Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Intronic U14 snoRNAs of Xenopus laevis are located in two different parent genes and can be processed from their introns during early oogenesis.

ABSTRACT: U14 is a member of the rapidly growing family of intronic small nucleolar RNAs (snoRNAs) that are involved in pre-rRNA processing and ribosome biogenesis. These snoRNA species are encoded within introns of eukaryotic protein coding genes and are synthesized via an intron processing pathway. Characterization of Xenopus laevis U14 snoRNA genes has revealed that in addition to the anticipated location of U14 within introns of the amphibian hsc70 gene (introns 4, 5 and 7), additional intronic U14 snoRNAs are also found in the ribosomal protein S13 gene (introns 3 and 4). U14 is thus far a unique intronic snoRNA in that it is encoded within two different parent genes of a single organism. Northern blot analysis revealed that U14 snoRNAs accumulate during early oocyte development and are rapidly expressed after the mid-blastula transition of developing embryos. Microinjection of hsc70 pre-mRNAs into developing oocytes demonstrated that oocytes as early as stages II and III are capable of processing U14 snoRNA from the pre-mRNA precursor. The ability of immature oocytes to process intronic snoRNAs is consistent with the observed accumulation of U14 during oocyte maturation and the developmentally regulated synthesis of rRNA during oogenesis.

SUBMITTER: Xia L

PROVIDER: S-EPMC307473 | biostudies-other | 1995 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Comparison of RNA localization during oogenesis within Acipenser ruthenus and Xenopus laevis [Xenopus laevis]

Project description:In this study we analyzed the spatial and temporal localization of maternal transcripts during oogenesis in Xenopus laevis. The occurrence of transcript asymmetry in X. laevis has been described at a global level only in matured eggs, while the establishment of the asymmetry during oogenesis has been described only for a few transcripts. In this model it was discerned that there exist three pathways (early, intermediate, late) for the establishment of the vegetal gradient, while for the animal gradient not much is known for its production. In this study we assessed the temporal establishment of the transcript localization at a global level for Xenopus laevis. We were able to determine that there are many transcripts that show temporal variability in the establishment of their localization. We observed the previously described early, intermediate (predefined) and also late pathways but found more member transcripts within these groups. We also described, perhaps for the first time, an early, intermediate (predefined) and late pathway for the animal genes as well. Additionally, we showed that some maternal transcripts are dynamic during oogenesis with degradation and de novo production being observed. Our study showed that in additional to spatial orientation to the transcripts, there is a strong temporal factor. The discovery of these new temporal profiles should help to better understand the driving forces during embryogenesis.

2022-08-23 | GSE211415 | GEO

Microtubule protein synthesis during oogenesis and early embryogenesis in Xenopus laevis.

Project description:A method is described which permits the preparation of descrete classes of oocytes of different sizes from all stages of oogenesis in Xenopus laevis. This technique is used in the determination of the content of microtubule protein in oocytes during the course of oogenesis. These experiments show that microtubule protein is present in oocytes of all sizes assayed and that the amount is simply related to the volume of the oocyte. In the largest oocytes microtubule protein constitutes 1% of the soluble protein and this amount does not change on maturation and fertilization. These results show that the changes occurring in the oocyte on maturation which allow the cytoplasm to support microtubule polymerization occur as a result of a modification of the pre-existing microtubule protein, not from protein synthesis de novo. These experiments also indicate that the synthesis of microtubule protein either form 'masked' mRNA or from newly synthesized mRNA plays an insignificant role in microtubule protein synthesis at maturation, ovulation and immediately post-fertilization.

| S-EPMC1165253 | biostudies-other

Comparison of RNA localization during oogenesis within <i>Acipenser ruthenus</i> and <i>Xenopus laevis</i>.

Project description:The oocyte is a unique cell, from which develops a complex organism comprising of germ layers, tissues and organs. In some vertebrate species it is known that the asymmetrical localization of biomolecules within the oocyte is what drives the spatial differentiation of the daughter cells required for embryogenesis. This asymmetry is first established to produce an animal-vegetal (A-V) axis which reflects the future specification of the ectoderm, mesoderm, and endoderm layers. Several pathways for localization of vegetal maternal transcripts have already been described using a few animal models. However, there is limited information about transcripts that are localized to the animal pole, even though there is accumulating evidence indicating its active establishment. Here, we performed comparative TOMO-Seq analysis on two holoblastic cleavage models: Xenopus laevis and Acipenser ruthenus oocytes during oogenesis. We found that there were many transcripts that have a temporal preference for the establishment of localization. In both models, we observed vegetal transcript gradients that were established during either the early or late oogenesis stages and transcripts that started their localization during the early stages but became more pronounced during the later stages. We found that some animal gradients were already established during the early stages, however the majority were formed during the later stages of oogenesis. Some of these temporally localized transcripts were conserved between the models, while others were species specific. Additionally, temporal de novo transcription and also degradation of transcripts within the oocyte were observed, pointing to an active remodeling of the maternal RNA pool.

| S-EPMC9531136 | biostudies-literature

Comparison of RNA localization during oogenesis within Acipenser ruthenus and Xenopus laevis

Project description:This SuperSeries is composed of the SubSeries listed below.

2022-08-23 | GSE211416 | GEO

Comparison of RNA localization during oogenesis within Acipenser ruthenus and Xenopus laevis [Acipenser ruthenus]

Project description:In this study we analyzed the spatial and temporal localization of maternal transcripts during oogenesis in Acipenser ruthenus. The occurrence of transcript asymmetry in A. ruthenus has been described at a global level only in matured eggs. However not much is known about the asymmetry during oogenesis. In this study we assessed the temporal establishment of the transcript localization at a global level for A. ruthenus. We were able to determine that there are many transcripts that show temporal variability in the establishment of their localization. We observed an early, predefined and also late pathways for both the vegetally and animally localized transcripts. Additionally, we showed that some maternal transcripts are dynamic during oogenesis with degradation and de novo production being observed. Our study showed that in additional to spatial orientation to the transcripts, there is a strong temporal factor. The discovery of these new temporal profiles should help to better understand the driving forces during embryogenesis.

2022-08-23 | GSE211412 | GEO

Asymmetric Localization of CK2α During Xenopus Oogenesis.

Project description:The establishment of the dorso-ventral axis is a fundamental process that occurs after fertilization. Dorsal axis specification in frogs starts immediately after fertilization, and depends upon activation of Wnt/β-catenin signaling. The protein kinase CK2α can modulate Wnt/β-catenin signaling and is necessary for dorsal axis specification in Xenopus laevis. Our previous experiments show that CK2α transcripts and protein are animally localized in embryos, overlapping the region where Wnt/β-catenin signaling is activated. Here we determined whether the animal localization of CK2α in the embryo is preceded by its localization in the oocyte. We found that CK2α transcripts were detected from stage I, their levels increased during oogenesis, and were animally localized as early as stage III. CK2α transcripts were translated during oogenesis and CK2α protein was localized to the animal hemisphere of stage VI oocytes. We cloned the CK2α 3'UTR and showed that the 2.8 kb CK2α transcript containing the 3'UTR was enriched during oogenesis. By injecting ectopic mRNAs, we demonstrated that both the coding and 3'UTR regions were necessary for proper CK2α transcript localization. This is the first report showing the involvement of coding and 3'UTR regions in animal transcript localization. Our findings demonstrate the pre-localization of CK2α transcript and thus, CK2α protein, in the oocyte. This may help restrict CK2α expression in preparation for dorsal axis specification.

| S-EPMC4207361 | biostudies-literature

Generation and Care of Xenopus laevis and Xenopus tropicalis Embryos.

Project description:Robust and efficient protocols for fertilization and early embryo care of Xenopus laevis and Xenopus tropicalis are essential for experimental success, as well as maintenance and propagation of precious animal stocks. The rapid growth of the National Xenopus Resource has required effective implementation and optimization of these protocols. Here, we discuss the procedures used at the National Xenopus Resource, which we found helpful for generation and early upkeep of Xenopus embryos and tadpoles.

| S-EPMC6396978 | biostudies-literature

Enp1, a yeast protein associated with U3 and U14 snoRNAs, is required for pre-rRNA processing and 40S subunit synthesis.

Project description:ENP1 is an essential Saccharomyces cerevisiae gene encoding a 483 amino acid polypeptide. Enp1 protein is localized in the nucleus and concentrated in the nucleolus. An enp1-1 temperature-sensitive mutant inhibited 35S pre-rRNA early processing at sites A(0), A(1) and A(2) as shown by northern analysis of steady state levels of rRNA precursors. Pulse-chase analysis further revealed that the enp1-1 strain was defective in the synthesis of 20S pre-rRNA and hence 18S rRNA, which led to reduced formation of 40S ribosomal subunits. Co-precipitation analysis revealed that Enp1 was associated with Nop1 protein, as well as with U3 and U14 RNAs, two snoRNAs implicated in early pre-rRNA processing steps. These results suggest a direct role for Enp1 in the early steps of rRNA processing.

| S-EPMC140510 | biostudies-literature