Walters Benjamin William, Yu Haoming, Kataruka Shubhangini, Lesch Bluma J
Department of Genetics, Yale School of Medicine, New Haven, CT, USA.
Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA.
Methods Mol Biol. 2025;2954:3-26. doi: 10.1007/978-1-0716-4698-4_1.
Paternal histone modifications are extensively remodeled during mammalian spermatogenesis. This remodeling is significant because histone modifications encode gene regulatory information important for fertility and potentially for development in the next generation. Most insight into these epigenetic changes has been gleaned from chromatin immunoprecipitation (ChIP)-seq analysis of male germ cells during the meiotic and postmeiotic stages of spermatogenesis due to their abundance in seminiferous tubules and long-standing methods for their purification. However, there is a paucity of research defining the epigenetic landscape of earlier spermatogenic populations, including spermatogonia, mainly because cell yields are low after purification, resulting in suboptimal conditions for ChIP-seq experiments. The recent emergence of Cleavage Under Targets and Tagmentation (CUT&Tag) as a tool to profile genome-wide histone modifications in low numbers of cells offers promising opportunities to overcome the limitations of ChIP-seq analysis in spermatogonia. Here, we describe a protocol that combines fluorescence-activated cell sorting with an optimized CUT&Tag workflow for as few as 50,000 dissociated, sorted cells to generate high-quality and reproducible datasets that faithfully capture enrichment of histone modifications in differentiating spermatogonia. This protocol will enable researchers to investigate the epigenetics of premeiotic cells in the male germ line easily and robustly.
在哺乳动物精子发生过程中,父本组蛋白修饰会发生广泛重塑。这种重塑意义重大,因为组蛋白修饰编码了对生育能力以及可能对下一代发育至关重要的基因调控信息。由于生精细胞在生精小管中数量丰富且有长期的纯化方法,对这些表观遗传变化的大多数认识是通过对精子发生减数分裂和减数分裂后阶段的雄性生殖细胞进行染色质免疫沉淀(ChIP)-seq分析获得的。然而,关于早期生精细胞群体(包括精原细胞)表观遗传格局的研究却很少,主要是因为纯化后细胞产量低,导致ChIP-seq实验条件不理想。最近出现的靶向切割与标记(CUT&Tag)技术作为一种在少量细胞中分析全基因组组蛋白修饰的工具,为克服精原细胞ChIP-seq分析的局限性提供了有前景的机会。在这里,我们描述了一种方案,该方案将荧光激活细胞分选与优化的CUT&Tag工作流程相结合,用于低至50,000个解离、分选的细胞,以生成高质量且可重复的数据集,忠实地捕捉分化精原细胞中组蛋白修饰的富集情况。该方案将使研究人员能够轻松、可靠地研究雄性生殖系减数分裂前细胞的表观遗传学。