TREX1 – Apex predator of cytosolic DNA metabolism

ABSTRACT A total of 34 third chromosomes of Drosophila melanogaster that render homozygous larvae hypersensitive to killing by chemical mutagens have been isolated. Genetic analyses have placed responsible mutations in more than eleven complementation groups. Mutants in three complementation groups are strongly sensitive to methyl methanesulfonate, those in one are sensitive to nitrogen mustard, and mutants in six groups are hypersensitive to both mutagens. Eight of the ten loci mapped fall within 15% of the genetic map that encompasses the centromere of chromosome 3. Mutants from four of the complementation groups are associated with moderate to strong meiotic effects in females. Preliminary biochemical analyses have implicated seven of these loci in DNA metabolism.

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Regulation of Septum Formation in Aspergillus nidulans by a DNA Damage Checkpoint Pathway

Genetics ◽

10.1093/genetics/148.3.1055 ◽

1998 ◽

Vol 148 (3) ◽

pp. 1055-1067

Author(s):

Steven D Harris ◽

Peter R Kraus

Keyword(s):

Dna Damage ◽

Aspergillus Nidulans ◽

Cellular Response ◽

Dna Damage Checkpoint ◽

Temperature Sensitive ◽

Dna Metabolism ◽

Chromosomal Dna ◽

Checkpoint Response ◽

Septum Formation ◽

Checkpoint Pathway

Abstract In Aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before the formation of the first septum. Previous characterization of temperature-sensitive sepB and sepJ mutations showed that although they block septation, they also cause moderate defects in chromosomal DNA metabolism. Results presented here demonstrate that a variety of other perturbations of chromosomal DNA metabolism also delay septum formation, suggesting that this is a general cellular response to the presence of sublethal DNA damage. Genetic evidence is provided that suggests that high levels of cyclin-dependent kinase (cdk) activity are required for septation in A. nidulans. Consistent with this notion, the inhibition of septum formation triggered by defects in chromosomal DNA metabolism depends upon Tyr-15 phosphorylation of the mitotic cdk p34nimX. Moreover, this response also requires elements of the DNA damage checkpoint pathway. A model is proposed that suggests that the DNA damage checkpoint response represents one of multiple sensory inputs that modulates p34nimX activity to control the timing of septum formation.

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A Role for MMS4 in the Processing of Recombination Intermediates During Meiosis in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/159.4.1511 ◽

2001 ◽

Vol 159 (4) ◽

pp. 1511-1525 ◽

Cited By ~ 6

Author(s):

Teresa de los Santos ◽

Josef Loidl ◽

Brittany Larkin ◽

Nancy M Hollingsworth

Keyword(s):

Saccharomyces Cerevisiae ◽

Meiotic Recombination ◽

Biochemical Data ◽

Dna Metabolism ◽

Spore Viability ◽

Vegetative Cells ◽

Recombination Checkpoint

Abstract The MMS4 gene of Saccharomyces cerevisiae was originally identified due to its sensitivity to MMS in vegetative cells. Subsequent studies have confirmed a role for MMS4 in DNA metabolism of vegetative cells. In addition, mms4 diploids were observed to sporulate poorly. This work demonstrates that the mms4 sporulation defect is due to triggering of the meiotic recombination checkpoint. Genetic, physical, and cytological analyses suggest that MMS4 functions after the single end invasion step of meiotic recombination. In spo13 diploids, red1, but not mek1, is epistatic to mms4 for sporulation and spore viability, suggesting that MMS4 may be required only when homologs are capable of undergoing synapsis. MMS4 and MUS81 are in the same epistasis group for spore viability, consistent with biochemical data that show that the two proteins function in a complex. In contrast, MMS4 functions independently of MSH5 in the production of viable spores. We propose that MMS4 is required for the processing of specific recombination intermediates during meiosis.

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Dhole pack size variation: Assessing the effect of Prey availability and Apex predator

Ecology and Evolution ◽

10.1002/ece3.7380 ◽

2021 ◽

Author(s):

Aishwarya Bhandari ◽

Pallavi Ghaskadbi ◽

Parag Nigam ◽

Bilal Habib

Keyword(s):

Prey Availability ◽

Size Variation ◽

Apex Predator ◽

Pack Size

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ALTERED FIDELITY OF MITOTIC CHROMOSOME TRANSMISSION IN CELL CYCLE MUTANTS OF S. CEREVISIAE

Genetics ◽

10.1093/genetics/110.3.381 ◽

1985 ◽

Vol 110 (3) ◽

pp. 381-395

Author(s):

Leland H Hartwell ◽

David Smith

Keyword(s):

Cell Cycle ◽

Gene Product ◽

Mitotic Chromosome ◽

Mitotic Recombination ◽

Chromosome Loss ◽

Temperature Sensitive ◽

Repair Pathway ◽

Dna Metabolism ◽

Temperature Sensitive Mutants ◽

Chromosome Transmission

ABSTRACT Thirteen of 14 temperature-sensitive mutants deficient in successive steps of mitotic chromosome transmission (cdc2, 4, 5, 6, 7, 8, 9, 13, 14, 15, 16, 17 and 20) from spindle pole body separation to a late stage of nuclear division exhibited a dramatic increase in the frequency of chromosome loss and/or mitotic recombination when they were grown at their maximum permissive temperatures. The increase in chromosome loss and/or recombination is likely to be due to the deficiency of functional gene product rather than to an aberrant function of the mutant gene product since the mutant alleles are, with one exception, recessive to the wild-type allele for this phenotype. The generality of this result suggests that a delay in almost any stage of chromosome replication or segregation leads to a decrease in the fidelity of mitotic chromosome transmission. In contrast, temperature-sensitive mutants defective in the control step of the cell cycle (cdc28), in cytokinesis (cdc3) or in protein synthesis (ils1) did not exhibit increased recombination or chromosome loss.—Based upon previous results with mutants and DNA-damaging agents in a variety of organisms, we suggest that the induction of mitotic recombination in certain mutants is due to the action of a repair pathway upon nicks or gaps left in the DNA. This interpretation is supported by the fact that the induced recombination is dependent upon the RAD52 gene product, an essential component in the recombinogenic DNA repair pathway. Gene products whose deficiency leads to induced recombination are, therefore, strong candidates for proteins that function in DNA metabolism. Among the mutants that induce recombination are those known to be defective in some aspect of DNA replication (cdc2, 6, 8, 9) as well as some mutants defective in the G2 (cdc13 and 17) and M (cdc5 and 14) phases of the mitotic cycle. We suggest that special aspects of DNA metabolism may be occurring in G2 and M in order to prepare the chromosomes for proper segregation.

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Enzymes in DNA Metabolism

Annual Review of Biochemistry ◽

10.1146/annurev.bi.38.070169.004051 ◽

1969 ◽

Vol 38 (1) ◽

pp. 795-840 ◽

Cited By ~ 110

Author(s):

C C Richardson

Keyword(s):

Dna Metabolism

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First wolves in Luxembourg since 1893, originating from the Alpine and Central European populations

Mammalia ◽

10.1515/mammalia-2020-0119 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Laurent Schley ◽

Marianne Jacobs ◽

Sebastian Collet ◽

Alexander Kristiansen ◽

Jan Herr

Keyword(s):

Canis Lupus ◽

Dna Analysis ◽

Carcass Characteristics ◽

Management Plan ◽

Apex Predator ◽

Grey Wolf ◽

Melting Pot ◽

Central European ◽

The Past ◽

Hard Evidence

Abstract Considering the spread of the grey wolf (Canis lupus) in Europe over the past 30 years, Luxembourg took some measures to prepare for the return of this apex predator, including the establishment of a management plan that notably addresses the issue of wolf depredation on livestock. Here we present the results of genetic analyses of putative wolf saliva, hair and scat samples collected from or near prey carcasses between 2015 and 2020. In two cases, the wolf was confirmed via DNA analysis: in July 2017 near Garnich and in April 2020 near Niederanven, both assigned to category C1 (hard evidence). A third case was classified as C2 (confirmed observation) based on prey carcass characteristics, while genetic analysis yielded no result. These are the first confirmed records of wolves in Luxemburg since 1893. Moreover, the two C1-cases originated from the Alpine (Garnich) and Central European (Niederanven) populations. Given similar developments in the neighboring countries and regions, we conclude that the area including the Benelux countries as well as Rhineland-Palatinate, Saarland and Northern France may well become a melting pot for wolves of the two aforementioned populations in the coming years and decades.

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