Department of Biology, University of Leicester, Leicester LE17RH, United Kingdom.
Plant Cell. 2011 Feb;23(2):534-49. doi: 10.1105/tpc.110.081059. Epub 2011 Feb 1.
The male germline in flowering plants arises through asymmetric division of a haploid microspore. The resulting germ cell undergoes mitotic division and specialization to produce the two sperm cells required for double fertilization. The male germline-specific R2R3 MYB transcription factor DUO1 POLLEN1 (DUO1) plays an essential role in sperm cell specification by activating a germline-specific differentiation program. Here, we show that ectopic expression of DUO1 upregulates a significant number (~63) of germline-specific or enriched genes, including those required for fertilization. We validated 14 previously unknown DUO1 target genes by demonstrating DUO1-dependent promoter activity in the male germline. DUO1 is shown to directly regulate its target promoters through binding to canonical MYB sites, suggesting that the DUO1 target genes validated thus far are likely to be direct targets. This work advances knowledge of the DUO1 regulon that encompasses genes with a range of cellular functions, including transcription, protein fate, signaling, and transport. Thus, the DUO1 regulon has a major role in shaping the germline transcriptome and functions to commit progenitor germ cells to sperm cell differentiation.
在有花植物中，雄性生殖细胞通过一个单倍体小孢子的不对称分裂产生。由此产生的生殖细胞经历有丝分裂和特化，以产生双受精所需的两个精子细胞。雄性生殖细胞特异性 R2R3 MYB 转录因子 DUO1 POLLEN1（DUO1）通过激活一个生殖细胞特异性分化程序，在精子细胞特化中发挥重要作用。在这里，我们表明 DUO1 的异位表达上调了大量（约 63 个）生殖细胞特异性或富集基因，包括那些受精所需的基因。我们通过证明在雄性生殖细胞中 DUO1 依赖性启动子活性验证了 14 个先前未知的 DUO1 靶基因。结果表明，DUO1 通过与典型的 MYB 结合位点直接调节其靶启动子，这表明迄今为止验证的 DUO1 靶基因可能是直接靶基因。这项工作推进了对 DUO1 调控因子的认识，该调控因子包含具有一系列细胞功能的基因，包括转录、蛋白质命运、信号转导和运输。因此，DUO1 调控因子在塑造生殖细胞转录组方面起着重要作用，并促使祖细胞向精子细胞分化。
