scholarly journals Control of events during early cleavage of the mouse embryo: an analysis of the ‘2-cell block’

Development ◽  
1983 ◽  
Vol 73 (1) ◽  
pp. 111-133
Author(s):  
Martin J. Goddard ◽  
Hester P. M. Pratt
Keyword(s):  
Mouse Embryo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Cell Block ◽  
Mouse Development ◽  
Early Cleavage ◽  
Cell Stage ◽  
Quantitative Changes ◽  
Early Mouse

Embryos from certain strains of mice do not develop into blastocysts when cultured in vitro from the 1- or 2-cell stages but arrest development as 2-cell embryos — a phenomenon referred to, as the ‘2-cell block’. Reciprocal crosses between eggs and sperm of a ‘blocking’ (CFLP) and ‘non-blocking’ (F1) strain show that in this combination the genotype of the egg alone determines whether the embryo ‘blocks’ at the 2-cell stage (or continues retarded development to the 4- to 6-cell stage in a minority of cases). A comparison of molecular and cellular development in normal and ‘blocked 2-cell’ embryos was therefore undertaken to investigate the influence of these maternal components on early mouse development. The results show that the majority of ‘blocked 2-cells’ arrest development at a stage equivalent to the late 2-cell stage in terms of cellular and nuclear division, DNA synthesis, activation of the embryonic genome, qualitative and quantitative changes in amino acid uptake, polypeptide synthesis and morphological maturation of organelles. These observations are compatiblewith the notion that maternally inherited developmental information plays an important role in controlling early cleavage of the mouse embryo.

Regulation of embryonic size in early mouse development in vitro culture system

Zygote ◽  
2013 ◽  
Vol 22 (3) ◽  
pp. 340-347 ◽  
Author(s):  
Tomoka Hisaki ◽  
Ikuma Kawai ◽  
Koji Sugiura ◽  
Kunihiko Naito ◽  
Kiyoshi Kano
Keyword(s):  
Culture System ◽  
Cell Number ◽  
Mouse Development ◽  
Cell Stage ◽  
Relative Growth ◽  
Development In Vitro ◽  
Early Mouse ◽  
Post Implantation

SummaryMammals self-regulate their body size throughout development. In the uterus, embryos are properly regulated to be a specific size at birth. Previously, size and cell number in aggregated embryos, which were made from two or more morulae, and half embryos, which were halved at the 2-cell stage, have been analysed in vivo in preimplantation and post-implantation development in mice. Here, we examined whether or not the mouse embryo has the capacity to self-regulate growth using an in vitro culture system. To elucidate embryonic histology, cells were counted in aggregated or half embryos in comparison with control embryos. Both double- and triple-aggregated embryos contained more cells than did control embryos during all culture periods, and the relative growth ratios showed no growth inhibition in an in vitro culture system. Meanwhile, half embryos contained fewer cells than control embryos, but the number grew throughout the culture period. Our data suggest that the growth of aggregated embryos is not affected and continues in an in vitro culture system. On the other hand, the growth of half embryos accelerates and continues in an in vitro culture system. This situation, in turn, implied that post-implantation mouse embryos might have some potential to regulate their own growth and size as seen by using an in vitro culture system without uterus factors. In conclusion, our results indicated that embryos have some ways in which to regulate their own size in mouse early development.

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.

The mechanisms of amino acid uptake byBrugia pahangi in vitro

1983 ◽  
Vol 69 (2) ◽  
pp. 247-253 ◽  
Author(s):  
R. E. Howells ◽  
A. M. Mendis ◽  
P. G. Bray
Keyword(s):  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake

The Foxh1-dependent autoregulatory enhancer controls the level of Nodal signals in the mouse embryo

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3455-3468 ◽  
Author(s):  
Dominic P. Norris ◽  
Jane Brennan ◽  
Elizabeth K. Bikoff ◽  
Elizabeth J. Robertson
Keyword(s):  
Mouse Embryo ◽  
Late Onset ◽  
Axis Formation ◽  
Visceral Endoderm ◽  
Mouse Development ◽  
Developmental Abnormalities ◽  
Intronic Enhancer ◽  
Vertebrate Embryo ◽  
Early Mouse ◽  
Pitx2 Expression

The TGFβ-related growth factor Nodal governs anteroposterior (AP) and left-right (LR) axis formation in the vertebrate embryo. A conserved intronic enhancer (ASE), containing binding sites for the fork head transcription factor Foxh1, modulates dynamic patterns of Nodal expression during early mouse development. This enhancer is responsible for early activation of Nodal expression in the epiblast and visceral endoderm, and at later stages governs asymmetric expression during LR axis formation. We demonstrate ASE activity is strictly Foxh1 dependent. Loss of this autoregulatory enhancer eliminates transcription in the visceral endoderm and decreases Nodal expression in the epiblast, but causes surprisingly discrete developmental abnormalities. Thus lowering the level of Nodal signaling in the epiblast disrupts both orientation of the AP axis and specification of the definitive endoderm. Targeted removal of the ASE also dramatically reduces left-sided Nodal expression, but the early events controlling LR axis specification are correctly initiated. However loss of the ASE disrupts Lefty2 (Leftb) expression and causes delayed Pitx2 expression leading to late onset, relatively minor LR patterning defects. The feedback loop is thus essential for maintenance of Nodal signals that selectively regulate target gene expression in a temporally and spatially controlled fashion in the mouse embryo.

Expression of the HSP 70.1 gene, a landmark of early zygotic activity in the mouse embryo, is restricted to the first burst of transcription

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 113-122 ◽  
Author(s):  
E. Christians ◽  
E. Campion ◽  
E.M. Thompson ◽  
J.P. Renard
Keyword(s):  
Dna Replication ◽  
Mouse Embryo ◽  
Culture Conditions ◽  
Hsp 70 ◽  
Cell Stage ◽  
Embryonic Genome ◽  
Genome Activation ◽  
Alpha Amanitin ◽  
Zygotic Genome

Activation of the mouse embryonic genome at the 2-cell stage is characterized by the synthesis of several alpha-amanitin-sensitive polypeptides, some of which belong to the multigenic hsp 70 family. In the present work we show that a member of this family, the HSP 70.1 gene, is highly transcribed at the onset of zygotic genome activation. Transcription of this gene began as early as the 1-cell stage. Expression of the gene continued through the early 2-cell stage but was repressed before the completion of the second round of DNA replication. During this period we observed that the level of transcription was modulated by in vitro culture conditions. The coincidence of repression of HSP70.1 transcription with the second round of DNA replication was not found for other transcription-dependent polypeptides synthesized at the 2-cell stage.

Cell division and cell allocation in early mouse development

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 37-51
Author(s):  
S. J. Kelly ◽  
J. G. Mulnard ◽  
C. F. Graham
Keyword(s):  
Cell Division ◽  
Tritiated Thymidine ◽  
Mouse Embryos ◽  
Mouse Development ◽  
Stages Of Development ◽  
Cell Stage ◽  
Cell Cycles ◽  
Short Cell ◽  
Early Mouse

Cell division was observed in intact and dissociated mouse embryos between the 2-cell stage and the blastocyst in embryos developing in culture. Division to the 4-cell stage was usually asynchronous. The first cell to divide to the 4-cell stage produced descendants which tended to divide ahead of those cells produced by its slow partner at all subsequent stages of development up to the blastocyte stage. The descendants of the first cell to divide to the 4-cell stage did not subsequently have short cell cycles. The first cell or last cell to divide from the 4-cell stage was labelled with tritiated thymidine. The embryo was reassembled, and it was found that the first pair of cells to reach the 8-cell stage contributed disproportionately more descendants to the ICM when compared with the last cell to divide to the 8-cell stage.

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

scholarly journals Comparative Analyses of Single-Cell Transcriptomic Profiles between In Vitro Totipotent Blastomere-like Cells and In Vivo Early Mouse Embryonic Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3111
Author(s):  
Po-Yu Lin ◽  
Denny Yang ◽  
Chi-Hsuan Chuang ◽  
Hsuan Lin ◽  
Wei-Ju Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Single Cell ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Developmental Potential ◽  
Functional Features ◽  
Early Mouse ◽  
Extraembryonic Tissues

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are ‘true’ totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely ‘cluster 3’, as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.

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