Worm Breeder's Gazette 11(1): 56a

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.

Title unknown.

Authors unknown.

Chemosensory neurons fill with fluorescein dyes entering through 
their exposed receptor cilia and fail to fill when their cilia are too 
short or the sensillar opening is obstructed.  Some mutants with 
abnormal assembly or degeneration of sensory cilia have been 
identified by reduced FITC staining (Perkins et al., Dev.  Biol.  117, 
456 (1986)).  In most cases, the defects are confined to sensory 
structures and, in particular, locomotion is normal.  Exceptionally, 
unc-33 and unc-44 mutants have both dendritic and axonal abnormalities.
In addition to having somewhat shortened chemosensory cilia, these 
mutants are profoundly paralyzed and have numerous defects in axon 
growth (Hedgecock et al., Dev.  Biol.  111, 158 (1985); Desai et al.  
Nature 336, 638 (1988); S. Siddiqui and J.  Culotti, J.  Neurosci.  (
in press); H.  Bhatt, E.  Hedgecock, and D.  Hall (in preparation)).  
In a screen for other uncoordinated mutants with reduced FITC-filling, 
a new unc-101 allele was isolated.  In both unc-101(rh6), and in the 
original unc-101(m1) mutant isolated by D.  Riddle, usually only 1 
pair of amphid neurons stains brightly (probably ADF) while the 
phasmid neurons are generally faint or unstained.  Amphid cilia are 
shorter than normal and may be dark and irregular in contour.  The AWC 
cilia fail to spread into wingshaped sheets and the AFD dendrites have 
an abnormally long cilium but few fingers.  The distal specializations 
of the CEP cilia are also abnormal.  Ciliary defects similar to some 
of these have been reported for che-11,  (
Albert et al., J.  Comp.  Neurol.  198, 435 (1981)).  In contrast, the 
axons of the chemosensory neurons appear to be normal in unc-101 
mutants and, to our knowledge, no axonal abnormalities have been 
reported for other classes of neurons in these strains.  Thus unc-101 
may represent a new pleiotropic mutant class with both ciliary and 
motor defects but normal axon growth.  The cellular focus of the 
locomotion defect is unknown.