Abstract: 【Aim】 To study the function of histone H3 Thr3 phosphorylation, an epigenetic marker, in Sf9 cells during mitosis. 【Methods】 One peptide of ARTKQTARKC containing the 1st-9th amino acids of histone H3 was synthesized by solid phase method, and the antibody was prepared by phosphorylation of H3 at threonin 3 (P-Pep 226555) or non-phosphorylation (NP-Pep 080472). The specificity of the antibody was detected through Western blot. Sf9 cells were cultured, slides of the mitotic cells at different stages were prepared by cell climbing, and the localization characteristics of phosphorylated H3 Thr3 (H3 Thr3ph) antibody at different stages of mitotic Sf9 cells were detected by cytology immunofluorescence. 【Results】 In Sf9 cells, the H3 Thr3 phosphorylation began to appear on chromosomes at the prophase with a specific distribution pattern, and the fluorescent signals of H3 Thr3 phosphorylation gradually increased and reached the maximum in metaphase as the cell cycle went on. At the anaphase, the fluorescent signals of H3 Thr3 phosphorylation were distributed uniformly on the equatorial plate where the new daughter cells form, and only very weak signal vestigital was located at specific places at the telophase. 【Conclusion】 Histone H3 Thr3 phosphorylation is associated with cytokinesis in Sf9 cells during mitosis.

Key words: Sf9 cell, histone H3, phosphorylation, mitosis, immunofluorescence, cytokinesis