scholarly journals Boom-Bust Turnovers of Megabase-Sized Centromeric DNA in Solanum Species: Rapid Evolution of DNA Sequences Associated with Centromeres

2014 ◽  
Vol 26 (4) ◽  
pp. 1436-1447 ◽  
Author(s):  
Haiqin Zhang ◽  
Andrea Koblížková ◽  
Kai Wang ◽  
Zhiyun Gong ◽  
Ludmila Oliveira ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Rapid Evolution ◽  
Solanum Species ◽  
Centromeric Dna

scholarly journals Selfish chromosomal drive shapes recent centromeric histone evolution in monkeyflowers

PLoS Genetics ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. e1009418
Author(s):  
Findley R. Finseth ◽  
Thomas C. Nelson ◽  
Lila Fishman
Keyword(s):  
Dna Sequences ◽  
Rapid Evolution ◽  
Mendelian Inheritance ◽  
Arms Race ◽  
Centromeric Dna ◽  
Kinetochore Protein ◽  
Individual Fitness ◽  
Histone 3 ◽  
Stable Frequency ◽  
Protein Components

Centromeres are essential mediators of chromosomal segregation, but both centromeric DNA sequences and associated kinetochore proteins are paradoxically diverse across species. The selfish centromere model explains rapid evolution by both components via an arms-race scenario: centromeric DNA variants drive by distorting chromosomal transmission in female meiosis and attendant fitness costs select on interacting proteins to restore Mendelian inheritance. Although it is clear than centromeres can drive and that drive often carries costs, female meiotic drive has not been directly linked to selection on kinetochore proteins in any natural system. Here, we test the selfish model of centromere evolution in a yellow monkeyflower (Mimulus guttatus) population polymorphic for a costly driving centromere (D). We show that theDhaplotype is structurally and genetically distinct and swept to a high stable frequency within the past 1500 years. We use quantitative genetic mapping to demonstrate that context-dependence in the strength of drive (from near-100%Dtransmission in interspecific hybrids to near-Mendelian in within-population crosses) primarily reflects variable vulnerability of the non-driving competitor chromosomes, but also map an unlinked modifier of drive coincident with kinetochore protein Centromere-specific Histone 3 A (CenH3A). Finally, CenH3A exhibits a recent (<1000 years) selective sweep in our focal population, implicating local interactions withDin ongoing adaptive evolution of this kinetochore protein. Together, our results demonstrate an active co-evolutionary arms race between DNA and protein components of the meiotic machinery inMimulus, with important consequences for individual fitness and molecular divergence.

scholarly journals Dynamic DNA Origami Devices: from Strand-Displacement Reactions to External-Stimuli Responsive Systems

2018 ◽  
Vol 19 (7) ◽  
pp. 2114 ◽  
Author(s):  
Heini Ijäs ◽  
Sami Nummelin ◽  
Boxuan Shen ◽  
Mauri Kostiainen ◽  
Veikko Linko
Keyword(s):  
Dna Sequences ◽  
Rapid Evolution ◽  
Dna Nanotechnology ◽  
Dna Origami ◽  
Dna Assembly ◽  
Stimuli Responsive ◽  
Nanoscale Structures ◽  
Displacement Reactions ◽  
Materials Research ◽  
External Stimuli

DNA nanotechnology provides an excellent foundation for diverse nanoscale structures that can be used in various bioapplications and materials research. Among all existing DNA assembly techniques, DNA origami proves to be the most robust one for creating custom nanoshapes. Since its invention in 2006, building from the bottom up using DNA advanced drastically, and therefore, more and more complex DNA-based systems became accessible. So far, the vast majority of the demonstrated DNA origami frameworks are static by nature; however, there also exist dynamic DNA origami devices that are increasingly coming into view. In this review, we discuss DNA origami nanostructures that exhibit controlled translational or rotational movement when triggered by predefined DNA sequences, various molecular interactions, and/or external stimuli such as light, pH, temperature, and electromagnetic fields. The rapid evolution of such dynamic DNA origami tools will undoubtedly have a significant impact on molecular-scale precision measurements, targeted drug delivery and diagnostics; however, they can also play a role in the development of optical/plasmonic sensors, nanophotonic devices, and nanorobotics for numerous different tasks.

scholarly journals Sequential de novo centromere formation and inactivation on a chromosomal fragment in maize

2015 ◽  
Vol 112 (11) ◽  
pp. E1263-E1271 ◽  
Author(s):  
Yalin Liu ◽  
Handong Su ◽  
Junling Pang ◽  
Zhi Gao ◽  
Xiu-Jie Wang ◽  
...  
Keyword(s):  
Dna Sequences ◽  
De Novo ◽  
B Chromosome ◽  
Chromosome 9 ◽  
Centromeric Dna ◽  
Repeat Sequences ◽  
Centromeric Repeat ◽  
And Function ◽  
Centromere Assembly ◽  
Derivatives Of

The ability of centromeres to alternate between active and inactive states indicates significant epigenetic aspects controlling centromere assembly and function. In maize (Zea mays), misdivision of the B chromosome centromere on a translocation with the short arm of chromosome 9 (TB-9Sb) can produce many variants with varying centromere sizes and centromeric DNA sequences. In such derivatives of TB-9Sb, we found a de novo centromere on chromosome derivative 3-3, which has no canonical centromeric repeat sequences. This centromere is derived from a 288-kb region on the short arm of chromosome 9, and is 19 megabases (Mb) removed from the translocation breakpoint of chromosome 9 in TB-9Sb. The functional B centromere in progenitor telo2-2 is deleted from derivative 3-3, but some B-repeat sequences remain. The de novo centromere of derivative 3-3 becomes inactive in three further derivatives with new centromeres being formed elsewhere on each chromosome. Our results suggest that de novo centromere initiation is quite common and can persist on chromosomal fragments without a canonical centromere. However, we hypothesize that when de novo centromeres are initiated in opposition to a larger normal centromere, they are cleared from the chromosome by inactivation, thus maintaining karyotype integrity.

scholarly journals Evolution in the Courtroom: Using Phylogenetics to Investigate Legal Claims of HIV Transmission

2020 ◽  
Author(s):  
Benjamin Toups ◽  
Jeremy M. Brown
Keyword(s):  
Biological Sciences ◽  
Dna Sequences ◽  
Hiv Transmission ◽  
Rapid Evolution ◽  
Rapid Rate ◽  
The Public ◽  
Rates Of Evolution ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Fast Rates

DNA sequences have become ubiquitous across the biological sciences and are even embedded in the public psyche, perhaps most famously in the context of forensic science. A human being’s DNA changes very little over his or her lifetime, and this inherent stability lends itself well to positively identifying individuals using DNA samples. However, not all genomes are so stable, even over short timespans. One particularly dramatic example is human immunodeficiency virus (HIV-1). Unlike the human genome, the HIV-1 genome has an extraordinarily high mutation rate. This, in combination with recombination, rapid proliferation, and strong selection exerted by host immune systems, leads to exceptionally fast rates of evolution. The result of these interacting processes is a population of diverse and dynamically evolving HIV-1 genomes in the host, which is one reason why the virus is so difficult to eradicate. HIV-1’s rapid rate of evolution also prevents the use of standard DNA fingerprinting techniques that rely on stable, unchanging genomes to connect the infections in different individuals, but such rapid evolution does lend itself particularly well to phylogenetic analysis.

scholarly journals Identification of Xenopus CENP-A and an Associated Centromeric DNA Repeat

2005 ◽  
Vol 16 (4) ◽  
pp. 1800-1810 ◽  
Author(s):  
Nathaniel S. Edwards ◽  
Andrew W. Murray
Keyword(s):  
Dna Sequences ◽  
Cultured Cells ◽  
Protein A ◽  
Centromeric Dna ◽  
Eukaryotic Chromosome ◽  
Centromeric Repeat ◽  
Kinetochore Assembly ◽  
Centromere Protein A ◽  
Dna Repeat ◽  
Egg Extracts

Kinetochores are the proteinaceous complexes that assemble on centromeric DNA and direct eukaryotic chromosome segregation. The mechanisms by which higher eukaryotic cells define centromeres are poorly understood. Possible molecular contributors to centromere specification include the underlying DNA sequences and epigenetic factors such as binding of the centromeric histone centromere protein A (CENP-A). Frog egg extracts are an attractive system for studying centromere definition and kinetochore assembly. To facilitate such studies, we cloned a Xenopus laevis homologue of CENP-A (XCENP-A). We identified centromere-associated DNA sequences by cloning fragments of DNA that copurified with XCENP-A by chromatin immunoprecipitation. XCENP-A associates with frog centromeric repeat 1 (Fcr1), a 174-base pair repeat containing a possible CENP-B box. Southern blots of partially digested genomic DNA revealed large ordered arrays of Fcr1 in the genome. Fluorescent in situ hybridization with Fcr1 probes stained most centromeres in cultured cells. By staining lampbrush chromosomes, we specifically identified the 11 (of 18) chromosomes that stain consistently with Fcr1 probes.

scholarly journals The Curious Case of Nonrepetitive Centromeric DNA Sequences in Candida auris and Related Species

mBio ◽  
2021 ◽  
Author(s):  
Alexander Lorenz ◽  
Nicolas Papon
Keyword(s):  
Intensive Care ◽  
Dna Sequences ◽  
Chromosome Structure ◽  
Whole Genome ◽  
Health Issues ◽  
Candida Auris ◽  
Centromeric Dna ◽  
Content Type ◽  
Genomic Divergence ◽  
Systemic Infections

2009 saw the first description of Candida auris , a yeast pathogen of humans. C. auris has since grown into a global problem in intensive care settings, where it causes systemic infections in patients with underlying health issues. Recent whole-genome sequencing has discerned five C. auris clades with distinct phenotypic features which display genomic divergence on a DNA sequence and a chromosome structure level.

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