Worm Breeder's Gazette 9(2): 98
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.
Both recombinant inbred (RI) lines and single gene mutants (see other abstracts in this issue) have been produced which have dramatic changes in life-span. Stocks average a 60% increase in mean and maximal life-span. We have been interested in knowing whether these changes also result in a change in developmental events (length of the embryonic period, timing of cell divisions, rate of larval growth, timing of larval molts) or in the length of the reproductive period. We have assayed the length of the embryonic period by isolating individual eggs at the 2-cell stage and transferring these eggs to incubation chambers at 16 C (chosen for convenience of monitoring). About 20 hours later the eggs hatch. We find no change in the length of this period in either the RI lines or in age-1(hx542) or age-1( hx546). Surprisingly, N2 seems to take about 1 hour longer to complete this phase than any other stock analyzed, including Bergerac BO. We see variation among the RI lines in the rate of larval growth, in the timing of larval molts, and in the time from hatch to 50% adult fecundity. These variations do not seem to correlate with the adult life-span but limited numbers of stocks have been assayed as of yet and we remain unclear about our level of statistical significance. It is clear that both(?) age-1 alleles are without effect on any aspect of larval development rate. There is marginal variation in the length of the reproductive period and in the total fecundity, among the RI lines. The quantitative variations in total fecundity showed statistically significant correlations with the length of life in one repeat which has not yet been confirmed. There is no correlation between the length of the fecund period and life-extension. For the age-1 locus, there is a significant reduction in total brood size but no significant change in the temporal distribution of progeny production, after normalizing to total brood size. As always, we welcome helpful and provocative suggestions of additional questions to ask and directions to proceed.