scholarly journals C. elegans Anillin proteins regulate intercellular bridge stability and germline syncytial organization

2014 ◽  
Vol 206 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Rana Amini ◽  
Eugénie Goupil ◽  
Sara Labella ◽  
Monique Zetka ◽  
Amy S. Maddox ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Germ Cells ◽  
Cytoplasmic Streaming ◽  
Intercellular Bridge ◽  
Cell Specification ◽  
Intercellular Bridges ◽  
C Elegans ◽  
Daughter Cells ◽  
Germ Cell Specification

Cytokinesis generally produces two separate daughter cells, but in some tissues daughter nuclei remain connected to a shared cytoplasm, or syncytium, through incomplete cytokinesis. How syncytia form remains poorly understood. We studied syncytial formation in the Caenorhabditis elegans germline, in which germ cells connect to a shared cytoplasm core (the rachis) via intercellular bridges. We found that syncytial architecture initiates early in larval development, and germ cells become progressively interconnected until adulthood. The short Anillin family scaffold protein ANI-2 is enriched at intercellular bridges from the onset of germ cell specification, and ANI-2 loss resulted in destabilization of intercellular bridges and germ cell multinucleation defects. These defects were partially rescued by depleting the canonical Anillin ANI-1 or blocking cytoplasmic streaming. ANI-2 is also required for elastic deformation of the gonad during ovulation. We propose that ANI-2 promotes germ cell syncytial organization and allows for compensation of the mechanical stress associated with oogenesis by conferring stability and elasticity to germ cell intercellular bridges.

scholarly journals TEX14 Interacts with CEP55 To Block Cell Abscission

2010 ◽  
Vol 30 (9) ◽  
pp. 2280-2292 ◽  
Author(s):  
Tokuko Iwamori ◽  
Naoki Iwamori ◽  
Lang Ma ◽  
Mark A. Edson ◽  
Michael P. Greenbaum ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Intercellular Bridge ◽  
Male Germ Cells ◽  
Physical Separation ◽  
Targeted Deletion ◽  
Intercellular Bridges ◽  
Daughter Cells ◽  
Stable Component ◽  
Evolutionarily Conserved

ABSTRACT In somatic cells, abscission, the physical separation of daughter cells at the completion of cytokinesis, requires CEP55, ALIX, and TSG101. In contrast, cytokinesis is arrested prior to abscission in differentiating male germ cells that are interconnected by TEX14-positive intercellular bridges. We have previously shown that targeted deletion of TEX14 disrupts intercellular bridges in all germ cells and causes male sterility. Although these findings demonstrate that intercellular bridges are essential for spermatogenesis, it remains to be shown how TEX14 and other proteins come together to prevent abscission and form stable intercellular bridges. Using a biochemical enrichment of male germ cell intercellular bridges, we identified additional bridge proteins, including CEP55. Although CEP55 is highly expressed in testes at the RNA level, there is no report of the presence of CEP55 in germ cells. We show here that CEP55 becomes a stable component of the intercellular bridge and that an evolutionarily conserved GPPX3Y motif of TEX14 binds strongly to CEP55 to block similar GPPX3Y motifs of ALIX and TSG101 from interacting and localizing to the midbody. Thus, TEX14 prevents the completion of cytokinesis by altering the destiny of CEP55 from a nidus for abscission to an integral component of the intercellular bridge.

scholarly journals Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1011-1022 ◽  
Author(s):  
T.L. Gumienny ◽  
E. Lambie ◽  
E. Hartwieg ◽  
H.R. Horvitz ◽  
M.O. Hengartner
Keyword(s):  
Cell Death ◽  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Mapk Pathway ◽  
Apoptotic Cell ◽  
C Elegans ◽  
Pathway Activation

Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as the previously described 131 somatic cell deaths. However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death requires ras/MAPK pathway activation and is used to maintain germline homeostasis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.

Great migration: epigenetic reprogramming and germ cell-oocyte metamorphosis determine individual ovarian reserve

2016 ◽  
Vol 25 (1) ◽  
Author(s):  
Onder Celik ◽  
Banu Kumbak Aygun ◽  
Nilufer Celik ◽  
Suleyman Aydin ◽  
Esra Tustas Haberal ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Reserve ◽  
Epigenetic Reprogramming ◽  
Cell Specification ◽  
Germ Cell Specification ◽  
Germ Cell Migration ◽  
Place Of Origin ◽  
Yolk Sack

AbstractEmigration is defined as a synchronized movement of germ cells between the yolk sack and genital ridges. The miraculous migration of germ cells resembles the remigration of salmon traveling from one habitat to other. This migration of germ cells is indispensible for the development of new generations. It is not, however, clear why germ cells differentiate during migration but not at the place of origin. In order to escape harmful somatic signals which might disturb the proper establishment of germ cells forced germ cell migration may be necessary. Another reason may be to benefit from the opportunities of new habitats. Therefore, emigration may have powerful effects on the population dynamics of the immigrant germ cells. While some of these cells do reach their target, some others die or reach to wrong targets. Only germ cell precursors with genetically, and structurally powerful can reach their target. Likewise, epigenetic reprogramming in both migratory and post-migratory germ cells is essential for the establishment of totipotency. During this journey some germ cells may sacrifice themselves for the goodness of the others. The number and quality of germ cells reaching the genital ridge may vary depending on the problems encountered during migration. If the aim in germ cell specification is to provide an optimal ovarian reserve for the continuity of the generation, then this cascade of events cannot be only accomplished at the same level for every one but also are manifested by several outcomes. This is significant evidence supporting the possibility of unique individual ovarian reserve.

scholarly journals Epigenetic erasure during C. elegans primordial germ cell specification

2009 ◽  
Vol 331 (2) ◽  
pp. 407-408
Author(s):  
Sujata Bhattacharyya ◽  
Hirofumi Furuhashi ◽  
William G. Kelly
Keyword(s):  
Germ Cell ◽  
Primordial Germ Cell ◽  
Cell Specification ◽  
C Elegans ◽  
Germ Cell Specification

scholarly journals Specification of germ cell fate in mice

2003 ◽  
Vol 358 (1436) ◽  
pp. 1363-1370 ◽  
Author(s):  
Mitinori Saitou ◽  
Bernhard Payer ◽  
Ulrike C. Lange ◽  
Sylvia Erhardt ◽  
Sheila C. Barton ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Transcriptional Repression ◽  
Single Cell Analysis ◽  
Primordial Germ Cells ◽  
Cell Specification ◽  
Signalling Molecules ◽  
Germ Cell Specification

An early fundamental event during development is the segregation of germ cells from somatic cells. In many organisms, this is accomplished by the inheritance of preformed germ plasm, which apparently imposes transcriptional repression to prevent somatic cell fate. However, in mammals, pluripotent epiblast cells acquire germ cell fate in response to signalling molecules. We have used single cell analysis to study how epiblast cells acquire germ cell competence and undergo specification. Germ cell competent cells express Fragilis and initially progress towards a somatic mesodermal fate. However, a subset of these cells, the future primordial germ cells (PGCs), then shows rapid upregulation of Fragilis with concomitant transcriptional repression of a number of genes, including Hox and Smad genes. This repression may be a key event associated with germ cell specification. Furthermore, PGCs express Stella and other genes, such as Oct – 4 that are associated with pluripotency. While these molecules are also detected in mature oocytes as maternally inherited factors, their early role is to regulate development and maintain pluripotency, and they do not serve the role of classical germline determinants.

scholarly journals Primordial Germ Cell Specification and Migration

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 1462 ◽  
Author(s):  
Florence Marlow
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Gene Products ◽  
Cell Specification ◽  
Zygotic Transcription ◽  
Germ Cell Specification ◽  
And Migration ◽  
Insight Into

Primordial germ cells are the progenitor cells that give rise to the gametes. In some animals, the germline is induced by zygotic transcription factors, whereas in others, primordial germ cell specification occurs via inheritance of maternally provided gene products known as germ plasm. Once specified, the primordial germ cells of some animals must acquire motility and migrate to the gonad in order to survive. In all animals examined, perinuclear structures called germ granules form within germ cells. This review focuses on some of the recent studies, conducted by several groups using diverse systems, from invertebrates to vertebrates, which have provided mechanistic insight into the molecular regulation of germ cell specification and migration.

scholarly journals To Be or Not to Be a Germ Cell: The Extragonadal Germ Cell Tumor Paradigm

2021 ◽  
Vol 22 (11) ◽  
pp. 5982
Author(s):  
Massimo De Felici ◽  
Francesca Gioia Klinger ◽  
Federica Campolo ◽  
Carmela Rita Balistreri ◽  
Marco Barchi ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Germ Cell Tumors ◽  
Cell Types ◽  
Cell Tumor ◽  
Cell Specification ◽  
Germ Cell Specification ◽  
Wide Range ◽  
Unique Cell

In the human embryo, the genetic program that orchestrates germ cell specification involves the activation of epigenetic and transcriptional mechanisms that make the germline a unique cell population continuously poised between germness and pluripotency. Germ cell tumors, neoplasias originating from fetal or neonatal germ cells, maintain such dichotomy and can adopt either pluripotent features (embryonal carcinomas) or germness features (seminomas) with a wide range of phenotypes in between these histotypes. Here, we review the basic concepts of cell specification, migration and gonadal colonization of human primordial germ cells (hPGCs) highlighting the analogies of transcriptional/epigenetic programs between these two cell types.

scholarly journals glp-3 Is Required for Mitosis and Meiosis in the Caenorhabditis elegans Germ Line

Genetics ◽  
1997 ◽  
Vol 145 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Lisa C Kadyk ◽  
Eric J Lambie ◽  
Judith Kimble
Keyword(s):  
Caenorhabditis Elegans ◽  
Germ Cells ◽  
Germ Line ◽  
Stem Cell Population ◽  
Phenotypic Characterization ◽  
Loss Of Function ◽  
Dapi Staining ◽  
Cell Cycles ◽  
C Elegans ◽  
Mitosis And Meiosis

The germ line is the only tissue in Caenorhabditis elegans in which a stem cell population continues to divide mitotically throughout life; hence the cell cycles of the germ line and the soma are regulated differently. Here we report the genetic and phenotypic characterization of the glp-3 gene. In animals homozygous for each of five recessive loss-of-function alleles, germ cells in both hermaphrodites and males fail to progress through mitosis and meiosis, but somatic cells appear to divide normally. Germ cells in animals grown at 15° appear by DAPI staining to be uniformly arrested at the G2/M transition with <20 germ cells per gonad on average, suggesting a checkpoint-mediated arrest. In contrast, germ cells in mutant animals grown at 25° frequently proliferate slowly during adulthood, eventually forming small germ lines with several hundred germ cells. Nevertheless, cells in these small germ lines never undergo meiosis. Double mutant analysis with mutations in other genes affecting germ cell proliferation supports the idea that glp-3 may encode a gene product that is required for the mitotic and meiotic cell cycles in the C. elegans germ line.

Sign in / Sign up

Export Citation Format

Share Document