The effect of Toxoplasma gondii infection in parental male mice on the transcriptome of their offspring’s brain

Abstract Background To investigate the mechanisms and intergenerational effects of Toxoplasma gondii infection in parental male mice on the transcriptome of the brain of their offspring. Methods Male parental mice were infected with the T. gondii strain TgCtwh6 and then mated with healthy female mice to produce offspring F1. Three independent and comparable groups were established: infected male mice (M) versus F1 male generation (F1♂) (M vs. F1♂), healthy female mice (F) versus F1 female generation (F1♀) (F vs. F1♀), and parental generation (P) versus F1 generation (F1) (P vs. F1). RNA was extracted from the brain tissues of both parental and offspring mice for transcriptome sequencing, screening for differentially expressed genes (DEGs) common to all three groups. DEGs were identified and validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, functional analyses including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and evolutionary genealogy of genes: Nonsupervised Orthologous Groups (eggNOG) classification were performed to reveal the potential functions of DEGs in mice and genes in biological processes, key metabolic or signaling pathways, which provide a molecular basis for further studies on how to affect transcriptional expression in offspring. Results An overlap in gene expression was observed among the M versus F1♂, F versus F1♀, and P versus F1 comparisons. Collectively, these three comparisons identified 66 DEGs that were consistently altered across all groups, comprising 19 upregulated and 47 downregulated genes. GO analysis revealed that these DEGs were predominantly enriched in categories such as identical protein binding, positive regulation of NF-kappa B transcription factor activity, and membrane raft. KEGG analysis further indicated that the majority of enriched pathways were associated with immune responses, including those involved in viral infection pathways. qRT-PCR was employed to validate the expression changes of key genes. Conclusions T. gondii infection of male parental mice significantly downregulates gene expression in the brain tissue of their offspring and negatively regulates the immune system and signal transduction pathways. This study provides valuable insights into the intergenerational effects of T. gondii infection and highlights the importance of further research in this critical area. Graphical Abstract