Fig. 1

Microglial density and distribution as well as peripheral cell infiltration are hormonally and chromosomally driven. Epifluorescence images of Iba1⁺ (in red) cells at 20x of magnification in the ventral hippocampus, illustrating the examined layers: CA1 stratum radiatum (Rad), CA1 stratum lacunosum-moleculare (LMol) and dentate gyrus polymorphic layer (PoDG). Panels A–F show representative images from FCG XX, Tg XY⁻, Tg XX^Sry, Tg XY^Sry, WT XX, and WT XY genotypes, respectively. Panel G’ features a magnified area from panel E with zoomed-in TMEM119⁺/DAPI ⁺ cells (in yellow and blue). Panel G’’ highlights a magnified area from panel E, showing Iba1⁺/TMEM119⁺ colocalization (in red and yellow), along with a delineation of the hippocampal layers (Rad, LMol with a few blood vessels (BV) and PoDG). Panels I, J, and K display the total density of Iba1⁺/TMEM119^+/− cells in the Rad, LMol and PoDG, respectively. Panels L, M, and N show the nearest neighbor distance results while panels O, P, and Q depict the spacing index findings. Panels R, S, and T represent the percentage of infiltration of Iba1⁺/TMEM119⁻ cells. Main sex chromosomal effects are represented by hashtags (#) while main sex hormone effects are represented by ampersands (&). Data is expressed as mean ± S.E.M., with dots representing averaged values from a single mouse (n = 5 mice per group). Ordinary two-way ANOVA was used to assess the interaction between sex hormones (ovaries versus testes) and genotype (FCG XX versus FCG XY versus WT), followed by Tukey’s post-hoc tests for multiple comparisons in cases of significance. a.u.: arbitrary units *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001. Scale (A–F and magnifications): 500 μm and 200 μm. Created in BioRender