Initial phases of DNA synthesis in Drosophila melanogaster

Chromosoma ◽  
1974 ◽  
Vol 47 (4) ◽  
pp. 403-413 ◽  
Author(s):  
Klaus H�gele ◽  
Wolf -Ekkehard Kalisch
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Synthesis

Morphological and molecular modifications induced by heat shock in Drosophila melanogaster embryos

Development ◽  
1983 ◽  
Vol 77 (1) ◽  
pp. 167-182
Author(s):  
Giorgio Graziosi ◽  
Franco de Cristini ◽  
Angelo di Marcotullio ◽  
Roberto Marzari ◽  
Fulvio Micali ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Dna Synthesis ◽  
Histological Analysis ◽  
Developmental Stages ◽  
Early Embryo ◽  
Direct Relation ◽  
Hsp 70 ◽  
Survival Pattern ◽  
Shock Proteins

The early embryo of Drosophila melanogaster did not survive treatment at 37 °C (heat shock) for 25 min. The histological analysis of eggs treated in this way showed that the heat shock caused disintegration of nuclei and of cytoplasmic islands, displacement and swelling of nuclei and blocked mitoses. These effects were not observed in embryos treatedafter blastoderm formation. After this stage, we noticed that development was slowed down. The heat shock proteins (hsp 83,70 and 68) were, under shock, synthesized at all developmental stages. There was little or no synthesis of hsp 70 and 68 in unfertilized eggs, but synthesis increased in proportion to the number of nuclei present. Most probably, hsp 70 synthesis was directed by zygotic mRNA. DNA synthesis was not blocked by the heat shock though the overall incorporation of [3H]thymidine was substantially reduced, presumably because of the block of mitoses. We did not find a direct relation between survival pattern and hsp synthesis. We concluded that some, at least, of the heat shock genes can be activated at all developmental stages and that heat shock could be used for synchronizing mitoses.

DNA synthesis during early development of Drosophila melanogaster

1974 ◽  
Vol 4 (4) ◽  
pp. 381-394 ◽  
Author(s):  
Susan J. Friedman ◽  
Philip J. Skehan ◽  
Mary Lake Polan ◽  
Anne Fausto-Sterling ◽  
P.R. Brown
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Synthesis ◽  
Early Development

scholarly journals The Drosophila melanogaster PIF1 helicase promotes survival during replication stress and processive DNA synthesis during double-strand gap repair

2019 ◽  
Author(s):  
Ece Kocak ◽  
Sarah Dykstra ◽  
Alexandra Nemeth ◽  
Catherine G. Coughlin ◽  
Kasey Rodgers ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Synthesis ◽  
Synthetic Lethality ◽  
Protein Complexes ◽  
Nuclear Genome ◽  
Replication Stress ◽  
Dna Helicase ◽  
Acid Protein ◽  
Brca2 Protein ◽  
High Concentrations

AbstractPIF1 is a 5’ to 3’ DNA helicase that can unwind double-stranded DNA and disrupt nucleic acid-protein complexes. In Saccharomyces cerevisiae, Pif1 plays important roles in mitochondrial and nuclear genome maintenance, telomere length regulation, unwinding of G-quadruplex structures, and DNA synthesis during break-induced replication. Some, but not all, of these functions are shared with other eukaryotes. To gain insight into the evolutionarily conserved functions of PIF1, we created pif1 null mutants in Drosophila melanogaster and assessed their phenotypes throughout development. We found that pif1 mutant larvae exposed to high concentrations of hydroxyurea, but not other DNA damaging agents, experience reduced survival to adulthood. Embryos lacking PIF1 fail to segregate their chromosomes efficiently during early nuclear divisions, consistent with a defect in DNA replication. Furthermore, loss of the BRCA2 protein, which is required for stabilization of stalled replication forks in metazoans, causes synthetic lethality in third instar larvae lacking either PIF1 or the polymerase delta subunit POL32. Interestingly, pif1 mutants have a reduced ability to synthesize DNA during repair of a double-stranded gap, but only in the absence of POL32. Together, these results support a model in which Drosophila PIF1 functions with POL32 during times of replication stress but acts independently of POL32 to promote synthesis during double-strand gap repair.

scholarly journals MUTAGENESIS IN OOCYTES OF DROSOPHILA MELANOGASTER. I. SCHEDULED SYNTHESIS OF NUCLEAR AND MITOCHONDRIAL DNA AND UNSCHEDULED DNA SYNTHESIS

Genetics ◽  
1983 ◽  
Vol 104 (2) ◽  
pp. 279-299
Author(s):  
Mark R Kelley ◽  
William R Lee
Keyword(s):  
Dna Repair ◽  
Mitochondrial Dna ◽  
Drosophila Melanogaster ◽  
Dna Synthesis ◽  
Nuclear Dna ◽  
Germ Line ◽  
Mutation Induction ◽  
Time Interval ◽  
Unscheduled Dna Synthesis ◽  
Female Germ Line

ABSTRACT As a model system for studying mutagenesis, the oocyte of Drosophila melanogaster has exhibited considerable complexity. Very few experiments have been conducted on the effect of exposing oocytes to chemical mutagens, presumably due to their lower mutational response relative to sperm and spermatids. This lower response may be due either to a change in probability of mutation induction per adduct due to a change in the type of DNA repair or to a lower dose of the mutagen to the female germ line. To study molecular dosimetry and DNA repair in the oocyte, the large number of intracellular constituents (mtDNA, RNA, nucleic acid precursors and large quantities of proteins and lipids) must be separated from nuclear DNA. In this paper we present results showing reliable separation of such molecules enabling us to detect scheduled nuclear and mitochondrial DNA synthesis. We also, by understanding the precise timing of such events, can detect unscheduled DNA synthesis (UDS) as a measure of DNA repair. Furthermore, by comparing the UDS results in a repair competent (Ore-R) vs. a repair deficient (mei-9L1) strain, we have shown the oocyte capable of DNA repair after treatment with ethyl methanesulfonate (EMS). We conclude that the important determinant of mutation induction in oocytes after treatment with EMS is the time interval between DNA alkylation and DNA synthesis after fertilization, i.e., the interruption of continuous DNA repair.

scholarly journals The Drosophila melanogaster PIF1 Helicase Promotes Survival During Replication Stress and Processive DNA Synthesis During Double-Strand Gap Repair

Genetics ◽  
2019 ◽  
Vol 213 (3) ◽  
pp. 835-847 ◽  
Author(s):  
Ece Kocak ◽  
Sarah Dykstra ◽  
Alexandra Nemeth ◽  
Catherine G. Coughlin ◽  
Kasey Rodgers ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Synthesis ◽  
Replication Stress ◽  
Pif1 Helicase

scholarly journals Molecular profile of the D. melanogaster mutant genotype w1118 in the presence of variable amount of deuterium (D)

2021 ◽  
Author(s):  
Gallia Butnaru ◽  
◽  
Sorina Popescu ◽  
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Synthesis ◽  
Nuclear Dna ◽  
Culture Media ◽  
Mutant Line ◽  
Molecular Profile ◽  
Variable Amount ◽  
Mutant Genotype ◽  
Very High

The Drosophila melanogaster w1118 mutant line was used to identify the effect of deuterium (D) on DNA synthesis. D concentrations ranged from 30ppm to 96.89% (low and very high amount respec-tively). Five generations of flies were bred on culture media prepared with 6 concentrations of D. For each generation the DNA was analyzed, and its variability was established. The results showed a small involvement of D in the successive synthesis of nuclear DNA.

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