Walrond JP et al. (1977) Worm Breeder's Gazette "electrophysiology of identified neurons of Ascaris."

Walrond JP, Rass IS

[Worm Breeder's Gazette, 1977]

The function of the seven commissural motorneurons in the second and third segments of Ascaris des has been determined physiologically by stimulating isolated commissural fibers and recording the evoked responses in the musculature. Of the seven neurons, three are inhibitory and four are excitatory. Dorsal activation of the two type B neurons in.each segment evoke hyperpolarizing responses in the ventral muscles while ventral activation of the type A neuron evokes hyperpolarizing responses in the dorsal muscles. When stimulated ventrally, both type C neurons in each segment produce depolarizing responses in the dorsal muscles. Both type D and E neurons also depolarize the dorsal musculature. The depolarizing responses are frequently slow potentials with superimposed spikes.

Moss EG et al. (1995) Worm Breeder's Gazette "The Heterochronic Gene lin-28 is Cloned."

Moss EG, Ambros VR

[Worm Breeder's Gazette, 1995]

The heterochronic gene lin-28 is cloned

Avery L et al. (1994) Worm Breeder's Gazette "M3 is an Inhibitory Glutamatergic Pharyngeal Motoneuron."

Avery L, Dent JA, Davis MW, Hess GP, Denk W

[Worm Breeder's Gazette, 1994]

M3 is an inhibitory glutamatergic pharyngeal motoneuron.

Hosono R (1977) Worm Breeder's Gazette "sinusoidal movement of C elegans in liquid phase."

Hosono R

[Worm Breeder's Gazette, 1977]

In liquid phase, the nematode propagates sinusoidal waves along the body, mostly initiated at the anterior end but occasionally at the tail. Although the movement on the agar plate is often stopped, the sinusoidal movement in liquid is rhythmic. The frequency of the wave, which propagates along the body is about 50 per 30 seconds in a young adult at 20 C. The behavior is utilizable for searching chemicals which stimulate or make nervous system paralysis but don't provoke a chemotactic behavior. Caution : I always use synchronously grown worms. Because the movement activity is changeable depending on ages.

Antebi A et al. (1995) Worm Breeder's Gazette "daf-12 is a Heterochronic Gene Acting During L2 and L3 Larval Stages."

Antebi A, Hedgecock EM

[Worm Breeder's Gazette, 1995]

daf-12 is a Heterochronic Gene Acting During L2 and L3 Larval Stages

White JG (1975) Worm Breeder's Gazette "a laser microbeam system for killing individual cells."

White JG

[Worm Breeder's Gazette, 1975]

A Zeiss universal microscope with Nomarski optics has been modified by the addition of a semi-silvered mirror mounted behind the objective. A dye laser giving 0.25 joule pulses at 450 nm wavelength is set up so that the beam is brought into focus in the plane of the object. A spot size of about 1.5 m is produced and this can be used to kill individual cells in the nematode with no apparent damage to their neighbors. It has been found that there is very little regulation of the nematode. When one of the precursors that migrate into the ventral cord is killed, the adjacent ones go through their normal sequence of divisions. The daughters of the precursor that migrates into the RVG behave differently from those in the rest of the cord. When this precursor is killed the next one along will go into the RVG. We are at the moment performing an E/M autopsy on one of these animals to see whether the daughter cells from this precursor behave as the original one would have done or as those from a normal cord precursor. When the mesodermal blast cell of the hermaphrodite is killed a perfectly normal looking animal is produced which is lacking in all the cells which derive from that cell. It cannot lay eggs however, as it has no vulval muscles. When the gonad primordium is killed in the hermaphrodite there is no gonad or vulva produced but the vulval muscles migrate to the right place and start twitching even though there is nothing there.

Williams BD et al. (1991) Worm Breeder's Gazette "GENETIC MAPPING WITH Tc1 POLYMORPHISMS DETECTED BY PCR"

Waterston RH, Schrank B, Williams BD

[Worm Breeder's Gazette, 1991]

On the table describing the primers used for our PCR assays the primer 723 is used for polymorphism maP1 (not hP4) and its fragment size is 234 base pairs (not 324 base pairs). Our apologies for these typos.

Roehl H et al. (1994) Worm Breeder's Gazette "A Screen For Proteins That Interact With GLP-1 Ankyrin Repeats"

Roehl H, Kimble JE

[Worm Breeder's Gazette, 1994]

GLP-1 is a receptor that is involved in several cell fate decisions during development. We previously showed that a fragment from the intracellular region of GLP-1 ,which is predominantly made up of ankyrin(cdc-10 /SWI6)repeats, is capable of directing cell fate decisions(1). The ankyrin repeats of other proteins (eg 1KB and GABP ) mediate protein-protein interactions. Our hypothesis is that the GLP-1 ankyrin repeats control cell fate by binding one or more downstream, target proteins. We are attempting to identify proteins that interact with GLP-1 ankyrin repeats in vitro, and then investigate the role of the interacting proteins in vivo. We have screened several expression libraries using radioactively labeled GLP-1 ankyrin repeats as a probe. This procedure has yielded several strong positives with little background. We are now checking these positives with several controls to see if the interaction is specific to the GLP-1 ]ankyrin repeats. Anyone who is using or is interested in using this method to identify interacting proteins should feel free to email me at in%"hroehl@macc.wisc.edu". (l) Roehl & Kimble, (1993) Nature 364: 632-635

Waterston RH (1977) Worm Breeder's Gazette "Informational Suppression in C. elegans"

Waterston RH

[Worm Breeder's Gazette, 1977]

In reversion studies of the null mutant E1214 of the paramyosin gene unc-15 a partial revertant has been isolated in which paramyosin is partially restored. This is due to a second mutation, e1464, which maps in the cluster of LG III. In addition, e1464, is able to suppress certain isolates and not others in several different complementation groups, some of which do not involve muscle. These and other observations are consistent with the hypothesis that e1464 results in informational suppression possibly of chain-terminating mutations, which is perhaps mediated by an altered tRNA species.

Thomas JH et al. (1988) Worm Breeder's Gazette "sensory cells for an endogenous C elegans avoidance factor."

Thomas JH, Horvitz HR

[Worm Breeder's Gazette, 1988]

When a worm encounters certain noxious conditions with its nose it backs up (see WBG 10-1, p. 89 for how we assay this behavior). In the process of testing various chemicals and extracts for activity in the avoidance assay, we found that C. elegans itself makes an avoidance factor which produces a response that is very similar to osmotic avoidance. This avoidance response is not due to any of the known avoidance chemicals. We have killed various cells with a laser to define which sensory neurons are required for the avoidance factor (Afa) response. The source of avoidance factor for the tests is an ultrafiltered crude lysate of C. elegans. When the amphid sheath is killed animals become Afa nonresponsive, suggesting that the amphid sensillum is required for Afa detection. When the amphid sensory cell ASH is killed animals are less sensitive, and when ASH and ADL are killed together animals are nonresponsive to Afa. When ADL is killed alone the animals respond normally. Interestingly, the primary Afa sensor, ASH, is the same cell that is the primary osmotic avoidance sensor ( WBG 10-1). Both ASH and ADL have synaptic wiring (White, et al. 1986. Phil. Trans. Royal Soc. London 314: 1-340) consistent with being avoidance sensory neurons, because they are unique among amphidial neurons in having synaptic output to AVA and AVD (the interneurons that drive backward movement, Chalfie, et al. 1984. J. Neurosci. 5: 956-964). One model for Afa avoidance is that ADL and ASH act by directly activating AVA and AVD, thus causing the avoidance behavior. This model can be tested by killing other cells to which ADL and ASH synapse, and by killing AVA and AVD. The C. elegans avoidance factor is not yet well characterized. It is not excreted into the medium, but is released upon boiling or sonication of worms. It is made at about normal levels by daf-22(m130) animals, which make no dauer pheromone. It is heat stable and passes through a filter with a 10,000 dalton exclusion limit. No avoidance factor is found in E. coli or Drosophila melanogaster larva extracts, but a factor that C. elegans avoids is found in soil nematodes of the genera Pelodera and Pellioditis. A possible function for avoidance factor is to signal the presence of a feeding predator of nematodes. Most such predators eat nematodes by puncturing their cuticle with a stylet or teeth and pumping up the insides. Other nematodes could detect and avoid the active predator by sensing some chemical(s) released from broken worms. A single adult C. elegans exploded on a plate using a glass needle causes a rapid (within one minute) and strong (maximum radius about 1 mm from the victim) avoidance responses in nearby worms.