scholarly journals Evidence for an inducible repair-recombination system in the female germ line of Drosophila melanogaster. I. Induction by inhibitors of nucleotide synthesis and by gamma rays.

Genetics ◽  
1995 ◽  
Vol 141 (2) ◽  
pp. 571-578 ◽  
Author(s):  
J C Bregliano ◽  
A Laurençon ◽  
F Degroote
Keyword(s):  
Drosophila Melanogaster ◽  
Gamma Rays ◽  
Line Element ◽  
Germ Line ◽  
Nucleotide Synthesis ◽  
Transposition Frequency ◽  
Recombination System ◽  
I Factor ◽  
Female Germ Line ◽  
Inducible Repair

Abstract In the I-R system of hybrid dysgenesis in Drosophila melanogaster, the transposition frequency of I factor, a LINE element-like retrotransposon, is regulated by the reactivity level of the R mother. This reactivity is a cellular state maternally inherited but chromosomally determined, which has been shown to undergo heritable, cumulative and reversible changes with aging and some environmental conditions. We propose the hypothesis that this reactivity level is one manifestation of an inducible repair-recombination system whose biological role might be analogous to the SOS response in bacteria. In this paper, we show that inhibitors of DNA synthesis and gamma rays enhance the reactivity level in a very similar way. This enhancement is heritable, cumulative and reversible.

scholarly journals Evidence for an inducible repair-recombination system in the female germ line of Drosophila melanogaster. II. Differential sensitivity to gamma rays.

Genetics ◽  
1995 ◽  
Vol 141 (2) ◽  
pp. 579-585 ◽  
Author(s):  
A Laurençon ◽  
J C Bregliano
Keyword(s):  
Drosophila Melanogaster ◽  
Gamma Rays ◽  
Germ Line ◽  
Differential Sensitivity ◽  
Repair System ◽  
Recombination System ◽  
I Factor ◽  
Female Germ Line ◽  
Dominant Lethals ◽  
Inducible Repair

Abstract In a previous paper, we reported that the reactivity level, which regulates the frequency of transposition of I factor, a LINE element-like retrotransposon, is enhanced by the same agents that induce the SOS response in Escherichia coli. In this report, we describe experimental evidence that, for identical genotypes, the reactivity levels correlate with the sensitivity of oogenesis to gamma rays, measured by the number of eggs laid and by frequency of dominant lethals. This strongly supports the hypothesis that the reactivity level is one manifestation of an inducible DNA repair system taking place in the female germ line of Drosophila melanogaster. The implications of this finding for the understanding of the regulation of I factor are discussed and some other possible biological roles of this system are outlined.

scholarly journals Evidence for an Inducible Repair-Recombination System in the Female Germ Line of Drosophila melanogaster. III. Correlation Between Reactivity Levels, Crossover Frequency and Repair Efficiency

Genetics ◽  
1997 ◽  
Vol 146 (4) ◽  
pp. 1333-1344 ◽  
Author(s):  
Anne Laurençon ◽  
Françoise Gay ◽  
Judith Ducau ◽  
Jean-Claude Bregliano
Keyword(s):  
Dna Repair ◽  
X Chromosome ◽  
Germ Line ◽  
Pericentromeric Region ◽  
Repair System ◽  
Recombination System ◽  
Repair Efficiency ◽  
Report Data ◽  
I Factor ◽  
Female Germ Line

We previously reported evidence that the so-called reactivity level, a peculiar cellular state of oocytes that regulates the frequency of transposition of I factor, a LINE element-like retrotransposon, might be one manifestation of a DNA repair system. In this article, we report data showing that the reactivity level is correlated with the frequency of crossing over, at least on the X chromosome and on the pericentromeric region of the third chromosome. Moreover, a check for X-chromosome losses and recessive lethals produced after gamma irradiation in flies with different reactivity levels, but common genetic backgrounds, brings more precise evidence for the relationship between reactivity levels and DNA repair. Those results support the existence of a repair-recombination system whose efficiency is modulated by endogenous and environmental factors. The implications of this biological system in connecting genomic variability and environment may shed new lights on adaptative mechanisms. We propose to call it VAMOS for variability modulation system.

Multiple products from the shavenbaby-ovo gene region of Drosophila melanogaster: relationship to genetic complexity

1994 ◽  
Vol 14 (10) ◽  
pp. 6809-6818
Author(s):  
M D Garfinkel ◽  
J Wang ◽  
Y Liang ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Gene Region ◽  
Multiple Products ◽  
Zinc Finger Motifs ◽  
Genetic Complexity ◽  
Complex Locus ◽  
Female Germ Line ◽  
Sensory Structures ◽  
Pole Cells

The Drosophila melanogaster shavenbaby (svb)-ovo gene region is a complex locus, containing two distinct but comutable genetic functions. ovo is required for survival and differentiation of female germ line cells and plays a role in germ line sex determination. In contrast, svb is required in both male and female embryos for the production of epidermal locomotor and sensory structures. Sequences required for the two genetic functions are partially overlapping. ovo corresponds to a previously described germ line-dependent 5.0-kb poly(A)+ mRNA that first appears in the germarium and accumulates in nurse cells during oogenesis. The 5.0-kb mRNA is stored in the egg, but it is rapidly lost in the embryos except for its continued presence in the germ line precursor pole cells. The ovo mRNA predicts a 1,028-amino-acid 110.6-kDa protein homologous with transcription factors. We have identified an embryonic mRNA, 7.1 kb in length, that contains exons partially overlapping those of the 5.0-kb poly(A)+ mRNA. The spatial distribution of this newly discovered transcript during midembryogenesis suggests that it corresponds to the svb function. The arrangement of exons common to the 5.0- and 7.1-kb mRNAs suggests that the Ovo and Svb proteins share DNA-binding specificity conferred by four Cys2-His2 zinc finger motifs but differ functionally in their capacity to interact with other components of the transcription machinery.

scholarly journals Maternal impairment of transposon regulation in Drosophila melanogaster by mutations in the genes aubergine, piwi and Suppressor of variegation 205

2010 ◽  
Vol 92 (4) ◽  
pp. 261-272 ◽  
Author(s):  
MICHAEL J. SIMMONS ◽  
MICHAEL W. THORP ◽  
JARED T. BUSCHETTE ◽  
KATHERINE PETERSON ◽  
ERIC W. CROSS ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Small Rnas ◽  
Germ Line ◽  
Associated Sequences ◽  
Female Germ Line ◽  
Maternal Impairment

SummaryTP5, a P element inserted in the telomere-associated sequences of the X chromosome, represses the excision of other P elements in the germ line through a combination of maternal and zygotic effects. The maternal component of this repression is impaired by heterozygous mutations in the aubergine and Suppressor of variegation 205 genes; one mutation in the piwi gene also appears to impair repression. In the female germ line, the level of TP5 mRNA is increased by these impairing mutations. The impairing aubergine and piwi mutations also increase the level of germ-line mRNA from CP, a transgene that encodes the P-element transposase; however, the Suppressor of variegation 205 mutation does not. These findings are discussed in terms of a model of P-element regulation that involves post-transcriptional and chromatin re-organizing events mediated by maternally transmitted small RNAs derived from the telomeric P element.

scholarly journals Multiple products from the shavenbaby-ovo gene region of Drosophila melanogaster: relationship to genetic complexity.

1994 ◽  
Vol 14 (10) ◽  
pp. 6809-6818 ◽  
Author(s):  
M D Garfinkel ◽  
J Wang ◽  
Y Liang ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Gene Region ◽  
Multiple Products ◽  
Zinc Finger Motifs ◽  
Genetic Complexity ◽  
Complex Locus ◽  
Female Germ Line ◽  
Sensory Structures ◽  
Pole Cells

The Drosophila melanogaster shavenbaby (svb)-ovo gene region is a complex locus, containing two distinct but comutable genetic functions. ovo is required for survival and differentiation of female germ line cells and plays a role in germ line sex determination. In contrast, svb is required in both male and female embryos for the production of epidermal locomotor and sensory structures. Sequences required for the two genetic functions are partially overlapping. ovo corresponds to a previously described germ line-dependent 5.0-kb poly(A)+ mRNA that first appears in the germarium and accumulates in nurse cells during oogenesis. The 5.0-kb mRNA is stored in the egg, but it is rapidly lost in the embryos except for its continued presence in the germ line precursor pole cells. The ovo mRNA predicts a 1,028-amino-acid 110.6-kDa protein homologous with transcription factors. We have identified an embryonic mRNA, 7.1 kb in length, that contains exons partially overlapping those of the 5.0-kb poly(A)+ mRNA. The spatial distribution of this newly discovered transcript during midembryogenesis suggests that it corresponds to the svb function. The arrangement of exons common to the 5.0- and 7.1-kb mRNAs suggests that the Ovo and Svb proteins share DNA-binding specificity conferred by four Cys2-His2 zinc finger motifs but differ functionally in their capacity to interact with other components of the transcription machinery.

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