Immunofluorescent Visualization of H3K79me2 and H3K27me3 Histone Modifications in Metaphase and PCC Obtained Interphase Chromosomes

Kartal C., Kuru R. D., Argüden Y.

15th European Cytogenomics Conference, Leuven, Belçika, 29 Haziran - 01 Ağustos 2025, sa.56, ss.92, (Özet Bildiri)

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Leuven
  • Basıldığı Ülke: Belçika
  • Sayfa Sayıları: ss.92
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Epigenetic alterations, heritable through cell divisions without DNA sequence changes, are mediated by DNA methylation, post-translational histone modifications, and non-coding RNAs. Immunofluorescence techniques, utilizing antibodies specific to histone modifications, allow the labeling of these modifications on chromosomes, yielding distinct banding patterns. There are a limited number of studies on metaphase chromosomes with these methods, which combine cytogenetic techniques with epigenetic studies and can therefore be called "Cytoepigenetics". However, no such studies have yet been reported on interphase chromosomes obtained using the PCC (Premature Chromosome Condensation) method. PCC, employing phosphatase inhibitors like calyculin A, enables chromosome retrieval from interphase. In this study, H3K79me2 and H3K27me3 histone modifications were visualized on both metaphase and PCC-derived interphase chromosomes using specific antibodies. The research was conducted on isolated lymphocytes obtained from healthy adult volunteers. To prepare chromosome spreads for immunofluorescence experiments, a method that does not contain acidic fixatives and preserves histone proteins was used while harvesting both cultures for interphase and metaphase chromosomes. The slides were then stained with antibodies specific to the selected histone modifications, and the preparations were examined under a fluorescence microscope. The results showed that both interphase and metaphase chromosomes displayed specific band patterns for the H3K79me2 and H3K27me3 modifications. This study represents the first attempt to visualize histone modifications in interphase chromatin at the single-cell level and in chromosome images, providing new insights into the epigenetic mechanisms underlying cell cycle and differentiation processes.