scholarly journals Genetic Evidence That Nonhomologous Disjunction and Meiotic Drive Are Properties of Wild-Type Drosophila melanogaster Male Meiosis

Genetics ◽  
2005 ◽  
Vol 172 (1) ◽  
pp. 305-316 ◽  
Author(s):  
Manuela Boschi ◽  
Massimo Belloni ◽  
Leonard G. Robbins
Keyword(s):  
Drosophila Melanogaster ◽  
Meiotic Drive ◽  
Male Meiosis ◽  
Genetic Evidence ◽  
Wild Type

scholarly journals Inseparability of X-Heterochromatic Functions Responsible for X:Y Pairing, Meiotic Drive, and Male Fertility in Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 116 (3) ◽  
pp. 399-407
Author(s):  
Bruce McKee ◽  
Dan L Lindsley
Keyword(s):  
Drosophila Melanogaster ◽  
Male Fertility ◽  
Meiotic Drive ◽  
Male Meiosis ◽  
Recovery Ratio ◽  
Strongly Correlated ◽  
Wild Type ◽  
Autosome Translocation ◽  
Ratio Distortion ◽  
Sperm Recovery

ABSTRACT Deficiencies encompassing part or all of the X heterochromatin of Drosophila melanogaster have been linked to three abnormalities in male meiosis and spermatogenesis: X-Y nondisjunction, skewed sperm recovery ratios favoring sperm with reduced chromatin content, and sterility in males carrying either a Y-autosome translocation or mal  +  Y. In this study, 18 X heterochromatic deficiencies of varying sizes were tested in XY males for their spermatogenic phenotypes. All 18 proved to be either mutant for all three phenotypes or wild type for all three. Although variable among mutant deficiencies, expression levels of all three phenotypes were strongly correlated. Deficiencies that cause high levels of nondisjunction also cause severe recovery ratio distortion and are completely sterile in conjunction with mal  +  Y. Low nondisjunction deficiencies cause comparable mild effects for the other phenotypes. The same deficiencies were also tested in males carrying a large heterochromatic free X duplication Dp(1;f)3. For all deficiencies which induce nondisjunction in XY males, the Y and free duplication pair regularly and the X fails to pair in XYDp males. Drive levels are constant across deficiencies in these males. Thus elimination of variability in the pairing phenotype also eliminates variability in sperm recovery ratios.

scholarly journals Drosophila BEACH domain autophagic adaptor blue cheese shuttles between vesicle populations and is required for an early step in autophagy

2016 ◽  
Author(s):  
Joan Sim ◽  
Kathleen A. Osborne ◽  
Irene Argudo Garcia ◽  
Artur S. Matysik ◽  
Rachel Kraut
Keyword(s):  
Drosophila Melanogaster ◽  
Neuronal Death ◽  
Adaptor Protein ◽  
Genetic Evidence ◽  
Wild Type ◽  
Human Homologue ◽  
Early Step ◽  
Blue Cheese ◽  
Family Protein ◽  
Different Parts

AbstractDrosophila melanogaster blue cheese (bchs) encodes a large BEACH (Beige and Chediak-Higashi) family protein that is postulated to function as an adaptor protein with roles in vesicle trafficking. Mutation in bchs leads to the accumulation of ubiquitinated aggregates in aged brains, presumably because of a conserved function with its human homologue Autophagy-Linked FYVE (ALFY), which interacts with Atg5 and p62 to promote the clearance of aggregate-prone proteins. In this study, we present pharmacological and genetic evidence using a well-defined larval motorneuron paradigm that in Drosophila bchs mutants, autophagic deficit contributes to neurodegeneration. Specifically, we show that motorneuron death in larvae is accompanied by the accumulation of prominent ubiquitinated aggregates in synaptic termini, and that these are sensitive to autophagy modulating drugs. In primary bchs neurons, early autophagic compartments increase in number and intensity based on Atg5 expression, but fail to progress to Atg8-labelled compartments, indicating non-clearance. A rescuing transgene encoding the longest Bchs BEACH domain isoform not only reverses this defect, but also greatly increases Atg8 compartment number and rescues neuronal death. Although only a small fraction of Bchs colocalizes with these markers under wild-type conditions, the population of Bchs that does associate with autophagosomes shuttles between different locations depending on how autophagy is induced. These observations, together with epistatic relationships between bchs mutant alleles and autophagy-modulating drugs and genetic backgrounds, points to a model whereby BEACH domain isoforms of Bchs participate in the early steps of autophagy by recruiting Atg5 to target substrates for clearance, and that Bchs’ association with different parts of the autophagy machinery depends upon the type of autophagic stress imposed upon the neuron.

Functional identification of the Segregation distorter locus of Drosophila melanogaster by germline transformation.

Genetics ◽  
1994 ◽  
Vol 137 (1) ◽  
pp. 201-209 ◽  
Author(s):  
J R McLean ◽  
C J Merrill ◽  
P A Powers ◽  
B Ganetzky
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Segregation ◽  
Genomic Dna ◽  
Tandem Duplication ◽  
Meiotic Drive ◽  
Wild Type ◽  
Functional Identification ◽  
Germline Transformation ◽  
Segregation Distorter ◽  
Distorter Locus

Abstract Segregation Distorter (SD) is a meiotic drive system in D. melanogaster that results in the failure of SD/SD+ males to transmit SD+ homologs owing to the induced dysfunction of spermatids carrying the normal chromosome. Segregation distorter (Sd), the gene primarily responsible for this distorted transmission, is associated with a novel 12-kb restriction fragment containing a tandem duplication of a 5-kb wild-type segment of genomic DNA. When introduced into appropriate genetic backgrounds by germline transformation, this 12-kb fragment causes full levels of distortion and directs the expression of an SD-specific 4-kb transcript. Transformants that have lost part of this segment are unable to cause distortion and do not express the 4-kb transcript. These results identify the tandem duplication as Sd.

scholarly journals Genetic analysis of Stellate elements of Drosophila melanogaster.

Genetics ◽  
1994 ◽  
Vol 138 (4) ◽  
pp. 1181-1197 ◽  
Author(s):  
G Palumbo ◽  
S Bonaccorsi ◽  
L G Robbins ◽  
S Pimpinelli
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Copy Number ◽  
Meiotic Drive ◽  
Genetic System ◽  
Male Meiosis ◽  
Meiotic Abnormalities ◽  
Y Chromosomes ◽  
Sperm Development ◽  
Dependent Failure

Abstract Repeated elements are remarkably important for male meiosis and spermiogenesis in Drosophila melanogaster. Pairing of the X and Y chromosomes is mediated by the ribosomal RNA genes of the Y chromosome and X chromosome heterochromatin, spermiogenesis depends on the fertility factors of the Y chromosome. Intriguingly, a peculiar genetic system of interaction between the Y-linked crystal locus and the X-linked Stellate elements seem to be also involved in male meiosis and spermiogenesis. Deletion of the crystal element of the Y, via an interaction with the Stellate elements of the X, causes meiotic abnormalities, gamete-genotype dependent failure of sperm development (meiotic drive), and deposition of protein crystals in spermatocytes. The current hypothesis is that the meiotic abnormalities observed in cry- males is due to an induced overexpression of the normally repressed Ste elements. An implication of this hypothesis is that the strength of the abnormalities would depend on the amount of the Ste copies. To test this point we have genetically and cytologically examined the relationship of Ste copy number and organization to meiotic behavior in cry- males. We found that heterochromatic as well as euchromatic Ste repeats are functional and that the abnormality in chromosome condensation and the frequency of nondisjunction are related to Ste copy number. Moreover, we found that meiosis is disrupted after synapsis and that cry-induced meiotic drive is probably not mediated by Ste.

scholarly journals Spindle Self-organization and Cytokinesis During Male Meiosis in asterless Mutants of Drosophila melanogaster

1998 ◽  
Vol 142 (3) ◽  
pp. 751-761 ◽  
Author(s):  
Silvia Bonaccorsi ◽  
Maria Grazia Giansanti ◽  
Maurizio Gatti
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Segregation ◽  
Spindle Assembly ◽  
Male Meiosis ◽  
Self Organization ◽  
Wild Type ◽  
Female Meiosis ◽  
Classical View ◽  
Central Spindle ◽  
Spindle Microtubules

While Drosophila female meiosis is anastral, both meiotic divisions in Drosophila males exhibit prominent asters. We have identified a gene we call asterless (asl) that is required for aster formation during male meiosis. Ultrastructural analysis showed that asl mutants have morphologically normal centrioles. However, immunostaining with antibodies directed either to γ tubulin or centrosomin revealed that these proteins do not accumulate in the centrosomes, as occurs in wild-type. Thus, asl appears to specify a function required for the assembly of centrosomal material around the centrioles. Despite the absence of asters, meiotic cells of asl mutants manage to develop an anastral spindle. Microtubules grow from multiple sites around the chromosomes, and then focus into a peculiar bipolar spindle that mediates chromosome segregation, although in a highly irregular way. Surprisingly, asl spermatocytes eventually form a morphologically normal ana–telophase central spindle that has full ability to stimulate cytokinesis. These findings challenge the classical view on central spindle assembly, arguing for a self-organization of this structure from either preexisting or newly formed microtubules. In addition, these findings strongly suggest that the asters are not required for signaling cytokinesis.

scholarly journals The hobo Transposable Element Excises and Has Related Elements in Tephritid Species

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1339-1347
Author(s):  
Alfred M Handler ◽  
Sheilachu P Gomez
Keyword(s):  
Drosophila Melanogaster ◽  
Ceratitis Capitata ◽  
Bactrocera Dorsalis ◽  
Parsimony Analysis ◽  
Wild Type ◽  
Anastrepha Suspensa ◽  
Tephritid Species ◽  
Mutant Strains ◽  
Almost All ◽  
Horizontal Transfers

Abstract Function of the Drosophila melanogaster hobo transposon in tephritid species was tested in transient embryonic excision assays. Wild-type and mutant strains of Anastrepha suspensa, Bactrocera dorsalis, B. cucurbitae, Ceratitis capitata, and Toxotrypana curvicauda all supported hobo excision or deletion both in the presence and absence of co-injected hobo transposase, indicating a permissive state for hobo mobility and the existence of endogenous systems capable of mobilizing hobo. In several strains hobo helper reduced excision. Excision depended on hobo sequences in the indicator plasmid, though almost all excisions were imprecise and the mobilizing systems appear mechanistically different from hobo. hobe-related sequences were identified in all species except T. curvicauda. Parsimony analysis yielded a subgroup including the B. cucurbitae and C. capitata sequences along with hobo and Hermes, and a separate, more divergent subgroup including the A. suspensa and B. dorsalis sequences. All of the sequences exist as multiple genomic elements, and a deleted form of the B. cucurbitae element exists in B. dorsalis. The hobo-related sequences are probably members of the hAT transposon family with some evolving from distant ancestor elements, while others may have originated from more recent horizontal transfers.

scholarly journals Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Cellular Aging ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

scholarly journals INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 289-299
Author(s):  
Margaret McCarron ◽  
William Gelbart ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Information Transfer ◽  
Large Scale ◽  
Genetic Basis ◽  
Xanthine Dehydrogenase ◽  
Specific Protein ◽  
Wild Type ◽  
Electrophoretic Variation ◽  
The Stability ◽  
Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

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