Fig. 1: An evolutionally conserved MAE shapes offspring adult traits in humans, Drosophila and C. elegans.

a, b Relationships of maternal (a) and paternal (b) age with offspring adult height in humans. c Adjusted sex-specific parental age effect on offspring adult height in humans. M | P (P | M) represents the MAE (PAE) when fitted jointly with paternal (maternal) age. d, e Comparisons of body length, wing size and head area for both male and female offspring from the MAE (d) and PAE (e) test groups in flies. f Strategy for offspring preparation from mothers of different ages (P0) in C. elegans. Offspring (F1) born to P0 individuals of Day 1–6 adults (D1–D6) were named OD1–OD6, respectively. All body length measurements in C. elegans were conducted on Day 3 of adulthood unless otherwise noted. g Adult body length comparison between OD2 and OD5 animals. h, i Analysis of sex-specific parental age effects on adult body length of offspring from parents of the indicated ages. The experimental designs are shown on the left. The fem-1(hc17) mutant animals were employed as females (♀) and crossed with WT males (♂) of the indicated ages to produce offspring for MAE tests. stands for hermaphrodite. The dots in box plots represent worm or fly numbers, and the triangles in the box pot (g) stand for the average adult body lengths of worms in each biological replicate. Box plots in d, e, g–i: the centerline is the median, the box range shows the 25th–75th percentiles, and the whiskers indicate the minimum–maximum values. All box plots (d, e, g–i) were analyzed by unpaired t-test. Biological replicates: 3 (d, e, h, i), 26 (g).