Fig. 1

Overview of experimental design, genotype distribution, and survival rates. (A) A heterozygous breeding strategy was applied to obtain male and female Tph2^−/− knockout and Tph2^+/− heterozygous rat pups, together with Tph2^+/+ wildtype littermate controls. Litters were randomly assigned to standard nesting (SN; one mother with her litter) or communal nesting (CN; two mothers with their two litters). An intensive health monitoring and care system was applied to mitigate for the low survival rates previously reported to be associated with Tph2 deficiency in mice and rats. (B) Genotype distribution of rat pups obtained through applying a heterozygous breeding strategy, including all N = 33 litters obtained. (C) Survival rate of Tph2^−/− (KO) and Tph2^+/− (HET) rat pups, as compared to Tph2^+/+ (WT) littermate controls; including all N = 33 litters obtained, with rat pups removed through culling from the litter to mitigate for the low survival rates not included in calculating survival rates as percentages. (D) Litter sizes of the N = 15 experimental litters from SN and CN included in the analyses on postnatal day 0 (P0) and postnatal day 3 (P3). (E) Genotype distribution of experimental rat pups included in the analyses, split according to sex