Identification and characterization of Caenorhabditis elegans gamma-tubulin in dividing cells and differentiated tissues

2000 ◽  
Vol 113 (21) ◽  
pp. 3747-3759 ◽  
Author(s):  
Y. Bobinnec ◽  
M. Fukuda ◽  
E. Nishida
Keyword(s):  
Caenorhabditis Elegans ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Loss Of Function ◽  
Tubulin Gene ◽  
Gfp Reporter ◽  
Dividing Cells ◽  
Gamma Tubulin ◽  
Identification And Characterization

gamma-Tubulin is an essential component of the microtubule-nucleation machinery and therefore plays a crucial role during mitosis. To gain further insights into the function of this protein in the events that take place during embryogenesis and differentiation, we carried out detailed studies on gamma-tubulin during all the developmental stages of Caenorhabditis elegans. We identified the gamma-tubulin gene from this organism and analyzed the localization of the protein by both immunofluorescence and GFP reporter construct. We show that gamma-tubulin association with the centrosome is highly dynamic in mitotic cells, being massively recruited at prophase and released at anatelophase. This accumulation in mitotic centrosomes is dramatic during the first embryonic divisions. We provide the first description of the morphological changes at the centrosome level during the orientation of the mitotic spindle and the flattening of the posterior aster. Loss of function of the gamma-tubulin gene by RNAi induces a strong polyploidization of mitotic germ cells and embryos, but does not affect meiosis and pronuclear migration. In addition, we demonstrate the prominent redistribution of gamma-tubulin in adults at basal bodies of amphid and phasmid neurons, and at the apical membrane of polarized intestinal cells.

scholarly journals Genetic and Molecular Characterization of the Caenorhabditis elegans Gene, mel-26, a Postmeiotic Negative Regulator of MEI-1, a Meiotic-Specific Spindle Component

Genetics ◽  
1998 ◽  
Vol 150 (1) ◽  
pp. 119-128
Author(s):  
M Rhys Dow ◽  
Paul E Mains
Keyword(s):  
Caenorhabditis Elegans ◽  
Protein Interactions ◽  
Negative Regulator ◽  
Meiotic Spindle ◽  
Loss Of Function ◽  
Protein Protein Interactions ◽  
Gain Of Function ◽  
Recessive Mutations ◽  
Female Germline

Abstract We have previously described the gene mei-1, which encodes an essential component of the Caenorhabditis elegans meiotic spindle. When ectopically expressed after the completion of meiosis, mei-1 protein disrupts the function of the mitotic cleavage spindles. In this article, we describe the cloning and the further genetic characterization of mel-26, a postmeiotic negative regulator of mei-1. mel-26 was originally identified by a gain-of-function mutation. We have reverted this mutation to a loss-of-function allele, which has recessive phenotypes identical to the dominant defects of its gain-of-function parent. Both the dominant and recessive mutations of mel-26 result in mei-1 protein ectopically localized in mitotic spindles and centrosomes, leading to small and misoriented cleavage spindles. The loss-of-function mutation was used to clone mel-26 by transformation rescue. As suggested by genetic results indicating that mel-26 is required only maternally, mel-26 mRNA was expressed predominantly in the female germline. The gene encodes a protein that includes the BTB motif, which is thought to play a role in protein-protein interactions.

scholarly journals Identification and Characterization of a Novel Allele of Caenorhabditis elegans bbs-7

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e113737 ◽  
Author(s):  
Kara Braunreiter ◽  
Shelby Hamlin ◽  
Jamie Lyman-Gingerich
Keyword(s):  
Caenorhabditis Elegans ◽  
Identification And Characterization ◽  
Novel Allele

Genetic characterization of ms (3) K81, a paternal effect gene of Drosophila melanogaster.

Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 219-229 ◽  
Author(s):  
G K Yasuda ◽  
G Schubiger ◽  
B T Wakimoto
Keyword(s):  
Drosophila Melanogaster ◽  
Developmental Stages ◽  
Normal Function ◽  
Loss Of Function ◽  
Male Sterile ◽  
Specific Product ◽  
Paternal Effect ◽  
Developmental Arrest ◽  
Effect Gene

Abstract The vast majority of known male sterile mutants of Drosophila melanogaster fail to produce mature sperm or mate properly. The ms(3) K81(1) mutation is one of a rare class of male sterile mutations in which sterility is caused by developmental arrest after sperm entry into the egg. Previous studies showed that males homozygous for the K81(1) mutation produce progeny that arrest at either of two developmental stages. Most embryos arrest during early nuclear cycles, whereas the remainder are haploid embryos that arrest at a later stage. This description of the mutant phenotype was based on the analysis of a single allele isolated from a natural population. It was therefore unclear whether this unique paternal effect phenotype reflected the normal function of the gene. The genetic analysis and initial molecular characterization of five new K81 mutations are described here. Hemizygous conditions and heteroallelic combinations of the alleles were associated with male sterility caused by defects in embryogenesis. No other mutant phenotypes were observed. Thus, the K81 gene acted as a strict paternal effect gene. Moreover, the biphasic pattern of developmental arrest was common to all the alleles. These findings strongly suggested that the unusual embryonic phenotype caused by all five new alleles was due to loss of function of the K81+ gene. The K81 gene is therefore the first clear example of a strict paternal effect gene in Drosophila. Based on the embryonic lethal phenotypes, we suggest that the K81+ gene encodes a sperm-specific product that is essential for the male pronucleus to participate in the first few embryonic nuclear divisions.

scholarly journals Identification and Characterization of Four Autophagy-Related Genes That Are Expressed in Response to Hypoxia in the Brain of the Oriental River Prawn (Macrobrachium nipponense)

2019 ◽  
Vol 20 (8) ◽  
pp. 1856 ◽  
Author(s):  
Shengming Sun ◽  
Ying Wu ◽  
Hongtuo Fu ◽  
Xianping Ge ◽  
Hongzheng You ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Open Reading Frames ◽  
Dependent Manner ◽  
Macrobrachium Nipponense ◽  
Oriental River Prawn ◽  
Adverse Environmental Conditions ◽  
The Brain ◽  
Identification And Characterization

Autophagy is a cytoprotective mechanism triggered in response to adverse environmental conditions. Herein, we investigated the autophagy process in the oriental river prawn (Macrobrachium nipponense) following hypoxia. Full-length cDNAs encoding autophagy-related genes (ATGs) ATG3, ATG4B, ATG5, and ATG9A were cloned, and transcription following hypoxia was explored in different tissues and developmental stages. The ATG3, ATG4B, ATG5, and ATG9A cDNAs include open reading frames encoding proteins of 319, 264, 268, and 828 amino acids, respectively. The four M. nipponense proteins clustered separately from vertebrate homologs in phylogenetic analysis. All four mRNAs were expressed in various tissues, with highest levels in brain and hepatopancreas. Hypoxia up-regulated all four mRNAs in a time-dependent manner. Thus, these genes may contribute to autophagy-based responses against hypoxia in M. nipponense. Biochemical analysis revealed that hypoxia stimulated anaerobic metabolism in the brain tissue. Furthermore, in situ hybridization experiments revealed that ATG4B was mainly expressed in the secretory and astrocyte cells of the brain. Silencing of ATG4B down-regulated ATG8 and decreased cell viability in juvenile prawn brains following hypoxia. Thus, autophagy is an adaptive response protecting against hypoxia in M. nipponense and possibly other crustaceans. Recombinant MnATG4B could interact with recombinant MnATG8, but the GST protein could not bind to MnATG8. These findings provide us with a better understanding of the fundamental mechanisms of autophagy in prawns.

scholarly journals Neuronal KGB-1 JNK MAPK signaling regulates the dauer developmental decision in response to environmental stress in C. elegans

2021 ◽  
Author(s):  
Deepshikha Dogra ◽  
Warakorn Kulalert ◽  
Frank Schroeder ◽  
Dennis H Kim
Keyword(s):  
Elevated Temperature ◽  
Signaling Pathways ◽  
Mapk Pathway ◽  
Negative Regulator ◽  
Loss Of Function ◽  
C Elegans ◽  
Metabolic Remodeling ◽  
Dauer Formation ◽  
Identification And Characterization

In response to stressful growth conditions of high population density, food scarcity and elevated temperature, young larvae of nematode Caenorhabditis elegans can enter a developmentally arrested stage called dauer that is characterized by dramatic anatomic and metabolic remodeling. Genetic analysis of dauer formation of C. elegans has served as an experimental paradigm for the identification and characterization of conserved neuroendocrine signaling pathways. Here, we report the identification and characterization of a conserved JNK-like mitogen-activated protein kinase (MAPK) pathway that is required for dauer formation in response to environmental stressors. We observed that loss-of-function mutations in the MLK-1-MEK-1-KGB-1 MAPK pathway suppress dauer entry. Loss-of-function mutation in the VHP-1 MAPK phosphatase, a known negative regulator of KGB-1 signaling, results in constitutive dauer formation which is dependent on the presence of dauer pheromone but independent of diminished food levels or elevated temperatures. Our data suggest that KGB-1 pathway acts in the sensory neurons, in parallel to established insulin and TGF-β signaling pathways, to transduce the dauer-inducing environmental cues of diminished food levels and elevated temperature.

scholarly journals IDENTIFICATION AND CHARACTERIZATION OF 22 GENES THAT AFFECT THE VULVAL CELL LINEAGES OF THE NEMATODE CAENORHABDITIS ELEGANS

Genetics ◽  
1985 ◽  
Vol 110 (1) ◽  
pp. 17-72
Author(s):  
Edwin L Ferguson ◽  
H Robert Horvitz
Keyword(s):  
Caenorhabditis Elegans ◽  
Gene Function ◽  
Ventral Side ◽  
Recessive Mutation ◽  
Partial Reduction ◽  
Nematode Caenorhabditis Elegans ◽  
Multiple Alleles ◽  
Cell Lineages ◽  
Identification And Characterization

ABSTRACT Ninety-five mutants of the nematode Caenorhabditis elegans altered in the cell lineages of the vulva have been isolated on the basis of their displaying one of two phenotypes, Vulvaless or Multivulva. In Vulvaless mutants, which define 12 genes, no vulva is present. In Multivulva mutants, which define ten genes, one or more supernumerary vulva-like protrusions are located along the ventral side of the animal. A single recessive mutation is responsible for the phenotypes of most, but not all, of these strains. Fifteen of these 22 genes are represented by multiple alleles. We have shown by a variety of genetic criteria that mutations that result in a Vulvaless or Multivulva phenotype in six of the 22 genes most likely eliminate gene function. In addition, Vulvaless or Multivulva mutations in seven of the other genes most likely result in a partial reduction of gene function; the absence of the activity of any of these genes probably results in lethality or sterility. Our results suggest that we may have identified most, or all, genes of these two classes.

Identification and characterization of a novel specific secreted protein family for selected members of the subfamily Ostertagiinae (Nematoda)

Parasitology ◽  
2007 ◽  
Vol 135 (1) ◽  
pp. 63-70 ◽  
Author(s):  
H. SAVERWYNS ◽  
A. VISSER ◽  
A. J. NISBET ◽  
I. PEELAERS ◽  
K. GEVAERT ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Cell Damage ◽  
Inflammatory Cells ◽  
Glycosylation Site ◽  
Protein Family ◽  
Protein Motif ◽  
Western Blots ◽  
Teladorsagia Circumcincta ◽  
Identification And Characterization

SUMMARYIt has been shown that the bovine abomasal parasite, Ostertagia ostertagi, drastically modulates its microenvironment, causing epithelial cell damage, accumulation of inflammatory cells and pH changes in the stomach. The mechanisms used by the parasite to change the abomasal environment are largely unknown, but an important role has been attributed to excretory-secretory (ES) products from the parasite. In this study we have identified proteins representing a novel ES protein family, characterized by the SCP/Tpx-1/Ag5/PR-1/Sc7 protein motif. These proteins were named Oo-AL1 and Oo-AL2 (O. ostertagi ASP-like protein). Both proteins contain a signal peptide and 1 predicted N-glycosylation site. The transcript for Oo-AL1 was present from the L4 stage onwards in both male and female adult worms, whereas the Oo-AL2 transcript was hardly detectable. Western blots of somatic extracts and ES products from different developmental stages of O. ostertagi, probed with anti-Oo-AL1 antibodies, revealed Oo-AL proteins in the ES products of adult worms. An analysis of the nematode genome and EST databases indicated that these novel ES proteins are unique to O. ostertagi and its relative, Teladorsagia circumcincta, suggesting a key function in these abomasal parasites.

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