Owens Dawn A, Butler Amanda M, Aguero Tristan H, Newman Karen M, Van Booven Derek, King Mary Lou
Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
The Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
Development. 2017 Jan 15;144(2):292-304. doi: 10.1242/dev.139220.
During oogenesis, hundreds of maternal RNAs are selectively localized to the animal or vegetal pole, including determinants of somatic and germline fates. Although microarray analysis has identified localized determinants, it is not comprehensive and is limited to known transcripts. Here, we utilized high-throughput RNA-sequencing analysis to comprehensively interrogate animal and vegetal pole RNAs in the fully grown Xenopus laevis oocyte. We identified 411 (198 annotated) and 27 (15 annotated) enriched mRNAs at the vegetal and animal pole, respectively. Ninety were novel mRNAs over 4-fold enriched at the vegetal pole and six were over 10-fold enriched at the animal pole. Unlike mRNAs, microRNAs were not asymmetrically distributed. Whole-mount in situ hybridization confirmed that all 17 selected mRNAs were localized. Biological function and network analysis of vegetally enriched transcripts identified protein-modifying enzymes, receptors, ligands, RNA-binding proteins, transcription factors and co-factors with five defining hubs linking 47 genes in a network. Initial functional studies of maternal vegetally localized mRNAs show that sox7 plays a novel and important role in primordial germ cell (PGC) development and that ephrinB1 (efnb1) is required for proper PGC migration. We propose potential pathways operating at the vegetal pole that highlight where future investigations might be most fruitful.
在卵子发生过程中，数百种母体RNA被选择性地定位到动物极或植物极，包括体细胞和生殖系命运的决定因素。尽管微阵列分析已经鉴定出了定位的决定因素，但它并不全面，并且仅限于已知的转录本。在这里，我们利用高通量RNA测序分析来全面研究完全成熟的非洲爪蟾卵母细胞的动物极和植物极RNA。我们分别在植物极和动物极鉴定出了411种（198种有注释）和27种（15种有注释）富集的mRNA。有90种是在植物极富集超过4倍的新mRNA，有6种是在动物极富集超过10倍的新mRNA。与mRNA不同，微小RNA没有不对称分布。全胚胎原位杂交证实了所有17种选定的mRNA都是定位的。对植物极富集转录本的生物学功能和网络分析确定了蛋白质修饰酶、受体、配体、RNA结合蛋白、转录因子和辅助因子，其中有五个定义节点在一个网络中连接了47个基因。对母体植物极定位mRNA的初步功能研究表明，sox7在原始生殖细胞（PGC）发育中发挥着新的重要作用，并且ephrinB1（efnb1）是PGC正常迁移所必需的。我们提出了在植物极起作用的潜在途径，突出了未来研究可能最有成效的方向。
