scholarly journals A NuRD Complex from Xenopus laevis Eggs Is Essential for DNA Replication during Early Embryogenesis

Cell Reports ◽  
2018 ◽  
Vol 22 (9) ◽  
pp. 2265-2278 ◽  
Author(s):  
Christo P. Christov ◽  
Kevin S. Dingwell ◽  
Mark Skehel ◽  
Helen S. Wilkes ◽  
Julian E. Sale ◽  
...  
Keyword(s):  
Dna Replication ◽  
Xenopus Laevis ◽  
Early Embryogenesis ◽  
Nurd Complex

Chromosome replication in early development of Xenopus laevis

Development ◽  
1985 ◽  
Vol 89 (Supplement) ◽  
pp. 285-296
Author(s):  
R. A. Laskey
Keyword(s):  
Dna Replication ◽  
Xenopus Laevis ◽  
Early Development ◽  
Chromosome Replication ◽  
Chromatin Assembly

Eggs of Xenopus laevis contain exceptionally large amounts of materials involved in chromosome replication. This maternal stockpile allows an embryo to produce about 80 000 cells in less than 24 h. The adaptations which achieve this involve the mechanisms of both DNA replication and chromatin assembly.

Gene expression in Xenopus embryogenesis

Development ◽  
1985 ◽  
Vol 89 (Supplement) ◽  
pp. 113-124
Author(s):  
Igor B. Dawid ◽  
Susan R. Haynes ◽  
Milan Jamrich ◽  
Erzsebet Jonas ◽  
Seiji Miyatani ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Xenopus Laevis ◽  
Cdna Cloning ◽  
Early Embryogenesis ◽  
Gene Activity ◽  
Complex Nature ◽  
Cdna Clones ◽  
Midblastula Transition ◽  
First Time

This article considers some aspects of the storage of macromolecules in the oocyte of Xenopus laevis and the activation of previously unexpressed genes during early embryogenesis. The large quantity and complex nature of poly(A)+ RNA accumulated in the egg provides the cleavage embryo with a supply of mRNA sufficient to sustain protein synthesis for several hours of development. Onset of gene activity at the midblastula transition (MBT) leads to the synthesis and accumulation of molecules of various RNA classes, including tRNAs, rRNAs, mRNAs and mitochondrial RNAs. At gastrulation the poly(A)+ RNA population is still qualitatively similar to that of the egg but some sequences not present in egg RNA have accumulated by this time. Through the use of a subtractive cDNA cloning procedure we have prepared a library of sequences that represent genes activated for the first time between MBT and gastrula. A study of several of these cDNA clones suggests that genes in this class are restricted in their activity to embryonic and tadpole stages.

Retinal growth in double dorsal and double ventral eyes in Xenopus

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 175-185
Author(s):  
K. Straznicky ◽  
D. Tay
Keyword(s):  
Xenopus Laevis ◽  
Compound Eye ◽  
Ganglion Cells ◽  
Cell Number ◽  
Early Embryogenesis ◽  
Time Points ◽  
Retinal Growth

The growth of normal and surgically produced compound dorsal and ventral retinae in Xenopus laevis has been studied autoradiographically following injections of [3H]thymidine at stages 50 and 58. The animals were sacrificed 3 weeks after metamorphosis. The histogenetic pattern of the dorsal and ventral retinal halves was different at the three time points investigated, i.e. up to stage 50, between stages 50 and 58 and between stage 58 and 3 weeks after metamorphosis. Asymmetrical dorsal retinal growth occurred up to stage 50. From stage 50 onwards the retinal growth tendency reversed so that more ganglion cells were produced along the ventral than the dorsal ciliary margins. The overall preponderance of ventral retinal growth was 32·4% in cell number and 12·4% in retinal length from early embryogenesis to 3 weeks after metamorphosis. The characteristic histogenetic pattern of the dorsal and ventral retinal halves was maintained in an ectopic position in the compound eye, indicating that this particular property of the retinal halves is intrinsically determined.

Selective enhancement of bovine papillomavirus type 1 DNA replication in Xenopus laevis eggs by the E6 gene product

1989 ◽  
Vol 9 (2) ◽  
pp. 406-414
Author(s):  
H Romanczuk ◽  
W M Wormington
Keyword(s):  
Dna Replication ◽  
Xenopus Laevis ◽  
Gene Product ◽  
Mammalian Cells ◽  
Xenopus Laevis Oocytes ◽  
Bovine Papillomavirus ◽  
In Vitro Synthesis ◽  
E6 Gene ◽  
E6 Protein

Genetic analyses of bovine papillomavirus type 1 (BPV-1) DNA in transformed mammalian cells have indicated that the E6 gene product is essential for the establishment and maintenance of a high plasmid copy number. In order to analyze the direct effect of the E6 protein on the replication of a BPV-1-derived plasmid, a cDNA containing the BPV-1 E6 open reading frame was subcloned into an SP6 vector for the in vitro synthesis of the corresponding mRNA. The SP6 E6 mRNA was injected into Xenopus laevis oocytes to determine the subcellular localization of the E6 gene product and to analyze the effect of the protein on BPV-1 DNA replication. SP6 E6 mRNA microinjected into stage VI oocytes was translated into a 15.5-kilodalton protein that was specifically immunoprecipitated by antibodies directed against the E6 gene product. The E6 protein preferentially accumulated in oocyte nuclei, a localization which is consistent with the replicative functions in which it has been implicated. The expression of E6 in replication-competent mature oocytes selectively enhanced the replication of a BPV-derived plasmid, indicating a direct role for this gene product in the control of BPV-1 DNA replication.

scholarly journals Regulation of the DNA-binding and transcriptional activities of Xenopus laevis NFI-X by a novel C-terminal domain.

1995 ◽  
Vol 15 (10) ◽  
pp. 5552-5562 ◽  
Author(s):  
E Roulet ◽  
M T Armentero ◽  
G Krey ◽  
B Corthésy ◽  
C Dreyer ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Binding ◽  
Xenopus Laevis ◽  
Transcriptional Activation ◽  
Binding Activity ◽  
New Members ◽  
Binding Domains ◽  
Dna Binding Activity

The nuclear factor I (NFI) family consists of sequence-specific DNA-binding proteins that activate both transcription and adenovirus DNA replication. We have characterized three new members of the NFI family that belong to the Xenopus laevis NFI-X subtype and differ in their C-termini. We show that these polypeptides can activate transcription in HeLa and Drosophila Schneider line 2 cells, using an activation domain that is subdivided into adjacent variable and subtype-specific domains each having independent activation properties in chimeric proteins. Together, these two domains constitute the full NFI-X transactivation potential. In addition, we find that the X. laevis NFI-X proteins are capable of activating adenovirus DNA replication through their conserved N-terminal DNA-binding domains. Surprisingly, their in vitro DNA-binding activities are specifically inhibited by a novel repressor domain contained within the C-terminal part, while the dimerization and replication functions per se are not affected. However, inhibition of DNA-binding activity in vitro is relieved within the cell, as transcriptional activation occurs irrespective of the presence of the repressor domain. Moreover, the region comprising the repressor domain participates in transactivation. Mechanisms that may allow the relief of DNA-binding inhibition in vivo and trigger transcriptional activation are discussed.

Region-specific regulation of the actin multi-gene family in early amphibian embryos

1984 ◽  
Vol 307 (1132) ◽  
pp. 337-342 ◽  
Keyword(s):  
Molecular Marker ◽  
Xenopus Laevis ◽  
Gene Family ◽  
Early Embryogenesis ◽  
Embryonic Tissue ◽  
Actin Genes ◽  
Amphibian Embryos ◽  
Specific Regulation ◽  
Somitic Mesoderm

The actin multi-gene family shows both spatial and tem poral regulation during early embryogenesis in the am phibian Xenopus laevis . Both muscle-specific and ubiquitous cytoskeletal actin genes are activated at the end of gastrulation; transcription of the α-cardiac and α-skeletal actin genes is restricted to the somitic mesoderm and its muscle-forming derivatives providing a convenient molecular marker for this early embryonic tissue.

scholarly journals The role of maternal CREB in early embryogenesis of Xenopus laevis

2003 ◽  
Vol 261 (2) ◽  
pp. 337-352 ◽  
Author(s):  
Nambirajan Sundaram ◽  
Qinghua Tao ◽  
Chris Wylie ◽  
Janet Heasman
Keyword(s):  
Xenopus Laevis ◽  
Early Embryogenesis

scholarly journals Roles of LAP2 Proteins in Nuclear Assembly and DNA Replication: Truncated LAP2β Proteins Alter Lamina Assembly, Envelope Formation, Nuclear Size, and DNA Replication Efficiency in Xenopus laevis Extracts

1999 ◽  
Vol 144 (6) ◽  
pp. 1083-1096 ◽  
Author(s):  
Tracey Michele Gant ◽  
Crafford A. Harris ◽  
Katherine L. Wilson
Keyword(s):  
Dna Replication ◽  
Xenopus Laevis ◽  
Chromatin Binding ◽  
Binding Region ◽  
Nuclear Assembly ◽  
Downstream Effector ◽  
Common Domain ◽  
Splicing Isoforms ◽  
High Concentrations ◽  
Better Than

Humans express three major splicing isoforms of LAP2, a lamin- and chromatin-binding nuclear protein. LAP2β and γ are integral membrane proteins, whereas α is intranuclear. When truncated recombinant human LAP2β proteins were added to cell-free Xenopus laevis nuclear assembly reactions at high concentrations, a domain common to all LAP2 isoforms (residues 1–187) inhibited membrane binding to chromatin, whereas the chromatin- and lamin-binding region (residues 1–408) inhibited chromatin expansion. At lower concentrations of the common domain, membranes attached to chromatin with a unique scalloped morphology, but these nuclei neither accumulated lamins nor replicated. At lower concentrations of the chromatin- and lamin-binding region, nuclear envelopes and lamins assembled, but nuclei failed to enlarge and replicated on average 2.5-fold better than controls. This enhancement was not due to rereplication, as shown by density substitution experiments, suggesting the hypothesis that LAP2β is a downstream effector of lamina assembly in promoting replication competence. Overall, our findings suggest that LAP2 proteins mediate membrane–chromatin attachment and lamina assembly, and may promote replication by influencing chromatin structure.

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