G1120 for h e

The mouse olfactory bulbs were fixed in 4% PFA solution, embedded in paraffin, and then cut into 5 μm slices. The slices were stained with HE and NISSL according to the manual (G1120 for HE and G1432 for NISSL; Solarbio, Beijing, China).

Modified Davidson’s Fixative solution was used to fix the fresh testes (4 °C for 24 h), which were then stored in 70% ethanol. Samples were embedded in paraffin and sectioned (5 μm), and the sections were mounted on slides (poly-L-lysine coated) followed by dewaxing and rehydration. Finally, hematoxylin and eosin (H&E) staining was performed according to the manufacturer’s instructions (G1120 for H&E, Solarbio, Beijing, China).

Fresh ileum and colon tissues were fixed with 4% paraformaldehyde (PFA) (fixed at 4 °C for 24 h). The samples were embedded in paraffin and sliced (5 μm). The slices were placed on a glass slide (polylysine coated) followed by dewaxing and rehydration. H&E staining was carried out according to the manufacturer’s instructions (G1120 for H&E, Solarbio, Beijing, China). Glycogen Periodic Acid Schiff (PAS/Hematoxylin) was performed according to manufacturer instructions in Stain Kit (G1281, Solarbio, Beijing, China). The Masson trichrome staining was done by Masson’s Trichrome Stain Kit (G1340, Solarbio, Beijing, China). Finally, the slides were placed in neutral balsam and photographed with a microscope (BX61VS, Olympus, Tokyo, Japan).