Fig 1.
Males are more resistant to osmotic stress, heat shock, and juglone than hermaphrodites in groups.
(A-D) Male and hermaphrodite worms were growth on standard 51 mM NaCl agar until the young adult stage and then exposed together in groups to 425 mM NaCl, 35°C for 8 h, or 175 μM juglone. Survival was scored after 24 h for 425 mM NaCl, 72 h of recovery for heat shock, and 12–24 h for juglone. Values are mean ± standard error. N = 4–12 replicate populations of 17–920 worms from 2–3 trials. *P > 0.01,**P < 0.01, and ***P < 0.001 versus hermaphrodites.
Fig 2.
Males are more resistant to osmotic stress, heat shock, and juglone than hermaphrodites as individuals.
Survival curves for single trials heat shock (A) or juglone (B); details for all trials are in S1 Fig. Male and hermaphrodite worms were growth together on standard 51 mM NaCl agar until the L4 larval stage; one L4 worm was picked to each well of a 96 well plate containing OP50 bacteria in liquid NGM buffer. On the first day of adulthood, worms were exposed to 35°C for 8 h or 175 μM juglone was added. Survival was scored for each worm. N = 47–49 worms of each sex.
Fig 3.
Stress response gene induction in N2 males and hermaphrodites.
Expression of stress response genes with and without exposure to (A) osmotic (250 mM NaCl for 24 h), (B) heat shock (35°C for 15 min), or (C) oxidative stressors (87.5 μM juglone for 1 h). Values are mean plus standard error. N = 4–10 replicate populations of 3–5 worms. *P < 0.05, **P < 0.01, and ***P < 0.001 versus control of the same sex; †P < 0.05 versus hermaphrodites of the same condition.
Fig 4.
Males induce hsp-16.2 and gst-4 in the same tissues as hermaphrodites.
Paired bright-field and fluorescence micrographs of hsp-16.2p::GFP (A) and gst-4p::GFP (B) expressing worms after heat shock (12 h after 35°C for 1 h) or juglone exposure (12 h after 87.5 μM juglone for 1 h). Images of the same magnification and strain were taken with the same exposure settings. Scale bars are 200 or 50 μm at low and high magnification, respectively. Images are representative of at least 10 worms.
Fig 5.
XX tra-1 pseudomales are more resistant to heat and juglone than hermaphrodites.
(A) Heat shock survival for N2 wild type hermaphrodites and homozygote tra-1(e1099) pseudomales; heat shock was 35°C for 8 h and then 72 h of recovery. Values are mean ± standard error. N = 4–6 replicate populations of 27 to 359 worms from 2 trials. (B) Survival curves for tra-1 pseudomales and N2 hermaphrodites in 175 μM juglone; details for all trials are in S1 Fig. Assay conditions were identical to Fig 2B.