Worm Breeder's Gazette 7(1): 64
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.
Recombinant inbred (RI) strains have been generated from crosses of Bristol (N2) and Bergerac (Lyon) parental strains. F1 hybrid progeny from this cross are isolated and allowed to self-fertilize. Resultant F2 progeny are then individually isolated and allowed to self- fertilize. After 3-5 days, individual F3 offspring are isolated to new plates. This procedure is repeated through 20 rounds of inbreeding, which leaves the genome homozygous to 1 part in 10+E6. These RI strains show remarkable variations in length of life. Mean lifespans vary from a low of near 11 days to a high of about 30 days. These differences are reproducible. The large variation in lifespan ( both parental strains have lifespans of about 18 days) is presumably due to the recombination and subsequent homozygosis of allelic differences at many genetic loci. There appear to be no major genes that affect lifespan segregating within this population. Since several other genetic characteristics of the Bristol and Bergerac strains (e.g., uncoordinated behavior of Bergerac, lower pharyngeal pump rate of Bergerac, slower rate of larval development of Bergerac, and the presence of a ts gene causing either a Zyg or a Gon phenotype; Wood et al., 1980) are also segregating within these strains, we can estimate the correlations between these factors and lifespan. For example, our studies, which are still in progress, show that about 10% of the variation in lifespan can be explained by the variation in pharyngeal pump rate. We are now using these RI strains for selective breeding experiments designed to obtain longer lived strains of worms.