Effects of in ovo stimulation with potential epigenetic modulators on immune system phenotype across three generations in a chicken model.

Epigenetic modifications can influence the phenotypes of subsequent generations through intergenerational and transgenerational effects. The aim of the research was to assess the impact of epigenetic factors acting during embryonic development on the structure and cellular composition of lymphoid organs in three generations of chickens. Two groups of eggs were injected once (in the F1 generation) with a synbiotic (SYNs) or a synbiotic + choline (SYNCHs), while two other groups were injected in each successive generation (F2, F3-SYNr, SYNCHr). Synbiotic administration resulted in an increased cortex/medulla ratio of the thymus in the F1 but not in subsequent generations. In the spleen, an intergenerational effect (from F1 to F2) was found in the choline-supplemented (SYNCHs) groups but not in the SYNs groups. Not all changes observed in the F1 were evident in the F2 generation. No intergenerational effect was found in the cecal tonsil, and no transgenerational effects were observed in any of the tested organs. In ovo administration of synbiotics with choline may induce intergenerational phenotypic effects on specific immune organs. However, these effects either persisted through the first two generations or appeared solely in the F1 or F2 generations. Changes were evident in young birds but not in mature ones.