scholarly journals Conjugational Genetic Exchange in the Hyperthermophilic Archaeon Sulfolobus acidocaldarius: Intragenic Recombination with Minimal Dependence on Marker Separation

2005 ◽  
Vol 187 (2) ◽  
pp. 805-809 ◽  
Author(s):  
Josh E. Hansen ◽  
Amy C. Dill ◽  
Dennis W. Grogan
Keyword(s):  
Genetic Linkage ◽  
Large Deletion ◽  
Genetic Exchange ◽  
Sulfolobus Acidocaldarius ◽  
Intragenic Recombination ◽  
Deletion Mutants ◽  
Hyperthermophilic Archaeon ◽  
Recombinant Frequency ◽  
Three Factor

ABSTRACT In Sulfolobus acidocaldarius conjugation assays, recombinant frequency was relatively constant for marker separations from 1,154 bp down to about 50 bp and readily detectable at 10 bp. Three-factor crosses revealed little, if any, genetic linkage over distances of 500 to 600 bp, and large deletion mutants were good donors but poor recipients in matings. The results indicate that most intragenic recombination events occur at one of the mutations, not in the interval between them.

scholarly journals Characterization of Intragenic Recombination in a Hyperthermophilic Archaeon via Conjugational DNA Exchange

2001 ◽  
Vol 183 (9) ◽  
pp. 2943-2946 ◽  
Author(s):  
Michelle S. Reilly ◽  
Dennis W. Grogan
Keyword(s):  
Base Pair ◽  
Genetic Recombination ◽  
Sulfolobus Acidocaldarius ◽  
Intragenic Recombination ◽  
Decarboxylase Activity ◽  
Hyperthermophilic Archaeon ◽  
Monophosphate Decarboxylase ◽  
Chromosomal Mutations ◽  
Deletion Interval

ABSTRACT Sulfolobus acidocaldarius is so far the only hyperthermophilic archaeon in which genetic recombination can be assayed by conjugation and simple selections. Crosses among spontanteous pyr mutants were able to resolve closely spaced chromosomal mutations, identify deletions and rearrangements, and map mutations to a given deletion interval. Frameshift mutations inpyrE exerted polar effects that depressed orotidine-5′-monophosphate decarboxylase activity (encoded bypyrF), whereas base pair substitutions and an 18-bp deletion had no effect.

GENETIC RECOMBINATION IN SEXUAL CROSSES OF PHYCOMYCES

Genetics ◽  
1975 ◽  
Vol 80 (3) ◽  
pp. 445-462
Author(s):  
A P Eslava ◽  
M I Alvarez ◽  
Patricia V Burke ◽  
M Delbrück
Keyword(s):  
Mating Type ◽  
Genetic Recombination ◽  
Recombination Frequency ◽  
Intragenic Recombination ◽  
Phycomyces Blakesleeanus ◽  
Sexual Crosses ◽  
Color Marker ◽  
Three Factor

ABSTRACT Sexual crosses between strains of Phycomyces blakesleeanus, involving three auxotrophic and one color marker and yielding a high proportion of zygospore germination, are described. Samples of 20-40 germ spores from 311 individual fertile germ sporangia originating from five two-factor and three three-factor crosses were characterized. The results show: (1) absence of any contribution of apogamic nuclei to the progeny, (2) confirmation of Burgeff's conjecture that the germ spores of any germ sporangium in most cases derive from one meiosis. In a cross involving two allelic markers the analysis of 175 pooled germ sporangia suggests an intragenic recombination frequency of 0.6%. All other factor combinations tested are unlinked. The bulk of the germ spores are homokaryotic. However, a small portion (4%) are heterokaryotic with respect to mating type.

Refined crystal structure of a superoxide dismutase from the hyperthermophilic archaeon Sulfolobus acidocaldarius at 2.2 Å resolution 1 1Edited by R. Huber

1999 ◽  
Vol 285 (2) ◽  
pp. 689-702 ◽  
Author(s):  
Stefan Knapp ◽  
Simone Kardinahl ◽  
Niklas Hellgren ◽  
Gudrun Tibbelin ◽  
Günter Schäfer ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Superoxide Dismutase ◽  
Sulfolobus Acidocaldarius ◽  
Hyperthermophilic Archaeon

Large deletion mutants of Escherichia coli tRNA1Tyr

1982 ◽  
Vol 155 (2) ◽  
pp. 83-103 ◽  
Author(s):  
George M. McCorkle ◽  
Sidney Altman
Keyword(s):  
Escherichia Coli ◽  
Large Deletion ◽  
Deletion Mutants

scholarly journals Analagous Population Structures for Two Alphabaculoviruses Highlight a Functional Role for Deletion Mutants

2012 ◽  
Vol 79 (4) ◽  
pp. 1118-1125 ◽  
Author(s):  
Amaya Serrano ◽  
Trevor Williams ◽  
Oihane Simón ◽  
Miguel López-Ferber ◽  
Primitivo Caballero ◽  
...  
Keyword(s):  
Lethal Dose ◽  
Large Deletion ◽  
Phenotypic Traits ◽  
Deletion Mutants ◽  
Content Type ◽  
Consensus Sequences ◽  
Population Structures ◽  
Occlusion Bodies ◽  
Genomic Regions ◽  
Functional Analyses

ABSTRACTA naturalSpodoptera exiguamultiple nucleopolyhedrovirus (SeMNPV) isolate from Florida shares a strikingly similar genotypic composition to that of a naturalSpodoptera frugiperdaMNPV (SfMNPV) isolate from Nicaragua. Both isolates comprise a high proportion of large-deletion genotypes that lack genes that are essential for viral replication or transmission. To determine the likely origins of such genotypically similar population structures, we performed genomic and functional analyses of these genotypes. The homology of nucleotides in the deleted regions was as high as 79%, similar to those of other colinear genomic regions, although some SfMNPV genes were not present in SeMNPV. In addition, no potential consensus sequences were shared between the deletion flanking sequences. These results indicate an evolutionary mechanism that independently generates and sustains deletion mutants within each virus population. Functional analyses using different proportions of complete and deletion genotypes were performed with the two viruses in mixtures of occlusion bodies (OBs) or co-occluded virions. Ratios greater than 3:1 of complete/deletion genotypes resulted in reduced pathogenicity (expressed as median lethal dose), but there were no significant changes in the speed of kill. In contrast, OB yields increased only in the 1:1 mixture. The three phenotypic traits analyzed provide a broader picture of the functional significance of the most extensively deleted SeMNPV genotype and contribute toward the elucidation of the role of such mutants in baculovirus populations.

scholarly journals Molecular Characteristics of Spontaneous Deletions in the Hyperthermophilic Archaeon Sulfolobus acidocaldarius

2003 ◽  
Vol 185 (4) ◽  
pp. 1266-1272 ◽  
Author(s):  
Dennis W. Grogan ◽  
Josh E. Hansen
Keyword(s):  
Consensus Sequence ◽  
Low Frequency ◽  
Sulfolobus Acidocaldarius ◽  
Nucleotide Sequence Analysis ◽  
Molecular Characteristics ◽  
Sequence Dependence ◽  
Stem Loop ◽  
High Frequencies ◽  
Hyperthermophilic Archaeon ◽  
Basic Parameters

ABSTRACT Prokaryotic genomes acquire and eliminate blocks of DNA sequence by lateral gene transfer and spontaneous deletion, respectively. The basic parameters of spontaneous deletion, which are expected to influence the course of genome evolution, have not been determined for any hyperthermophilic archaeon. We therefore screened a number of independent pyrimidine auxotrophs of Sulfolobus acidocaldarius for deletions and sequenced those detected. Deletions accounted for only 0.4% of spontaneous pyrE mutations, corresponding to a frequency of about 10−8 per cell. Nucleotide sequence analysis of five independent deletions showed no significant association of the endpoints with short direct repeats, despite the fact that several such repeats occur within the pyrE gene and that duplication mutations in pyrE reverted at high frequencies. Endpoints of the spontaneous deletions did not coincide with short inverted repeats or potential stem-loop structures. No consensus sequence common to all the deletions could be identified, although two deletions showed the potential of being stabilized by octanucleotide sequences elsewhere in pyrE, and another pair of deletions shared an octanucleotide at their 3′ ends. The unusually low frequency and low sequence dependence of spontaneous deletions in the S. acidocaldarius pyrE gene compared to other genetic systems could not be explained in terms of possible constraints imposed by the 5-fluoroorotate selection.

Characterization of a trehalose-degrading enzyme from the hyperthermophilic archaeon Sulfolobus acidocaldarius

2016 ◽  
Vol 122 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Jeong Hyun Moon ◽  
Whiso Lee ◽  
Jihee Park ◽  
Kyoung-Hwa Choi ◽  
Jaeho Cha
Keyword(s):  
Sulfolobus Acidocaldarius ◽  
Hyperthermophilic Archaeon ◽  
Degrading Enzyme

Homologous recombination in Sulfolobus acidocaldarius: genetic assays and functional properties

2009 ◽  
Vol 37 (1) ◽  
pp. 88-91 ◽  
Author(s):  
Dennis W. Grogan
Keyword(s):  
Homologous Recombination ◽  
Functional Properties ◽  
Point Mutations ◽  
Sulfolobus Acidocaldarius ◽  
Intragenic Recombination ◽  
Chromosomal Markers ◽  
Cell To Cell Transfer ◽  
Initial Results ◽  
Pyre Gene

HR (homologous recombination) is expected to play important roles in the molecular biology and genetics of archaea, but, so far, few functional properties of archaeal HR have been measured in vivo. In the extreme thermoacidophile Sulfolobus acidocaldarius, a conjugational mechanism of DNA transfer enables quantitative analysis of HR between chromosomal markers. Early studies of this system indicated that HR occurred frequently between closely spaced mutations within the pyrE gene, and this result was later supported by various analyses involving defined point mutations and deletions. These properties of intragenic HR suggested a non-reciprocal mechanism in which donor sequences become incorporated into the recipient genome as short segments. Because fragmentation of donor DNA during cell-to-cell transfer could not be excluded from contributing to this result, subsequent analyses have focused on electroporation of selectable donor DNA directly into recipient strains. For example, S. acidocaldarius was found to incorporate synthetic ssDNA (single-stranded DNA) of more than ∼20 nt readily into its genome. With respect to various molecular properties of the ssDNA substrates, the process resembled bacteriophage λRed-mediated ‘recombineering’ in Escherichia coli. Another approach used electroporation of a multiply marked pyrE gene to measure donor sequence tracts transferred to the recipient genome in individual recombination events. Initial results indicate multiple discontinuous tracts in the majority of recombinants, representing a relatively broad distribution of tract lengths. This pattern suggests that properties of the HR process could, in principle, account for many of the apparent peculiarities of intragenic recombination initiated by S. acidocaldarius conjugation.

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