634 results match your criteria rdna telomeric


First Record of a B Chromosome in Polybia fastidiosuscula Saussure (Vespidae) and Investigation of Chromatin Composition Through Microsatellite Mapping.

Cytogenet Genome Res 2020 22;160(11-12):711-718. Epub 2021 Mar 22.

Laboratório de Citogenética de Insetos, Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Brazil,

The characterization of karyotypes is an important aspect in understanding the structure and evolution of genomes. Polybia is a genus of social wasps of the family Vespidae. This genus has 58 species, but for only 8 of these chromosome number and morphology have been reported in the literature. Read More

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Bloom syndrome and the underlying causes of genetic instability.

Authors:
Mouna Ababou

Mol Genet Metab 2021 Mar 10. Epub 2021 Mar 10.

Laboratory of Human Pathologies Biology, Department of Biology, Faculty of Sciences, University Mohammed V, Rabat, Morocco; Genomic Center of Human Pathologies, Faculty of medicine and Pharmacy, University Mohammed V, Rabat, Morocco. Electronic address:

Autosomal hereditary recessive diseases characterized by genetic instability are often associated with cancer predisposition. Bloom syndrome (BS), a rare genetic disorder, with <300 cases reported worldwide, combines both. Indeed, patients with Bloom's syndrome are 150 to 300 times more likely to develop cancers than normal individuals. Read More

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Molecular cytogenetic analysis of a triploid population of the human broad tapeworm, (Diphyllobothriidea).

Parasitology 2021 Mar 8:1-11. Epub 2021 Mar 8.

Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, České Budějovice37005, Czech Republic.

The large-sized tapeworm Dibothriocephalus latus is known as the broad or fish-borne cestode of mammals that is capable to infect humans and cause diphyllobothriosis. Recently, molecular data on D. latus has been accumulating in the literature and a complete genome sequence has been published; however, little is known about the karyotype and chromosome architecture. Read More

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Comparative FISH analysis of Senna tora tandem repeats revealed insights into the chromosome dynamics in Senna.

Genes Genomics 2021 Mar 3;43(3):237-249. Epub 2021 Mar 3.

Department of Chemistry and Life Science, Bioscience Institute, Sahmyook University, Seoul, 01795, Republic of Korea.

Background: DNA tandem repeats (TRs) are often abundant and occupy discrete regions in eukaryotic genomes. These TRs often cause or generate chromosomal rearrangements, which, in turn, drive chromosome evolution and speciation. Tracing the chromosomal distribution of TRs could therefore provide insights into the chromosome dynamics and speciation among closely related taxa. Read More

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Cytogenetic Analysis in Trigona spinipes Fabricius (Hymenoptera, Meliponina) Reveals Intraspecific Variation.

Neotrop Entomol 2021 Mar 1. Epub 2021 Mar 1.

Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil.

Trigona spinipes Fabricius is a stingless bee with wide geographical distribution. Although being sometimes considered an agricultural pest, in fact, it has great pollinating potential, and therefore economic interest. Conventional and molecular cytogenetic techniques have been little used to verify genetic diversity in this species, despite its potential to reveal information about the reorganization of the genome having been demonstrated in other species. Read More

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Chromosomal Mapping of Tandem Repeats Revealed Massive Chromosomal Rearrangements and Insights Into Dysploidy.

Front Plant Sci 2021 10;12:629898. Epub 2021 Feb 10.

Department of Chemistry and Life Science, BioScience Institute, Sahmyook University, Seoul, South Korea.

Tandem repeats can occupy a large portion of plant genomes and can either cause or result from chromosomal rearrangements, which are important drivers of dysploidy-mediated karyotype evolution and speciation. To understand the contribution of tandem repeats in shaping the extant dysploid karyotype, we analyzed the composition and abundance of tandem repeats in the genome and compared the chromosomal distribution of these repeats between and a closely related euploid, . Using a read clustering algorithm, we identified the major tandem repeats and visualized their chromosomal distribution by fluorescence hybridization. Read More

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February 2021

Chromosomal Diversity in Two Allopatric Populations of Meinken 1937 (Teleostei: Siluriformes): Cytogenetics and Cytochrome Analyses.

Zebrafish 2021 Feb 3;18(1):66-72. Epub 2021 Feb 3.

Programa de Pós-Graduação em Biologia Comparada, Universidade Estadual de Maringá, Maringá, Brazil.

is the second richest genus in Loricariinae, broadly distributed in freshwater streams and rivers of South America. In this article, we aimed to expand on the cytogenetic and molecular data available for two allopatric populations of . Both populations had diploid chromosome number 58, but with karyotype differences, indicative of chromosomal rearrangements. Read More

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February 2021

EPIGENETIC MODIFICATION UNDER THE INFLUENCE OF PEPTIDE BIOREGULATORS ON "AGED" HETEROCHROMATIN.

Georgian Med News 2020 Dec(309):120-124

1Tbilisi State University, Department of Genetics; 2Tbilisi State University, Institute of Genetics; Georgia.

Following the completion of the Human Genome Project, the strategic direction of modern genetics has moved toward functional genomics, to explore the functions of non-coding regions of DNA. These non-coding regions are localized in heterochromatin. The functions of heterochromatin largely remain unclear. Read More

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December 2020

Repression of a large number of genes requires interplay between homologous recombination and HIRA.

Nucleic Acids Res 2021 02;49(4):1914-1934

Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, 840 05 Bratislava, Slovakia.

During homologous recombination, Dbl2 protein is required for localisation of Fbh1, an F-box helicase that efficiently dismantles Rad51-DNA filaments. RNA-seq analysis of dbl2Δ transcriptome showed that the dbl2 deletion results in upregulation of more than 500 loci in Schizosaccharomyces pombe. Compared with the loci with no change in expression, the misregulated loci in dbl2Δ are closer to long terminal and long tandem repeats. Read More

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February 2021

Cytogenetic Analysis of the Asian Box Turtles of the Genus (Testudines, Geoemydidae).

Genes (Basel) 2021 Jan 25;12(2). Epub 2021 Jan 25.

Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic.

The Asian box turtle genus currently comprises 13 species with a wide distribution in Southeast Asia, including China and the islands of Indonesia and Philippines. The populations of these species are rapidly declining due to human pressure, including pollution, habitat loss, and harvesting for food consumption. Notably, the IUCN Red List identifies almost all species of the genus as Endangered (EN) or Critically Endangered (CR). Read More

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January 2021

Fission Yeast Methylenetetrahydrofolate Reductase Ensures Mitotic and Meiotic Chromosome Segregation Fidelity.

Int J Mol Sci 2021 Jan 11;22(2). Epub 2021 Jan 11.

Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore.

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the folate metabolic pathway, and its loss of function through polymorphisms is often associated with human conditions, including cancer, congenital heart disease, and Down syndrome. MTHFR is also required in the maintenance of heterochromatin, a crucial determinant of genomic stability and precise chromosomal segregation. Here, we characterize the function of a fission yeast gene , which encodes a protein that is highly homologous to the mammalian MTHFR. Read More

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January 2021

Cytogenetic characterization and mapping of the repetitive DNAs in Cycloramphus bolitoglossus (Werner, 1897): More clues for the chromosome evolution in the genus Cycloramphus (Anura, Cycloramphidae).

PLoS One 2021 13;16(1):e0245128. Epub 2021 Jan 13.

Departamento de Genética, Setor de Ciências Biológicas, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, Brazil.

Cycloramphus bolitoglossus (Werner, 1897) is a rare species with a low population density in the Serra do Mar region of Paraná and Santa Catarina, in southern Brazil. Currently, it has been assigned to the Near Threatened (NT) category in the Brazilian List of Endangered Animal Species. Here, we described the karyotype of this species for the first time and investigated the patterns of some repetitive DNA classes in the chromosomes using molecular cytogenetic approaches. Read More

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January 2021

Karyotypes diversity in some Iranian Pamphagidae grasshoppers (Orthoptera, Acridoidea, Pamphagidae): new insights on the evolution of the neo-XY sex chromosomes.

Comp Cytogenet 2020 10;14(4):549-566. Epub 2020 Nov 10.

Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia.

For the first time, cytogenetic features of grasshoppers from Iran have been studied. In this paper we conducted a comparative cytogenetic analysis of six species from the family Pamphagidae. The species studied belong to subfamilies Thrinchinae Stål, 1876 ( (Moritz, 1928), (Uvarov, 1918)) and Pamphaginae ( (Dirsh, 1927), Bolívar, 1912, sp. Read More

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November 2020

Chromosomal Locations of a Non-LTR Retrotransposon, Menolird18, in Cucumis melo and Cucumis sativus, and Its Implication on Genome Evolution of Cucumis Species.

Cytogenet Genome Res 2020 10;160(9):554-564. Epub 2020 Nov 10.

Laboratory of Genetics and Plant Breeding, Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan,

Mobile elements are major regulators of genome evolution through their effects on genome size and chromosome structure in higher organisms. Non-long terminal repeat (non-LTR) retrotransposons, one of the subclasses of transposons, are specifically inserted into repetitive DNA sequences. While studies on the insertion of non-LTR retrotransposons into ribosomal RNA genes and other repetitive DNA sequences have been reported in the animal kingdom, studies in the plant kingdom are limited. Read More

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December 2020

The insertion of a mitochondrial selfish element into the nuclear genome and its consequences.

Ecol Evol 2020 Oct 31;10(20):11117-11132. Epub 2020 Aug 31.

Max Planck Institute for Terrestrial Microbiology Marburg Germany.

Homing endonucleases (HE) are enzymes capable of cutting DNA at highly specific target sequences, the repair of the generated double-strand break resulting in the insertion of the HE-encoding gene ("homing" mechanism). HEs are present in all three domains of life and viruses; in eukaryotes, they are mostly found in the genomes of mitochondria and chloroplasts, as well as nuclear ribosomal RNAs. We here report the case of a HE that accidentally integrated into a telomeric region of the nuclear genome of the fungal maize pathogen . Read More

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October 2020

Comparative Cytogenetics of Four Sea Turtle Species (Cheloniidae): G-Banding Pattern and in situ Localization of Repetitive DNA Units.

Cytogenet Genome Res 2020 29;160(9):531-538. Epub 2020 Oct 29.

Programa de Pós-Graduação em Biologia Evolutiva, Universidade Estadual de Ponta Grossa, Ponta Grossa, Brazil,

Sea turtles are considered flagship species for marine biodiversity conservation and are considered to be at varying risk of extinction globally. Cases of hybridism have been reported in sea turtles, but chromosomal analyses are limited to classical karyotype descriptions and a few molecular cytogenetic studies. In order to compare karyotypes and understand evolutive mechanisms related to chromosome dif-ferentiation in this group, Chelonia mydas, Caretta caretta, Eretmochelys imbricata, and Lepidochelys olivacea were cytogenetically characterized in the present study. Read More

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December 2020

Evaluation of copper-induced DNA damage in Vitis vinifera L. using Comet-FISH.

Environ Sci Pollut Res Int 2021 Feb 1;28(6):6600-6610. Epub 2020 Oct 1.

Biosystems & Integrative Sciences Institute-University of Tras-os-Montes and Alto Douro (BioISI-UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal.

The contamination of soils and water with copper (Cu) can compromise the crops production and quality. Fungicides containing Cu are widely and intensively used in viticulture contributing to environmental contamination and genotoxicity in Vitis vinifera L. Despite the difficulty in reproducing field conditions in the laboratory, hydroponic solutions enriched with Cu (1, 10, 25 and 50 μM) were used in forced V. Read More

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February 2021

Rapid chromosomal evolution in the bush-cricket Hemp, 2016 (Orthoptera, Phaneropterinae).

Comp Cytogenet 2020 28;14(3):417-435. Epub 2020 Aug 28.

University of Bayreuth, Dept. Plant Systematics, Bayreuth, Germany University of Bayreuth Bayreuth Germany.

Hemp, 2016 is one of the most widespread bush-crickets of the genus Karsch, 1889 in East Africa. This species with seven large chromosomes (2n♂ = 7) differs from other representatives of the genus drastically by its reduced chromosome number, the asymmetrical karyotype including karyomorphs rarely found in tettigoniids, as well as in irregularities in the course of meiosis. To better understand the origin of such an exceptional karyotype, chromosomes of 29 specimens from four populations/localities were studied using classical techniques, such as C-banding, silver impregnation, fluorochrome double staining and fluorescence hybridization (FISH) technique with 18S rDNA and (TTAGG) telomeric probes. Read More

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The Beginning of the End: A Chromosomal Assembly of the New World Malaria Mosquito Ends with a Novel Telomere.

G3 (Bethesda) 2020 10 5;10(10):3811-3819. Epub 2020 Oct 5.

Department of Biochemistry, Virginia Tech, Blacksburg, VA24061

Chromosome level assemblies are accumulating in various taxonomic groups including mosquitoes. However, even in the few reference-quality mosquito assemblies, a significant portion of the heterochromatic regions including telomeres remain unresolved. Here we produce a assembly of the New World malaria mosquito, by integrating Oxford Nanopore sequencing, Illumina, Hi-C and optical mapping. Read More

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October 2020

Evidence of Interspecific Chromosomal Diversification in Rainbowfishes (Melanotaeniidae, Teleostei).

Genes (Basel) 2020 07 18;11(7). Epub 2020 Jul 18.

Centre for Conservation Ecology and Genetics, Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia.

Rainbowfishes (Melanotaeniidae) are the largest monophyletic group of freshwater fishes occurring in Australia and New Guinea, with 112 species currently recognised. Despite their high taxonomic diversity, rainbowfishes remain poorly studied from a cytogenetic perspective. Using conventional (Giemsa staining, C banding, chromomycin A staining) and molecular (fluorescence in situ hybridisation with ribosomal DNA (rDNA) and telomeric probes) cytogenetic protocols, karyotypes and associated chromosomal characteristics of five species were examined. Read More

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Karyotypic diversity within the genus Makalata (Echimyidae: Echimyinae) of Brazilian Amazon: Chromosomal evidence for multiple species.

PLoS One 2020 7;15(7):e0235788. Epub 2020 Jul 7.

Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.

The genus Makalata is a taxonomically complex group of rodents on which few cytogenetic studies have been performed. Most of the published karyotypes were described based only on conventional chromosome staining. Here, we studied the karyotypes of Makalata from two Brazilian Amazonian states, Amapá and Pará, by Giemsa-staining, G- and C-banding, AgNO3-staining and FISH with 18S rDNA and telomeric sequences probes. Read More

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September 2020

Molecular Cytogenetic Characterization of the Sicilian Endemic Pond Turtle and the Yellow-Bellied Slider (Testudines, Emydidae).

Genes (Basel) 2020 06 25;11(6). Epub 2020 Jun 25.

Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90100 Palermo, Italy.

Turtles, a speciose group consisting of more than 300 species, demonstrate karyotypes with diploid chromosome numbers ranging from 2n = 26 to 2n = 68. However, cytogenetic analyses have been conducted only to 1/3rd of the turtle species, often limited to conventional staining methods. In order to expand our knowledge of the karyotype evolution in turtles, we examined the topology of the (TTAGGG) telomeric repeats and the rDNA loci by fluorescence in situ hybridization (FISH) on the karyotypes of two emydids: the Sicilian pond turtle, and the yellow-bellied slider, (family Emydidae). Read More

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Replicative aging is associated with loss of genetic heterogeneity from extrachromosomal circular DNA in Saccharomyces cerevisiae.

Nucleic Acids Res 2020 08;48(14):7883-7898

Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark.

Circular DNA can arise from all parts of eukaryotic chromosomes. In yeast, circular ribosomal DNA (rDNA) accumulates dramatically as cells age, however little is known about the accumulation of other chromosome-derived circles or the contribution of such circles to genetic variation in aged cells. We profiled circular DNA in Saccharomyces cerevisiae populations sampled when young and after extensive aging. Read More

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Sex Chromosomes and Internal Telomeric Sequences in (Richardson 1844) (Eleotridae: Eleotrinae): An Insight into their Origin in the Genus.

Genes (Basel) 2020 06 17;11(6). Epub 2020 Jun 17.

Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza-Università di Roma, Via Alfonso Borelli 50, 00161 Rome, Italy.

The freshwater fish species , commonly named the Pacific fat sleeper, is an important food resource in CentralSouth America, yet almost no genetic information on it is available. A cytogenetic analysis of this species was undertaken by standard and molecular techniques (chromosomal mapping of 18S rDNA, 5S rDNA, and telomeric repeats), aiming to describe the karyotype features, verify the presence of sex chromosomes described in congeneric species, and make inferences on chromosome evolution in the genus. The karyotype (2n = 46) is mainly composed of metacentric and submetacentic chromosomes, with nucleolar organizer regions (NORs) localized on the short arms of submetacentric pair 10. Read More

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Transposon-mediated telomere destabilization: a driver of genome evolution in the blast fungus.

Nucleic Acids Res 2020 07;48(13):7197-7217

Department of Plant Pathology, University of Kentucky, 1405 Veteran's Dr., Lexington, KY 40546, USA.

The fungus Magnaporthe oryzae causes devastating diseases of crops, including rice and wheat, and in various grasses. Strains from ryegrasses have highly unstable chromosome ends that undergo frequent rearrangements, and this has been associated with the presence of retrotransposons (Magnaporthe oryzae Telomeric Retrotransposons-MoTeRs) inserted in the telomeres. The objective of the present study was to determine the mechanisms by which MoTeRs promote telomere instability. Read More

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Cytogenetic and Molecular Characterization of Three Mimetic Species of the Genus Alagoasa Bechyné 1955 (Coleoptera: Alticinae) from the Neotropical Region.

Cytogenet Genome Res 2020 6;160(4):214-223. Epub 2020 May 6.

Coleoptera is a mega-diverse order, but only about 1% of its species have been analyzed cytogenetically. In this order, the subfamily Alticinae presents many identification problems, mainly due to the occurrence of mimicry. The objective of this work was to cytogenetically characterize 3 very similar species of the genus Alagoasa (A. Read More

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Advances in the cytogenetics of Annonaceae, the case of L.

Genome 2020 Jul 4;63(7):357-364. Epub 2020 May 4.

Department of Agricultural, Food and Environmental Sciences, University of Perugia, Borgo XX Giugno, 06121 Perugia, Italy.

Annonaceae represent the largest extant family among the early divergent angiosperms. Despite the long-standing interest in its evolutionary and taxonomic aspects, cytogenetic studies on this family remain extremely few even on economically important species. With this study, we realized a detailed characterization of the chromosomes of (2 = 14) by a combination of in situ hybridization techniques, fluorochrome banding, and karyomorphological analysis. Read More

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Taxonomic Diversity Not Associated with Gross Karyotype Differentiation: The Case of Bighead Carps, Genus (Teleostei, Cypriniformes, Xenocyprididae).

Genes (Basel) 2020 04 28;11(5). Epub 2020 Apr 28.

Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 277-21 Liběchov, Czech Republic.

The bighead carps of the genus ( and ) are important aquaculture species. They were subjected to extensive multidisciplinary research, but with cytogenetics confined to conventional protocols only. Here, we employed Giemsa-/C-/CMA- stainings and chromosomal mapping of multigene families and telomeric repeats. Read More

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Sex is determined by XX/XY sex chromosomes in Australasian side-necked turtles (Testudines: Chelidae).

Sci Rep 2020 03 9;10(1):4276. Epub 2020 Mar 9.

Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague, Czech Republic.

Turtles demonstrate variability in sex determination and, hence, constitute an excellent model for the evolution of sex chromosomes. Notably, the sex determination of the freshwater turtles from the family Chelidae, a species-rich group with wide geographical distribution in the southern hemisphere, is still poorly explored. Here we documented the presence of an XX/XY sex determination system in seven species of the Australasian chelid genera Chelodina, Emydura, and Elseya by conventional (karyogram reconstruction, C-banding) and molecular cytogenetic methods (comparative genome hybridization, in situ hybridization with probes specific for GATA microsatellite motif, the rDNA loci, and the telomeric repeats). Read More

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