scholarly journals GENETIC AND PHENOTYPIC CHARACTERIZATION OF ROLLER MUTANTS OF CAENORHABDITIS ELEGANS

Genetics ◽  
1980 ◽  
Vol 95 (2) ◽  
pp. 317-339
Author(s):  
George N Cox ◽  
John S Laufer ◽  
Meredith Kusch ◽  
Robert S Edgar
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Developmental Stages ◽  
Developmental Process ◽  
Phenotypic Characterization ◽  
Gene Interactions ◽  
C Elegans ◽  
Nematode Cuticle ◽  
Six Genes

ABSTRACT Eighty-eight mutants of C. elegans that display a roller phenotype (a helically twisted body) have been isolated and characterized genetically and phenotypically. The mutations are located in 14 different genes. Most genes contain a number of alleles. Their distribution among the chromosomes appears nonrandom, with seven of the genes being located on linkage group 11, some very closely linked. The phenotypes of the mutants suggest that there are five different classes of genes, each class representing a set of similar phenotypic effects: Left Roller (four genes), Right Roller (one gene), Left Squat (one gene), Right Squat (two genes) and Left Dumpy Roller (six genes). The classes of mutants differ with respect to a number of characteristics that include the developmental stages affected and the types of aberrations observed in cuticle structure. A variety of gene interactions were found, arguing that these genes are involved in a common developmental process. The presence of alterations in cuticle morphology strongly suggests that these genes are active in the formation of the nematode cuticle.

The genetic and RFLP characterization of the left end of linkage group III in Caenorhabditis elegans

Genome ◽  
1993 ◽  
Vol 36 (4) ◽  
pp. 712-724 ◽  
Author(s):  
Dave Pilgrim
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Genetic Map ◽  
Physical Map ◽  
Group Iii ◽  
C Elegans ◽  
Genomic Regions ◽  
Caenorhabditis Elegans Genome ◽  
Selection Of

A genetic approach was taken to identify new transposable element Tc1 -dependent polymorphisms on the left end of linkage group III in the nematode Caenorhabditis elegans. The cloning of the genomic DNA surrounding the Tc1 allowed the selection of overlapping clones (from the collection being used to assemble the physical map of the C. elegans genome). A contig of approximately 600–800 kbp in the region has been identified, the genetic map of the region has been refined, and 10 new RFLPs as well as at least four previously characterized genetic loci have been positioned onto the physical map, to the resolution of a few cosmids. This analysis demonstrated the ability to combine physical and genetic mapping for the rapid analysis of large genomic regions (0.5–1 Mbp) in genetically amenable eukaryotes.Key words: Caenorhabditis elegans, genome analysis, RFLP, physical map, genetic map.

scholarly journals The Levels of the RoRNP-Associated Y RNA Are Dependent Upon the Presence of ROP-1, the Caenorhabditis elegans Ro60 Protein

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 143-150
Author(s):  
Jean-Claude Labbé ◽  
Siegfried Hekimi ◽  
Luis A Rokeach
Keyword(s):  
Caenorhabditis Elegans ◽  
Laboratory Culture ◽  
Culture Conditions ◽  
Developmental Expression ◽  
Phenotypic Characterization ◽  
Major Protein ◽  
Transgenic Expression ◽  
C Elegans ◽  
Developmental Expression Pattern

Abstract The Ro ribonucleoproteins (RoRNP) consist of at least one major protein of 60 kD, Ro60, and one small associated RNA, designated Y RNA. Although RoRNP have been found in all vertebrate species examined so far, their function remains unknown. The Caenorhabditis elegans rop-1 gene previously has been identified as encoding a Ro60 homologue. We report here the phenotypic characterization of a C. elegans strain in which rop-1 has been disrupted. This is the first report regarding the inactivation of a major RoRNP constituent in any organism. The rop-1 mutant worms display no visible defects. However, at the molecular level, the disruption of rop-1 results in a dramatic decrease in the levels of the ROP-1-associated RNA (CeY RNA). Moreover, transgenic expression of wild-type rop-1 partially rescues the levels of CeY RNA. Considering that transgenes are poorly expressed in the germline, the fact that the rescue is only partial is most likely related to the high abundance of the CeY RNA in the adult germline and in embryos. The developmental expression pattern and localization of CeY RNA suggest a role for this molecule during embryogenesis. We conclude that, under laboratory culture conditions, ROP-1 does not play a crucial role in C. elegans.

scholarly journals Functional characterization of Caenorhabditis elegans cbs-2 gene during meiosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pamela Santonicola ◽  
Marcello Germoglio ◽  
Domenico Scotto d’Abbusco ◽  
Adele Adamo
Keyword(s):  
Dna Damage ◽  
Caenorhabditis Elegans ◽  
Functional Characterization ◽  
Genotoxic Stress ◽  
Phenotypic Characterization ◽  
Chromosome Fragmentation ◽  
C Elegans ◽  
Synaptonemal Complex Formation ◽  
Induced Apoptosis

AbstractCystathionine β-synthase (CBS) is a eukaryotic enzyme that maintains the cellular homocysteine homeostasis and catalyzes the conversion of homocysteine to L-cystathionine and Hydrogen sulfide, via the trans-sulfuration pathway. In Caenorhabditis elegans, two cbs genes are present: cbs-1 functions similarly as to human CBS, and cbs-2, whose roles are instead unknown. In the present study we performed a phenotypic characterization of the cbs-2 mutant. The null cbs-2 mutant is viable, fertile and shows the wild-type complement of six bivalents in most oocyte nuclei, which is indicative of a correct formation of crossover recombination. In absence of synaptonemal complex formation (syp-2 mutant), loss of cbs-2 leads to chromosome fragmentation, suggesting that cbs-2 is essential during inter-sister repair. Interestingly, although proficient in the activation of the DNA damage checkpoint after exposure to genotoxic stress, the cbs-2 mutant is defective in DNA damage-induced apoptosis in meiotic germ cells. These results suggest possible functions for CBS-2 in meiosis, distinct from a role in the trans-sulfuration pathway. We propose that the C. elegans CBS-2 protein is required for both inter-sister repair and execution of DNA damage-induced apoptosis.

The glycomes of Caenorhabditis elegans and other model organisms

2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell
Keyword(s):  
Caenorhabditis Elegans ◽  
Current Knowledge ◽  
Structural Data ◽  
Model Organisms ◽  
Entire Genome ◽  
C Elegans ◽  
The Face ◽  
Area Of Concern ◽  
Nematode Worm

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.

scholarly journals Characterization of Caenorhabditis elegans Homologs of the Down Syndrome Candidate Gene DYRK1A

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 571-580 ◽  
Author(s):  
William B Raich ◽  
Celine Moorman ◽  
Clay O Lacefield ◽  
Jonah Lehrer ◽  
Dusan Bartsch ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Caenorhabditis Elegans ◽  
Trisomy 21 ◽  
Gene Dosage ◽  
Inducible Promoters ◽  
C Elegans ◽  
Dual Specificity ◽  
Specificity Protein

Abstract The pathology of trisomy 21/Down syndrome includes cognitive and memory deficits. Increased expression of the dual-specificity protein kinase DYRK1A kinase (DYRK1A) appears to play a significant role in the neuropathology of Down syndrome. To shed light on the cellular role of DYRK1A and related genes we identified three DYRK/minibrain-like genes in the genome sequence of Caenorhabditis elegans, termed mbk-1, mbk-2, and hpk-1. We found these genes to be widely expressed and to localize to distinct subcellular compartments. We isolated deletion alleles in all three genes and show that loss of mbk-1, the gene most closely related to DYRK1A, causes no obvious defects, while another gene, mbk-2, is essential for viability. The overexpression of DYRK1A in Down syndrome led us to examine the effects of overexpression of its C. elegans ortholog mbk-1. We found that animals containing additional copies of the mbk-1 gene display behavioral defects in chemotaxis toward volatile chemoattractants and that the extent of these defects correlates with mbk-1 gene dosage. Using tissue-specific and inducible promoters, we show that additional copies of mbk-1 can impair olfaction cell-autonomously in mature, fully differentiated neurons and that this impairment is reversible. Our results suggest that increased gene dosage of human DYRK1A in trisomy 21 may disrupt the function of fully differentiated neurons and that this disruption is reversible.

Maternal-effect lethal mutations on linkage group II of Caenorhabditis elegans.

Genetics ◽  
1988 ◽  
Vol 120 (4) ◽  
pp. 977-986
Author(s):  
K J Kemphues ◽  
M Kusch ◽  
N Wolf
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Maternal Effect ◽  
Essential Genes ◽  
The Other ◽  
C Elegans ◽  
Lethal Mutations ◽  
Embryonic Lethal ◽  
Embryonic Lethal Mutations ◽  
F1 Progeny

Abstract We have analyzed a set of linkage group (LG) II maternal-effect lethal mutations in Caenorhabditis elegans isolated by a new screening procedure. Screens of 12,455 F1 progeny from mutagenized adults resulted in the recovery of 54 maternal-effect lethal mutations identifying 29 genes. Of the 54 mutations, 39 are strict maternal-effect mutations defining 17 genes. These 17 genes fall into two classes distinguished by frequency of mutation to strict maternal-effect lethality. The smaller class, comprised of four genes, mutated to strict maternal-effect lethality at a frequency close to 5 X 10(-4), a rate typical of essential genes in C. elegans. Two of these genes are expressed during oogenesis and required exclusively for embryogenesis (pure maternal genes), one appears to be required specifically for meiosis, and the fourth has a more complex pattern of expression. The other 13 genes were represented by only one or two strict maternal alleles each. Two of these are identical genes previously identified by nonmaternal embryonic lethal mutations. We interpret our results to mean that although many C. elegans genes can mutate to strict maternal-effect lethality, most genes mutate to that phenotype rarely. Pure maternal genes, however, are among a smaller class of genes that mutate to maternal-effect lethality at typical rates. If our interpretation is correct, we are near saturation for pure maternal genes in the region of LG II balanced by mnC1. We conclude that the number of pure maternal genes in C. elegans is small, being probably not much higher than 12.

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.

scholarly journals QTL Across Fruit Development in Red Raspberry, A Study of A Primocane X Biennial Raspberry Population.

2021 ◽  
Author(s):  
Julie Graham ◽  
Kay Smith ◽  
Katrin MacKenzie ◽  
Linda Milne ◽  
Nikki Jennings ◽  
...  
Keyword(s):  
Linkage Group ◽  
Genetic Control ◽  
Fruit Ripening ◽  
Fruit Development ◽  
Developmental Stages ◽  
Developmental Process ◽  
Linkage Groups ◽  
Red Raspberry ◽  
Ripening Process ◽  
Second Year

Abstract Background The changing climate is altering timing of key fruit ripening processes and increasing the occurrence of fruit defects. This work aimed to expand our knowledge of the genetic control of the ripening process in raspberry by examining a biennial x primocane F1 population to determine if the progeny exhibited both primocane and biennial flowering modes, which if any was dominant, and to identify QTL and genome locations associated with fruit development to understand how developmental control in this population differs from a biennial x biennial F1 population previously studied. Results The progeny from this biennial x primocane population exhibited primocane fruiting completing their lifecycle in a single season and also fruiting on second-year wood not removed in season one. QTL associated with rate of fruit development were identified on both primocane and fruiting canes with both parents impacting. Conclusions Novel QTL associated with the developmental process of primocane fruiting were identified. These in the main, differed from developmental QTL for similar developmental stages on fruiting canes (second year canes) with only one significant overlap on linkage group 6. In general, the process of development on fruiting canes overall differed from that in a biennial x biennial population, with the differences being greatest on linkage groups 3 and 6 suggesting control of development differs in the different fruiting types. Further understanding will be achieved by examining genome regions linked to QTL to allow breeding to meet climate requirements for yield stability.

scholarly journals Baculovirus expression of two protein disulphide isomerase isoforms from Caenorhabditis elegans and characterization of prolyl 4-hydroxylases containing one of these polypeptides as their β subunit

1996 ◽  
Vol 317 (3) ◽  
pp. 721-729 ◽  
Author(s):  
Johanna VEIJOLA ◽  
Pia ANNUNEN ◽  
Peppi KOIVUNEN ◽  
Antony P. PAGE ◽  
Taina PIHLAJANIEMI ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Cloning And Expression ◽  
Β Subunit ◽  
Α Subunit ◽  
Protein Disulphide Isomerase ◽  
C Elegans ◽  
Baculovirus Expression ◽  
Expression Studies ◽  
Α Subunits

Protein disulphide isomerase (PDI; EC 5.3.4.1) is a multifunctional polypeptide that is identical to the β subunit of prolyl 4-hydroxylases. We report here on the cloning and expression of the Caenorhabditis elegans PDI/β polypeptide and its isoform. The overall amino acid sequence identity and similarity between the processed human and C. elegans PDI/β polypeptides are 61% and 85% respectively, and those between the C. elegans PDI/β polypeptide and the PDI isoform 46% and 73%. The isoform differs from the PDI/β and ERp60 polypeptides in that its N-terminal thioredoxin-like domain has an unusual catalytic site sequence -CVHC-. Expression studies in insect cells demonstrated that the C. elegans PDI/β polypeptide forms an active prolyl 4-hydroxylase α2β2 tetramer with the human α subunit and an αβ dimer with the C. elegans α subunit, whereas the C. elegans PDI isoform formed no prolyl 4-hydroxylase with either α subunit. Removal of the 32-residue C-terminal extension from the C. elegans α subunit totally eliminated αβ dimer formation. The C. elegans PDI/β polypeptide formed less prolyl 4-hydroxylase with both the human and C. elegans α subunits than did the human PDI/β polypeptide, being particularly ineffective with the C. elegans α subunit. Experiments with hybrid polypeptides in which the C-terminal regions had been exchanged between the human and C. elegans PDI/β polypeptides indicated that differences in the C-terminal region are one reason, but not the only one, for the differences in prolyl 4-hydroxylase formation between the human and C. elegans PDI/β polypeptides. The catalytic properties of the C. elegans prolyl 4-hydroxylase αβ dimer were very similar to those of the vertebrate type II prolyl 4-hydroxylase tetramer, including the Km for the hydroxylation of long polypeptide substrates.

Broad oxygen tolerance in the nematode Caenorhabditis elegans

2000 ◽  
Vol 203 (16) ◽  
pp. 2467-2478 ◽  
Author(s):  
W.A. Van Voorhies ◽  
S. Ward
Keyword(s):  
Caenorhabditis Elegans ◽  
Metabolic Rate ◽  
Developmental Stages ◽  
Small Body ◽  
Metabolic Cost ◽  
Soil Nematode ◽  
Nematode Caenorhabditis Elegans ◽  
Oxygen Levels ◽  
C Elegans ◽  
Short Period

This study examined the effects of oxygen tensions ranging from 0 to 90 kPa on the metabolic rate (rate of carbon dioxide production), movement and survivorship of the free-living soil nematode Caenorhabditis elegans. C. elegans requires oxygen to develop and survive. However, it can maintain a normal metabolic rate at oxygen levels of 3.6 kPa and has near-normal metabolic rates at oxygen levels as low as 2 kPa. The ability to withstand low ambient oxygen levels appears to be a consequence of the small body size of C. elegans, which allows diffusion to supply oxygen readily to the cells without requiring any specialized respiratory or metabolic adaptations. Thus, the small size of this organism pre-adapts C. elegans to living in soil environments that commonly become hypoxic. Movement in C. elegans appears to have a relatively minor metabolic cost. Several developmental stages of C. elegans were able to withstand up to 24 h of anoxia without major mortality. Longer periods of anoxia significantly increased mortality, particularly for eggs. Remarkably, long-term exposure to 100 % oxygen had no effect on the metabolic rate of C. elegans, and populations were able to survive for a least 50 generations in 100 % (90 kPa) oxygen. Such hyperoxic conditions are fatal to most organisms within a short period.

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