A novel HLA-DR4 haplotype generated by a rare recombinational event between DRB1 and DQA1 loci

1992 ◽  
Vol 36 (5) ◽  
Author(s):  
Carlo Carcassi ◽  
Roberto Giorda ◽  
Massimo Trucco ◽  
Licinio Contu
Keyword(s):  
Recombinational Event

scholarly journals bla CTX-M-2 Is Located in an Unusual Class 1 Integron (In35) Which Includes Orf513

2002 ◽  
Vol 46 (7) ◽  
pp. 2303-2306 ◽  
Author(s):  
Sonia M. Arduino ◽  
Paul H. Roy ◽  
George A. Jacoby ◽  
Betina E. Orman ◽  
Silvia A. Pineiro ◽  
...  
Keyword(s):  
Pcr Analysis ◽  
Chromosomal Dna ◽  
Recombinational Event ◽  
Class 1 Integron ◽  
Class 1 ◽  
Kluyvera Ascorbata

ABSTRACT Examination of the bla CTX-M-2 gene in plasmid pMAR-12 by sequencing and PCR analysis revealed that the bla gene and the surrounding DNA, which is closely related (99% homology) to the Kluyvera ascorbata chromosomal DNA that contains the bla KLUA-1 gene, are located in a complex sul1-type integron, termed In35, that includes Orf513. It is possible that bla CTX-M-2 was acquired by plasmid pMAR-12 through an uncharacterized recombinational event in which Orf513 could be involved.

scholarly journals Evolutionary dynamics of Begomoviruses causing Papaya leaf curl disease in India

2021 ◽  
Author(s):  
Aarshi Srivasatava ◽  
Vineeta Pandey ◽  
Anurag Kumar Sahu ◽  
Dinesh Yadav ◽  
R.K. Gaur
Keyword(s):  
Selection Pressure ◽  
Nucleotide Diversity ◽  
Evolutionary Dynamics ◽  
Branch Length ◽  
Genetic Variations ◽  
Evolutionary Divergence ◽  
Agricultural Crops ◽  
Recombinational Event ◽  
Leaf Curl Disease ◽  
Leaf Curl

AbstractThe genus begomovirus represents a group of multipartite viruses that significantly damages many agricultural crops, including papaya and drastically influence the overall production. Understanding the genetic variations, mutations and recombination of the begomovirus population infecting papaya has several important implications in alleviating substantial losses, mainly in developing countries, including India. In an attempt for a bioinformatics driven study of diversity and variability of papaya leaf curl disease in India, a total of thirty-two (32) DNA-A and sixteen (16) betasatellite sequences were retrieved from GenBank. An uneven distribution of evolutionary divergence has been observed across the branch length, which triggered the estimated recombinational event. Interestingly, a maximum of the begomoviruses were found to be intra-species recombinants. Further genetic variability, selection pressure, and substitution rate acting on the population were estimated and found to be high enough to support the evolution of geminiviruses. Genetic divergence composition in all begomovirus datasets revealed predominance of nucleotide diversity driven by mutation. The analysis indicates that even though a significant fraction of the genetic variations might be due to recombination but, it was constantly lower than the mutation rate. Thus, the diversification of the begomovirus population is principally impelled by mutational dynamics.

Change in chromosome number associated with a double deletion in the Neurospora crassa mitochondrial chromosome.

Genetics ◽  
1989 ◽  
Vol 121 (4) ◽  
pp. 685-691
Author(s):  
S R Gross ◽  
A Mary ◽  
P H Levine
Keyword(s):  
Mitochondrial Genome ◽  
Unit Length ◽  
Recombinational Event ◽  
Dna Molecule ◽  
Double Deletion ◽  
Splice Junctions ◽  
Circular Chromosomes ◽  
Derivatives Of ◽  
Mitochondrial Chromosome ◽  
Very High

Abstract The mitochondrial genome of Neurospora is usually found in a single covalently closed circular 62-kbp DNA molecule. We report here that the mitochondrial genome of a phenotypic revertant of a stopper mutant (stp-ruv) is contained primarily in two separate, nonoverlapping, autonomously replicating circular chromosomes. The circles, one about 21 kbp and the other somewhat less than 36 kbp are derived from the most frequent classes of recombinant chromosomes (21 and 41 kbp) in the chromosomal population of mitochondria in the original stopper mutant. The new, more stable chromosomal configuration, is associated with the deletion of two sequences (1 kbp and 4 kbp) at the splice junctions of the two circles. The data suggest that both deletions are likely to have originated from a single recombinational event involved in generating the 36-kbp circle. Secondary, spontaneously arising derivatives of stp-ruv have been found to yield, at high copy number, short sections of the 21-kbp circle in covalently closed supercoiled circles varying from unit length to very high multimers. The amplified segments span a common segment likely to contain the replication origin of the 21-kbp chromosome.

scholarly journals Extensive turnover of telomeric DNA at aPlasmodium bergheichromosomal extremity marked by a rare recombinational event

1992 ◽  
Vol 20 (17) ◽  
pp. 4491-4497 ◽  
Author(s):  
Marta Ponzi ◽  
Tomasino Pace ◽  
Elisabetta Dore ◽  
Leonardo Picci ◽  
Elisabetta Pizzi ◽  
...  
Keyword(s):  
Telomeric Dna ◽  
Recombinational Event

scholarly journals Intragenic recombination in an E beta gene for a murine Ia antigen.

1982 ◽  
Vol 155 (3) ◽  
pp. 937-942 ◽  
Author(s):  
M L Plunkett ◽  
J E Coligan ◽  
C S David ◽  
J H Freed
Keyword(s):  
Plasma Membrane ◽  
Recombinant Strain ◽  
Intragenic Recombination ◽  
Two Dimensional ◽  
Beta Chain ◽  
Terminal Portion ◽  
Recombinational Event ◽  
Amino Terminal ◽  
Normal Behavior ◽  
Beta Gene

The recombinant strain D2.GD was originally typed as I-Ad by serological methods. Indeed, the A alpha and A beta chains of the I-A antigens appear to exhibit normal behavior by the criteria of serology and two dimensional gel analysis. However, the E beta chain encoded by the I-A subregion of this strain, one of the two components of the plasma membrane located I-E antigens produced in D2.GD X A.TFR5)F1 animals, has been demonstrated to be the product of an intragenic recombinational event between E beta genes from the d and b haplotypes. Sequence analysis suggests that the amino-terminal portion of the Eg2 beta chain is derived from the d haplotype and, therefore, that the coding strand for this gene is oriented centromeric leads to telomeric (5' to 3' direction). Finally, these data combined with the data of Rose and Cullen (17) allow the ordering of the genes within the I-A subregion as (H-2K), A alpha, A beta, E beta ... (H-2D).

scholarly journals The replication advantage of a free linear rRNA gene is restored by somatic recombination in Tetrahymena thermophila

1989 ◽  
Vol 9 (2) ◽  
pp. 452-460
Author(s):  
P C Yaeger ◽  
E Orias ◽  
W L Shaiu ◽  
D D Larson ◽  
E H Blackburn
Keyword(s):  
Inbred Strain ◽  
Southern Blot Analysis ◽  
Tetrahymena Thermophila ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Wild Type ◽  
Recombinational Event ◽  
Somatic Nucleus ◽  
Somatic Recombination ◽  
General Method

The autonomously replicating rRNA genes (rDNA) in the somatic nucleus of Tetrahymena thermophila are maintained at a copy number of approximately 10(4) per nucleus. A mutant in which the replication properties of this molecule were altered was isolated and characterized. This mutation of inbred strain C3, named rmm4, was shown to have the same effect on rDNA replication and to be associated with the same 1-base-pair (bp) deletion as the previously reported, independently derived rmm1 mutation (D. L. Larson, E. H. Blackburn, P. C. Yaeger, and E. Orias, Cell 47:229-240, 1986). The rDNA of inbred strain B, which is at a replicational disadvantage compared with wild-type C3 rDNA, has a 42-bp deletion. This deletion is separated by 25 bp from the 1-bp deletion of rmm4 or rmm1. Southern blot analysis and DNA sequencing revealed that during prolonged vegetative divisions of C3-rmm4/B-rmm heterozygotes, somatic recombination produced rDNAs lacking both the rmm4-associated deletion and the 42-bp deletion. In somatic nuclei in which this rare recombinational event had occurred, all 10(4) copies of nonrecombinant rDNA were eventually replaced by the recombinant rDNA. The results prove that each of the two deletions is the genetic determinant of the observed replication disadvantage. We propose that the analysis of somatically recombinant rDNAs can be used as a general method in locating other mutations which affect rDNA propagation in T. thermophilia.

scholarly journals MAPPING OF THE polA LOCUS OF ESCHERICHIA COLI K12: GENETIC FINE STRUCTURE OF THE CISTRON

Genetics ◽  
1980 ◽  
Vol 95 (1) ◽  
pp. 15-38
Author(s):  
William S Kelley
Keyword(s):  
Fine Structure ◽  
Nonsense Mutation ◽  
Exact Order ◽  
Dna Polymerase I ◽  
Recombinational Event ◽  
Genetic Fine Structure ◽  
Carboxy Terminal ◽  
Polymerase I ◽  
Order Four ◽  
Generalized Transduction

ABSTRACT The close linkage of the glnA gene with polA was exploited to construct a fine structure map of polA by means of generalized transduction with phage P1. Nine different polA- alleles were mapped by recombinational crosses. The results indicate a gene order consistent with previous observations (KELLEYand GRINDLEY 19 76a; MURRAY an d KELLEY 1979). Three mutations, polA5, polA6 and polA12 map within the "carboxy-terminal" or "large-fragment'' portion of the gene in unambiguous order. Four alleles, known to affect the "aminoterminal" portion of the gene, polA107, polA214, polA480ex and polA4113, appear to be closely linked with certain ambiguities in their exact order. All four of these mutations are known to alter the 5'→3' exonuclease activity of DNA polymerase I and three of them result in the conditional lethal polA- phenotype. The polA1 nonsense mutation maps between these two groups in a position consistent with its known effect, production of an amber fragment that includes the 5'→3' exonuclease. The final allele, resAl, is another nonsense mutation that maps at; the extreme "amino-terminus" of the cistron.—A number of control experiments were conducted to determine the effects of pol.A- mutatims on the PI-mediated recombinational event. These experiments indicated that abortive transduction occurs quite frequently, but the formation of abortive transductants and segregation of unselected transduced markers among daughter progeny is like that observed by other investigators. There was no evidence that any individual polA- allele behaved in an exceptional fashion during recombination.

Genetic variability, evidence of potential recombinational event and selection of LEI0258 in chicken

Gene ◽  
2014 ◽  
Vol 537 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Guangxin E. ◽  
Rinai Sha ◽  
Shengcheng Zeng ◽  
Chen Wang ◽  
Jianfei Pan ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Recombinational Event ◽  
Selection Of

scholarly journals The replication advantage of a free linear rRNA gene is restored by somatic recombination in Tetrahymena thermophila.

1989 ◽  
Vol 9 (2) ◽  
pp. 452-460 ◽  
Author(s):  
P C Yaeger ◽  
E Orias ◽  
W L Shaiu ◽  
D D Larson ◽  
E H Blackburn
Keyword(s):  
Inbred Strain ◽  
Southern Blot Analysis ◽  
Tetrahymena Thermophila ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Wild Type ◽  
Recombinational Event ◽  
Somatic Nucleus ◽  
Somatic Recombination ◽  
General Method

The autonomously replicating rRNA genes (rDNA) in the somatic nucleus of Tetrahymena thermophila are maintained at a copy number of approximately 10(4) per nucleus. A mutant in which the replication properties of this molecule were altered was isolated and characterized. This mutation of inbred strain C3, named rmm4, was shown to have the same effect on rDNA replication and to be associated with the same 1-base-pair (bp) deletion as the previously reported, independently derived rmm1 mutation (D. L. Larson, E. H. Blackburn, P. C. Yaeger, and E. Orias, Cell 47:229-240, 1986). The rDNA of inbred strain B, which is at a replicational disadvantage compared with wild-type C3 rDNA, has a 42-bp deletion. This deletion is separated by 25 bp from the 1-bp deletion of rmm4 or rmm1. Southern blot analysis and DNA sequencing revealed that during prolonged vegetative divisions of C3-rmm4/B-rmm heterozygotes, somatic recombination produced rDNAs lacking both the rmm4-associated deletion and the 42-bp deletion. In somatic nuclei in which this rare recombinational event had occurred, all 10(4) copies of nonrecombinant rDNA were eventually replaced by the recombinant rDNA. The results prove that each of the two deletions is the genetic determinant of the observed replication disadvantage. We propose that the analysis of somatically recombinant rDNAs can be used as a general method in locating other mutations which affect rDNA propagation in T. thermophilia.

scholarly journals Regular responses to selection I. Description of responses

1961 ◽  
Vol 2 (2) ◽  
pp. 161-176 ◽  
Author(s):  
J. M. Thoday ◽  
T. B. Boam
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
Gene Interactions ◽  
Selection Experiment ◽  
Recombinational Event ◽  
Set Up

1. Several lines of Drosophila melanogaster have been selected for increase of sternopleural chaeta-number.2. Three lines of the same origin, dp 1, dp 2 and dp 6, showed remarkably similar patterns of response involving an accelerated response from 24 to 28 chaetae and a plateau at about 30 chaetae. A line formed by crossing two of these was not responsive to selection, suggesting that the two parent lines were genetically similar.3. A fourth line, vg 4, related to these others, showed a similar accelerated response but continued to respond beyond 30 chaetae, reaching a plateau at about 37 chaetae.4. A further line, vg 6, set up by crossing two ‘improved’ lines, one with 30, the other with 22 chaetae, reached 46 chaetae and suggests there may sometimes be merit in selecting from the hybrids of ‘improved’ strains.5. It is argued that the event making possible the accelerated response is probably a recombinational event.6. The line vg 4 clearly demonstrates that some of the genes that may be exploited in a selection experiment have to be exploited in a particular order because of gene interactions.

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