Germline/soma distinction in Drosophila embryos requires regulators of zygotic genome activation.
Germline/soma distinction in Drosophila embryos requires regulators of zygotic genome activation.
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DOI：
10.7554/elife.78188
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发表时间：
2023-01-04
期刊：
影响因子：
7.7
通讯作者：
Deshpande G
中科院分区：
文献类型：
--
作者：
Colonnetta MM;Schedl P;Deshpande G
在黑腹果蝇胚胎中，体细胞身份与种系身份是细胞命运的第一个决定。合子基因组激活（ZGA）协调区域化基因表达，赋予体细胞特异性身份。在染色质可及性因子（Zelda， CLAMP， GAF）的引导下，ZGA开始于核周期（NC）8，然后是NC14期间的主波。相比之下，原始生殖细胞（PGC）规范需要母体沉积和后锚定的生殖系决定因子。这是通过在NC10中PGCs的早熟细胞化过程中中心体协调释放和隔离种质来完成的。在这里，我们报告了在建立种系/体细胞区分过程中对Zelda和CLAMP的新要求。当它们的活性受到损害时，PGC决定因子就不能被适当地隔离，规范就会中断。相反，PGC决定因子从后极扩散会对邻近体细胞核的转录产生不利影响。这些互反畸变可能与中心体复制/分离缺陷有关，这些缺陷已知会诱导种质的不适当传递。有趣的是，与骨形态发生蛋白（BMP）信号传导影响胚胎PGCs规范的能力一致，BMP家族配体decapentapletic （dpp）转录水平的降低在后极加剧。
In Drosophila melanogaster embryos, somatic versus germline identity is the first cell fate decision. Zygotic genome activation (ZGA) orchestrates regionalized gene expression, imparting specific identity on somatic cells. ZGA begins with a minor wave that commences at nuclear cycle (NC)8 under the guidance of chromatin accessibility factors (Zelda, CLAMP, GAF), followed by the major wave during NC14. By contrast, primordial germ cell (PGC) specification requires maternally deposited and posteriorly anchored germline determinants. This is accomplished by a centrosome coordinated release and sequestration of germ plasm during the precocious cellularization of PGCs in NC10. Here, we report a novel requirement for Zelda and CLAMP during the establishment of the germline/soma distinction. When their activity is compromised, PGC determinants are not properly sequestered, and specification is disrupted. Conversely, the spreading of PGC determinants from the posterior pole adversely influences transcription in the neighboring somatic nuclei. These reciprocal aberrations can be correlated with defects in centrosome duplication/separation that are known to induce inappropriate transmission of the germ plasm. Interestingly, consistent with the ability of bone morphogenetic protein (BMP) signaling to influence specification of embryonic PGCs, reduction in the transcript levels of a BMP family ligand, decapentaplegic (dpp), is exacerbated at the posterior pole.