Research Paper Volume 6, Issue 2 pp 98—117

Figure 3. Distinct epistatic relationships between daf-2 and mdl-1 in hyperplasia and hypertrophy.

(A, B). mdl-1 is a direct transcriptional target of DAF-16. (A). mdl-1 mRNA levels are increased in daf-2 relative to daf-2; daf-16 (Q-PCR data). ** 0.001 < p < 0.01. (B) DAF-16 binds to the mdl-1 promoter (ChIP-PCR data). One experiment is shown which contained 3 immunoprecipitation replicates from the same chromatin preparation (error bars show the standard deviation between them). The dotted line shows the average inputs from 3 genes/genomic regions that do not show enrichment for DAF-16 binding in daf-2 vs daf-16; daf-2 in this particular trial, i.e. it reflects background DAF-16 binding levels. Significant DAF-16 binding was detected one of two additional trials. The position of the DAF-16 binding site detected is shown in Figure 1A. (C)mdl-1, daf-2 and daf-16 epistasis analysis with respect to unfertilized oocytes production (Uno). Total unfertilized oocyte production per worm was measured at 25°C. Means of 12 broods assessed; error bars, standard error. ** 0.001 < p < 0.01; *** p < 0.001 (Student's t test). (D) Model for interactions between DAF-2, DAF-16 and MDL-1, deduced from interactions between mutations. DAF-16 promotes oocyte production in daf-2(+) worms, but inhibits it in daf-2(m577) worms. MDL-1 acts via DAF-16 to inhibit oocyte formation in daf-2(+) worms, but does not influence oocyte production in daf-2(m577) worms. (E) Resistance to 7.5 mM tert-butylhydroperoxide (t-BOOH). Sample sizes (censored values): N2, 67 [7]; daf-2(m577), 61 [8]; mdl-1, 67 [8]; daf-2; mdl-1, 70 [12]. Probability of being the same: N2 vs.mdl-1, p = 0.24; daf-2vs.daf-2; mdl-1, p < 0.001 (log rank test).