Fig 2: Synonymous mutations affect Maoa mRNA secondary structure and protein translation initiation. (A) Schematic of RNA pull-down experiment. Biotin-labeled RNA probes are perfused with primary cell extracts, and this complex binds to streptavidin-labeled magnetic beads and thus separates them from other components in the incubation solution. Elute proteins on complexes for mass spectrometry or western blot detection. (B) Differential protein Veen diagram (C,D) Differential protein GO analysis (E) Liquid chromatography–tandem mass spectrometry (LC–MS/MS) screening of differential protein with wild type (WT) and mutant (Mut) synthetic RNA.

Fig 3: (A) Differential gene KEGG enrichment bubble chart, A is the pathway enrichment map, (B) is the metabolic enrichment map. (C) The expression of the Maoa gene in six brain regions. (D) KEGG pathway classify of PFc.

Fig 4: Synonymous mutations reduce Maoa transcription and translation levels in mouse brain regions. (A) mRNA expression of the Maoa gene in the brain regions of wild-type mice and KI mice (n = 3, ****p < 0.0001).(B) Mutant Maoa (KI) mice reduced the transcription level of the Maoa gene (n = 5, ** p < 0.01). (C) Western Blot detected the expression of MAOA protein in the (ventral tegmental area, VTA) brain region of mice (n = 3, **p < 0.01). (D) ELISA enzyme-linked kit detected MAOA expression, and the level of MAOAin the brain region of mice in the KI group was significantly lower than that in the WT group (n = 6, **p < 0.01). (E) The MAOA enzyme activation kit showed that the MAOA enzyme activity of KI mice was significantly lower than that of KI mice (n = 5, ****p < 0.0001).

Fig 5: Species homology comparison results and gene use frequency analysis of species at gene mutation sites (A) Maoa c.1409 T > C in different ancestry before and after gene frequency. (B) Schematic diagram of the homology of the amino acid sequence in the Maoa gene, the total length of the Maoa amino acid sequence is 526aa, the same length as the human amino acid sequence is 460aa, so the homology is 87.4525%. (C) Prediction of the alpha fold of Maoa protein structure in humans and mice. RMSD is 0.65 and TM-score is 0.98, Target coverage is 98%.Template modeling score (TM-score) is a measure of topological similarity between the template and model structures, and it is 0.98 indicating high similarity. (D) Sequence plots of wild-type (WT) mice and knock-in (KI) mice Maoa gene sequencing. The yellow marker represents the mutation site, and the codon of the 470th aspartate amino acid is mutated from GAT to GAC. (E) Mutation sites and corresponding amino acid sequences and DNA sequences control diagram, yellow indicates rs1137070, c.1409 T > C synonymous mutations, green indicates rs76204226, c.1401C > A and rs766439090 c.1413A > C synonymous mutations.