Worm Breeder's Gazette 2(2): 3

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.

A Nematode Variant with Increased Lifespan

D.H. Mitchell

The nematode Caenorhabditis fespan (50% 
survival time) of about 12 days when grown at 25 C on agar with a 
layer of the bacterium Escherichia coli as food source.  I have 
isolated a variant organism that lives 20 to 30% longer than the wild 
type under these conditions.  The variant was isolated by exposing the 
wild type to repeated starvation-and mild dehydration for periods of a 
month or so on agar from which the bacteria had been exhausted and 
which was partly dehydrated.  The surviving organisms (always juvenile 
stages) were used to produce progeny for the next cycle of selection.  
The variant was detected after twelve cycles of selection.  
Mutagenesis was not employed.  The variant appears indistinguishable 
from the wild type through young adulthood.  Both the wild type and 
the variant show characteristic senescent changes beginning at the 
fifth day of life, when egg-laying ceases.  These changes include loss 
of fertility and atrophy of the gonads, changes in the appearance of 
the intestine, increased granularity and vacuolation of internal 
tissues, slowness of movement and marked loss of coordination.