Expression and subcellular distribution of rel/NFκB transcription factors in the preimplantation mouse embryo: novel κB binding activities in the blastocyst stage embryo

Zygote ◽  
1998 ◽  
Vol 6 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Justine N. Parrott ◽  
Nicholas J. Gay
Keyword(s):  
Transcription Factors ◽  
Mouse Embryo ◽  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Blastocyst Stage ◽  
Subcellular Localisation ◽  
Alternative Mechanism ◽  
Preimplantation Mouse ◽  
Stage Embryo ◽  
Early Mouse

We describe the expression patterns and subcellular localisation of murine rel/NFκB transcription factors and their inhibitors during preimplantation development in the mouse. We find that the known rel and IκB proteins are ubiquitously expressed during early murine embryogenesis. The differential persistence of individual rel and IκB transcripts in the first cleavage stage embryo and analysis of the 3'UTR suggests that rel and IκB protein expression may be regulated at the level of mRNA stability and translation. At the stages of early mouse embryogenesis examined, there was no evidence for strong induction of rel dimer translocation into the nucleus. However, novel κB-binding proteins are found in the mouse blastocyst and may provide an alternative mechanism for regulation of gene expression via the κB motif in the early mouse embryo.

Cell-matrix interactions in the early mouse embryo

1992 ◽  
Vol 50 (1) ◽  
pp. 600-601
Author(s):  
A.E. Sutherland ◽  
P.G. Calarco ◽  
C.H. Damsky
Keyword(s):  
Mouse Embryo ◽  
Giant Cells ◽  
Blastocyst Stage ◽  
Integrin Subunit ◽  
Β1 Integrin ◽  
Cell Stage ◽  
Early Mouse Embryo ◽  
Migratory Activity ◽  
Early Mouse ◽  
Cell Matrix Interactions

Cell-extracellular matrix (ECM) interactions mediated by the integrin family of receptors are critical for morphogenesis and may also play a regulatory role in differentiation during early development. We have examined the onset of expression of individual integrin subunit proteins in the early mouse embryo, and their roles in early morphogenetic events. As detected by immunoprecipitation, the α6, αV, β1, and β3 subunits are detected as early as the 4-cell stage, α5 at the hatched blastocyst stage and αl and α3 following blastocyst attachment. We tested the role of these integrins in the attachment and migratory activity of two cell populations of the early mouse embryo: the trophoblast giant cells, which invade the uterine stroma and ultimately contribute to the chorio-allantoic placenta, and the parietal endoderm, which migrates over the inner surface of the trophoblast and ultimately forms Reichert's membrane and the parietal yolk sac. Experiments were done in serum-free medium on substrates coated with laminin (Ln) and fibronectin (Fn). Trophoblast outgrowth occurs on Ln and its E8 fragment (long arm), but not on the E1’ fragment (cross region) (Figs. 1, 2 ). This outgrowth is inhibited by anti-E8, anti-Ln, and by the anti-β1 family antiserum anti-ECMR, but not by anti-αV or the function-perturbing GoH3 antibody that recognizes the α6/β1 integrin, a major Ln (E8) receptor. This suggests that trophoblast outgrowth on Ln or E8 is mediated by a different β1 integrin such as α3/β1. Early stages of trophoblast outgrowth (up to 48 hours) on Fn are inhibited by anti-Fn and by function-perturbing anti-αV antibodies, whereas at later times outgrowth becomes insensitive to anti-αV but remains sensitive to the anti-β1 family antiserum anti-ECMr, indicating that trophoblast cells modulate their interaction with Fn during outgrowth. Trophoblast outgrowth on vitronectin (Vn) is sensitive to anti-αV antibodies throughout the 5-day period examined.

Localization of cytoskeletal proteins in preimplantation mouse embryos

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 211-225
Author(s):  
E. Lehtonen ◽  
R. A. Badley
Keyword(s):  
Blastocyst Stage ◽  
Cytoskeletal Proteins ◽  
Mouse Embryos ◽  
Trophectoderm Cells ◽  
Apparent Concentration ◽  
Preimplantation Mouse ◽  
Early Mouse ◽  
Filament Protein

The immunofluorescence technique was used to detect the presence and distribution of actin, alpha-actinin, tubulin and 10 nm filament protein in early mouse embryos. Actin and alpha-actinin stainings showed a distinct concentration to a peripheral layer in the cleavage-stage blastomeres and in trophectoderm cells. Dots of fluorescence appeared in this cortical staining pattern. The distribution of tubulin staining in the blastomere cytoplasm was relatively even with apparent concentration at the perinuclear region and frequently at wide intercellular contact areas. 10 nm filament protein was distributed evenly in the blastomere cytoplasm without cortical concentration of the label. At the blastocyst stage, the trophectoderm cells in blastocyst outgrowths in vitro developed well organized cytoskeletons including both microfilament, microtubule and 10 nm filament elements. Comparable structures were not observed in blastocysts in vivo, or in late hatched blastocysts cultured in suspension. The morphogenetic significance of the observations is discussed.

scholarly journals MreA Functions in the Global Regulation of Methanogenic Pathways in Methanosarcina acetivorans

mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Matthew J. Reichlen ◽  
Venkata R. Vepachedu ◽  
Katsuhiko S. Murakami ◽  
James G. Ferry
Keyword(s):  
Transcription Factors ◽  
Specific Binding ◽  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Methanosarcina Acetivorans ◽  
Wild Type ◽  
Global Regulation ◽  
Altered Expression ◽  
Content Type ◽  
Expression Of Genes

ABSTRACT Results are presented supporting a regulatory role for the product of the MA3302 gene locus (designated MreA) previously annotated as a hypothetical protein in the methanogenic species Methanosarcina acetivorans of the domain Archaea. Sequence analysis of MreA revealed identity to the TrmB family of transcription factors, albeit the sequence is lacking the sensor domain analogous to TrmBL2, abundant in nonmethanogenic species of the domain Archaea. Transcription of mreA was highly upregulated during growth on acetate versus methylotrophic substrates, and an mreA deletion (ΔmreA) strain was impaired for growth with acetate in contrast to normal growth with methylotrophic substrates. Transcriptional profiling of acetate-grown cells identified 280 genes with altered expression in the ΔmreA strain versus the wild-type strain. Expression of genes unique to the acetate pathway decreased whereas expression of genes unique to methylotrophic metabolism increased in the ΔmreA strain relative to the wild type, results indicative of a dual role for MreA in either the direct or indirect activation of acetate-specific genes and repression of methylotrophic-specific genes. Gel shift experiments revealed specific binding of MreA to promoter regions of regulated genes. Homologs of MreA were identified in M. acetivorans and other Methanosarcina species for which expression patterns indicate roles in regulating methylotrophic pathways. IMPORTANCE Species in the domain Archaea utilize basal transcription machinery resembling that of the domain Eukarya, raising questions addressing the role of numerous putative transcription factors identified in sequenced archaeal genomes. Species in the genus Methanosarcina are ideally suited for investigating principles of archaeal transcription through analysis of the capacity to utilize a diversity of substrates for growth and methanogenesis. Methanosarcina species switch pathways in response to the most energetically favorable substrate, metabolizing methylotrophic substrates in preference to acetate marked by substantial regulation of gene expression. Although conversion of the methyl group of acetate accounts for most of the methane produced in Earth’s biosphere, no proteins involved in the regulation of genes in the acetate pathway have been reported. The results presented here establish that MreA participates in the global regulation of diverse methanogenic pathways in the genus Methanosarcina. Finally, the results contribute to a broader understanding of transcriptional regulation in the domain Archaea.

Gp330 is specifically expressed in outer cells during epithelial differentiation in the preimplantation mouse embryo

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3289-3299 ◽  
Author(s):  
C. Gueth-Hallonet ◽  
A. Santa-Maria ◽  
P. Verroust ◽  
B. Maro
Keyword(s):  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Transcriptional Level ◽  
Cell Stage ◽  
Preimplantation Mouse ◽  
Extensive Cell ◽  
High Level ◽  
Endocytic Activity

During preimplantation development of the mouse embryo, a layer of outer cells differentiates into a perfect epithelium, the trophectoderm. The divergence between the trophectoderm and the inner cell mass takes place from the 8-cell stage to the 64-cell stage and precedes their commitment at the blastocyst stage. In this work, we have investigated the expression of gp330, a 330 × 10(3) M(r) glycoprotein found in clathrin-coated areas of the plasma membrane of some epithelial cells characterized by a high level of endocytic activity. Our results show that gp330 is first synthesized in 16-cell stage embryos and that its appearance is restricted to outer cells until the blastocyst stage. Furthermore, its expression is repressed in inner cells at a post-transcriptional level, probably through the development of extensive cell-cell contacts.

Disruption of the cytokeratin filament network in the preimplantation mouse embryo

Development ◽  
1988 ◽  
Vol 104 (2) ◽  
pp. 219-234
Author(s):  
J.A. Emerson
Keyword(s):  
Mouse Embryo ◽  
Blastocyst Stage ◽  
Cell Stage ◽  
Trophectoderm Cells ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Morula Stage ◽  
Cytokeratin Filaments

The distribution of the cytokeratin network in the intact preimplantation mouse embryo and the role of cytokeratin filaments in trophectoderm differentiation were investigated by means of whole-mount indirect immunofluorescence microscopy and microinjection of anti-cytokeratin antibody. Assembled cytokeratin filaments were detected in some blastomeres as early as the compacted 8-cell stage. The incidence and organization of cytokeratin filaments increased during the morula stage, although individual blastomeres varied in their content of assembled filaments. At the blastocyst stage, each trophectoderm cell contained an intricate network of cytokeratin filaments, and examination of sectioned blastocysts confirmed that extensive arrays of cytokeratin filaments were restricted to cells of the trophectoderm. Microinjection of anticytokeratin antibody into individual mural trophectoderm cells of expanded blastocysts resulted in a dramatic rearrangement of the cytokeratin network in these cells. Moreover, antibody injection into 2-cell embryos inhibited assembly of the cytokeratin network during the next two days of development. Despite this disruption of cytokeratin assembly, the injected embryos compacted and developed into blastocysts with normal morphology and nuclear numbers. These results suggest that formation of an elaborate cytokeratin network in preimplantation mouse embryos is unnecessary for the initial stages of trophectoderm differentiation resulting in blastocyst formation.

scholarly journals 255EXPRESSION OF TRANSCRIPTION FACTORS PRIOR TO THE MATERNAL-TO-ZYGOTIC TRANSITION IN BOVINE EMBRYOS

2004 ◽  
Vol 16 (2) ◽  
pp. 247
Author(s):  
C. Vigneault ◽  
S. McGraw ◽  
G. Bujold ◽  
M.-A. Sirard
Keyword(s):  
Transcription Factors ◽  
Expression Patterns ◽  
Blastocyst Stage ◽  
Cell Stage ◽  
Transcript Levels ◽  
Significant Difference ◽  
Maternal To Zygotic Transition ◽  
La Jolla ◽  
Triton X

During the first stages of bovine embryonic development, until the 8- to 16-cell stage, the zygote is maintained by the mRNA and proteins stored in the oocyte. New embryonic transcription is reported to begin only at the 8- to 16-cell stage even if some minor transcription is detected from the 2-cell stage. In order for this to occur, several factors are required to remodel the chromatin and activate the transcription machinery. Some regulating transcription factors are possibly present in the oocyte in their mRNA form, and their translation could enhance the maternal-to-zygotic transition (MZT). In our study, we observed the expression patterns of five transcription factors (ATF2, HMGN2, HMGB2, HUEL and MSY2) in bovine in vitro-produced embryos. Embryos were produced in vitro using selected cumulus-oocyte complexes from 3-5-mm follicles of slaughterhouse ovaries. Pooled GV or MII oocytes, and 2-, 4-, 8-cell and blastocyst-stage embryos (n=40/stage) were washed in PBS and frozen at −80°C. Each pool was spiked with 1 pg of GFP RNA containing a poly(A) tail. The RNA was extracted using the Absolutely RNA Microprep Kit (Stratagene, La Jolla, CA, USA), co-precipitated with linear acrylamide (Ambion, Austin, TX, USA) and reverse-transcribed with Omniscript (Quiagen). The quantitative amplification of the transcription factors was performed in triplicate using the equivalent of 1 oocyte or embryo per reaction on a Lightcycler (Roche, Indianapolis, IN, USA). Data were normalized with the GFP levels found in each pool and a Least-Significant-Difference method was used for statistical analysis. Immunocytochemistry studies were performed on oocytes and embryos fixed and permeabilized in a solution of paraformaldehyde and Triton X-100, and results were observed on a confocal microscope. Our results show that the transcripts of the transcription factors studied are found at higher levels in pre-MZT embryos and at lower levels in subsequent stages. For HMGN2 and MSY2, there is a decrease in mRNA during oocyte maturation. For both genes, the residual mRNA remains constant up to the 4-cell stage before another loss in transcript levels in the 8-cell stage. In the case of ATF2, HMGB2 and HUEL, the maternal transcript levels are maintained until the 4-cell stage, suggesting that the mRNA is protected from degradation until its possible translation at the MZT. These results, combined to immunolocalization of the proteins, suggest a possible implication of some of these factors in the bovine MZT.

The nature of intercellular coupling within the preimplantation mouse embryo

Development ◽  
1984 ◽  
Vol 79 (1) ◽  
pp. 53-76
Author(s):  
H. Goodall ◽  
M. H. Johnson
Keyword(s):  
Mouse Embryo ◽  
Intercellular Junctions ◽  
Intercellular Coupling ◽  
Cell Stage ◽  
Cell Cycles ◽  
Junctional Communication ◽  
Preimplantation Mouse Embryo ◽  
Intact Embryo ◽  
Preimplantation Mouse ◽  
Early Mouse

The changing nature of intercellular coupling during the 4- and 8-cell stages of mouse early development has been investigated by iontophoretic injection of carboxyfluorescein, horse-radish peroxidase and current into individual blastomeres in either the intact embryo or after their disaggregation and reaggregation into pairs. Coupling junctions that allowed only molecules of low molecular weight (putative gap junctions) were found not to appear until 2–5 h beyond the 3rd cleavage division (8-cell stage). However, intercellular junctions that were not size selective were detected in intact embryos only throughout the 4- and 8-cell stages. It is proposed that this junctional communication results from the persistence of midbodies through all or part of the two, and in a few cases the three, cell cycles following their formation at the first and second cleavage divisions. We conclude that the cells of the early mouse embryo may be linked in a more extensive syncytial network than was hitherto suspected.

Regulation of gene expression in the preimplantation mouse embryo

1995 ◽  
Vol 44 (8) ◽  
pp. 1115-1131 ◽  
Author(s):  
R.M. Schultz ◽  
D.M. Worrad ◽  
W. Davis ◽  
P.A. De Sousa
Keyword(s):  
Gene Expression ◽  
Mouse Embryo ◽  
Regulation Of Gene Expression ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse
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