A New Form of Symbiotic Bacteria Wolbachia Found in the Endoplasmic Reticulum of Early Embryos of Drosophila melanogaster

Abstract Rex is a multicopy genetic element that maps within an X-linked ribosomal RNA gene (rDNA) array of D. melanogaster. Acting maternally, Rex causes recombination between rDNA arrays in a few percent of early embryos. With target chromosomes that contain two rDNA arrays, the exchanges either delete all of the material between the two arrays or invert the entire intervening chromosomal segment. About a third of the embryos produced by Rex homozygotes have cytologically visible chromosome damage, nearly always involving a single chromosome. Most of these embryos die during early development, displaying a characteristic apoptosis-like phenotype. An experiment that tests whether the cytologically visible damage is rDNA-specific is reported here. In this experiment, females heterozygous for Rex and an rDNA-deficient X chromosome were crossed to males of two genotypes. Some of the progeny from the experimental cross entirely lacked rDNA, while all of the progeny from the control cross had at least one rDNA array. A significantly lower frequency of early-lethal embryos in the experimental cross, proportionate to the fraction of rDNA-deficient embryos, demonstrates that Rex preferentially damages rDNA.

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Intergenerational transmission of symbiotic bacteria in oviparous and viviparous demosponges, with emphasis on intracytoplasmically-compartmented bacterial types

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315407058080 ◽

2007 ◽

Vol 87 (6) ◽

pp. 1701-1713 ◽

Cited By ~ 40

Author(s):

Manuel Maldonado

Keyword(s):

Microbial Communities ◽

Symbiotic Bacteria ◽

Free Swimming ◽

Transmission Electron ◽

Early Embryos ◽

Membrane Bound ◽

Chondrilla Nucula ◽

New Generation ◽

Swimming Larva ◽

Free Swimming Larva

Recent molecular detection of vast microbial communities exclusively associated with sponges has made evident the need for a better understanding of the mechanisms by which these symbiotic microbes are handled and transferred from one sponge generation to another. This transmission electron microscopy (TEM) study investigated the occurrence of symbiotic bacteria in free-swimming larvae of two viviparous species (Haliclona caerulea and Corticium candelabrum) and spawned gametes of two oviparous species (Chondrilla nucula and Petrosia ficiformis). Complex microbial communities were found in these sponges, which in two cases included bacteria characterized by an intra-cytoplasmic membrane (ICM). When ICM-bearing and ICM-lacking bacteria co-existed, they were transferred following identical pathways. Nevertheless, the mechanism for microbial transference varied substantially between species. In C. nucula, a combination of intercellular symbiotic ICM-bearing and ICM-lacking bacteria, along with cyanobacteria and yeasts, were collected from the mesohyl by amoeboid nurse cells, then transported and transferred to the oocytes. In the case of Corticium candelabrum, intercellular bacteria did not enter the gametes, but spread into the division furrows of early embryos and proliferated in the central cavity of the free-swimming larva. Surprisingly, symbiotic bacteria were not vertically transmitted by P. ficiformis gametes or embryos, but apparently acquired from the environment by the juveniles of each new generation. This study failed to unravel the mechanism by which the intercellular endosymbiotic bacterium found in the central mesohyl of the H. caerulea larva got there. Nevertheless, the ultrastructure of this bacterial rod, which was characterized by a star-shaped cross section with nine radial protrusions, an ICM-bound riboplasm, and a putative membrane-bound acidocalcisome, suggested that it may represent a novel organization grade within the prokaryotes. It combines traits occurring in members of Poribacteria, Planctomycetes and Verrucomicrobia, emerging as one of the most complex prokaryotic architectures known to date.

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Bacterial influence on the maintenance of symbiotic yeast through Drosophila metamorphosis

10.1101/2020.05.31.126185 ◽

2020 ◽

Author(s):

Robin Guilhot ◽

Antoine Rombaut ◽

Anne Xuéreb ◽

Kate Howell ◽

Simon Fellous

Keyword(s):

Young Adults ◽

Drosophila Melanogaster ◽

Life Cycle ◽

Symbiotic Bacteria ◽

Bacterial Symbionts ◽

Tripartite Symbiosis ◽

Summary Statement ◽

Key Features ◽

Microbial Symbionts

AbstractInteractions between microbial symbionts of metazoan hosts are emerging as key features of symbiotic systems. Little is known about the role of such interactions on the maintenance of symbiosis through host’s life cycle. We studied the influence of symbiotic bacteria on the maintenance of symbiotic yeast through metamorphosis of the fly Drosophila melanogaster. To this end we mimicked the development of larvae in natural fruit. In absence of bacteria yeast was never found in young adults. However, yeast could maintain through metamorphosis when larvae were inoculated with symbiotic bacteria isolated from D. melanogaster faeces. Furthermore, an Enterobacteriaceae favoured yeast transstadial maintenance. Because yeast is a critical symbiont of D. melanogaster flies, bacterial influence on host-yeast association may have consequences for the evolution of insect-yeast-bacteria tripartite symbiosis and their cooperation.Summary statementBacterial symbionts of Drosophila influence yeast maintenance through fly metamorphosis, a novel observation that may have consequences for the evolution of insect-yeast-bacteria interactions.

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Cytoplasmic membrane transplants in early Xenopus embryos indicate cell-cycle-specific effects

Biochemistry and Cell Biology ◽

10.1139/o92-176 ◽

1992 ◽

Vol 70 (12) ◽

pp. 1290-1300 ◽

Cited By ~ 2

Author(s):

Jacques Paiement ◽

J. Manuel Dominguez ◽

Paul-Emil Messier

Keyword(s):

Cell Cycle ◽

Endoplasmic Reticulum ◽

Membrane Protein ◽

Rough Endoplasmic Reticulum ◽

Primary Tumors ◽

Adult Rat ◽

Xenopus Embryos ◽

Specific Effects ◽

Early Embryos ◽

Cytoplasmic Membranes

Fragments of rough endoplasmic reticulum or Golgi complex isolated from normal adult rat liver homogenates were injected into one cell of cleaving two-cell Xenopus laevis embryos and the effects on development were monitored during early cleavage by morphological analysis. Scanning electron microscopy revealed the formation of large cells on the injected side of the embryos. Such large cells were not present in controls and thus were considered to have been formed as a consequence of delayed cleavage. Delay of cleavage was obtained with as little as 1 ng of membrane protein giving a ratio of membrane protein to embryo protein of 1:105. Cytological observations of microinjected embryos confirmed the occurrence of delayed cytokinesis and suggested that nuclear division became asynchronous. Since rough microsomes from proliferating tissues (i.e., livers with primary tumors and livers undergoing regeneration) showed little or no effect on cytokinesis after microinjection into early embryos, we conclude that cytoplasmic membranes may exhibit cell-cycle-specific properties important for normal development.Key words: rough endoplasmic reticulum and Golgi membranes, hepatectomy, hepatocellular carcinoma, cell cycle, membrane transplants, Xenopus embryos, cleavage arrest.

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Homologous Recombination and DNA-End Joining Reactions in Zygotes and Early Embryos of Zebrafish (Danio rerio) and Drosophila melanogaster

Biological Chemistry ◽

10.1515/bchm.1998.379.6.673 ◽

1998 ◽

Vol 379 (6) ◽

Cited By ~ 41

Author(s):

Michael Hagmann ◽

Rémy Bruggmann ◽

Lei Xue ◽

Oleg Georgiev ◽

Walter Schaffner ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Homologous Recombination ◽

Danio Rerio ◽

End Joining ◽

Early Embryos

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Lysosomal calcium homeostasis defects, not proton pump defects, cause endo-lysosomal dysfunction in PSEN-deficient cells

The Journal of Cell Biology ◽

10.1083/jcb.201201076 ◽

2012 ◽

Vol 198 (1) ◽

pp. 23-35 ◽

Cited By ~ 123

Author(s):

Katrijn Coen ◽

Ronald S. Flannagan ◽

Szilvia Baron ◽

Luciene R. Carraro-Lacroix ◽

Dong Wang ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

Drosophila Melanogaster ◽

Alternative Hypothesis ◽

Atpase Subunit ◽

Lysosomal Dysfunction ◽

Calcium Storage ◽

And Function ◽

Lysosomal Acidification

Presenilin (PSEN) deficiency is accompanied by accumulation of endosomes and autophagosomes, likely caused by impaired endo-lysosomal fusion. Recently, Lee et al. (2010. Cell. doi: http://dx.doi.org/10.1016/j.cell.2010.05.008) attributed this phenomenon to PSEN1 enabling the transport of mature V0a1 subunits of the vacuolar ATPase (V-ATPase) to lysosomes. In their view, PSEN1 mediates the N-glycosylation of V0a1 in the endoplasmic reticulum (ER); consequently, PSEN deficiency prevents V0a1 glycosylation, compromising the delivery of unglycosylated V0a1 to lysosomes, ultimately impairing V-ATPase function and lysosomal acidification. We show here that N-glycosylation is not a prerequisite for proper targeting and function of this V-ATPase subunit both in vitro and in vivo in Drosophila melanogaster. We conclude that endo-lysosomal dysfunction in PSEN−/− cells is not a consequence of failed N-glycosylation of V0a1, or compromised lysosomal acidification. Instead, lysosomal calcium storage/release is significantly altered in PSEN−/− cells and neurons, thus providing an alternative hypothesis that accounts for the impaired lysosomal fusion capacity and accumulation of endomembranes that accompanies PSEN deficiency.

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The casein kinase 1 alpha gene of Drosophila melanogaster is developmentally regulated and the kinase activity of the protein induced by DNA damage

Journal of Cell Science ◽

10.1242/jcs.109.7.1847 ◽

1996 ◽

Vol 109 (7) ◽

pp. 1847-1856 ◽

Cited By ~ 1

Author(s):

J.A. Santos ◽

E. Logarinho ◽

C. Tapia ◽

C.C. Allende ◽

J.E. Allende ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Kinase Activity ◽

Early Embryo ◽

Casein Kinase ◽

Early Embryogenesis ◽

Kinase Gene ◽

Casein Kinase 1 ◽

Adult Females ◽

Early Embryos

We report the molecular cloning and characterisation of the first CK1(casein kinase) gene of Drosophila melanogaster (dmCK1). The protein sequence (DMCK1) shares significant homology with other mammalian CK1 protein kinases of the alpha sub-class. The dmCK1 gene is expressed only in adult females and during early embryonic development as a single transcript. Western blot analysis of total protein extracts of different stages of development show that the gene product is likewise present during early embryogenesis and in adult females. Kinase activity studies show that DMCK1 is active when in vitro translated but inactive when immunoprecipitated from total early embryo extracts. However, after dephosphorylation treatment the immunoprecipitates show high kinase activity. More significantly, DMCK1 kinase activity present in the immunoprecipitates can be specifically activated by gamma-irradiation of early embryos. Also, when DMCK1 is immunoprecipitated after irradiation it appears to undergo phosphorylation. Immunolocalization of DMCK1 in early embryos shows that the protein is predominantly cytoplasmic but after irradiation there is a significant relocalization to the interphase nucleus. The results suggest a possible requirement of the Drosophila CK1 alpha for mechanisms associated with DNA repair during early embryogenesis.

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Detection of virus-specific sequences in Drosophila melanogaster mutants induced by injection of RSV DNA into early embryos

Nature ◽

10.1038/311394a0 ◽

1984 ◽

Vol 311 (5984) ◽

pp. 394-395 ◽

Cited By ~ 8

Author(s):

A. G. Tatosyan ◽

S. D. Nabirochkin ◽

A. K. Shakhbazyan ◽

K. G. Gazaryan ◽

F. L. Kisseljov

Keyword(s):

Drosophila Melanogaster ◽

Early Embryos ◽

Specific Sequences

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SPERMATOCYTE GRANULES IN DROSOPHILA MELANOGASTER

Canadian Journal of Genetics and Cytology ◽

10.1139/g69-020 ◽

1969 ◽

Vol 11 (1) ◽

pp. 153-168 ◽

Cited By ~ 3

Author(s):

John Erickson ◽

A. B. Acton

Keyword(s):

Electron Microscopy ◽

Endoplasmic Reticulum ◽

Drosophila Melanogaster ◽

Host Cell ◽

Acridine Orange ◽

Meiotic Drive ◽

Adult Males ◽

Unit Membrane ◽

The Third ◽

The Individual

Granular inclusions are found in testes from a cn bw stock of Drosophila melanogaster, and maternally derived lines, such as SD. In late larval and early pupal stages, these granules show a polarized distribution within primary spermatocytes corresponding to the polarity basic to the type of meiotic drive where certain homologues reach that pole of the spermatocyte leading to functional sperm. In adult males, the granules are found in intercellular patches in the testes. Electron microscopy shows the spermatocyte granules to be spheroids of about 0.7 μ; dividing, or double forms resulting from division, are about 1.8 μ long. They contain numbers of ribosome-like particles and fine strands presumed to be DNA. The acridine orange test for nucleic acids was positive. Each granule is surrounded by two layers of unit membrane and a third such membrane envelopes the individual or the pair of granules, as the case may be. The third membrane layer (and additional membranes sometimes seen) is thought to be due to entrance of the granules into the host cell through the cisternae of the endoplasmic reticulum. Transmission of the granules is strictly maternal and independent of chromosome constitution. Transmission by contagion was not found. Spermatocyte granules are not requisite to the effectiveness of the SD meiotic drive system, which regularly carries them. A slightly lowered fertility of females carrying the granules was found but no similar effect is produced in males. The evidence suggests that they are parasitic organisms, probably Rickettsiae.

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