scholarly journals The 'GO' system--a novel method of microculture for in vitro development of mouse zygotes to the blastocyst stage

Reproduction ◽  
2003 ◽  
pp. 161-169 ◽  
Author(s):  
GA Thouas ◽  
GM Jones ◽  
AO Trounson

A novel system of in vitro culture termed the 'glass oviduct' or 'GO' culture system is described. Mouse zygotes were cultured in pairs to the blastocyst stage in open-ended 1 microl glass capillaries. 'GO' culture supported the development of significantly more hatching or hatched blastocysts than did a standard microdroplet (10 zygotes per 20 microl) control culture (48.3 versus 3.3%, respectively). 'GO' bslastocysts contained significantly larger populations of cells (92+/-3 versus 75+/-3), and inner cell mass (25+/-1 versus 21+/-1) and trophectoderm (68+/-2 versus 53+/-3) subpopulations, compared with microdroplet-derived blastocysts. Before blastulation, 'GO'-derived morulae were found to contain significantly more cells than microdroplet-derived morulae (27+/-0.7 versus 14+/-0.5). After implantation, 'GO' blastocysts formed fetuses at a similar rate to microdroplet-derived blastocysts (55 versus 62%), but at a lower rate than blastocysts derived in vivo (80%). 'GO'- and microdroplet-derived fetuses were similar in wet weight to each other (0.412 and 0.415 g, respectively) but were heavier than fetuses derived from flushed blastocysts (0.390 g). An additional experiment investigated whether the beneficial effect of 'GO' culture was due to the significantly increased embryo density. Proportions of hatching or hatched blastocysts after 'GO' culture (50%) were higher than after standard microdroplet culture (7.6%), but were not different from culture in high embryo density microdroplets (20 zygotes per 10 microl; 42%). 'GO' blastocysts contained more cells (79.6+/-2.1) than did standard microdroplet-derived blastocysts (68.7+/-2.0), but were similar to high density microdroplet-derived blastocysts (85.8+/-2.7). Similarly, 'GO' blastocysts contained more trophectoderm cells (62.2+/-2.0) than did standard microdroplet-derived blastocysts (52.7+/-1.7), but were similar to the high density microdroplet blastocysts (68.8+/-2.5). Numbers of inner cell mass cells ('GO', standard microdroplet and high density microdroplet culture) were not different from each other (17.4+/-0.5, 16+/-0.5 and 17+/-0.4, respectively). In conclusion, the 'GO' culture system represents an alternative method to the microdroplet system for small numbers of preimplantation embryos, without detriment to implantation potential.

2007 ◽  
Vol 27 (8) ◽  
pp. 3123-3130 ◽  
Author(s):  
Klaus Fortschegger ◽  
Bettina Wagner ◽  
Regina Voglauer ◽  
Hermann Katinger ◽  
Maria Sibilia ◽  
...  

ABSTRACT SNEV (Prp19, Pso4, NMP200) is a nuclear matrix protein known to be involved in pre-mRNA splicing, ubiquitylation, and DNA repair. In human umbilical vein endothelial cells, SNEV overexpression delayed the onset of replicative senescence. Here we analyzed the function of the mouse SNEV gene in vivo by employing homologous recombination in mice and conclude that SNEV is indispensable for early mouse development. Mutant preimplantation embryos initiated blastocyst formation but died shortly thereafter. Outgrowth of SNEV-null blastocysts showed a lack of proliferation of cells of the inner cell mass, which subsequently underwent cell death. While SNEV-heterozygous mice showed no overt phenotype, heterozygous mouse embryonic fibroblast cell lines with reduced SNEV levels displayed a decreased proliferative potential in vitro. Our experiments demonstrate that the SNEV protein is essential, functionally nonredundant, and indispensable for mouse development.


Reproduction ◽  
2020 ◽  
Vol 159 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Wei Cui ◽  
Agnes Cheong ◽  
Yongsheng Wang ◽  
Yuran Tsuchida ◽  
Yong Liu ◽  
...  

Microspherule protein 1 (MCRS1, also known as MSP58) is an evolutionarily conserved protein that has been implicated in various biological processes. Although a variety of functions have been attributed to MCRS1 in vitro, mammalian MCRS1 has not been studied in vivo. Here we report that MCRS1 is essential during early murine development. Mcrs1 mutant embryos exhibit normal morphology at the blastocyst stage but cannot be recovered at gastrulation, suggesting an implantation failure. Outgrowth (OG) assays reveal that mutant blastocysts do not form a typical inner cell mass (ICM) colony, the source of embryonic stem cells (ESCs). Surprisingly, cell death and histone H4 acetylation analysis reveal that apoptosis and global H4 acetylation are normal in mutant blastocysts. However, analysis of lineage specification reveals that while the trophoblast and primitive endoderm are properly specified, the epiblast lineage is compromised and exhibits a severe reduction in cell number. In summary, our study demonstrates the indispensable role of MCRS1 in epiblast development during early mammalian embryogenesis.


2009 ◽  
Vol 21 (9) ◽  
pp. 63
Author(s):  
L. Ganeshan ◽  
C. O'Neill

The developmental viability of the early embryo requires the formation of the inner cell mass (ICM) at the blastocyst stage. The ICM contributes to all cell lineages within the developing embryo in vivo and the embryonic stem cell (ESC) lineage in vitro. Commitment of cells to the ICM lineage and its pluripotency requires the expression of core transcription factors, including Nanog and Pou5f1 (Oct4). Embryos subjected to culture in vitro commonly display a reduced developmental potential. Much of this loss of viability is due to the up-regulation of TRP53 in affected embryos. This study investigated whether increased TRP53 disrupts the expression of the pluripotency proteins and the normal formation of the ICM lineage. Mouse C57BL6 morulae and blastocysts cultured from zygotes (modHTF media) possessed fewer (p < 0.001) NANOG-positive cells than equivalent stage embryos collected fresh from the uterus. Blocking TRP53 actions by either genetic deletion (Trp53–/–) or pharmacological inhibition (Pifithrin-α) reversed this loss of NANOG expression during culture. Zygote culture also resulted in a TRP53-dependent loss of POU5F1-positive cells from resulting blastocysts. Drug-induced expression of TRP53 (by Nutlin-3) also caused a reduction in formation of pluripotent ICM. The loss of NANOG- and POU5F1-positive cells caused a marked reduction in the capacity of blastocysts to form proliferating ICM after outgrowth, and a consequent reduced ability to form ESC lines. These poor outcomes were ameliorated by the absence of TRP53, resulting in transmission distortion in favour of Trp53–/– zygotes (p < 0.001). This study shows that stresses induced by culture caused TRP53-dependent loss of pluripotent cells from the early embryo. This is a cause of the relative loss of viability and developmental potential of cultured embryos. The preferential survival of Trp53–/– embryos after culture due to their improved formation of pluripotent cells creates a genetic danger associated with these technologies.


Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 43-55
Author(s):  
J. Rossant ◽  
K. M. Vijh

Embryos homozygous for the velvet coat mutation, Ve/Ve, were recognized at 6·5 days post coitum by the reduced size of the ectodermal portions of the egg cylinder and the loose, columnar nature of the overlying endoderm. Later in development ectoderm tissues were sometimes entirely absent. Abnormalities appeared in the ectoplacental cone at 8·5 days but trophoblast giant cells and parietal endoderm appeared unaffected. Homozygotes could not be unequivocally identified at 5·5 days nor at the blastocyst stage but were recognized in blastocyst outgrowths by poor development of the inner cell mass derivatives, It has previously been suggested that Ve may exert its action at the blastocyst stage by reducing the size of the inner cell mass, but no evidence for such a reduction was found. Most of the observations on Ve/Ve homozygotes are, however, consistent with the hypothesis that Ve exerts its action primarily on later primitive ectoderm development.


1982 ◽  
Vol 35 (2) ◽  
pp. 187 ◽  
Author(s):  
GM Harlow ◽  
P Quinn

The culture conditions for the development in vitro of (C57BL/6 X CBA) F2 hybrid two-cell embryos to the blastocyst stage have been optimized. Commercially available pre-sterile disposable plastic culture dishes supported more reliable development than re-usable washed glass tubes. The presence of an oil layer reduced the variability in development. An average of 85 % of blastocysts developed from hybrid two-cell embryos cultured in drops of Whitten's medium under oil in plastic culture dishes in an atmosphere of 5% O2 : 5% CO2 : 90% N2 ? The time taken for the total cell number to double in embryos developing in vivo was 10 h, and in cultured embryos 17 h. Embryos cultured in vitro from the two-cell stage to blastocyst stage were retarded by 18-24 h in comparison with those remaining in vivo. Day-4 blastocysts in vivo contained 25-70 cells (mean 50) with 7-28 (mean 16) of these in the inner cell mass. Cultured blastocysts contained 19-73 cells (mean 44) with 8-34 (mean 19) of these in the inner cell mass. In the uterine environment, inner-cell-mass blastomeres divided at a faster rate than trophectoderm blastomeres and it is suggested that a long cell cycle is associated with terminal differentiation. Although cultured blastocysts and inner cell masses contained the same number of cells as blastocysts and inner cell masses in vivo, the rate of cell division in cultured inner cell masses was markedly reduced.


2003 ◽  
Vol 23 (15) ◽  
pp. 5346-5353 ◽  
Author(s):  
Elisabeth Larsen ◽  
Christine Gran ◽  
Barbro Elisabet Sæther ◽  
Erling Seeberg ◽  
Arne Klungland

ABSTRACT Flap endonuclease 1 (FEN1) has been shown to remove 5′ overhanging flap intermediates during base excision repair and to process the 5′ ends of Okazaki fragments during lagging-strand DNA replication in vitro. To assess the in vivo role of the mammalian enzyme in repair and replication, we used a gene-targeting approach to generate mice lacking a functional Fen1 gene. Heterozygote animals appear normal, whereas complete depletion of FEN1 causes early embryonic lethality. Fen1−/− blastocysts fail to form inner cell mass during cellular outgrowth, and a complete inactivation of DNA synthesis in giant cells of blastocyst outgrowth was observed. Exposure of Fen1−/− blastocysts to gamma radiation caused extensive apoptosis, implying an essential role for FEN1 in the repair of radiation-induced DNA damage in vivo. Our data thus provide in vivo evidence for an essential function of FEN1 in DNA repair, as well as in DNA replication.


Reproduction ◽  
2007 ◽  
Vol 134 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Gnanaratnam Giritharan ◽  
Said Talbi ◽  
Annemarie Donjacour ◽  
Francesca Di Sebastiano ◽  
Anthony T Dobson ◽  
...  

In vitro culture (IVC) of preimplantation mouse embryos is associated with changes in gene expression. It is however, not known if the method of fertilization affects the global pattern of gene expression. We compared gene expression and development of mouse blastocysts produced by in vitro fertilization (IVF) versus blastocysts fertilized in vivo and cultured in vitro from the zygote stage (IVC) versus control blastocysts flushed out of the uterus on post coital day 3.5. The global pattern of gene expression was assessed using the Affymetrix 430 2.0 chip. It appears that each method of fertilization has a unique pattern of gene expression and development. Embryos cultured in vitro had a reduction in the number of trophoblastic cells (IVF 33.5 cells, IVC 39.9 cells, and 49.6 cells in the in vivo group) and, to a lesser degree, of inner cell mass cells (12.8, 11.7, and 13.8 respectively). The inner cell mass nuclei were larger after culture in vitro (140 μm2, 113 μm2, and 86 μm2 respectively). Although a high number of genes (1912) was statistically different in the IVF cohort when compared with the in vivo control embryos, the magnitude of the changes in gene expression were low and only a minority of genes (29 genes) was changed more than fourfold. Surprisingly, IVF embryos were different from IVC embryos (3058 genes were statistically different, but only three changed more than fourfold). Proliferation, apoptosis, and morphogenetic pathways are the most common pathways altered after IVC. Overall, IVF and embryo culture have a profound effect on gene expression pattern and phenotype of mouse preimplantation embryos.


Reproduction ◽  
2003 ◽  
pp. 91-99 ◽  
Author(s):  
R Augustin ◽  
P Pocar ◽  
C Wrenzycki ◽  
H Niemann ◽  
B Fischer

Insulin improves development of mammalian preimplantation embryos and, in addition to the regulation of glucose transport, it exerts mitogenic and anti-apoptotic activities. The expression of glucose transporters (Glut) mediating the uptake of this essential energy substrate is critical for embryo survival. An impaired expression of Glut leads to an increase in apoptosis at the blastocyst stage and involves Bax. The various effects of insulin were unravelled by supplementing the in vitro culture medium with insulin (1.7 micromol l(-1)) and (i) the rates of cleavage and blastocyst development were recorded; (ii) mitogenic activity was studied by determining the total number of blastocyst cells and the ratio between trophectoderm and inner cell mass (ICM) cells; (iii) the frequency of apoptosis in blastocysts was determined by the TdT-mediated duTP nick-end labelling (TUNEL) assay and by quantification of the relative amounts of mRNA for Bax and Bcl-XL; and (iv) expression for Glut1, Glut3 and Glut8 transcripts was compared between embryos cultured in the presence or absence of insulin. Insulin increased rates of cleavage (81.2+/-2.2 (control) to 86.0+/-2.5) and blastocyst development (24.7+/-1.9 to 31.3+/-1.2), and number of blastocyst cells (123.7+/-6.0 to 146.3+/-6.6); the increase in the number of blastocyst cells was due to a significantly higher number of trophectoderm cells (82.3+/-5.0 versus 100.3+/-5.5). Blastocysts derived from cultures supplemented with insulin showed a significant decrease in apoptosis as determined by the TUNEL assay (14.8+/-0.9 to 12.2+/-0.7). No effects of insulin on the mRNA expression of Glut isoforms and Bax and Bcl-XL were found. These results demonstrate that the mitogenic and anti-apoptotic effects of insulin on bovine preimplantation embryos did not correlate with changes in the amounts of mRNA for the glucose transporter isoforms Glut1, -3 and -8, or transcripts for Bax and Bcl-XL.


Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 653-662
Author(s):  
Marilyn Monk ◽  
John Ansell

Following blastocyst implantation, or outgrowth in vitro, the LDH isozyme pattern changes from that of the maternally inherited B subunit isozyme form (LDH-1) to a pattern dominated by A subunits (Auerbach & Brinster, 1967, 1968). In preimplantation embryos we have also observed additional isozyme bands, as yet unidentified. An analysis of the pattern of newly synthesized LDH isozymes and specific activity of LDH in different regions of early post implantation embryos suggests that there is a sequential activation of A and B subunits, and that activity first appears in ICM- (inner cell mass) derived tissues and then in trophoblast-derived tissues. In vitro, in the absence of ICM cells, the transition of LDHisozyme pattern does not occur in outgrowing trophoblast giant cells. This suggests a possible inductive interaction between ICM and trophoblast.


2019 ◽  
Vol 25 (7) ◽  
pp. 397-407
Author(s):  
Yvonne Wilson ◽  
Ian D Morris ◽  
Susan J Kimber ◽  
Daniel R Brison

Abstract Apoptosis occurs primarily in the blastocyst inner cell mass, cells of which go on to form the foetus. Apoptosis is likely to play a role in ensuring the genetic integrity of the foetus, yet little is known about its regulation. In this study, the role of the mouse gene, transformation-related protein 53 (Trp53) in the response of embryos to in vitro culture and environmentally induced DNA damage was investigated using embryos from a Trp53 knockout mouse model. In vivo-derived blastocysts were compared to control embryos X-irradiated at the two-cell stage and cultured to Day 5. An analysis of DNA by comet assay demonstrated that 1.5 Gy X-irradiation directly induced damage in cultured two-cell mouse embryos; this was correlated with retarded development to blastocyst stage and increased apoptosis at the blastocyst stage but not prior to this. Trp53 null embryos developed to blastocysts at a higher frequency and with higher cell numbers than wild-type embryos. Trp53 also mediates apoptosis in conditions of low levels of DNA damage, in vivo or in vitro in the absence of irradiation. However, following DNA damage induced by X-irradiation, apoptosis is induced by Trp53 independent as well as dependent mechanisms. These data suggest that Trp53 and apoptosis play important roles in normal mouse embryonic development both in vitro and in vivo and in response to DNA damage. Therefore, clinical ART practices that alter apoptosis in human embryos and/or select embryos for transfer, which potentially lack a functional Trp53 gene, need to be carefully considered.


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