Worm Breeder's Gazette 14(1): 101 (October 1, 1995)

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.

Isolation and Characterization of Age Mutants.

Stacey A. Duhon, Tom Johnson

The Institute for Behavioral Genetics, University of Colorado, Boulder, CO, 80309-0447

We have isolated three new EMS-induced alleles of age-1 (z10, z12, and
z25) with life spans ranging from 18.9 - 25.9 days at 25C with an average
46% increase in life span. All of these alleles fail to complement age-1
(hx546) for life-span extension. After backcrossing, alleles in a wild-
type background were examined for resistance to several environmental
stresses: heat (35C), ultraviolet light (20 J/m2) and hydrogen peroxide
(0.5 M).

Two replicates for the test of thermotolerance were completed on each
strain. Their mean survivals (+/- SD) were 842 +/- 50 minutes (hx546), 810
+/- 56 minutes (z10), 862 +/- 69 minutes (z12), and 860 +/- 81 minutes
(z25) for the age-1 alleles compared to 562 +/- 66 minutes for wild type.
All of the age-1 alleles were significantly different from wild type (p
<.001).

Two replicates for UV resistance were also completed with mean survivals
of 4.7 +/- 0.2 days, 4.9 +/- 0.3 days, 4.5 +/- 0.3 days, and 4.4 +/- 0.2
days, respectively. These means were compared to 3.8 +/- 0.2 days for wild
type. Although the difference was significant, it was not as large as the
difference for thermotolerance.

One test of hydrogen peroxide resistance has shown that z12 and N2 had a
mean survival of 1.7 +/- 0.5 days while the other age-1 alleles had mean
survival of 2.6 +/- 0.2 days (hx546), 2.6 +/- 0.2 days (z10), and 2.7 +/-
0.6 days (z25). This is the only environmental stress that differentiates
among the age-1 alleles.

age-1 is a constitutive dauer at 27C (Takao Inoue and Jim Thomas, this
news letter). We have examined our new alleles for the Daf-c phenotype at
27C and found that after 48 hours z10 had 90 % dauers, z12 had 100% dauers
and z25 had 60 % dauers. We have completed this experiment three times
with similar results (our age-1 (hx546) control has never reached 100%
dauers). These alleles also fail to complement daf-23 for the 27C Daf
phenotype, as reported by Inoue and Thomas elsewhere in this volume. This
is consistent with daf-23 being allelic with age-1, but we haven't ruled
out unusual intergenic interactions being responsible for the 27C Daf
phenotype.