Worm Breeder's Gazette 5(1): 30

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.

Characterization of Two Sub Populations in C. elegans, Bergerac by Bacteria in the Digestive Tract

Y. Charnay, J. Brun

In our laboratory C.  elegans, Bergerac strain,has been routinely 
cultivated in xenic conditions on nutrient agar since several years.  
Different populations were maintained separately.
The intestinal tractus of the worm was studied cytologically by the 
'frottis' technique followed by Feulgen reaction.  We have 
distinguished two populations categories.  Results are homogeneous in 
each of them what ever the larval and adult stages considered and are 
similar after 100 generations.
- First category (majority of populations) - The intestine nuclei 
alone are Feulgen positive, intestine lumen is clear.
- Second category - Feulgen positive material is found throughout 
the intestine lumen with the same intensity from the very anterior 
region to the rectum.  This Feulgen positive material when observed 
under Nomarski differential interference contrast optics in the light 
microscope appears to be constituted by many thousand particles.  
Their size is just larger than resolution power allowed by microscope. 
These Feulgen positive particles are neither revealed in Nematodes 
cultivated in axenic conditions, nor when the hydrolysis is omitted 
during Feulgen reaction.
All these results allowed us to consider that the positive Feulgen 
material originates in the staining of bacterial chromosomes.
So, one or more bacteria strains would be able to colonize the 
intestine lumen of this Bergerac sub population and to be tolerated by 
the worm even in large amounts.  This result is interesting in the 
perspective of better knowledge of Nematode-bacteria relations.  Which 
and how much bacteria species are implicated in the nutritional 
requirements?  Are these bacteria symbiot or not?