a, Scheme for generating wildtype descendents from RNAi treated parents. b, ash-2 mRNA levels at day 7 in different generations of worms treated with ash-2 RNAi or empty vector (control) only in the P0 generation. Mean ± s.e.m. of 3 independent experiments. ***p=0.0002 with paired t-test. c, ASH-2 protein levels at L3 stage in different generations of worms treated with ash-2 RNAi or empty vector (control) only in the P0 generation. Representative of 2 independent experiments. *: non-specific band; Arrow: ASH-2; Arrowhead: protein related to ASH-2, possibly a degradation product. d–h, Lifespan of P0 (d), F1 (e), F2 (f), F3 (g), and F4 (h) generations of worms with RNAi knock-down of ash-2 in parents only. Control RNAi: empty vector. Mean lifespan and statistics are presented in .