|
| |
| | Polyploidy in plants |
 | | Having looked into some specific examples as to how polyploid was involved in some of the early speciation events in may be useful to review in brief some of the traditional views on polyploidy and restructuring of some of these which have been made possible by modern molecular techniques. | | | In a 39 year experiment with diploid and tetraploid Ehrharta erecta he found that the polyploid was inferior in behavior to their diploid ancestors under field conditions(29). | | | This is a more common route of polyploid formation from unreduced gametes (though the frequent sterility of most triploid hybrids has lead to a questioning of this method by some authors (13)) rather than the former one (13,19). |
|
http://www.as.wvu.edu/~kgarbutt/QuantGen/Gen535_2_2004/Polyploidy.html
(4736 words)
|
|
| |
| | Evolution: The Evolution of Polyploidy |
| | Therefore, some explanation is required as to how polyploids originate and evolve. | | | In the gymnosperms, for example, no polyploids have yet been found in ginkgo or in the cycads (Grant, 1971, p 225). | | | As such, different species need to be characterized and systematically analysed to determine what mechanisms are responsible for bringing about the observed polyploid frequencies and subsequent evolutionary patterns. |
|
http://www.geocities.com/we_evolve/Plants/polyploidy.html
(3218 words)
|
|
| |
| | Centre for Plant Biodiversity Research |
| | Several authors have pointed out that the pivotal studies that may lead us to learn more about the adaptive significance of polyploidy may be ecological studies of diploids and their polyploid derivatives. | | | The diploids give rise to polyploids through the processes of interspecific hybridization and backcrossing among themselves and probably through hybridization with facultatively sexual apomicts. | | | On the other hand the speciose Catipes group is regarded as being the most specialized lineage and it is from this group of sexual diploids that all the polyploid pillar complexes within the genus have been derived. |
|
http://www.anbg.gov.au/people/bayer1.html
(7095 words)
|
|
| |
| | SOLTIS, DOUGLAS E.* AND PAMELA S. SOLTIS. |
| | Despite these advances in our understanding of polyploidy, surprising little is known about the processes responsible for the origin of polyploids, the conditions that favor the establishment and coexistence of polyploid cytotypes in diploid populations, and the impact of polyploidy on plant-animal interactions. | | | Perhaps one of the most significant discoveries is that most polyploid species have originated repeatedly. | | | Several studies suggest, however, that polyploidy may result in changes in the interactions with pollinators; such changes could have important evolutionary implications. |
|
http://www.ou.edu/cas/botany-micro/bsa-abst/sympos1/abstracts/5.shtml
(264 words)
|
|
| |
| | Polyploid????????? - Edge Forums |
| | If you do enduce the polyploid cell condition then you have the next factor to consider which is passing the condition on to future offspring. | | | I've read a llot about polyploids and there is very little if anything besides warmke's that has any evidence of increase potency in poloyploids. | | | I could guess that his use of Colchicine acted as a mutagen and he had the luck of creating a highly potent mother, which had nothing to do with the Polyploid condition but someone else guessed that it was directly linked in some manner. |
|
http://www.overgrow.com/edge/showthread.php?t=47518&onlyuser=&perpage=15&highlight=polypoid?pagenumber=2
(5742 words)
|
|
| |
| | Population genetics - encyclopedia article about Population genetics. |
| | Typically, one refers to an individual's genotype with regard to a particular gene of interest and, in polyploid individuals, it refers to what combination of alleles the individual carries (see homozygous, heterozygous). |
|
http://encyclopedia.thefreedictionary.com/population+genetics
(2362 words)
|
|
| |
| | Polyploidy: From Evolution to Landscape Plant Improvement |
| | Despite the drawbacks of somatically induced polyploides, they may be valuable if they are in turn used in a breeding program to enhance the degree of heterozygosity and select for desirable traits. | | | A similar approach may have utility for enhancing tolerance to certain environmental stresses. | | | What is polyploidy and how does it arise? |
|
http://www.ces.ncsu.edu/fletcher/programs/nursery/metria/metria11/ranney/polyploidy.htm
(2880 words)
|
|
| |
| | UBC Department of Botany - People |
| | Our first objective is to examine phylogenetic relationships among diploid and polyploid members of the genus, using nucleotide sequence variation. | | | Through experimental manipulations and with the use of genetic markers, I hope to further our understanding of genetic and environmental factors that affect this balance. | | | The phylogeny will provide the framework for further experimental and comparative studies in the genus. |
|
http://www.botany.ubc.ca/people/whitton.htm
(981 words)
|
|
| |
| | Functional Genomics of Plant Polyploids |
| | Most importantly, they should reveal some of the major mechanisms giving rise to these changes, and illuminate our overall understanding of why polyploids have been so successful in nature and agriculture. | | | Although the importance of polyploidy has been widely recognized, the reasons for its success are not fully understood. | | | The theme of the proposed research is to investigate changes in gene expression and genome structure in resynthesized and natural autopolyploids and/or allopolyploids of Arabidopsis,Brassica and maize. |
|
http://polyploid.agronomy.wisc.edu/project.html
(469 words)
|
|
| |
| | EUROPA - Research - Quality of Life - Cell factory - Community funded projects |
| | Complementary approaches on the same material will enable accurate appraisal of the utility of each techniques in: (i) genotyping polyploid individuals; (ii) revealing hybrid identity, and; (iii) estimating the extent of introgression in natural populations. | | | The use of different complementary approaches on the same carefully sampled material will enable accurate appraisal of the usefulness of the different techniques in: | | | The evaluation of these techniques in hybridisation-related research will allow different end-users to apply this knowledge. |
|
http://europa.eu.int/comm/research/quality-of-life/cell-factory/volume1/projects/qlk3-2000-00227_en.html
(591 words)
|
|
| |
| | Soltis, Pamela S. |
| | This genetic diversity and the potential for change in turn undoubtedly contribute to the success of polyploids in nature. | | | - The genetic consequences of polyploidy: Keys to the success of polyploids in nature? | | | Botanists have long sought to explain the success of polyploid species, with increases in size, colonizing and/or competitive ability, biochemical diversity, and heterozygosity all suggested as possible reasons for the observed success of polyploids in nature. |
|
http://www.ou.edu/cas/botany-micro/bsa-abst/section5/abstracts/18.shtml
(305 words)
|
|
| |
| | Hurst - Creative Evolution |
| | Genetical experiments confirm this hypothesis so far as the characters of the diploid and polyploid species are concerned, but as yet duplication of the chromosomes in hybrid roses has not been observed under experimental conditions. | | | The polyploids arising from it are termed secondary polyploids. | | | With regard to the unequal polyploid species with unbalanced bivalent and univalent chromosomes: omitting those with more than one septet of bivalents which are natural hybrids and omitting triploids which are not found in a wild state as established species, 55 polyploid septet species are possible, viz. |
|
http://www.bulbnrose.com/Roses/Hurst/HURST.HTM
(2599 words)
|
|
| |
| | Glossary |
| | Term that applies to the condition of being polyploid. | | | Pattern of multiple anomalies often in different body areas resulting from disturbance of a single developmental field. | | | Many neoplastic cells are polyploid, and if the normal cells they are derived from were already polyploid, then the neoplastic cells have a higher degree of polyploidy (i.e. |
|
http://www.il-st-acad-sci.org/geneticsbook/help000p.html
(189 words)
|
|
| |
| | Polyploidy |
| | From 30% to 70% of today's angiosperms are thought to be polyploid. | | | 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 cells are larger than diploid ones; not surprising in view of the increased amount of DNA in their nucleus. |
|
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Polyploidy.html
(733 words)
|
|
| |
| | PG-II: MOLECULAR CYTOGENETIC MAPPING AND MANIPULATION OF THE POLYPLOID GENOMES: THE WHEAT MODEL |
| | Many classical techniques and research paradigms of polyploid genome analysis and chromosome manipulation were established in wheat. | | | The application of C-banding, in situ hybridization and RFLP mapping have laid the foundation for new research methodologies for polyploid genetics research. | | | Bread wheat, the world's most important crop plant, is also a model plant par excellence for genetic analysis of disomic polyploids (allopolyploids). |
|
http://www.intl-pag.org/2/abstracts/11pg2.html
(187 words)
|
|
| |
| | Re: What is it about plants that enables polyploid conditions? |
| | Re: What is it about plants that enables polyploid conditions? | | | Many amphibians are tetraploid, which is why frogs are a lousy genetic model organism despite their utility in studying development. | | | The current hot theory is that recombination is simply a process evolved to help hold the chromosome pairs together at the metaphase plate so that the chromosomes will segregate properly into the gametes during meiosis, and that the genetic effects of this process are merely byproducts. |
|
http://www.madsci.org/posts/archives/dec99/946001996.Ge.r.html
(869 words)
|
|
| |
| | American Journal of Botany, 31, 8, October, 1944 |
| | Other parts and organs of the epidermal-polyploids did not vary in size or shape from the parts and organs of diploids in any appreciable degree. | | | Stem or lateral-bud apexes were seldom changed totally into a polyploid condition by colchicine treatment. | | | The results emphasize that special propagation as well as treatment techniques must be employed to obtain polyploid forms from colchicine-treated material of such a semiwoody plant as cranberry, and presumably in the case of other semiwoody as well as woody plants. |
|
http://www.botany.org/ajb/00029122_di001425.html
(2088 words)
|
|
| |
| | Self Assessment Question # 3 for Lesson # 4 : Meiosis |
| | Yes, this is a long and difficult question but it is very important that you understand it and it's good practice! | | | how many chromosomes will each nucleus have after mitosis and are the nuclei haploid, diploid or polyploid. | | | how many chromosomes will each nucleus have after meiosis I and are the nuclei haploid, diploid or polyploid. |
|
http://www.synapses.co.uk/genetics/saq4_3.html
(510 words)
|
|
| |
| | The Polyploid Genome Porject |
| | A multivalent pairing model of linkage analysis in autotetraploids. | | | To facilitate the linkage analysis of polymorphic markers in polyploids that undergo different meiotic mechanisms, our genetic models will be developed specifically for bivalent, multivalent and mixed polyploids. | | | For bivalent polyploids, two chromosomes may occur more probably between two homologues than homoeologues, with a degree described by the preferential pairing factor. |
|
http://www.biostat.ufl.edu/~cma/polyploid
(435 words)
|
|
| |
| | Turfgrass genetic resistance to insects, polyploid Stenotaphrum secundatum St. Augustinegrass and virulent southern ... |
| | This study examined polyploid germplasm for resistance to the PDP southern chinch bug. | | | The Floratam- adapted southern chinch bug has been described as the polyploid damaging population (PDP), because polyploid germplasm had previously shown resistance. | | | Resistance of FX-33 was verified against PDP southern chinch bugs (representing laboratory colonies and field recollections) in mated pairs and congregations, and against southern chinch bugs that had received different prior food sources. |
|
http://grove.ufl.edu/~turf/refs/ref27.htm
(240 words)
|
|
| |
| | Gilding the Lily: Developments in Asiatic Hybrid Lilies |
| | Polyploids may arise in other ways as well. | | | From the point of view of a lily grower, however, the most important aspects of polyploid plants includes the bigger flowers, thicker petals and stronger stems which are often found on polyploid plants. | | | The word "polyploid" is a specific term which indicates that a plant has more than the normal quantity of genetic information. |
|
http://www.gardenline.usask.ca/misc/tetraplo.html
(913 words)
|
|
| |
| | Polyploid nuclei in human artery wall smooth muscle cells. |
| | Although polyploid nuclei have long been known to be present in many adult human tissues, the ploidy of smooth muscle cells in human artery wall has never been determined. | | | We suggest that the regular existence of a subset of polyploid smooth muscle cells may indicate an important functional role for this phenotype. | | | Polyploid nuclei in human artery wall smooth muscle cells. |
|
http://www.arclab.org/medlineupdates/abstract_6572376.html
(206 words)
|
|
| |
| | Instant Evolution |
| | Essentially all polyploids that have been tested have been found to have done so. | | | And these numbers may be low, for each time the Soltises use a more sensitive technique for testing, they find that there are more origins for each species than they had found previously. | | | One of the polyploids has arisen 20 separate times, the other 13 – all within just 60 years. |
|
http://www.wsu.edu/NIS/Universe/instant.html
(1118 words)
|
|
| |
| | Zeng Publication |
| | In this article, we use a maximum-likelihood method to develop a general polyploid model for estimating gene segregation patterns from molecular markers in a full-sib family derived from an arbitrary polyploid combining meiotic behaviors of both bivalent and multivalent pairings. | | | Simulation studies show that our polyploid model is well suited to estimate the preferential pairing factor and the frequency of double reduction at meiosis, which should help to characterize gene segregation in the progeny of autopolyploids. | | | For autopolyploids, however, all homologous chromosomes can pair at the same time so that multivalents and, therefore, double reductions are formed. |
|
http://www.cals.ncsu.edu/genetics/zeng/zz1.html
(239 words)
|
|
| |
| | ARS Publication request: Sequence Characterization of Microsatellites in Diploid and Polyploid Ipomoea |
| | Citation: Buteler, M.I. Jarret, R.L. Labonte, D.R. Sequence Characterization Of Microsatellites In Diploid And Polyploid Ipomoea. | | | However, in some cases insertions/deletions and base substitutions in the microsatellite flanking regions were responsible for polymorphisms in both, polyploid and diploid species. | | | These results provide strong empirical evidence that complex genetic mechanisms are responsible for SSR allelic variation in Ipomoea. |
|
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=105853
(312 words)
|
|
| |
| | Plant Materials |
| | Polyploids can be resynthesized from diploid species in such a way as to create very pure (homozygous) genetic stocks for analysis. | | | Autopolyploid series can be created for corn and hybrids can be made between polyploid genotypes, allowing us to study the relationship of polyploidy and heterosis. | | | The wealth of genetic stocks, biological information, and genomics resources available for this model organism will allow us to broadly and deeply explore the effects of polyploidy on plant function. |
|
http://polyploid.agronomy.wisc.edu/material.html
(218 words)
|
|
| |
| | The Cell Cycle in Polyploid Megakaryocytes Is Associated with Reduced Activity of Cyclin B1-dependent Cdc2 Kinase -- ... |
| | If so, our model of polyploid MegT cells with significantly reduced levels of cyclin B1 may be used for studying the roles of different mitosis-related kinases in endomitosis. | | | MegT cells which become polyploid upon inactivation of the oncogene were used to determine the role of different cyclins in promoting endomitosis. | | | Because of the leaky nature of this conditional oncogene, large T antigen may not have been completely destroyed in the rest of the cells which remained adhering to the dish. |
|
http://www.jbc.org/cgi/content/full/271/8/4266
(6636 words)
|
|
| |
| | Plant DNA C-Value Database Conference Abstracts |
| | Genome sequencing of Arabidopsis and Oryza suggests that both are polyploids. | | | Indeed, most angiosperms are considered to be polyploid. | | | This expectation is obeyed in many polyploid series, especially those newly formed, but examples are found where genome size in polyploids is smaller than expected. |
|
http://www.rbgkew.org.uk/cval/abstracts/cvalAbstract5.html
(251 words)
|
|
| |
| | morula |
| | In one common example, most animals and plants have tissues in which the cells become polyploid or polytene by means of an S-G cycle, but the mechanism by which mitosis is inhibited in the endo cycle is not understood. | | | The requirement of APC/C activity for the endo cycle leading to polyploid chromosomes that is observed in Drosophila may be a characteristic feature of endo cycles in many organisms. | | | This activity would explain why the APC/C becomes crucial in the nurse cells when the transition from polyteny to polyploidy occurs. |
|
http://www.sdbonline.org/fly/newgene/morula1.htm
(2436 words)
|
|
| |
| | Evolution: Summary: Polyploid Evolution |
| | The minority cytotype exclusion principle is a frequency-dependent process that must be overcome in order for rare polyploids to spread in a (randomly mating) parental diploid population. | | | There are a variety of factors that can influence polyploid establishment (e.g. | | | Triploids can act as a "bridge" between diploids and tetraploids, and therefore the level of triploid survival and fertility will influence polyploid establishment. |
|
http://www.geocities.com/we_evolve/Plants/polyploid_summary.html
(392 words)
|
|
| |
| | Plant Sciences, Moshe Feldman,Genetics and Evolution of Wheat |
| | Despite intensive studies over the last 80 years, little is known about the nature of genomic changes that occurred at the polyploid level and facilitated harmonious coexistence of the three genomes in the same nucleus. | | | Indeed, probing a wide range of newly-synthesized polyploids with these sequences showed that their elimination was a very rapid process occurring soon after polyploidization. | | | This indicates elimination of these specific sequences from some of the genomes at the polyploid level. |
|
http://www.weizmann.ac.il/plants/moshe/moshe.html
(790 words)
|
|
| |
| | Cucurbit Genetics Coop. 2:25-26 (1979) |
| | These observations are supported by a study of the dynamics of polyploid populations (12). | | | Numerous polyploid species are important crops that show superiority over their diploid progenitors, and natural polyploid species exhibit a much wider range of adaptation than their related diploids (6). | | | In morphological characters and seed productivity, there were no significant differences between the two kinds of tetraploids or the performance of the different triploid hybrids. |
|
http://www.umresearch.umd.edu/CGC/cgc2/cgc2_15.htm
(558 words)
|
|
| |
| | Animal -- Facts, Info, and Encyclopedia article |
| | These fuse to form (The cell resulting from the union of an ovum and a spermatozoon (including the organism that develops from that cell)) zygotes, which develop into new individuals. | | | Nearly all animals undergo some form of (Reproduction involving the union or fusion of a male and a female gamete) sexual reproduction. | | | Adults are ((genetics) an organism or cell having two sets of chromosomes or twice the haploid number) diploid or occasionally ((genetics) an organism or cell having more than twice the haploid number of chromosomes) polyploid. |
|
http://www.absoluteastronomy.com/encyclopedia/a/an/animal.htm
(2210 words)
|
|
| |
| | polyploid |
| | Plant breeders can induce the formation of polyploids by treatment with a chemical, colchicine. | | | Many crop plants are natural polyploids, including wheat, which has four sets of chromosomes per cell (durum wheat) or six sets (common wheat). | | | Helicon Publishing is a division of Research Machines plc. |
|
http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0008096.html
(144 words)
|
|
| |
| | Plant Hybrids #1 |
| | In addition, Niehaus states that "no meiotic irregularities or quadrivalents were observed in any polyploids." Normally homologous chromosomes pair up in 2's (bivalent) during synapsis of meiosis I. If homologous chromosomes associate in 4's rather than 2's, this is called a quadrivalent. | | | iehaus (1971) suggests that Brodiaea polyploids are alloploids (crosses between different species), but then suggests that autoploidy may also be present. | | | Aneuploid duckweeds often lack vigor and are sterile. |
|
http://waynesword.palomar.edu/hybrids1.htm
(6131 words)
|
|
| |
| | Animal - Open Encyclopedia |
| | During development it forms a relatively flexible framework upon which cells can move about and be reorganized, making a wide variety of complex structures possible. | | | In sexual reproduction animals produce small motile sperm and large non-motile ova by meiosis. | | | Most animals are diploid, but polyploid species are known. |
|
http://open-encyclopedia.com/Animal
(1953 words)
|
|
| |
| | polyploid - definition of polyploid by the Free Online Dictionary, Thesaurus and Encyclopedia. |
| | This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. | | | polyploid - (genetics) an organism or cell having more than twice the haploid number of chromosomes | | | polyploid - of a cell or organism having more than twice the haploid number of chromosomes; "a polyploid cell"; "a polyploid species" |
|
http://www.thefreedictionary.com/polyploid
(209 words)
|
|
|
