Reduction-of-function mutation (rf) in the age-1/PI3 kinase gene, age-1(hx546), made worms long-lived in the L1 starvation assay and was able to suppress the reduced L1 survival rate of mir-71(lf); the rate of the double mutants was comparable to that of wild type (Fig. 2A). In worms that recovered from 4 d of L1 starvation, we also found that a significant portion of the mir-71(lf) mutants displayed egg-laying defects and overproliferating or precociously reflexed gonads. (A) The mir-71(n4115, lf) mutant displayed severe reduction in L1 starvation survival rate, and the reduced survival rate of mir-71(lf) was suppressed by a reduction-of-function allele of age-1(hx546). To investigate the roles of miRNAs in animal survival during starvation-induced L1 diapause, we impaired the overall miRISC function with loss-of-function (lf) mutants of ain-1 (ku322, ku425, and tm3681) and ain-2(tm2432) and examined their L1 starvation survival rate (Materials and Methods). To test the hypothesis that these developmental timing genes mediate the regulatory role of miR-71 in larval development during recovery from starvation-induced L1 diapause, we examined whether knocking down HBL-1 function can suppress the retarded VPC timing defect of mir-71(lf). Note that the daf-16(lf) worms recovering from 3 d of L1 starvation displayed a ∼12-h delay in overall development and that the mir-71(lf); daf-16(lf) double mutants displayed an ∼24-h delay.
