Dosage dependence of maternal contribution to somatic cell division in Drosophila melanogaster

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1357-1364 ◽  
Author(s):  
M. Carmena ◽  
C. Gonzalez ◽  
J. Casal ◽  
P. Ripoll

Most mitotic mutants in Drosophila do not lead to lethality in early development despite the highly abnormal chromosome behaviour that they elicit. This has been explained as being the effect of maternally provided wild-type products. We have tested this hypothesis by studying cuticular clones derived from cells in which there has been loss of a marked Y chromosome due to chromosome nondisjunction in individuals homozygous for the mutation abnormal spindle who are progeny of heterozygous mothers. We have found that the size and frequency of these clones are higher than in control flies. Furthermore, by analysing flies whose female parents have different doses of the asp+ gene, we have found that there is a correlation between the amount of maternally contributed asp+ product and the frequency and size of cuticular clones. We have also estimated the time in development when the first mitotic mistakes take place, i.e. the time when maternal products are no longer sufficient to carry out normal cell division.

Open Biology ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 160334 ◽  
Author(s):  
E. L. Fishman ◽  
Kyoung Jo ◽  
Andrew Ha ◽  
Rachel Royfman ◽  
Ashtyn Zinn ◽  
...  

Typical centrioles are made of microtubules organized in ninefold symmetry. Most animal somatic cells have two centrioles for normal cell division and function. These centrioles originate from the zygote, but because the oocyte does not provide any centrioles, it is surprising that the zygotes of many animals are thought to inherit only one centriole from the sperm. Recently, in the sperm of Drosophila melanogaster , we discovered a second centriolar structure, the proximal centriole-like structure (PCL), which functions in the zygote. Whether the sperm of other insects has a second centriolar structure is unknown. Here, we characterized spermiogenesis in the red flour beetle, Tribolium castaneum . Electron microscopy suggests that Tribolium has one microtubule-based centriole at the tip of the axoneme and a structure similar to the PCL, which lacks microtubules and lies in a cytoplasmic invagination of the nucleus. Immunostaining against the orthologue of the centriole/PCL protein, Ana1, also recognizes two centrioles near the nucleus during spermiogenesis: one that is microtubule-based at the tip of the axoneme, suggesting it is the centriole; and another that is more proximal and appears during early spermiogenesis, suggesting it is the PCL. Together, these findings suggest that Tribolium sperm has one microtubule-based centriole and one microtubule-lacking centriole.


CellBio ◽  
2015 ◽  
Vol 04 (02) ◽  
pp. 30-36
Author(s):  
Feifeng Liu ◽  
Huize Chen ◽  
Rong Han

2009 ◽  
Vol 9 (1) ◽  
pp. 155-163 ◽  
Author(s):  
Rebecca Lindsey ◽  
Susan Cowden ◽  
Yainitza Hernández-Rodríguez ◽  
Michelle Momany

ABSTRACT Septins are cytoskeletal proteins found in fungi, animals, and microsporidia, where they form multiseptin complexes that act as scaffolds recruiting and organizing other proteins to ensure normal cell division and development. Here we characterize the septins AspA and AspC in the multicellular, filamentous fungus A spergillus nidulans. Mutants with deletions of aspA, aspC, or both aspA and aspC show early and increased germ tube and branch emergence, abnormal septation, and disorganized conidiophores. Strains in which the native aspA has been replaced with a single copy of aspA-GFP driven by the native septin promoter or in which aspC has been replaced with a single copy of aspC-GFP driven by the native promoter show wild-type phenotypes. AspA-GFP and AspC-GFP show identical localization patterns as discrete spots or bars in dormant and expanding conidia, as rings at forming septa and at the bases of emerging germ tubes and branches, and as punctate spots and filaments in the cytoplasm and at the cell cortex. In conidiophores, AspA-GFP and AspC-GFP localize as diffuse bands or rings at the bases of emerging layers and conidial chains and as discrete spots or bars in newly formed conidia. AspA-GFP forms abnormal structures in ΔaspC strains while AspC-GFP does not localize in ΔaspA strains. Our results suggest that AspA and AspC interact with each other and are important for normal development, especially for preventing the inappropriate emergence of germ tubes and branches. This is the first report of a septin limiting the emergence of new growth foci in any organism.


1993 ◽  
Vol 62 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Peter R. Holden ◽  
Peter Jones ◽  
John F. Y. Brookfield

SummaryThe bacterial cell division gene, ftsZ, was used as a specific probe to show the presence of a symbiotic bacterium in two wild type strains of Drosophila melanogaster. Under stringent hybridization conditions we have shown that the bacterium is transferred to the progeny of these strains from infected mothers and can be eradicated by treatment with the antibiotic tetracycline. We have characterized this bacterium, by amplifying and sequencing its 16S rRNA gene, as being a member of the genus Wolbachia, an organism that is known to parasitize a range of insects including Drosophila simulans. In a series of reciprocal crosses no evidence was found that the symbiont causes cytoplasmic incompatibility (CI) which is known to occur in infected strains of D. simulans. The implications of these findings are discussed.


Genetics ◽  
1979 ◽  
Vol 92 (3) ◽  
pp. 833-847
Author(s):  
Bruce S Baker ◽  
David A Smith

ABSTRACT The effects of 13 mutagen-sensitive (mus) mutants (representing seven loci) on mitotic chromosome stability in nonmutagenized cells have been examined genetically. To do this, mus-bearing flies heterozygous for the recessive somatic-cell marker, multiple wing hairs (mwh), were examined for increased frequencies of mwh clones in the wing blade. Mutants at the mus-103, mus-104 and mus-106 loci do not affect the frequency of mwh clones, while mus-101, mus-102, mus-105 and mus-109 alleles cause increases in the frequency of mwh clones. These data show that the wild-type alleles of latter four loci specify functions that are required for chromosome stability in nonmutagenized cells. Analysis of the size distribution of mwh clones produced by these mutants suggests that most chromosome instability caused by these mutants is the consequence of chromosome breakage; in the presence of mus-105 and mus-109 alleles a small fraction of the mwh clones are produced by an event (mitotic recombination, mutation, nondisjunction) that produces euploid clones. To inquire whether any of the extant alleles of the mus-101, mus-102, mus-105 and mus-209 loci might be leaky alleles of loci that carry out essential mitotic functions, chromosome stability in females homozygous for alleles of these loci has been compared to that of females carrying one dose of a mutant over a deficiency for that mus locus. These comparisons show that the extant alleles at the mus-102, mus-1O9 and mus-105 loci are all leaky mutants. It is suggested that all three of these loci may specify essential mitotic functions.


1964 ◽  
Vol 5 (1) ◽  
pp. 80-84 ◽  
Author(s):  
B. M. Slizynski

On the basis of chromosome behaviour in three strains of Drosophila melanogaster males—a wild-type strain, a translocation heterozygote strain and a double translocation strain—it is concluded that the cytologically detected apparent chiasmata in the autosomes are only surface associations of homologous chromosomes and do not involve exchange of chromosome material. Such chiasma-like associations occur also between non-homologous chromosomes. The stainable, Feulgen-positive material of the chromosomes is thought to be responsible for the surface associations.


Author(s):  
Krishan Awtar

Exposure of cells to low sublethal but mitosis-arresting doses of vinblastine sulfate (Velban) results in the initial arrest of cells in mitosis followed by their subsequent return to an “interphase“-like stage. A large number of these cells reform their nuclear membranes and form large multimicronucleated cells, some containing as many as 25 or more micronuclei (1). Formation of large multinucleate cells is also caused by cytochalasin, by causing the fusion of daughter cells at the end of an otherwise .normal cell division (2). By the repetition of this process through subsequent cell divisions, large cells with 6 or more nuclei are formed.


2001 ◽  
Vol 7 (S2) ◽  
pp. 1012-1013
Author(s):  
Uyen Tram ◽  
William Sullivan

Embryonic development is a dynamic event and is best studied in live animals in real time. Much of our knowledge of the early events of embryogenesis, however, comes from immunofluourescent analysis of fixed embryos. While these studies provide an enormous amount of information about the organization of different structures during development, they can give only a static glimpse of a very dynamic event. More recently real-time fluorescent studies of living embryos have become much more routine and have given new insights to how different structures and organelles (chromosomes, centrosomes, cytoskeleton, etc.) are coordinately regulated. This is in large part due to the development of commercially available fluorescent probes, GFP technology, and newly developed sensitive fluorescent microscopes. For example, live confocal fluorescent analysis proved essential in determining the primary defect in mutations that disrupt early nuclear divisions in Drosophila melanogaster. For organisms in which GPF transgenics is not available, fluorescent probes that label DNA, microtubules, and actin are available for microinjection.


Author(s):  
Emmanuel Tiyo Ayikobua ◽  
Josephine Kasolo ◽  
Keneth Iceland Kasozi ◽  
Ejike Daniel Eze ◽  
Abass Safiriyu ◽  
...  

AbstractBackgroundThe Phosphatase and tensin-induced putative kinase 1 (PINK1B9) mutant for Drosophila melanogaster is a key tool that has been used in assessing the pathology of Parkinsonism and its possible remedy. This research was targeted toward determining the effects of ethanolic extract of propolis, with levodopa therapy in the management of Parkinsonism.MethodThe PINK1B9 flies were divided into groups and fed with the different treatment doses of ethanoic extract of propolis. The treatment groups were subjected to 21 days of administration of propolis and the levodopa at different doses after which percentage climbing index, antioxidant activity and lifespan studies were done.ResultsPropolis alone improved motor activity, antioxidant and lifespan in Drosophila melanogaster than in PINK1 flies. Propolis in combination with levodopa significantly (P<0.05) improved physiological parameters at higher than lower concentrations in Parkinsonism Drosophila melanogaster demonstrating its importance in managing side effects associated with levodopa.ConclusionPropolis is a novel candidate as an alternative and integrative medicinal option to use in the management of Parkinsonism in both animals and humans at higher concentrations.


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