Fig. 3

Experimental design of the crosses using type A eggs. A Type A specimen and a type B specimen, both wild-caught, were dissected, and A eggs were fertilized with B sperm. At 8 h post fertilization, half of the embryos were heat treated at 26.5 ºC for 1 h and then reared at 17 °C until they settled, metamorphosed and started feeding, whereas others were reared at 17 °C without heat shock. F1 juveniles of both batches were transferred to a marina and cultured side-by-side. When they matured, eggs were collected from one heat-shocked individual (ABH) and one non-shocked individual (ABC). Some eggs were subjected to scRNA-seq while others from the same clutches were crossed with sperm from another laboratory-reared type B specimen (BBC). Embryos were cultured without heat treatment until they matured (F2: ABCB and ABHB). Eggs from mature F2 animals were collected and subjected to scRNA-seq while others were crossed with a type B specimen taken from the wild. The resulting F3 embryos were examined to determine the proportion of normal development after hatching without heat treatment. Green rectangles show eggs collected for single-egg sequencing analyses. NP, proportion of normal development at hatching. Red square means NP after heat treatment, and white square without heat treatment