RNA-Seq analysis of vegetal and animal cortices isolated from Xenopus oocytes reveals novel signaling pathways and functions

DAWN OWENS; AMANDA BUTLER; TRISTÁN AGÜERO; DEREK VAN BOOVEN; KAREN NEWMAN; MARY LOU KING

Saint Augustine, FLorida

Congreso; SE-SDB annual meeting; 2016

Society for Developmental Biology

During oogenesis hundreds ofRNAs are selectively localized to either the animal or vegetal corticalregion.  These maternal RNAs includedeterminants of both somatic and germline fates. Although microarray analysishas contributed to identifying localized determinants, it is not comprehensiveand is limited to known transcripts. Here, we utilized high throughput RNA-sequencing analysis tocomprehensively interrogate both animal and vegetal pole RNAs in thefully-grown Xenopus laevis oocyte. We identified 411 enriched RNAs at thevegetal pole, 198 of them known transcripts, and 27 RNAs enriched at the animalpole, 15 known. Of these, 160 were novel RNAs over 4-fold enriched at thevegetal pole and 11 over 10-fold at the animal pole. Surprisingly, microRNAswere not asymmetrically distributed.  Wholemount in situ hybridization revealedall 18 selected RNAs were localized, confirming our data set.   Biological function and network analysis ofvegetally enriched transcripts identified protein-modifying enzymes, receptors,ligands, RNA binding proteins and 10 transcription factors or co-factors with 5defining hubs linking 47 genes in a network. Initial functional studies ofmaternal vegetally localized RNAs show, for the first time, that sox7 plays animportant role in primordial germ cell (PGC) development and efnb1(ephrinb1),known to play important roles in migration/adhesion in the nervous system, isrequired for proper PGC migration.  Basedon our findings, we propose potential pathways operating at the vegetal pole thathighlight where future investigations might be most fruitful.