Worm Breeder's Gazette 5(1): 19

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.

The Nematode Soul

J.E. Sulston, J.A. Hodgkin

Figure 1

Halfway along each posterior excretory canal is a small cell, 
probably secretory in function, that sends processes anteriorly and 
posteriorly along the 
canal:
[See Figure 1]
Laser ablation of these cells in young L1's has an unexpectedly 
dramatic effect: the animals take on a starved appearance, and die 
before becoming adult.  Although the excretory canals are interrupted 
at the site of ablation, and consequently their posterior sections 
disappear, they can be seen to regenerate in the course of the next 24 
hours.  In any case, it is known that individuals in which the 
excretory system has been destroyed are capable of becoming adults (
Singh and Sulston, Nematologica, 24, 63-71,1978).  Similarly, the 
other adjacent cells (V3, P5/6, hsn) can be ablated without killing 
the animal.  Therefore, it appears that the canal associated cells are 
essential to the survival of C.  elegans.The mutant vab-87 (E1017) 
matures into an adult whose anterior half appears normal but whose 
posterior half is thin, pale and uncoordinated.  Nomarski examination 
shows that all the tissues of the posterior half look starved; the 
canal associated cells are displaced into the head, and sometimes one 
of them seems to be missing.  These cells are difficult to distinguish 
from neurons in L1's, but in older larvae they enlarge and can be 
recognized.  One animal was found whose posterior half was of normal 
size; subsequent Nomarski examination showed that one of the canal 
associated cells was in the wild type position.  Although various 
other cells are displaced in E1017, these observations suggest that 
its principal character results from the abnormal position of the 
canal associated cells.

Figure 1