scholarly journals The role of chromosomal rearrangements and geographical barriers in the divergence of lineages in a South American subterranean rodent (Rodentia: Ctenomyidae: Ctenomys minutus)

Heredity ◽  
2013 ◽  
Vol 111 (4) ◽  
pp. 293-305 ◽  
Author(s):  
C M Lopes ◽  
S S F Ximenes ◽  
A Gava ◽  
T R O de Freitas
Keyword(s):  
Chromosomal Rearrangements ◽  
South American ◽  
Subterranean Rodent

SINE-B1 Distribution and Chromosome Rearrangements in the South American Proechimys gr. goeldii (Echimyidae, Rodentia)

2021 ◽  
pp. 1-8
Author(s):  
Naiara P. Araújo ◽  
Radarane S. Sena ◽  
Cibele R. Bonvicino ◽  
Gustavo C.S. Kuhn ◽  
Marta Svartman
Keyword(s):  
Transposable Element ◽  
Genome Evolution ◽  
Significant Role ◽  
Sex Chromosomes ◽  
Chromosomal Rearrangements ◽  
Evolutionary Relationship ◽  
Chromosome Rearrangements ◽  
South American ◽  
Gross Chromosomal Rearrangements

<i>Proechimys</i> species are remarkable for their extensive chromosome rearrangements, representing a good model to understand genome evolution. Herein, we cytogenetically analyzed 3 different cytotypes of <i>Proechimys</i> gr. <i>goeldii</i> to assess their evolutionary relationship. We also mapped the transposable element SINE-B1 on the chromosomes of <i>P.</i> gr. <i>goeldii</i> in order to investigate its distribution among individuals and evaluate its possible contribution to karyotype remodeling in this species. SINE-B1 showed a dispersed distribution along chromosome arms and was also detected at the pericentromeric regions of some chromosomes, including pair 1 and the sex chromosomes, which are involved in chromosome rearrangements. In addition, we describe a new cytotype for <i>P.</i> gr. <i>goeldii</i>, reinforcing the significant role of gross chromosomal rearrangements during the evolution of the genus. The results of FISH with SINE-B1 suggest that this issue should be more deeply investigated for a better understanding of its role in the mechanisms involved in the wide variety of <i>Proechimys</i> karyotypes.

scholarly journals Involvement of Very Short DNA Tandem Repeats and the Influence of the RAD52 Gene on the Occurrence of Deletions in Saccharomyces cerevisiae

Genetics ◽  
2000 ◽  
Vol 156 (2) ◽  
pp. 549-557 ◽  
Author(s):  
Anne J Welcker ◽  
Jacky de Montigny ◽  
Serge Potier ◽  
Jean-Luc Souciet
Keyword(s):  
Fusion Proteins ◽  
Tandem Repeats ◽  
Chromosomal Rearrangements ◽  
Reversion Rate ◽  
Wild Type ◽  
Recombination Mechanism ◽  
Nonhomologous Recombination ◽  
Deletion Rate ◽  
Dna Tandem Repeats

Abstract Chromosomal rearrangements, such as deletions, duplications, or Ty transposition, are rare events. We devised a method to select for such events as Ura+ revertants of a particular ura2 mutant. Among 133 Ura+ revertants, 14 were identified as the result of a deletion in URA2. Of seven classes of deletions, six had very short regions of identity at their junctions (from 7 to 13 bp long). This strongly suggests a nonhomologous recombination mechanism for the formation of these deletions. The total Ura+ reversion rate was increased 4.2-fold in a rad52Δ strain compared to the wild type, and the deletion rate was significantly increased. All the deletions selected in the rad52Δ context had microhomologies at their junctions. We propose two mechanisms to explain the occurrence of these deletions and discuss the role of microhomology stretches in the formation of fusion proteins.

scholarly journals The Role of RNA in DNA Breaks, Repair and Chromosomal Rearrangements

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 550
Author(s):  
Matvey Mikhailovich Murashko ◽  
Ekaterina Mikhailovna Stasevich ◽  
Anton Markovich Schwartz ◽  
Dmitriy Vladimirovich Kuprash ◽  
Aksinya Nicolaevna Uvarova ◽  
...  
Keyword(s):  
Chromosomal Rearrangements ◽  
Gene Mutations ◽  
Nonhomologous End Joining ◽  
Published Data ◽  
Dna Double Strand Breaks ◽  
Dna Breaks ◽  
End Joining ◽  
Homology Directed Repair ◽  
Chromosome Aberration Frequency

Incorrect reparation of DNA double-strand breaks (DSB) leading to chromosomal rearrangements is one of oncogenesis’s primary causes. Recently published data elucidate the key role of various types of RNA in DSB formation, recognition and repair. With growing interest in RNA biology, increasing RNAs are classified as crucial at the different stages of the main pathways of DSB repair in eukaryotic cells: nonhomologous end joining (NHEJ) and homology-directed repair (HDR). Gene mutations or variation in expression levels of such RNAs can lead to local DNA repair defects, increasing the chromosome aberration frequency. Moreover, it was demonstrated that some RNAs could stimulate long-range chromosomal rearrangements. In this review, we discuss recent evidence demonstrating the role of various RNAs in DSB formation and repair. We also consider how RNA may mediate certain chromosomal rearrangements in a sequence-specific manner.

Modelling the role of Atlantic air-sea interaction in the impact of Madden-Julian Oscillation on South American climate

2018 ◽  
Vol 39 (2) ◽  
pp. 1104-1116 ◽  
Author(s):  
Marcelo Barreiro ◽  
Lina Sitz ◽  
Santiago de Mello ◽  
Ramon Fuentes Franco ◽  
Madeleine Renom ◽  
...  
Keyword(s):  
South American ◽  
Madden Julian Oscillation ◽  
The Impact ◽  
South American Climate

scholarly journals Almacenamiento energético frente al inminente paradigma renovable: el rol de las baterías ion-litio y las perspectivas sudamericanas/Energy storage towards the imminent renewable paradigm: the role of ion-lithium batteries and South American perspectives

2018 ◽  
pp. 108-132 ◽  
Author(s):  
Martin Ariel Kazimierski
Keyword(s):  
Electric Propulsion ◽  
Fossil Fuels ◽  
Lithium Ion ◽  
Energy System ◽  
South American ◽  
Potential Market ◽  
Wide Range ◽  
New Energy ◽  
A Current

El actual sistema energético mundial se caracteriza por una alta dependencia de los combustibles fósiles, un paradigma que empieza a encontrar dificultades en tanto se agotan las reservas existentes y aumentan los costos ecológicos. Así, la incorporación de energías renovables, su generación en forma distribuida y el crecimiento del parque automotor eléctrico, se presentan como la triada más prometedora en la conformación de un nuevo paradigma más eficiente y sustentable. Este artículo se centra en la importancia que adquieren los acumuladores energéticos ante este panorama, principalmente por su rol en la estabilización de las redes y posibilitar el autoconsumo y la propulsión eléctrica. Identifica en las baterías de ion-litio un abanico de posibilidades para Sudamérica, que posee las reservas más importantes de litio en el mundo, incorporando la idea del desarrollo dentro del nuevo patrón energético y en un mercado actual y potencial de grandes dimensiones. Abstract The current global energy system is characterized by a high dependence on fossil fuels, a paradigm that begins to encounter difficulties as existing reserves are depleted and ecological costs increase. Thus, the incorporation of renewable energies, their generation in a distributed form and the growth of the electric motor park, are presented as the most promising triad in the conformation of a new, more efficient and sustainable paradigm. This article focuses on the importance that energy accumulators acquire in this scenario, mainly due to their role in stabilizing networks and enabling self-consumption and electric propulsion. It identifies lithium-ion batteries with a wide range of possibilities for South America, which has the most important reserves of lithium in the world, incorporating the idea of ​​development within the new energy pattern and in a current and potential market of large dimensions.

Slavery, Resistance(s) and Abolition in Early Nineteenth-Century Chile

2019 ◽  
Vol 4 (3) ◽  
pp. 372-403 ◽  
Author(s):  
Thomas Mareite
Keyword(s):  
Nineteenth Century ◽  
South American ◽  
Early Nineteenth Century ◽  
Slave Emancipation ◽  
Proactive Role

Abstract Chile’s abolition of slavery (1823) has commonly been framed within a self-congratulatory narrative that emphasizes the philanthropic role of republican elites and the peaceful nature of slave emancipation. The traditional narrative not only views abolition as an ideologically inspired gift from the elites, but also underscores Chile’s exceptionalism vis-à-vis other South American emancipation processes—in Chile, unlike in the rest of the continent, the eradication of slavery was supposedly both politically and socially insignificant. This article challenges two of this narrative’s assumptions: first, that consensus characterized the abolition of slavery in Chile, and second, that abolition was simply a philanthropic concession from the new nation’s republican elites. Instead, this study highlights how officials, slaveholders and enslaved people transformed slavery and its dismantlement into a contested issue. It also explores the proactive role that enslaved people played in undermining the institution of slavery throughout Chile, ultimately leading to its abolition.

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