Worm Breeder's Gazette 11(2): 59

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Transposon Tagging of Genes Affecting Axon Growth and Process Placement of Sensory Lumbar Neurons in C. elegans

M.A. Shakir and Shahid Siddiqui

A pair of lumbar ganglia are situated in the posterior-most region 
of the tail nervous system in C.  elegans, each consisting of 12 
neurons.  The neurons have a simple morphology and most of them are 
either monopolar or bipolar cells (White et al.  1986).  We have begun 
screening the mutator strains TR679 and RW7097 to isolate mutations 
affecting the morphology of lumbar neurons by transposon tagging, by 
light microscopic techniques.  These include, FITC dye filling of the 
phasmid neurons PHA and PHB (Hedgecock et al.  1985), 
immunocytochemical staining of PHC and PVN neurons (Siddiqui and 
Culotti, 1984), and staining of PLM and PVR neurons (Siddiqui et al.  
1989).  It was shown previously by Hedgecock et al. that mutations in 
unc-6, unc-44, 
he axonal growth and guidance of 
PHA and PHB neurons, using FITC staining of live animals.  In addition,
to these genes, mutants in unc-13, unc-71, 
wn by immunocytochemical staining 
with anti-HRP antibodies, to be affected in the process placement of 
PHC and PVN lumbar neurons (Siddiqui and Culotti).  The mechanosensory 
neurons PLML and PLMR, were shown to be affected in unc-53 and unc-73 
mutants by staining these neurons with anti-tubulin antibody 6-11B-1.
Several mutants have been isolated using the mutator strains, and we 
are using the well established techniques to clone these genes by 
identifying the Tc1 element rendering these genes mutant.  SQ141 is a 
strain which fails to stain PHA and PHB neurons with FITC dye, but 
shows normal PLM and PVR neurons, as determined cytochemically.  The 
postembryonic neurons PHC and PVN are also normal in this strain, 
suggesting that this mutation is specific for the dye uptake in the 
phasmid neurons PHA and PHB, whereas, it does not affect other lumbar 
neurons (PLM, PVR, PHC, and PVN).  Similarly other strains show 
specific neuronal defects limited to one class of lumbar neurons.
We are also examining the morphology of the male tail neurons, in 
Tc1 tagged mutants.  Antibodies to mouse neural cell adhesion molecule 
(N-CAM) were previously reported to stain the male specific neurons 
CEMs and a set of ray neurons.  We would like to request members of 
the worm community to kindly send us their isolates of unc mutants in 
Tc1 induced mutants, or mutants abnormal in the tail morphology.