Salser SJ et al. (1994) Worm Breeder's Gazette "mab-5 Expression Repeatedly Switches ON and OFF in the V5 Lineage"

Kenyon CJ, Salser SJ

[Worm Breeder's Gazette, 1994]

mab-5 Expression Repeatedly Switches ON and OFF in the V5 Lineage S. Salser and C. Kenvon, UCSF, San Francisco, CA. 94143

Palmer RE et al. (1994) Worm Breeder's Gazette "Use of an Expression Library to Clone Genes by Complementation"

Palmer RE, Sternberg PW

[Worm Breeder's Gazette, 1994]

Use of an expression library to clone genes by complemcntation. RE. Palmer and P.W. Sternberg, HHMI and Division of Biology, Caltech, Pasadena, CA 91125

Simske JS et al. (1994) Worm Breeder's Gazette "Specification of Vulval Cell Fates By Sequential Signalling Pathways."

Simske JS, Kim SK

[Worm Breeder's Gazette, 1994]

Specification of vulval cell fates by sequential signaling pathways Jeffrey S. Simske and Stuart K. Kim, Dept. of Developmental Biology, Stanford University Medical Center, Stanford CA 94305

Edgley ML et al. (1997) Worm Breeder's Gazette "New Balancers for LG II"

Riddle DL, Edgley ML, Turner CA

[Worm Breeder's Gazette, 1997]

We have been screening for new genetic balancers for the left arm of chromosome II as part of the C. elegans Genetic Toolkit Project, in cooperation with the Rose and Baillie laboratories. We seek to isolate rearrangements that balance to the left of dpy-10, perhaps extending to the end of the chromosome. The existing rearrangement mnC1 balances well from the right end of the chromosome to just left of dpy-10. The semidominant mutation dpy-25(e817) has been used successfully to isolate deficiencies in a relatively small region (Chen et al., Science 256: 240-243, 1992), but we wanted a balancer for generating overlapping deficiencies across the entire left arm. Irradiated dpy-10(e128) + / + unc-104(e1265) males were crossed with unc-85(e1414) rol-1(e91) hermaphrodites. Wild-type F1 cross progeny were isolated and the F2 screened for the absence of Rol-1 non-Unc-85 recombinant animals, indicating suppression of recombination. These screens yielded four balancers (mC4, mC5, mC6 and mC7) in 2048 mutagenized chromosomes, all marked with dpy-10. One of the balancers, mC6, has been found to balance well from rol-1 leftward to let-552, but balancing activity is reduced sharply between let-552 and sqt-2. Initial characterization shows mC6 to be homozygous-viable, and it is probably an intrachromosomal rearrangement. It is stable in crosses and reduces recombination frequency by roughly 98% across the balanced interval. We are using it now to isolate deficiencies in the balanced region. The remaining three balancers do not seem particularly useful to us for isolating deficiencies, since they don't suppress recombination adequately in the region of interest, but two of them are interesting for other reasons. mC7 may be a translocation, as it has relatively small broods and segregates large numbers of dead eggs. Homozygous mC7 animals are segregated at low frequency, and are invariably sterile. We have found that it balances rol-1 quite well (so far), but does not balance unc-85 at all. mC5 suppresses recombination between unc-85 and rol-1, but not nearly as well as mC6, and it alters segregation ratios. Balancer homozygotes account for 31% to 34% of the progeny from an mC5 heterozygote, while animals homozyous for the balanced chromosome, which was never subjected to mutagenesis, account for only 7% to 10%. We see this in both the original isolate (mC5/unc-85 rol-1) and in a constructed stock (mC5/unc-104 rol-1).

Sommer RJ et al. (1994) Worm Breeder's Gazette "Evolution of Vulva-Formation: Part II: Species With a Central Vulva"

Sommer RJ, Sternberg PW

[Worm Breeder's Gazette, 1994]

Evolution of vulva-formation: Part II: Species with a central vulva Ralf J. Sommer & Paul W. Sternberg, California Institute of Technology, Division of Biology 156-29, Pasadena, CA 91125

Kenyon CJ et al. (1994) Worm Breeder's Gazette "Activity of the polyray-1 Maintenance Gene Must Be Overcome To Allow For Correct Temporal Expression of HOM-C Genes"

Kenyon CJ, Maloof JN

[Worm Breeder's Gazette, 1994]

Activity of the polyray-1 maintenance gene must be overcome to allow for correct temporal expression of HOM-C genes Julin Maloof and Cynthia Kenyon, Dept of Biochemistry, UCSF, San Francisco, CA 94143 0554

Schachat FH et al. (1981) Worm Breeder's Gazette "characterization and roles of calmodulin and a second calcium regulatory protein from C elegans."

Schachat FH, Vanaman TC, Bronson DD, Jamieson G

[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.

Sommer RJ et al. (1994) Worm Breeder's Gazette "Evolution of Vulva Formation: Part IV: Variation in AC Position Can Cause a Shift of Vulva Formation Towards P(4-6).p."

Sternberg PW, Sommer RJ

[Worm Breeder's Gazette, 1994]

Evolution of vulva formation: Part IV: Variation in AC position can cause a shift of vulva formation towards p(4- 6).p Ralf J. Sommer & Paul W. Sternberg, HHMI & California Institute of Technology, Division of Biology 156-29, Pasadena, CA

Weisblat D et al. (1975) Worm Breeder's Gazette "Electrophysiological Studies of Ascaris Muscle"

Byerly L, Russell RL, Weisblat D

[Worm Breeder's Gazette, 1975]

Using Ascaris as a model system, we are studying ionic mechanisms of the spontaneous electrical activity in nematode somatic muscle. The fast spike potentials appear to be Ca+2 mediated; their amplitude depends on the external Ca+2 concentration, they are TTX insensitive, they persist when Na+ is replaced by Tris+, choline+, or Cs+, and they are blocked by Co+2 and La+3. When the normal solution is replaced by one containing 11 mM Ba+2 and 0.15 mM Ca+2 as the only divalent cations, the slow waves underlying the normal spike activity appear to increase dramatically in amplitude and duration; spike activity gradually disappears. The duration and amplitude of the slow waves at steady state under these conditions increase with Ba+2 concentration, reaching values of 1-2 minutes and 50-60 mV, respectively, in 26 mM Ba+2. These results and others lead us to conclude that the slow waves are also Ca+2 mediated. The muscles are depolarized by 0.1 mM ouabain, suggesting some involvement of an electrogenic pump in maintaining the membrane potential. TEA, in concentrations as low as 1 mM, has pronounced effects on the spontaneous myogenic activity, consistent with the effects observed when TEA is injected iontophoretically into C. elegans.

Chuang P-T et al. (1994) Worm Breeder's Gazette "DPY-27: A Protein Required For Dosage Compensation is Associated With the X Chromosome in XX Animals"

Chuang P-T, Meyer BJ, Albertson DG

[Worm Breeder's Gazette, 1994]

Dpy-27: A Protein Required for Dosage Compensation Is Associated with the X chromosome in XX Animals Pao-Tien Chuangl, Donna Albertson2 and Barbara Meyerl, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720~ and MRC Laboratory of Molecular biology, Hills Road, Cambridge, CB2 2QH UK2