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Mol Biol Cell
2015 Nov 05; doi: 10.1091/mbc.E15-02-0115.
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Global analysis of asymmetric RNA enrichment in oocytes reveals low conservation between closely related Xenopus species.
Claußen M
,
Lingner T
,
Pommerenke C
,
Opitz L
,
Salinas G
,
Pieler T
.
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RNAs that localize to the vegetal cortex during Xenopus laevis oogenesis have been reported to function in germ layer patterning, axis determination and development of the primordial germ cells. Here we report on the genome-wide, comparative analysis of differentially localizing RNAs in Xenopus laevis and Xenopus tropicalis oocytes, revealing a surprisingly weak degree of conservation in respect to the identity of animally as well as vegetally enriched transcripts in these closely related species. Heterologous RNA injections and protein binding studies indicate that the different RNA localization patterns in these two species are due to gain/loss of cis-acting localization signals rather than to differences in the RNA localizing machinery.
FIGURE 1:. Identification of novel vegetally localizing RNAs in X. laevis oocytes. (A) Candidate RNAs were tested for vegetal localization by in situ hybridization with X. laevis oocytes and listed according to their localization pattern (early and late). JgiID and gene symbol/GenBank accession number, as well as relative enrichment in the vegetal hemisphere as revealed by deep sequencing analysis (expressed as log2FC). RNAs for which no vegetal localization was detectable by in situ hybridization, as well as RNAs with very low expression levels that did not allow for the determination of localization patterns, are also listed. (BâD) Early-pathway localization pattern with characteristic mitochondrial cloud staining and spatially restricted localization at the vegetal pole (red arrows) for fnd3ca, tuft, and armc5 in stage I/II oocytes. (EâG) Late-pathway localization with typical broader vegetal cortex staining (black arrows) for slc12a9, sox7, and magi1 in stage III/IV oocytes.
FIGURE 2:. Identification of animally enriched RNAs in X. laevis oocytes. (A) Fourteen candidate transcripts with at least fourfold animal enrichment were selected for in situ hybridization analysis with X. laevis oocytes. JgiID, gene symbol, and relative enrichment in the animal hemisphere (expressed as log2FC) as revealed by deep sequencing and qPCR analysis. Detection of animal localization by in situ hybridization is indicated. For some of the transcripts, the localization pattern could not be determined due to very low expression levels. (BâE) Animal enrichment as revealed by in situ hybridization for aen, lima, frmd8, and scl18a1 transcripts. Bisected X. laevis stage VI oocytes. Animal (a) and vegetal (v) poles.
FIGURE 3:. Differential RNA distribution is only weakly conserved in a comparison between X. laevis and X. tropicalis. (A) Numbers of vegetally enriched RNAs from X. laevis (green) and X. tropicalis (orange) as identified by deep sequencing analysis in the form of Venn diagrams. Thresholds for vegetal localization were set to either log2FC ⥠1 (left) or ⥠2 (right). (B) Numbers of RNAs with animal enrichment in X. laevis (blue) and X. tropicalis (pink) oocytes in the form of Venn diagrams with thresholds set to log2FC ⤠1 (left) and ⤠2 (right). This comparative analysis was restricted to transcripts with expression in oocytes from both species.
FIGURE 4:. Comparative in situ hybridization analysis confirms species-specific localization in X. laevis and X. tropicalis oocytes. (AâC) In situ hybridization with species-specific antisense RNA probes was performed with stage IâIV oocytes from X. laevis and X. tropicalis. (A) Gdf1, grip2, gplt, and cnksr2 localize to the vegetal cortex in both X. laevis and X. tropicalis oocytes. (B) Ppp1r2, pgam1, atrx, and tob2 vegetally localize in X. laevis only. (C) Mogat1, pld2, acp6, and krt8 transcripts localize to the vegetal cortex in X. tropicalis but not X. laevis oocytes.
FIGURE 5:. Differential localization behavior of orthologous RNAs appears to rely on the RNA signal sequence but not on differences in the RNA localization machinery. (AâC) Isolated localization elements, as well as 5â²-UTR, ORF, and 3â²-UTRs from different transcripts and species as indicated, were labeled with cyanine-3 and injected into X. laevis and X. tropicalis oocytes. Representative confocal images of fixed oocytes. Average vegetal/animal ratios of injected RNA are listed in Supplemental Table S9. Vegetal poles are oriented toward the bottom (if assignable). Scale bars, 100 μm. (A) Injection of gdf1 and grip2 localization elements from X. laevis and X. tropicalis, as well as nonlocalizing β-globin 3â²-UTR (negative control), into oocytes from both species. (B) Injection of X. laevis and X. tropicalis ppp1r2 3â²-UTRs. (C) Injection of X. laevis and X. tropicalis acp6-5â²-UTRs.
FIGURE 6:. Interaction of localization proteins with LE-RNAs is conserved in X. tropicalis. Assembly of localization complexes with X. tropicalis oocyte extracts and tagged X. laevis gdf1-LE, grip2-LE, and β-globin-3â²-UTR control RNA was performed in vitro. Copurifying localization proteins were detected by Western blot analysis.
Allison,
Two distinct Staufen isoforms in Xenopus are vegetally localized during oogenesis.
2004, Pubmed,
Xenbase
Allison,
Two distinct Staufen isoforms in Xenopus are vegetally localized during oogenesis.
2004,
Pubmed
,
Xenbase
Altschul,
Basic local alignment search tool.
1990,
Pubmed
Arthur,
Participation of Xenopus Elr-type proteins in vegetal mRNA localization during oogenesis.
2009,
Pubmed
,
Xenbase
Bally-Cuif,
Characterization of the zebrafish Orb/CPEB-related RNA binding protein and localization of maternal components in the zebrafish oocyte.
1998,
Pubmed
,
Xenbase
Bauermeister,
A novel role for Celf1 in vegetal RNA localization during Xenopus oogenesis.
2015,
Pubmed
,
Xenbase
Beckham,
Localization of RNAs in oocytes of Eleutherodactylus coqui, a direct developing frog, differs from Xenopus laevis.
2003,
Pubmed
,
Xenbase
Betley,
Kinesin II mediates Vg1 mRNA transport in Xenopus oocytes.
2004,
Pubmed
,
Xenbase
Bewick,
The pipid root.
2012,
Pubmed
,
Xenbase
Chan,
fatvg encodes a new localized RNA that uses a 25-nucleotide element (FVLE1) to localize to the vegetal cortex of Xenopus oocytes.
1999,
Pubmed
,
Xenbase
Chang,
Localization of RNAs to the mitochondrial cloud in Xenopus oocytes through entrapment and association with endoplasmic reticulum.
2004,
Pubmed
,
Xenbase
Claussen,
Functional dissection of the RNA signal sequence responsible for vegetal localization of XGrip2.1 mRNA in Xenopus oocytes.
2011,
Pubmed
,
Xenbase
Claussen,
Identification of vegetal RNA-localization elements in Xenopus oocytes.
2010,
Pubmed
,
Xenbase
Claussen,
Xvelo1 uses a novel 75-nucleotide signal sequence that drives vegetal localization along the late pathway in Xenopus oocytes.
2004,
Pubmed
,
Xenbase
Cote,
A Xenopus protein related to hnRNP I has a role in cytoplasmic RNA localization.
1999,
Pubmed
,
Xenbase
Cuykendall,
Identification of germ plasm-associated transcripts by microarray analysis of Xenopus vegetal cortex RNA.
2010,
Pubmed
,
Xenbase
Czaplinski,
Identification of 40LoVe, a Xenopus hnRNP D family protein involved in localizing a TGF-beta-related mRNA during oogenesis.
2005,
Pubmed
,
Xenbase
De Domenico,
Molecular asymmetry in the 8-cell stage Xenopus tropicalis embryo described by single blastomere transcript sequencing.
2015,
Pubmed
,
Xenbase
Deshler,
Localization of Xenopus Vg1 mRNA by Vera protein and the endoplasmic reticulum.
1997,
Pubmed
,
Xenbase
Dupont,
Germ-layer specification and control of cell growth by Ectodermin, a Smad4 ubiquitin ligase.
2005,
Pubmed
,
Xenbase
Edgar,
Gene Expression Omnibus: NCBI gene expression and hybridization array data repository.
2002,
Pubmed
Elinson,
Germ plasm in Eleutherodactylus coqui, a direct developing frog with large eggs.
2011,
Pubmed
,
Xenbase
Gagnon,
Visualization of mRNA localization in Xenopus oocytes.
2011,
Pubmed
,
Xenbase
Gagnon,
Directional transport is mediated by a Dynein-dependent step in an RNA localization pathway.
2013,
Pubmed
,
Xenbase
Grant,
Novel animal pole-enriched maternal mRNAs are preferentially expressed in neural ectoderm.
2014,
Pubmed
,
Xenbase
Gururajan,
The Xenopus localized messenger RNA An3 may encode an ATP-dependent RNA helicase.
1991,
Pubmed
,
Xenbase
Harland,
In situ hybridization: an improved whole-mount method for Xenopus embryos.
1991,
Pubmed
,
Xenbase
Havin,
RNA-binding protein conserved in both microtubule- and microfilament-based RNA localization.
1998,
Pubmed
,
Xenbase
Horvay,
Xenopus Dead end mRNA is a localized maternal determinant that serves a conserved function in germ cell development.
2006,
Pubmed
,
Xenbase
Houston,
Regulation of cell polarity and RNA localization in vertebrate oocytes.
2013,
Pubmed
,
Xenbase
Howley,
mRNA localization patterns in zebrafish oocytes.
2000,
Pubmed
Huang,
Bioinformatics enrichment tools: paths toward the comprehensive functional analysis of large gene lists.
2009,
Pubmed
Huang,
Systematic and integrative analysis of large gene lists using DAVID bioinformatics resources.
2009,
Pubmed
Imbrie,
Asymmetric Localization of CK2α During Xenopus Oogenesis.
2012,
Pubmed
,
Xenbase
Kalinka,
The evolution of early animal embryos: conservation or divergence?
2012,
Pubmed
Kataoka,
Identification of asymmetrically localized transcripts along the animal-vegetal axis of the Xenopus egg.
2005,
Pubmed
,
Xenbase
King,
Putting RNAs in the right place at the right time: RNA localization in the frog oocyte.
2005,
Pubmed
,
Xenbase
Kloc,
Translocation of repetitive RNA sequences with the germ plasm in Xenopus oocytes.
1993,
Pubmed
,
Xenbase
Koebernick,
Elr-type proteins protect Xenopus Dead end mRNA from miR-18-mediated clearance in the soma.
2010,
Pubmed
,
Xenbase
Kosaka,
Spatiotemporal localization of germ plasm RNAs during zebrafish oogenesis.
2007,
Pubmed
,
Xenbase
Langmead,
Fast gapped-read alignment with Bowtie 2.
2012,
Pubmed
Lewis,
Conserved and clustered RNA recognition sequences are a critical feature of signals directing RNA localization in Xenopus oocytes.
2004,
Pubmed
,
Xenbase
Linnen,
Two related localized mRNAs from Xenopus laevis encode ubiquitin-like fusion proteins.
1993,
Pubmed
,
Xenbase
Maegawa,
Maternal mRNA localization of zebrafish DAZ-like gene.
1999,
Pubmed
,
Xenbase
Messitt,
Multiple kinesin motors coordinate cytoplasmic RNA transport on a subpopulation of microtubules in Xenopus oocytes.
2008,
Pubmed
,
Xenbase
Mosquera,
A mRNA localized to the vegetal cortex of Xenopus oocytes encodes a protein with a nanos-like zinc finger domain.
1993,
Pubmed
,
Xenbase
Mowry,
Vegetal messenger RNA localization directed by a 340-nt RNA sequence element in Xenopus oocytes.
1992,
Pubmed
,
Xenbase
Nath,
Status of RNAs, localized in Xenopus laevis oocytes, in the frogs Rana pipiens and Eleutherodactylus coqui.
2005,
Pubmed
,
Xenbase
Rebagliati,
Identification and cloning of localized maternal RNAs from Xenopus eggs.
1985,
Pubmed
,
Xenbase
Rice,
EMBOSS: the European Molecular Biology Open Software Suite.
2000,
Pubmed
Robinson,
edgeR: a Bioconductor package for differential expression analysis of digital gene expression data.
2010,
Pubmed
Sindelka,
Spatial expression profiles in the Xenopus laevis oocytes measured with qPCR tomography.
2010,
Pubmed
,
Xenbase
Snedden,
RNA localization in Xenopus oocytes uses a core group of trans-acting factors irrespective of destination.
2013,
Pubmed
,
Xenbase
Suzuki,
Vegetal localization of the maternal mRNA encoding an EDEN-BP/Bruno-like protein in zebrafish.
2000,
Pubmed
,
Xenbase
White,
Maternal control of pattern formation in Xenopus laevis.
2008,
Pubmed
,
Xenbase
Yamaguchi,
Restriction of the Xenopus DEADSouth mRNA to the primordial germ cells is ensured by multiple mechanisms.
2014,
Pubmed
,
Xenbase
Yanai,
Mapping gene expression in two Xenopus species: evolutionary constraints and developmental flexibility.
2011,
Pubmed
,
Xenbase
Yoon,
Xenopus Staufen is a component of a ribonucleoprotein complex containing Vg1 RNA and kinesin.
2004,
Pubmed
,
Xenbase
Zhang,
Vg1 RBP intracellular distribution and evolutionarily conserved expression at multiple stages during development.
1999,
Pubmed
,
Xenbase
Zhou,
Polarized distribution of mRNAs encoding a putative LDL receptor adaptor protein, xARH (autosomal recessive hypercholesterolemia) in Xenopus oocytes.
2004,
Pubmed
,
Xenbase