title: High-throughput analysis reveals novel maternal germline RNAs crucial for primordial germ cell preservation and proper migration.
abstract: 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.
authors.affiliation: Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Owens
authors.affiliation: Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Butler
authors.affiliation: Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
authors.forename: Tristan H
authors.initials: TH
authors.lastname: Aguero
authors.affiliation: Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Newman
authors.affiliation: The Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Van Booven
authors.affiliation: Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA mking@med.miami.edu.
authors.forename: Mary Lou
authors.identifier: 0000-0002-1923-4283
authors.initials: ML
authors.lastname: King
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002465:Cell Movement / Q000235:genetics*; D000066473:Embryonic Germ Cells / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005854:Germ Cells / Q000378:metabolism*; D059014:High-Throughput Nucleotide Sequencing; D009865:Oocytes / Q000378:metabolism; D009866:Oogenesis / Q000235:genetics; D012313:RNA / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D023121:RNA, Messenger, Stored / Q000235:genetics* / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics
chemical_list: D023121:RNA, Messenger, Stored; D012313:RNA
keywords: Gene pathways; Localized RNAs; PGCs; RNA-seq; Scaffold; Xenopus