scholarly journals Rec-8 dimorphism affects longevity, stress resistance and X-chromosome nondisjunction in C. elegans, and replicative lifespan in S. cerevisiae

2014 ◽  
Vol 5 ◽  
Author(s):  
Srinivas Ayyadevara ◽  
Çagdas Tazearslan ◽  
Ramani Alla ◽  
James C. Jiang ◽  
S. Michal Jazwinski ◽  
...  
Keyword(s):  
X Chromosome ◽  
Stress Resistance ◽  
Replicative Lifespan ◽  
C Elegans ◽  
Chromosome Nondisjunction

RADIATION-SENSITIVE MUTANTS OF CAENORHABDITIS ELEGANS

Genetics ◽  
1982 ◽  
Vol 102 (2) ◽  
pp. 159-178
Author(s):  
Philip S Hartman ◽  
Robert K Herman
Keyword(s):  
Caenorhabditis Elegans ◽  
X Chromosome ◽  
Spontaneous Mutation ◽  
Radiation Sensitivity ◽  
Temperature Sensitive ◽  
X Rays ◽  
C Elegans ◽  
Elevated Frequency ◽  
Rad Mutants ◽  
Chromosome Nondisjunction

ABSTRACT Nine rad (for abnormal radiation sensitivity) mutants hypersensitive to ultraviolet light were isolated in the small nematode Caenorhabditis elegans. The mutations are recessive to their wild-type alleles, map to four of the six linkage groups in C. elegans and define nine new games named rad-1 through rad-9. Two of the mutants—rad-1 and rad-2—are very hypersensitive to X rays, and three—rad-2, rad-3 and rad-4—are hypersensitive to methyl methanesulfonate under particular conditions of exposure. The hypersensitivity of these mutants to more than one DNA-damaging agent suggests that they may be abnormal in DNA repair. One mutant—rad-5, a temperature-sensitive sterile mutant—shows an elevated frequency of spontaneous mutation at more than one locus; rad-4, which shows a cold-sensitive embryogenesis, reduces meiotic X-chromosome nondisjunction tenfold and partially suppresses some but not all mutations that increase meiotic X-chromosome nondisjunction; the viability of rad-6 hermaphrodites is half that of rad-6 males at 25°; and newly mature (but not older) rad-8 hermaphrodites produce many inviable embryo progeny. Meiotic recombination frequencies were measured for seven rad mutants and found to be close to normal.

scholarly journals Natural variations in reproductive aging phenotypes reveal the importance of early reproductive period in Caenorhabditis elegans

2021 ◽  
Author(s):  
Jiseon Lim ◽  
Jun Kim ◽  
Junho Lee
Keyword(s):  
Caenorhabditis Elegans ◽  
X Chromosome ◽  
Brood Size ◽  
Current Knowledge ◽  
Reproductive Capacity ◽  
Initial Population ◽  
Reproductive Aging ◽  
C Elegans ◽  
Wild Strains ◽  
Chromosome Nondisjunction

Although reproductive capacity is a major factor in individual fitness, aging of the reproductive system precedes somatic aging and may reduce the total brood size. Genetic studies have led to the development of a body of evolutionary theory in the nematode Caenorhabditis elegans, but these studies did not take into account current knowledge about the natural history of C. elegans. To enhance our understanding of reproductive aging in C. elegans, we measured and compared two reproductive aging-related traitsthe number of progeny and the X-chromosome nondisjunction rateof 96 wild strains during early, late and total reproductive periods. We found that the two traits exhibited natural phenotypic variation, with few outliers, and that the brood size and the X-chromosome nondisjunction rate were not genetically correlated. Contrary to a previous hypothesis, that reproductive aging contributes to the generation of an optimal total number of offspring, we found that the total brood size did not converge to an optimal value, and early brood size was more constant than total brood size among wild strains. We speculate that reproductive aging is a by-product of a rapid increase in the initial population size, which might be related to the boom-and-bust lifestyle of C. elegans. We also identified loci and candidate genetic variants significantly associated with X-chromosome nondisjunction rate in the late and total reproductive periods. Our results provide an insight into reproductive aging in wild C. elegans strains.

scholarly journals Natural variation in reproductive timing and X-chromosome nondisjunction in Caenorhabditis elegans

2021 ◽  
Author(s):  
Jiseon Lim ◽  
Jun Kim ◽  
Junho Lee
Keyword(s):  
Caenorhabditis Elegans ◽  
X Chromosome ◽  
Reproductive Timing ◽  
Male Production ◽  
C Elegans ◽  
In The Wild ◽  
Wild Strains ◽  
Large Brood ◽  
Insight Into ◽  
Chromosome Nondisjunction

Abstract Caenorhabditis elegans hermaphrodites first produce a limited number of sperm cells, before their germline switches to oogenesis. Production of progeny then ensues until sperm is depleted. Male production in the self-progeny of hermaphrodites occurs following X-chromosome nondisjunction during gametogenesis, and in the reference strain increases with age of the hermaphrodite parent. To enhance our understanding of the reproductive timecourse in C. elegans, we measured and compared progeny production and male proportion during the early and late reproductive periods of hermaphrodites for 96 wild C. elegans strains. We found that the two traits exhibited natural phenotypic variation with few outliers and a similar reproductive timing pattern as previous reports. Progeny number and male proportion were not correlated in the wild strains, implying that wild strains with a large brood size did not produce males at a higher rate. We also identified loci and candidate genetic variants significantly associated with male-production rate in the late and total reproductive periods. Our results provide an insight into life-history traits in wild C. elegans strains.

Streblus asper Lour. exerts MAPK and SKN-1 mediated anti-aging, anti-photoaging activities and imparts neuroprotection by ameliorating Aβ in Caenorhabditis elegans

2021 ◽  
pp. 1-17
Author(s):  
Mani Iyer Prasanth ◽  
James Michael Brimson ◽  
Dicson Sheeja Malar ◽  
Anchalee Prasansuklab ◽  
Tewin Tencomnao
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Stress Resistance ◽  
Vital Role ◽  
Transgenic Strain ◽  
Wild Type ◽  
Neuroprotective Effects ◽  
C Elegans ◽  
Streblus Asper

BACKGROUND: Streblus asper Lour., has been reported to have anti-aging and neuroprotective efficacies in vitro. OBJECTIVE: To analyze the anti-aging, anti-photoaging and neuroprotective efficacies of S. asper in Caenorhabditis elegans. METHODS: C. elegans (wild type and gene specific mutants) were treated with S. asper extract and analyzed for lifespan and other health benefits through physiological assays, fluorescence microscopy, qPCR and Western blot. RESULTS: The plant extract was found to increase the lifespan, reduce the accumulation of lipofuscin and modulate the expression of candidate genes. It could extend the lifespan of both daf-16 and daf-2 mutants whereas the pmk-1 mutant showed no effect. The activation of skn-1 was observed in skn-1::GFP transgenic strain and in qPCR expression. Further, the extract can extend the lifespan of UV-A exposed nematodes along with reducing ROS levels. Additionally, the extract also extends lifespan and reduces paralysis in Aβ transgenic strain, apart from reducing Aβ expression. CONCLUSIONS: S. asper was able to extend the lifespan and healthspan of C. elegans which was independent of DAF-16 pathway but dependent on SKN-1 and MAPK which could play a vital role in eliciting the anti-aging, anti-photoaging and neuroprotective effects, as the extract could impart oxidative stress resistance and neuroprotection.

Transcriptional targets of DAF-16 insulin signaling pathway protect C. elegans from extreme hypertonic stress

2005 ◽  
Vol 288 (2) ◽  
pp. C467-C474 ◽  
Author(s):  
S. Todd Lamitina ◽  
Kevin Strange
Keyword(s):  
Insulin Signaling ◽  
Stress Resistance ◽  
Molecular Mechanisms ◽  
Organic Osmolytes ◽  
Dependent Manner ◽  
Animal Cells ◽  
Hypertonic Stress ◽  
C Elegans ◽  
Downstream Target ◽  
Molecular Damage

All cells adapt to hypertonic stress by regulating their volume after shrinkage, by accumulating organic osmolytes, and by activating mechanisms that protect against and repair hypertonicity-induced damage. In mammals and nematodes, inhibition of signaling from the DAF-2/IGF-1 insulin receptor activates the DAF-16/FOXO transcription factor, resulting in increased life span and resistance to some types of stress. We tested the hypothesis that inhibition of insulin signaling in Caenorhabditis elegans also increases hypertonic stress resistance. Genetic inhibition of DAF-2 or its downstream target, the AGE-1 phosphatidylinositol 3-kinase, confers striking resistance to a normally lethal hypertonic shock in a DAF-16-dependent manner. However, insulin signaling is not inhibited by or required for adaptation to hypertonic conditions. Microarray studies have identified 263 genes that are transcriptionally upregulated by DAF-16 activation. We identified 14 DAF-16-upregulated genes by RNA interference screening that are required for age- 1 hypertonic stress resistance. These genes encode heat shock proteins, proteins of unknown function, and trehalose synthesis enzymes. Trehalose levels were elevated approximately twofold in age- 1 mutants, but this increase was insufficient to prevent rapid hypertonic shrinkage. However, age- 1 animals unable to synthesize trehalose survive poorly under hypertonic conditions. We conclude that increased expression of proteins that protect eukaryotic cells against environmental stress and/or repair stress-induced molecular damage confers hypertonic stress resistance in C. elegans daf- 2/ age- 1 mutants. Elevated levels of solutes such as trehalose may also function in a cytoprotective manner. Our studies provide novel insights into stress resistance in animal cells and a foundation for new studies aimed at defining molecular mechanisms underlying these essential processes.

Checkpoint proteins determine organismal stress resistance and lifespan in C. elegans

Toxicology ◽  
2006 ◽  
Vol 226 (1) ◽  
pp. 16
Author(s):  
Anders Olsen ◽  
Maithili C. Vantipalli ◽  
Glenda A. Walker ◽  
Gordon J. Lithgow
Keyword(s):  
Stress Resistance ◽  
Checkpoint Proteins ◽  
C Elegans

scholarly journals Developmental Dynamics of X-Chromosome Dosage Compensation by the DCC and H4K20me1 in C. elegans

PLoS Genetics ◽  
2015 ◽  
Vol 11 (12) ◽  
pp. e1005698 ◽  
Author(s):  
Maxwell Kramer ◽  
Anna-Lena Kranz ◽  
Amanda Su ◽  
Lara H. Winterkorn ◽  
Sarah Elizabeth Albritton ◽  
...  
Keyword(s):  
X Chromosome ◽  
Dosage Compensation ◽  
C Elegans ◽  
Developmental Dynamics

SDC-3 coordinates the assembly of a dosage compensation complex on the nematode X chromosome

Development ◽  
1997 ◽  
Vol 124 (5) ◽  
pp. 1019-1031 ◽  
Author(s):  
T.L. Davis ◽  
B.J. Meyer
Keyword(s):  
Zinc Finger ◽  
X Chromosome ◽  
Dosage Compensation ◽  
Protein Complex ◽  
Terminal Region ◽  
X Chromosomes ◽  
C Elegans ◽  
Amino Terminal ◽  
Zinc Finger Motifs ◽  
Specific Association

X chromosome expression in C. elegans is controlled by a chromosome-wide regulatory process called dosage compensation that specifically reduces by half the level of transcripts made from each hermaphrodite X chromosome. This process equalizes X expression between the sexes (XX hermaphrodites and XO males), despite their two-fold difference in X chromosome dose, and thereby prevents sex-specific lethality. Dosage compensation is achieved by a protein complex that associates with X in a sex-specific fashion to modulate gene expression. SDC-3, a protein that coordinately controls both sex determination and dosage compensation, activates dosage compensation by directing the dosage compensation protein complex to the hermaphrodite X chromosomes. We show that SDC-3 coordinates this assembly through its own sex-specific association with X. SDC-3 in turn requires other members of the dosage compensation gene hierarchy for its stability and its X localization. In addition, SDC-3 requires its own zinc finger motifs and an amino-terminal region for its X association. Our experiments suggest the possible involvement of zinc finger motifs in X chromosome recognition and the amino-terminal region in interactions with other dosage compensation proteins.

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