Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Chromosoma
1992 Aug 01;1019:549-56. doi: 10.1007/bf00660314.
Show Gene links
Show Anatomy links
Amphibian oocytes and sphere organelles: are the U snRNA genes amplified?
Phillips S
,
Cotten M
,
Laengle-Rouault F
,
Schaffner G
,
Birnstiel ML
.
???displayArticle.abstract???
The sphere organelles (spheres) of Xenopus and other amphibian oocytes are known to contain small nuclear ribonucleoprotein particles (snRNPs) and have been suggested to play a role in snRNP complex assembly. Coupled with the similarities that exist between spheres and nucleoli and the quantitative and kinetic aspects of snRNA synthesis in the Xenopus oocyte, we have investigated whether or not the U snRNA encoding genes are amplified in Xenopus oogenesis, the spheres being possible sites for the location of such extrachromosomal gene copies. By applying a number of quantitative nucleic acid hybridization procedures to both total and fractionated oocyte and somatic DNA, employing both homologous and heterologous U snRNA gene probes and suitable amplification and non-amplification control probes, we show that the U snRNA genes do not undergo any major amplification in Xenopus oogenesis. Therefore, the analogy between the sphere organelles and nucleoli appears to be limited. The role of the spheres and their relationship to other snRNP containing structures, specifically B snurposomes, and the sphere organizer loci remains obscure.
Bird,
A timing study of DNA amplification in Xenopus laevis oocytes.
1971, Pubmed,
Xenbase
Bird,
A timing study of DNA amplification in Xenopus laevis oocytes.
1971,
Pubmed
,
Xenbase
Boseley,
Sequence organization of the spacer DNA in a ribosomal gene unit of Xenopus laevis.
1979,
Pubmed
,
Xenbase
Brown,
Specific gene amplification in oocytes. Oocyte nuclei contain extrachromosomal replicas of the genes for ribosomal RNA.
1968,
Pubmed
Brown,
Gene linkage by RNA-DNA hybridization. I. Unique DNA sequences homologous to 4 s RNA, 5 s RNA and ribosomal RNA.
1968,
Pubmed
,
Xenbase
Carmo-Fonseca,
Mammalian nuclei contain foci which are highly enriched in components of the pre-mRNA splicing machinery.
1991,
Pubmed
Carroll,
Repeating units of Xenopus laevis oocyte-type 5S DNA are heterogeneous in length.
1976,
Pubmed
,
Xenbase
Ciliberto,
Transcription signals in embryonic Xenopus laevis U1 RNA genes.
1985,
Pubmed
,
Xenbase
Coggins,
The timing of meiosis and DNA synthesis during early oogenesis in the toad, Xenopus laevis.
1972,
Pubmed
,
Xenbase
Dawid,
Composition and structure of chromosomal and amplified ribosomal DNA's of Xenopus laevis.
1970,
Pubmed
,
Xenbase
Dawid,
The mitochondrial and ribosomal DNA components of oocytes of Urechis caupo.
1970,
Pubmed
Dawid,
Deoxyribonucleic acid in amphibian eggs.
1965,
Pubmed
Evans,
Localization of amplified ribosomal DNA in the oocyte of Xenopus laevis.
1968,
Pubmed
,
Xenbase
Fedoroff,
The nucleotide sequence of oocyte 5S DNA in Xenopus laevis. I. The AT-rich spacer.
1978,
Pubmed
,
Xenbase
Feinberg,
A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity.
1983,
Pubmed
Forbes,
Small nuclear RNA transcription and ribonucleoprotein assembly in early Xenopus development.
1983,
Pubmed
,
Xenbase
Fritz,
Small nuclear U-ribonucleoproteins in Xenopus laevis development. Uncoupled accumulation of the protein and RNA components.
1984,
Pubmed
,
Xenbase
Gall,
Histone genes are located at the sphere loci of newt lampbrush chromosomes.
1981,
Pubmed
Gall,
Differential synthesis of the genes for ribosomal RNA during amphibian oögenesis.
1968,
Pubmed
Gall,
The sphere organelle contains small nuclear ribonucleoproteins.
1989,
Pubmed
,
Xenbase
Georgiev,
Processing and nucleo-cytoplasmic transport of histone gene transcripts.
1984,
Pubmed
,
Xenbase
Kay,
The 1723 element: a long, homogeneous, highly repeated DNA unit interspersed in the genome of Xenopus laevis.
1983,
Pubmed
,
Xenbase
Kazmaier,
Functional characterization of X. laevis U5 snRNA genes.
1987,
Pubmed
,
Xenbase
Kidder,
The ribosomal RNA cistrons in clam gametes.
1976,
Pubmed
,
Xenbase
Krol,
The two embryonic U1 RNA genes of Xenopus laevis have both common and gene-specific transcription signals.
1985,
Pubmed
,
Xenbase
Lund,
The two embryonic U1 small nuclear RNAs of Xenopus laevis are encoded by a major family of tandemly repeated genes.
1984,
Pubmed
,
Xenbase
Mattaj,
Xenopus laevis U2 snRNA genes: tandemly repeated transcription units sharing 5' and 3' flanking homology with other RNA polymerase II transcribed genes.
1983,
Pubmed
,
Xenbase
Mattaj,
U snRNA gene families in Xenopus laevis.
1985,
Pubmed
,
Xenbase
Miller,
The nucleotide sequence of oocyte 5S DNA in Xenopus laevis. II. The GC-rich region.
1978,
Pubmed
,
Xenbase
Perkowska,
Gene amplification in the oocyte nucleus of mutant and wild-type Xenopus laevis.
1968,
Pubmed
,
Xenbase
Reddy,
Primary and secondary structure of U8 small nuclear RNA.
1985,
Pubmed
Rochaix,
Ribosomal RNA gene amplification by rolling circles.
1974,
Pubmed
,
Xenbase
Wallace,
Ribosomal cistrons and the nucleolar organizer.
1966,
Pubmed
Wu,
Small nuclear ribonucleoproteins and heterogeneous nuclear ribonucleoproteins in the amphibian germinal vesicle: loops, spheres, and snurposomes.
1991,
Pubmed
,
Xenbase
Zeller,
Xenopus laevis U1 snRNA genes: characterisation of transcriptionally active genes reveals major and minor repeated gene families.
1984,
Pubmed
,
Xenbase
