scholarly journals Ring canals permit extensive cytoplasm sharing among germline cells independent of fusomes inDrosophilatestes

2019 ◽  
Author(s):  
Ronit S. Kaufman ◽  
Kari L. Price ◽  
Katelynn M. Mannix ◽  
Kathleen Ayers ◽  
Andrew M. Hudson ◽  
...  
Keyword(s):  
Oocyte Growth ◽  
Minimal Impact ◽  
Daughter Cells ◽  
Male Germline ◽  
Ring Canals ◽  
Sperm Development ◽  
Intercellular Movement ◽  
Germline Cells ◽  
Endogenous Proteins ◽  
Leaving Groups

AbstractIntercellular bridges, also called ring canals (RCs), connect germline cells during gametogenesis in males and females. They form as a consequence of incomplete cytokinesis during cell division leaving groups of daughter cells connected in syncytia. InDrosophilafemales, RCs are required for oocyte growth but little is known about the role of RCs during spermatogenesis. Using live imaging, we document extensive intercellular movement of GFP and a subset of endogenous proteins through RCs during spermatogenesis from two-cell diploid spermatogonia to clusters of 64 post-meiotic haploid spermatids. Loss of the fusome, a large cytoplasmic structure extending through RCs that is known to be important during oogenesis, has minimal impact on RC development or intercellular protein movement during spermatogenesis. Our results reveal that male germline RCs remain persistently open and mediate extensive sharing of cytoplasmic information, supporting multiple roles for RCs throughout sperm development.

scholarly journals Drosophila sperm development and intercellular cytoplasm sharing through ring canals do not require an intact fusome

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev190140
Author(s):  
Ronit S. Kaufman ◽  
Kari L. Price ◽  
Katelynn M. Mannix ◽  
Kathleen M. Ayers ◽  
Andrew M. Hudson ◽  
...  
Keyword(s):  
Quality Control ◽  
Germ Cells ◽  
Male Fertility ◽  
Intercellular Bridges ◽  
Male Germline ◽  
Cytoplasmic Structure ◽  
Ring Canals ◽  
Sperm Development ◽  
Intercellular Movement ◽  
Endogenous Proteins

ABSTRACTAnimal germ cells communicate directly with each other during gametogenesis through intercellular bridges, often called ring canals (RCs), that form as a consequence of incomplete cytokinesis during cell division. Developing germ cells in Drosophila have an additional specialized organelle connecting the cells called the fusome. Ring canals and the fusome are required for fertility in Drosophila females, but little is known about their roles during spermatogenesis. With live imaging, we directly observe the intercellular movement of GFP and a subset of endogenous proteins through RCs during spermatogenesis, from two-cell diploid spermatogonia to clusters of 64 post-meiotic haploid spermatids, demonstrating that RCs are stable and open to intercellular traffic throughout spermatogenesis. Disruption of the fusome, a large cytoplasmic structure that extends through RCs and is important during oogenesis, had no effect on spermatogenesis or male fertility under normal conditions. Our results reveal that male germline RCs allow the sharing of cytoplasmic information that might play a role in quality control surveillance during sperm development.

scholarly journals Sir2 non-autonomously controls differentiation of germline cells in the ovary of Drosophila melanogaster

2019 ◽  
Author(s):  
Champakali Ayyub ◽  
Ullas Kolthur-Seetharam
Keyword(s):  
Genetic Interaction ◽  
Ovary Development ◽  
Dependent Manner ◽  
Germline Stem Cells ◽  
Daughter Cells ◽  
Survival And Development ◽  
Germline Differentiation ◽  
Germline Cells ◽  
Cell Niche

AbstractIn Drosophila ovary, germline stem cells (GSCs) reside in a somatic cell niche that provides them signals necessary for their survival and development. Escort cells (ECs), one of the constituents of the niche, help in differentiation of GSC daughter cells. Since nutritional state is known to affect oogenesis, we set out to address the role of a metabolic sensor. NAD-dependent Sir2 is known to acts as a regulator of organismal life-span in a diet dependent manner. Our current study reveals that Sir2 in somatic cells is necessary for germline differentiation. Specifically, Sir2 in ECs upregulates Dpp signalling giving rise to tumorous germaria. In addition to this non-autonomous role of Sir2 in regulation of the germline cell homeostasis, we have demonstrated that EC-specific Sir2 has a role in attributing the identity of Cap cells as well as in de-differentiation of germline cells. Our study also shows that a genetic interaction between Sir2 and upd2 is important for the development of germline cells. Thus, we provide novel insights into the role of Sir2 in ovary development.

scholarly journals Nessun Dorma, a novel centralspindlin partner, is required for cytokinesis in Drosophila spermatocytes

2010 ◽  
Vol 191 (7) ◽  
pp. 1351-1365 ◽  
Author(s):  
Emilie Montembault ◽  
Wei Zhang ◽  
Marcin R. Przewloka ◽  
Vincent Archambault ◽  
Emeric W. Sevin ◽  
...  
Keyword(s):  
Essential Gene ◽  
Male Meiosis ◽  
Carbohydrate Binding ◽  
Ring Canal ◽  
Daughter Cells ◽  
High Affinity ◽  
Evolutionarily Conserved ◽  
Ring Canals ◽  
Female Germline

Cytokinesis, the final step of cell division, usually ends with the abscission of the two daughter cells. In some tissues, however, daughter cells never completely separate and remain interconnected by intercellular bridges or ring canals. In this paper, we report the identification and analysis of a novel ring canal component, Nessun Dorma (Nesd), isolated as an evolutionarily conserved partner of the centralspindlin complex, a key regulator of cytokinesis. Nesd contains a pectin lyase–like domain found in proteins that bind to polysaccharides, and we present evidence that it has high affinity for β-galactosides in vitro. Moreover, nesd is an essential gene in Drosophila melanogaster, in which it is required for completion of cytokinesis during male meiosis and possibly in female germline cells. Our findings indicate that Nesd is a novel carbohydrate-binding protein that functions together with centralspindlin in late cytokinesis, thus highlighting the importance of glycosylation in this process.

scholarly journals Pluripotent cell derivation from male germline cells by suppression of Dmrt1 and Trp53

2015 ◽  
Vol 61 (5) ◽  
pp. 473-484 ◽  
Author(s):  
Takashi TANAKA ◽  
Mito KANATSU-SHINOHARA ◽  
Michiko HIROSE ◽  
Atsuo OGURA ◽  
Takashi SHINOHARA
Keyword(s):  
Pluripotent Cell ◽  
Male Germline ◽  
Germline Cells

scholarly journals Loss of the extraproteasomal ubiquitin receptor Rings lost impairs ring canal growth in Drosophila oogenesis

2011 ◽  
Vol 193 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Tobias Morawe ◽  
Mona Honemann-Capito ◽  
Walter von Stein ◽  
Andreas Wodarz
Keyword(s):  
Essential Gene ◽  
26S Proteasome ◽  
Ovary Development ◽  
Ring Canal ◽  
Ribonucleic Acids ◽  
Cytoplasmic Transport ◽  
Ring Canals ◽  
Germline Cells ◽  
First Time

In Drosophila melanogaster oogenesis, there are 16 germline cells that form a cyst and stay connected to each other by ring canals. Ring canals allow the cytoplasmic transport of proteins, messenger ribonucleic acids, and yolk components from the nurse cells into the oocyte. In this paper, we describe the protein Rings lost (Rngo) and show that it is required for ring canal growth in germline cysts. rngo is an essential gene, and germline clones of a rngo-null allele show defects in ovary development, including mislocalization of ring canal proteins and fusion of germline cells. Rngo appears to be a ubiquitin receptor that possesses a ubiquitin-like domain, a ubiquitin-associated domain, and a retroviral-like aspartate protease (RVP) domain. Rngo binds to ubiquitin and to the 26S proteasome and colocalizes with both in germline cells, and its RVP domain is required for dimerization of Rngo and for its function in vivo. Our results thus show, for the first time, a function for a ubiquitin receptor in Drosophila development.

An A-kinase anchoring protein is required for Protein kinase A regulatory subunit localization and morphology of actin structures during oogenesis inDrosophila

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4423-4433 ◽  
Author(s):  
Stephen M. Jackson ◽  
Celeste A. Berg
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Membrane Integrity ◽  
Regulatory Subunit ◽  
Small Ring ◽  
Nurse Cells ◽  
Ring Canal ◽  
Ring Canals ◽  
Germline Cells ◽  
Kinase A

Protein kinase A (PKA) holoenzyme is anchored to specific subcellular regions by interactions between regulatory subunits (Pka-R) and A-kinase anchoring proteins (AKAPs). We examine the functional importance of PKA anchoring during Drosophila oogenesis by analyzing membrane integrity and actin structures in mutants with disruptions in Akap200, an AKAP. In wild-type ovaries, Pka-RII and Akap200 localized to membranes and to the outer rim of ring canals, actin-rich structures that connect germline cells. In Akap200 mutant ovaries, Pka-RII membrane localization decreased, leading to a destabilization of membrane structures and the formation of binucleate nurse cells. Defects in membrane integrity could be mimicked by expressing a constitutively active PKA catalytic subunit (Pka-C) throughout germline cells. Unexpectedly, nurse cells in Akap200 mutant ovaries also had enlarged, thin ring canals. In contrast, overexpressing Akap200 in the germline resulted in thicker, smaller ring canals. To investigate the role of Akap200 in regulating ring canal growth, we examined genetic interactions with other genes that are known to regulate ring canal morphology. Akap200 mutations suppressed the small ring canal phenotype produced by Src64B mutants, linking Akap200 with the non-receptor tyrosine kinase pathway. Together, these results provide the first evidence that PKA localization is required for morphogenesis of actin structures in an intact organism.

A Comparative study of Reproductive Cycles in Four polychaete Species belonging to the Family Cirratulidae

1971 ◽  
Vol 51 (4) ◽  
pp. 745-769 ◽  
Author(s):  
P. E. Gibbs
Keyword(s):  
Comparative Study ◽  
Growth Curve ◽  
Annual Cycle ◽  
Sperm Cells ◽  
Oocyte Growth ◽  
Polychaete Species ◽  
The Family ◽  
Sperm Development ◽  
Fourth Species ◽  
Reproductive Cycles

Gametogenesis has been studied in four cirratulid polychaetes: Caulleriella caput-esocis, Tharyx marioni, Cirriformia tentaculata and Cirratulus cirratus.In all four species, sperm development follows a similar course of events, with the sperm cells being grouped in spheres and then platelets before developing tails to give rosettes which finally disintegrate to release the active spermatozoa. Except in Cirratulus, there is a well-defined annual cycle in the development of sperm.Oogenesis in Caulleriella and Cirriformia is similar in that the growth curve of the oocytes is roughly sigmoid. In Tharyx the release of the oocytes to the coelom is delayed and discrete ovaries are formed, only the later stages of oocyte growth taking place within the coelom. In contrast to the above three species, oogenesis in Cirratulus does not show an annual cycle.Maturation of the oocytes within the coelom prior to shedding has been established in Tharyx, Cirratulus and Cirriformia. In the former two species meiosis proceeds as far as the metaphase I stage and in the latter to the anaphase I stage, before the oocytes are released. Fertilizations were achieved only with oocytes which had matured in all three species. In the fourth species, Caulleriella, no fertile oocytes were discovered.The diameters of the mature oocytes and the main spawning seasons of the four species at Plymouth are as follows: Caulleriella, about 110 μ (August to October); Tharyx, 200– 220 μ (late October to early November); Cirriformia, about 117 μ (late June to early July); Cirratulus, 135–150 μ (throughout the year).

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