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Worm Breeder's Gazette,
2001]
La quatrieme reunion annuelle des equipes francaises ayant un interet pour C. elegans se tiendra le Vendredi 23 fevrier 2001 a Luminy, Marseille. Contact: pujol@ibdm.univ-mrs.fr ewbank@ciml.univ-mrs.fr
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Worm Breeder's Gazette,
1994]
Mutagenesis of C. elegans using N-ethyl-N-nitrosourea Elizabeth De Stasio, Dinesh Stanislaus and Catherine Lephoto. Department of Biology, Lawrence University, Appleton, Wl 54911
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Worm Breeder's Gazette,
1994]
mab-3 YAC rescue David Zarkower, Mario de Bono, and Jonathan Hodgkin MRC Laboratory of Molecular Biology, Cambridge, England
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Worm Breeder's Gazette,
1994]
Reverse genetics using transposon Tcl: A progress report Ronald H.A. Plasterk, Marianne de Vroomen, the Netherlands Cancer Institute, Division of Molecular Biology, Plesmanlaan 121,1066 CX Amsterdam, the Netherlands, fax + 31 20 6172625, phone +31 20 5122081, E-mail RPLAS@NKI.NL
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Worm Breeder's Gazette,
1994]
The tpa-l gene encodes two forms of a protein kinase C homolog Yo Tabuse, Tohru Sano, and Johji Miwa NEC Fundamental Research Laboratories, Tsukuba, Ibaraki 305, Japan. Typical tumor-promoting phorbol esters (TPA and PDD) cause severe disorders in the growth and behavior of C. elegans. The tpa-l gene, which mediates the action of the agents, encodes a protein kinase C (PKC) homolog. The tpa-l gene consists of eleven exons and spans a genomic region of about 20 kb. Two mRNA species, 2.8 kb and 2.4 kb, are transcribed from the tpa-l locus and both are trans-spliced to SL1. The former contains all the eleven exons and codes for a protein of 80 kDa (TPA-lA); on the other hand, the latter lacks the first four exons and codes for a 65-kDa protein (TPA-lB) without some 150 amino acids at the amino-terminal portion of TPA-lA (Sano et al. C. elegans meeting '93, see Figure). In order to examine whether the two mRNA species are produced by two alternate promoters, we have tried to rescue a TPA- resistant mutant strain, MJ563, by microinjecting genomic fragments of the tpa-l gene, variously lacking its 5' region. Microinjection of plasmid constructs of these fragments showed rescuing activity. One of these rescuing constTucts, pSK14, contained a fragment covering only about 1 kb upstream of the 5th exon through the end of tpa-l, indicating that there is another promoter within 1 kb upstream of the 5th exon for the 2.4-kb mRNA. The result also shows that TPA-lB is sufficient to confer TPA-sensitivity on C. elegans. We are now examining tissue expression patterns of the 2.8-kb and 2.4-kb mRNAs with tpa-l-lacZ fusions to ask whether there are any differences in the distribution of these two mRNAs.
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Worm Breeder's Gazette,
1991]
In the last few years our group has been studying the large scale organization of repetitive DNA sequences. We are characterizing six repetitive DNA families interspersed in the genome of C. elegans: RcA1, RcD1, Rc35, RcC9, RcS5 and RcB1. We presented in CSH 1989 the physical distribution of our repeated elements in the genome. Some of these families (RcD1, Rc35, RcC9, see also La Volpe et al. (1988) Nucl. Acids Res. 16, 82138231 ) are characterized by the presence of short tandemly repeated modules (satellite-like repetitive DNA). We compared the sequence of three elements belonging to the RcA1 family (Copy number: 161) localized on chromosomes I, II and V respectively; each member is 118 bp in length and the core region of 46bp is perfectly conserved between the three. The elements of the RcD1 family (present at 138 loci in the genome) are characterized by tandem repetitions of an extremely conserved 15bp unit. The Rc35 is another satellite-like family localized at 76 loci; the tandem repeated module is 35bp long. The RcC9 family described in La Volpe et al. (1988) has the basic tandemly repeated unit of 10bp (and the same consensus of the Heat-Shock Element) and is present at 84 positions on C. elegans genome. An element belonging to the RcB1 family (copy number 57) is characterized by the presence of direct terminal repeats of 64 bp. We observed that, although they are present along all the chromosomes, these families are not distributed completely randomly, but there are some regions of accumulation of elements belonging to different repetitive families, some of which we analyzed in detail by sequencing. There is an inverse correlation between the presence of repetitive regions along the chromosomes and the frequency of recombination, that recalls the repression of legitimate recombination near the centromeres of Drosophila and Schizosaccharomyces pombe.
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Worm Breeder's Gazette,
1976]
Robert Wyman (Department of Biology, Yale University) reports that Theodore Bullock (University of California at San Diego, La Jolla, California) has isolated a 4.1-meter long nematode from a 3.8-meter whale. The specimen is preserved, and Dr. Bullock is searching for a taxonomist interested in taking the beast. Want Ad: Does anyone know a way to cause a large population of males to release their sperm into the medium? CONTEST REMINDER: Don t forget that bottle of champagne from S. Ward and D. Hirsh promised to whoever scores the most progeny from a single hermaphrodite (see Newsletter, Vol. 1, # 2 for details). Deadline for submission of entries to either judge is February 23rd.
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Worm Breeder's Gazette,
1994]
C. elegans U2AF65
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Worm Breeder's Gazette,
1994]
An Electronic Discussion Group For C. elegans Researchers
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Worm Breeder's Gazette,
1981]
In these studies we have purified and characterized two proteins involved in Ca-regulation in Caenorhabditis st is calmodulin (CaM) which is considered to be an intracellular receptor for calcium because of the large number of cellular processes it activates in a Ca-dependent manner. The second protein which is similar to CaM in many of its physical and chemical properties, we have called the troponin-C like protein (TnCLP) . Because of a report which suggested invertebrate CaMs are dissimilar to those of vertebrates our studies on C. elegans CaM have focused on a comparison of its properties to those of bovine brain CaM. The C. elegans protein shows no major difference in amino acid composition, cyanogen bromide (CNBr) peptide maps, electrophoretic behavior or enzymatic properties in those studies. The C. elegans TnCLP, which copurifies with the CaM until DE-52 ion exchange chromatography, can be distinguished from CaM. It differs in amino acid composition, CNBr peptide maps and molecular weight, and lacks the ability to activate bovine brain cyclic nucleotide phosphodiesterase. Our concern with it has centered about defining its possible physiological roles. TnCLP forms Ca-dependent complexes with rabbit fast skeletal muscle troponin I and troponin T. It copurifies with thin myofilaments. These observations coupled with its inability to activate bovine brain cyclic nucleotide phosphodiesterase suggest that C. elegans TnCLP is not a second generalized Ca-dependent activator like CaM, but functions as a troponin C. We believe that the C. elegans TnCLP and CaM are responsible for the 2 thin and thick myofilament Ca-regulation that has been reported in C. elegans. The TnCLP acting in a troponin-like complex to regulate thin filaments. The CaM acting on thick filaments through a myosin light chain kinase as has been reported for other actomyosin contractile systems. In support of that later contention we have shown that there is an in vitro Ca and CaM dependent phosphorylation of one of the C. elegans myosin light chains. We expect these studies will serve as the basis for elucidating the Ca-dependent events in muscle contraction (as well as in other processes) both in vivo and in vitro through the analysis of genetic variants of C. elegans that may be blocked in different steps or pathways of Ca-regulation.