed that the increased ploidy level in P. × acerifolia led to more transcribed isoforms, accompanied by an increase in the number of isoforms per gene. The functional enrichment of genes indicated that novel genes transcribed specifically in the dodecaploids may have been highly correlated with the ability to maintain genome stability. The dodecaploids showed a higher number of genes with upregulated differentially expressed genes (DEGs) compared with the hexaploid counterpart. The genome duplication of P. × acerifolia resulted mainly in the DEGs involved in basic biological pathways. It was noted that there was a greater abundance of alternative splicing (AS) events and AS genes in the dodecaploids compared with the hexaploids in P. × acerifolia. In addition, a significant difference between the structure and expression of AS events between the hexaploids and dodecaploids of Platanus was found. Of note, some DEGs and differentially spliced genes (DSGs) related to floral transition and flower development were consistent with the few flower traits in the dodecaploids of P. × acerifolia. Collectively, our findings explored the difference in transcription and AS regulation between the hexaploids and dodecaploids of P. × acerifolia and gained new insight into the molecular mechanisms underlying the few-flower phenotype of P. × acerifolia. These results contribute to uncovering the regulatory role of transcription and AS in polyploids and breeding few-flower germplasms.
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Affiliation(s)
| | | | | | | | | | | | | | - Manzhu Bao
- National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China; (X.Y.); (J.Z.)
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6
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Zong D, Qiao Z, Zhou J, Li P, Gan P, Ren M, He C. Chloroplast genome sequence of triploid Toxicodendron vernicifluum and comparative analyses with other lacquer chloroplast genomes. BMC Genomics 2023; 24:56. [PMID: 36721120 PMCID: PMC9887819 DOI: 10.1186/s12864-023-09154-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/27/2023] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Toxicodendron vernicifluum, belonging to the family Anacardiaceae, is an important commercial arbor species, which can provide us with the raw lacquer, an excellent adhesive and painting material used to make lacquer ware. Compared with diploid, triploid lacquer tree has a higher yield of raw lacquer and stronger resistance to stress. Triploid T. vernicifluum was a newly discovered natural triploid lacquer tree. However, the taxonomy of triploid T. vernicifluum has remained uncertain. Here, we sequenced and analyzed the complete chloroplast (cp) genome of triploid T. vernicifluum and compared it with related species of Toxicodendron genus based on chloroplast genome and SSR markers. RESULTS The plastome of triploid T. vernicifluum is 158,221 bp in length, including a pair of inverted repeats (IRs) of 26,462 bp, separated by a large single-copy region of 86,951 bp and a small single-copy region of 18,346 bp. In total, 132 genes including 87 protein-coding genes, 37 tRNA genes and 8 rRNA genes were identified in the triploid T. vernicifluum. Among these, 16 genes were duplicated in the IR regions, 14 genes contain one intron, while three genes contain two introns. After nucleotide substitutions, seven small inversions were analyzed in the chloroplast genomes, eight hotspot regions were found, which could be useful molecular genetic markers for future population genetics. Phylogenetic analyses showed that triploid T. vernicifluum was a sister to T. vernicifluum cv. Dahongpao and T. vernicifluum cv. Hongpigaobachi. Moreover, phylogenetic clustering based on the SSR markers showed that all the samples of triploid T. vernicifluum, T. vernicifluum cv. Dahongpao and T. vernicifluum cv. Hongpigaobachi in one group, while the samples of T. vernicifluum and T. succedaneum in another group, which is consistent with the cp genome and morphological analysis. CONCLUSIONS The current genomic datasets provide pivotal genetic resources to determine the phylogenetic relationships, variety identification, breeding and resource exploitation, and future genetic diversity-related studies of T. vernicifluum.
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Affiliation(s)
- Dan Zong
- grid.412720.20000 0004 1761 2943Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory for Forest Genetics and Tree Improvement & Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming, China
| | - Zhensheng Qiao
- grid.412720.20000 0004 1761 2943Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory for Forest Genetics and Tree Improvement & Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming, China
| | - Jintao Zhou
- grid.412720.20000 0004 1761 2943Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory for Forest Genetics and Tree Improvement & Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming, China
| | - Peiling Li
- grid.412720.20000 0004 1761 2943Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory for Forest Genetics and Tree Improvement & Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming, China
| | - Peihua Gan
- grid.412720.20000 0004 1761 2943Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory for Forest Genetics and Tree Improvement & Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming, China
| | - Meirong Ren
- grid.412720.20000 0004 1761 2943Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming, China
| | - Chengzhong He
- grid.412720.20000 0004 1761 2943Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory for Forest Genetics and Tree Improvement & Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming, China ,grid.412720.20000 0004 1761 2943Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming, China
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7
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Williams JH. Consequences of whole genome duplication for 2n pollen performance. PLANT REPRODUCTION 2021; 34:321-334. [PMID: 34302535 DOI: 10.1007/s00497-021-00426-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 07/17/2021] [Indexed: 06/13/2023]
Abstract
The vegetative cell of the angiosperm male gametophyte (pollen) functions as a free-living, single-celled organism that both produces and transports sperm to egg. Whole-genome duplication (WGD) should have strong effects on pollen because of the haploid to diploid transition and because of both genetic and epigenetic effects on cell-level phenotypes. To disentangle historical effects of WGD on pollen performance, studies can compare 1n pollen from diploids to neo-2n pollen from diploids and synthetic autotetraploids to older 2n pollen from established neo-autotetraploids. WGD doubles both gene number and bulk nuclear DNA mass, and a substantial proportion of diploid and autotetraploid heterozygosity can be transmitted to 2n pollen. Relative to 1n pollen, 2n pollen can exhibit heterosis due to higher gene dosage, higher heterozygosity and new allelic interactions. Doubled genome size also has consequences for gene regulation and expression as well as epigenetic effects on cell architecture. Pollen volume doubling is a universal effect of WGD, whereas an increase in aperture number is common among taxa with simultaneous microsporogenesis and pored apertures, mostly eudicots. WGD instantly affects numerous evolved compromises among mature pollen functional traits and these are rapidly shaped by highly diverse tissue interactions and pollen competitive environments in the early post-WGD generations. 2n pollen phenotypes generally incur higher performance costs, and the degree to which these are met or evolve by scaling up provisioning and metabolic vigor needs further study.
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Affiliation(s)
- Joseph H Williams
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA.
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8
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Glazier DS. Genome Size Covaries More Positively with Propagule Size than Adult Size: New Insights into an Old Problem. BIOLOGY 2021; 10:270. [PMID: 33810583 PMCID: PMC8067107 DOI: 10.3390/biology10040270] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022]
Abstract
The body size and (or) complexity of organisms is not uniformly related to the amount of genetic material (DNA) contained in each of their cell nuclei ('genome size'). This surprising mismatch between the physical structure of organisms and their underlying genetic information appears to relate to variable accumulation of repetitive DNA sequences, but why this variation has evolved is little understood. Here, I show that genome size correlates more positively with egg size than adult size in crustaceans. I explain this and comparable patterns observed in other kinds of animals and plants as resulting from genome size relating strongly to cell size in most organisms, which should also apply to single-celled eggs and other reproductive propagules with relatively few cells that are pivotal first steps in their lives. However, since body size results from growth in cell size or number or both, it relates to genome size in diverse ways. Relationships between genome size and body size should be especially weak in large organisms whose size relates more to cell multiplication than to cell enlargement, as is generally observed. The ubiquitous single-cell 'bottleneck' of life cycles may affect both genome size and composition, and via both informational (genotypic) and non-informational (nucleotypic) effects, many other properties of multicellular organisms (e.g., rates of growth and metabolism) that have both theoretical and practical significance.
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Waselkov K, Santiago M, Heidel B, Mayfield MH, Ferguson CJ. Population Genetics of the Wyoming Endemic Phlox pungens Dorn (Polemoniaceae). WEST N AM NATURALIST 2020. [DOI: 10.3398/064.080.0309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | - Mercedes Santiago
- Herbarium and Division of Biology, Kansas State University, Manhattan, KA 66506
| | - Bonnie Heidel
- Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY 82071
| | - Mark H. Mayfield
- Herbarium and Division of Biology, Kansas State University, Manhattan, KA 66506
| | - Carolyn J. Ferguson
- Herbarium and Division of Biology, Kansas State University, Manhattan, KA 66506
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10
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Dobeš C, Steccari I, Köstenberger S, Lompo D. Relative genome size variation in the African agroforestry tree Parkia biglobosa (Fabaceae: Caesalpinioideae) and its relation to geography, population genetics, and morphology. Genome 2019; 62:665-676. [PMID: 31306046 DOI: 10.1139/gen-2019-0069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Variation in genome size and in chromosome number can be linked to genetic, morphological, and ecological characteristics, and thus be taxonomically significant. We screened the relative genome size (RGS) and counted the number of mitotic chromosomes in the African agroforestry tree Parkia biglobosa, a widely distributed savannah species that shows conspicuous morphological clinal variation and strong genetic structure, and tested for linkage of RGS variation to geography, leaf morphology, and population genetic variation. An improved protocol for the preparation of chromosomes was developed. The study is based on 58 individuals from 15 populations covering most of the distribution range of the species. We observed differences in RGS among individuals of up to 10.2%, with some of the individuals differing statistically in RGS from the bulk of screened individuals. Most of the RGS variation was within populations, whereas variation was unrelated to any of the tested features of the species. Those chromosome numbers that could be exactly established were invariable 2n = 2x = 26. In conclusion, there was no evidence from the karyological data for structured intraspecific taxonomic heterogeneity.
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Affiliation(s)
- Christoph Dobeš
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, A-1131 Vienna
| | - Irene Steccari
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, A-1131 Vienna
| | - Selina Köstenberger
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, A-1131 Vienna
| | - Djingdia Lompo
- Centre National de Semences Forestieres, 01 BP 2682, Route de Kossodo, Ouagadougou, Burkina Faso
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11
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Bigl K, Paule J, Dobeš C. The morphometrics of autopolyploidy: insignificant differentiation among sexual-apomictic cytotypes. AOB PLANTS 2019; 11:plz028. [PMID: 31198530 PMCID: PMC6548344 DOI: 10.1093/aobpla/plz028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/11/2019] [Accepted: 05/22/2019] [Indexed: 06/09/2023]
Abstract
Polyploidization of the plant genome affects the phenotype of individuals including their morphology, i.e. size and form. In autopolyploids, we expect mainly nucleotypic effects, from a number of monoploid genomes (i.e. chromosome sets) or genome size, seen from an increase in size or dimension of the polyploids compared with the diploids (or lower ploids). To identify nucleotypic effects, confounding effects of hybridity (observed in allopolyploids), postpolyploidization processes or environmental effects need to be considered. We morphometrically analysed five ploidy cytotypes of the sexual-apomictic species Potentilla puberula cultivated ex situ under the same experimental conditions. Sexuals are mainly tetraploid, while higher ploidy (penta- to octoploidy) is typically associated with the expression of apomixis. The cytotypes likely arose via autopolyploidization although historic involvement of another species in the origin of apomicts cannot be fully ruled out, suggested by a slight molecular differentiation among reproductive modes. We (i) revisited molecular differentiation using amplified fragment length polymorphisms and performed a morphometric analysis to test (ii) if cytotypes are morphologically differentiated from each other and (iii) if the size of individuals is related to their ploidy. Weak molecular differentiation of sexual versus apomictic individuals was confirmed. Cytotypes and reproductive modes were also morphologically poorly differentiated from each other, i.e. apomicts largely resampled the variation of the sexuals and did not exhibit a unique morphology. Overall size of individuals increased moderately but significantly with ploidy (ca. 14 % in the comparison of octo- with tetraploids). The results support an autopolyploid origin of the P. puberula apomicts and suggest a nucleotypic effect on overall plant size. We discuss taxonomic consequences of the results in the context of data on reproductive relationships among cytotypes and their ecological preferences and evolutionary origin, and conclude that cytotypes are best treated as intraspecific variants within a single species.
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Affiliation(s)
- Karin Bigl
- Department of Pharmacognosy, Pharmacobotany, University of Vienna, Althanstrasse, Vienna, Austria
| | - Juraj Paule
- Department of Botany and Molecular Evolution, Senckenberg Research Institute & Natural History Museum Frankfurt, Senckenberganlage, Frankfurt/Main, Germany
| | - Christoph Dobeš
- Department of Pharmacognosy, Pharmacobotany, University of Vienna, Althanstrasse, Vienna, Austria
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12
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MacKintosh C, Ferrier DEK. Recent advances in understanding the roles of whole genome duplications in evolution. F1000Res 2017; 6:1623. [PMID: 28928963 PMCID: PMC5590085 DOI: 10.12688/f1000research.11792.2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2018] [Indexed: 01/21/2023] Open
Abstract
Ancient whole-genome duplications (WGDs)- paleopolyploidy events-are key to solving Darwin's 'abominable mystery' of how flowering plants evolved and radiated into a rich variety of species. The vertebrates also emerged from their invertebrate ancestors via two WGDs, and genomes of diverse gymnosperm trees, unicellular eukaryotes, invertebrates, fishes, amphibians and even a rodent carry evidence of lineage-specific WGDs. Modern polyploidy is common in eukaryotes, and it can be induced, enabling mechanisms and short-term cost-benefit assessments of polyploidy to be studied experimentally. However, the ancient WGDs can be reconstructed only by comparative genomics: these studies are difficult because the DNA duplicates have been through tens or hundreds of millions of years of gene losses, mutations, and chromosomal rearrangements that culminate in resolution of the polyploid genomes back into diploid ones (rediploidisation). Intriguing asymmetries in patterns of post-WGD gene loss and retention between duplicated sets of chromosomes have been discovered recently, and elaborations of signal transduction systems are lasting legacies from several WGDs. The data imply that simpler signalling pathways in the pre-WGD ancestors were converted via WGDs into multi-stranded parallelised networks. Genetic and biochemical studies in plants, yeasts and vertebrates suggest a paradigm in which different combinations of sister paralogues in the post-WGD regulatory networks are co-regulated under different conditions. In principle, such networks can respond to a wide array of environmental, sensory and hormonal stimuli and integrate them to generate phenotypic variety in cell types and behaviours. Patterns are also being discerned in how the post-WGD signalling networks are reconfigured in human cancers and neurological conditions. It is fascinating to unpick how ancient genomic events impact on complexity, variety and disease in modern life.
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Affiliation(s)
- Carol MacKintosh
- Division of Cell and Developmental Biology, University of Dundee, Dundee, Scotland, DD1 5EH, UK
| | - David E K Ferrier
- The Scottish Oceans Institute, University of St Andrews, Scotland, KY16 8LB, UK
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