Search results for "polyploidy"
showing 10 items of 40 documents
Relationships of the Woody Medicago Species (Section Dendrotelis) Assessed by Molecular Cytogenetic Analyses
2008
†Background and Aims The organization of rDNA genes in the woody medic species from the agronomically important Medicago section Dendrotelis was analysed to gain insight into their taxonomic relationships, to assess the levels of infraspecific variation concerning ribosomal loci in a restricted and fragmented insular species (M. citrina) and to assess the nature of its polyploidy. †Methods Fluorescence in situ hybridization (FISH) was used for physical mapping of 5S and 45S ribosomal DNA genes in the three species of section Dendrotelis (M. arborea, M. citrina, M. strasseri) and the related M. marina from section Medicago. Genomic in situ hybridization (GISH) was used to assess the genomic …
Evolutionary site-number changes of ribosomal DNA loci during speciation: complex scenarios of ancestral and more recent polyploid events.
2015
Genes encoding ribosomal RNA are universal key constituents of eukaryotic genomes, but the number of loci varies between species. We assessed the evolutionary trends in site-number changes of rDNA loci during speciation in a lineage of the cabbage family, characterized by complex scenarios of polyploidy. Our results suggest the existence of constrictions to burst loci amplification in the 5S rDNA family in polyploids and an overall trend to further reduce their number. The 45S rDNA site change in polyploids tells a different story, implying loci amplification in most of the polyploid entities.
Chromosome numbers for the Italian flora: 11
2021
In this contribution, new chromosome data obtained on material collected in Italy are presented. It includes counts for Centaurea aegusae, Hieracium racemosum subsp. lucanum, H. australe subsp. australe, Lysimachia arvensis subsp. arvensis, Micromeria graeca subsp. graeca, and M. graeca subsp. consentina.
Targeting the chromosomal passenger complex subunit INCENP induces polyploidization, apoptosis and senescence in neuroblastoma
2019
Abstract Chromosomal passenger complex (CPC) has been demonstrated to be a potential target of cancer therapy by inhibiting Aurora B or survivin in different types of cancer including neuroblastoma. However, chemical inhibition of either Aurora B or survivin does not target CPC specifically due to off-target effects or CPC-independent activities of these two components. In a previous chromatin-focused siRNA screen, we found that neuroblastoma cells were particularly vulnerable to loss of INCENP, a gene encoding a key scaffolding component of the CPC. In this study, INCENP was highly expressed by neuroblastoma cells, and its expression decreased following retinoic acid–induced neuroblastoma …
Genomic instability in an interspecific hybrid of the genus Saccharomyces: a matter of adaptability
2020
Ancient events of polyploidy have been linked to huge evolutionary leaps in the tree of life, while increasing evidence shows that newly established polyploids have adaptive advantages in certain stress conditions compared to their relatives with a lower ploidy. The genus Saccharomyces is a good model for studying such events, as it contains an ancient whole-genome duplication event and many sequenced Saccharomyces cerevisiae are, evolutionary speaking, newly formed polyploids. Many polyploids have unstable genomes and go through large genome erosions; however, it is still unknown what mechanisms govern this reduction. Here, we sequenced and studied the natural S. cerevisiae × Saccharomyces…
Topoisomerase II inhibition and high yield of endoreduplication induced by the flavonoids luteolin and quercetin
2006
Luteolin and quercetin are widely distributed plant flavonoids that possess a variety of chemical and biological activities, including free-radical scavenging and antioxidant activity. Recently, both flavonoids have been reported to inhibit DNA topoisomerases I and II (topo I and topo II), a property that, together with their ability to induce DNA and chromosome damage, has made them candidate anticancer compounds. In the present study, we confirmed that both compounds are topo II inhibitors by conducting a comparative study of their effect on topo II activity from Chinese hamster ovary AA8 cells. Because interference with the function of topo II to resolve DNA entanglement at the end of re…
Allopolyploidisation in a geological collision zone: on the origin of the tetraploid Anthemis cupaniana Nyman (Compositae, Anthemideae) in Sicily
2022
AbstractThe genus Anthemis has a circum-Mediterranean distribution and comprises c. 175 annual, biennial, and perennial species with polyploid species and species complexes found in its section A. sect. Hiorthia. In Sicily, the genus is represented by 13 species, one of these being the tetraploid A. cupaniana, which is endemic to the island and is distributed throughout the limestone mountains at elevations between 500 and 1800 m a.s.l. Discordant positions in phylogenetic trees based on two plastid regions (psbA-trnH and trnC-petN) and on one nuclear marker (nrDNA ITS1 + 5.8S + ITS2) reveal that the species is of allopolyploid origin, with the maternal parent from the species group around …
Chromosomal rearrangements in childhood acute myeloid leukemia and myelodysplastic syndromes.
1999
Recurrent chromosomal abnormalities present in the malignant cells of children with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) often correlate closely with specific clinical and biologic characteristics of the disease. Certain unique cytogenetic rearrangements are associated with distinct morphologic leukemic subtypes. These rearrangements should be detectable in most children with AML and MDS with the use of complementary molecular techniques such as fluorescence in situ hybridization (FISH), Southern blotting, and polymerase chain reaction. Apart from the diagnostic assessment, cytogenetic findings sometimes predict clinical outcome and thus also serve as prognostic …
Amplified fragment length polymorphisms and sequence data in the phylogenetic analysis of polyploids: multiple origins of Veronica cymbalaria (Planta…
2007
Summary • The origin of polyploid Veronica cymbalaria (Plantaginaceae) was investigated using DNA sequence data and amplified fragment length polymorphism (AFLP) fingerprints to reveal the parentage of this taxon. The use of AFLP fingerprints in phylogenetic analysis is problematic and various methods have therefore been compared. • DNA sequence data (for the internal transcribed spacer (ITS) region and the plastid trnL-F region (trnL intron, 3’exon, and trnL-F spacer)) and polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis of the ITS region suggested a reliable hypothesis for the evolution of the V. cymbalaria complex. This hypothesis allowed evaluation …
Genetic and Ecotypic Differentiation in a Californian Plant Polyploid Complex (Grindelia, Asteraceae)
2014
Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae). W…