Abstract 3171: Powerful target capture/NGS approach reveals extensive genetic changes including SNVs, CNVs and gross chromosomal rearrangements in colorectal cancers

Proechimys species are remarkable for their extensive chromosome rearrangements, representing a good model to understand genome evolution. Herein, we cytogenetically analyzed 3 different cytotypes of Proechimys gr. goeldii to assess their evolutionary relationship. We also mapped the transposable element SINE-B1 on the chromosomes of P. gr. goeldii 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 P. gr. goeldii, 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 Proechimys karyotypes.

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RELATIONSHIP OF TAXA IN THE GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. I. M. STRIATA × M. LITTORALIS

Canadian Journal of Genetics and Cytology ◽

10.1139/g68-038 ◽

1968 ◽

Vol 10 (2) ◽

pp. 263-275 ◽

Cited By ~ 10

Author(s):

K. Lesins ◽

A. Erac

Keyword(s):

High Mortality ◽

Genetic Factor ◽

Genetic Factors ◽

Chromosomal Rearrangements ◽

Cytoplasmic Factor ◽

Reciprocal Crosses ◽

Gross Chromosomal Rearrangements ◽

Coiling Direction ◽

Chlorophyll Deficiencies ◽

Relationship Of

In crosses between the two taxa Medicago striata Bast, and M. littoralis Rohde a high mortality of gametes and seedlings, and sterility of some plants were noted which were not related to gross chromosomal rearrangements. Although the F1, F2 and F3 generations from reciprocal crosses differed in chlorophyll deficiencies (indicating a cytoplasmic influence) a genic cause became evident from segregations for chlorophyll characters in the F2 and F3. Transference of the cytoplasmic factor by the pollen is indicative.Segregation for pod coiling direction indicated that the character was determined by one or two genetic factors of which the clockwise coiling direction is recessive. The spininess appeared to be determined by one genetic factor, of which the spineless allele is recessive.On the basis of genetic differences (especially on the built-in repulsion systems for normal chlorophyll development of opposite species) the two taxa should be considered two different species.

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Mitotic checkpoint function in the formation of gross chromosomal rearrangements in Saccharomyces cerevisiae

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0407010101 ◽

2004 ◽

Vol 101 (45) ◽

pp. 15980-15985 ◽

Cited By ~ 37

Author(s):

K. Myung ◽

S. Smith ◽

R. D. Kolodner

Keyword(s):

Saccharomyces Cerevisiae ◽

Chromosomal Rearrangements ◽

Mitotic Checkpoint ◽

Gross Chromosomal Rearrangements

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Suppression of gross chromosomal rearrangements by the multiple functions of the Mre11–Rad50–Xrs2 complex in Saccharomyces cerevisiae

DNA Repair ◽

10.1016/j.dnarep.2005.01.004 ◽

2005 ◽

Vol 4 (5) ◽

pp. 606-617 ◽

Cited By ~ 26

Author(s):

Stephanie Smith ◽

Amitabha Gupta ◽

Richard D. Kolodner ◽

Kyungjae Myung

Keyword(s):

Saccharomyces Cerevisiae ◽

Chromosomal Rearrangements ◽

Multiple Functions ◽

Gross Chromosomal Rearrangements

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Meiosis-specific recombinase Dmc1 is a potent inhibitor of the Srs2 antirecombinase

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1810457115 ◽

2018 ◽

Vol 115 (43) ◽

pp. E10041-E10048 ◽

Cited By ~ 14

Author(s):

J. Brooks Crickard ◽

Kyle Kaniecki ◽

Youngho Kwon ◽

Patrick Sung ◽

Eric C. Greene

Keyword(s):

Chromosome Segregation ◽

Single Molecule ◽

Atp Hydrolysis ◽

Potent Inhibitor ◽

Chromosomal Rearrangements ◽

Motor Protein ◽

Product Formation ◽

Gross Chromosomal Rearrangements ◽

Strand Annealing ◽

Hydrolysis Activity

Cross-over recombination products are a hallmark of meiosis because they are necessary for accurate chromosome segregation and they also allow for increased genetic diversity during sexual reproduction. However, cross-overs can also cause gross chromosomal rearrangements and are therefore normally down-regulated during mitotic growth. The mechanisms that enhance cross-over product formation upon entry into meiosis remain poorly understood. In Saccharomyces cerevisiae, the Superfamily 1 (Sf1) helicase Srs2, which is an ATP hydrolysis-dependent motor protein that actively dismantles recombination intermediates, promotes synthesis-dependent strand annealing, the result of which is a reduction in cross-over recombination products. Here, we show that the meiosis-specific recombinase Dmc1 is a potent inhibitor of Srs2. Biochemical and single-molecule assays demonstrate that Dmc1 acts by inhibiting Srs2 ATP hydrolysis activity, which prevents the motor protein from undergoing ATP hydrolysis-dependent translocation on Dmc1-bound recombination intermediates. We propose a model in which Dmc1 helps contribute to cross-over formation during meiosis by antagonizing the antirecombinase activity of Srs2.

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Patterns of genome duplication within the Brassica napus genome

Genome ◽

10.1139/g03-006 ◽

2003 ◽

Vol 46 (2) ◽

pp. 291-303 ◽

Cited By ~ 96

Author(s):

I A.P Parkin ◽

A G Sharpe ◽

D J Lydiate

Keyword(s):

Brassica Napus ◽

Genome Duplication ◽

Chromosomal Rearrangements ◽

Centric Fusion ◽

Linkage Groups ◽

Gross Chromosomal Rearrangements ◽

A Genome ◽

C Genome ◽

Homologous Locus ◽

Duplicate Loci

The progenitor diploid genomes (A and C) of the amphidiploid Brassica napus are extensively duplicated with 73% of genomic clones detecting two or more duplicate sequences within each of the diploid genomes. This comprehensive duplication of loci is to be expected in a species that has evolved through a polyploid ancestor. The majority of the duplicate loci within each of the diploid genomes were found in distinct linkage groups as collinear blocks of linked loci, some of which had undergone a variety of rearrangements subsequent to duplication, including inversions and translocations. A number of identical rearrangements were observed in the two diploid genomes, suggesting they had occurred before the divergence of the two species. A number of linkage groups displayed an organization consistent with centric fusion and (or) fission, suggesting this mechanism may have played a role in the evolution of Brassica genomes. For almost every genetically mapped locus detected in the A genome a homologous locus was found in the C genome; the collinear arrangement of these homologous markers allowed the primary regions of homoeology between the two genomes to be identified. At least 16 gross chromosomal rearrangements differentiated the two diploid genomes during their divergence from a common ancestor.Key words: genome evolution, Brassicaeae, polyploidy, homoeologous linkage groups.

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Chromosomal Rearrangements in Salmonella enterica Serovar Typhi Strains Isolated from Asymptomatic Human Carriers

mBio ◽

10.1128/mbio.00060-11 ◽

2011 ◽

Vol 2 (3) ◽

Cited By ~ 13

Author(s):

T. David Matthews ◽

Wolfgang Rabsch ◽

Stanley Maloy

Keyword(s):

Salmonella Enterica ◽

Large Scale ◽

Chromosomal Rearrangements ◽

Growth Conditions ◽

Genetic Changes ◽

Content Type ◽

Long Term Storage ◽

Bacterial Chromosomes ◽

Over Time

ABSTRACTHost-specific serovars ofSalmonella entericaoften have large-scale chromosomal rearrangements that occur by recombination betweenrrnoperons. Two hypotheses have been proposed to explain these rearrangements: (i) replichore imbalance from horizontal gene transfer drives the rearrangements to restore balance, or (ii) the rearrangements are a consequence of the host-specific lifestyle. Although recent evidence has refuted the replichore balance hypothesis, there has been no direct evidence for the lifestyle hypothesis. To test this hypothesis, we determined therrnarrangement type for 20Salmonella entericaserovar Typhi strains obtained from human carriers at periodic intervals over multiple years. These strains were also phage typed and analyzed for rearrangements that occurred over long-term storage versus routine culturing. Strains isolated from the same carrier at different time points often exhibited different arrangement types. Furthermore, colonies isolated directly from the Dorset egg slants used to store the strains also had different arrangement types. In contrast, colonies that were repeatedly cultured always had the same arrangement type. Estimated replichore balance of isolated strains did not improve over time, and some of the rearrangements resulted in decreased replicore balance. Our results support the hypothesis that the restricted lifestyle of host-specificSalmonellais responsible for the frequent chromosomal rearrangements in these serovars.IMPORTANCEAlthough it was previously thought that bacterial chromosomes were stable, comparative genomics has demonstrated that bacterial chromosomes are dynamic, undergoing rearrangements that change the order and expression of genes. While mostSalmonellastrains have a conserved chromosomal arrangement type, rearrangements are very common in host-specificSalmonellastrains. This study suggests that chromosome rearrangements in the host-specificSalmonella entericaserovar Typhi, the causal agent of typhoid fever, occur within the human host over time. The results also indicate that rearrangements can occur during long-term maintenance on laboratory medium. Although these genetic changes do not limit survival under slow-growth conditions, they may limit the survival ofSalmonellaTyphi in other environments, as predicted for the role of pseudogenes and genome reduction in niche-restricted bacteria.

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