Role of Chromatin Modifications in Drosophila Germline Stem Cell Differentiation.
Role of Chromatin Modifications in Drosophila Germline Stem Cell Differentiation.
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DOI：
10.1007/978-3-319-44820-6_1
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发表时间：
2017-01-01
影响因子：
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通讯作者：
Rangan, Prashanth
中科院分区：
文献类型：
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作者：
Flora, Pooja;McCarthy, Alicia;Rangan, Prashanth
在果蝇卵子发生过程中，生殖干细胞（GSC）自我更新和分化产生成熟的卵子。GSC的自我更新和分化受到内在机制（例如生殖系中基因表达的调节）和来自周围体细胞生态位的外在信号传导途径的调节。表观遗传机制，包括组蛋白修饰蛋白，核小体重塑复合物和组蛋白变体，在调节内在基因表达和来自体细胞生态位的外在信号线索中起着关键作用。在GSC中，需要内在表观遗传修饰剂通过促进自我更新因子的表达和抑制分化程序来维持干细胞命运。随后，在GSC子代中，表观遗传调节因子激活分化程序以促进GSC分化。在分化过程中，GSC子体经历减数分裂以产生发育中的卵子，其包含称为核小体的致密染色质结构。表观遗传修饰剂控制染色体与核纤层的附着，以帮助减数分裂重组和从纤层释放以形成核小体。在整个发育过程中，生殖细胞系与索马密切相关。这种接近有助于从体细胞生态位向发育中的生殖系发出信号。表观遗传修饰剂在体细胞生态位中起着关键作用，调节信号通路以协调GSC向卵子的过渡。总之，内在和外在的表观遗传机制调节这个微妙的平衡程序。
During Drosophila oogenesis, germline stem cells (GSCs) self-renew and differentiate to give rise to a mature egg. Self-renewal and differentiation of GSCs are regulated by both intrinsic mechanisms such as regulation of gene expression in the germ line and extrinsic signaling pathways from the surrounding somatic niche. Epigenetic mechanisms, including histone-modifying proteins, nucleosome remodeling complexes, and histone variants, play a critical role in regulating intrinsic gene expression and extrinsic signaling cues from the somatic niche. In the GSCs, intrinsic epigenetic modifiers are required to maintain a stem cell fate by promoting expression of self-renewal factors and repressing the differentiation program. Subsequently, in the GSC daughters, epigenetic regulators activate the differentiation program to promote GSC differentiation. During differentiation, the GSC daughter undergoes meiosis to give rise to the developing egg, containing a compacted chromatin architecture called the karyosome. Epigenetic modifiers control the attachment of chromosomes to the nuclear lamina to aid in meiotic recombination and the release from the lamina for karyosome formation. The germ line is in close contact with the soma for the entirety of this developmental process. This proximity facilitates signaling from the somatic niche to the developing germ line. Epigenetic modifiers play a critical role in the somatic niche, modulating signaling pathways in order to coordinate the transition of GSC to an egg. Together, intrinsic and extrinsic epigenetic mechanisms modulate this exquisitely balanced program.