scholarly journals Foetal fibroblasts introduced to cleaving mouse embryos contribute to full-term development

Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 207-218 ◽  
Author(s):  
Anna Piliszek ◽  
Jacek A Modliński ◽  
Kazimiera Pyśniak ◽  
Jolanta Karasiewicz

Foetal fibroblasts (FFs) labelled with vital fluorescent dye were microsurgically introduced into eight-cell mouse embryos, three cells to each embryo. FFs were first identified in the inner cell mass (ICM) in about one-third of embryos, whereas in three quarters of embryos FFs were located among trophoblast cells. Some elimination of FFs from trophoblast occurred later on. Eventually, in blastocysts’ outgrowths, an equally high contribution from FFs progeny (60%) was found in both ICM and trophoblast. Three days after manipulation, FFs resumed proliferation in vitro. More than three FFs were found in 46.2% of embryos on day 4. On the 7th day in vitro in 70% of embryos more than 12 FFs were found, proving at least three cell divisions. To study postimplantation development, the embryos with FFs were transferred to pseudopregnant recipients a day after manipulation. After implantation, FFs were identified by electrophoresis for isozymes of glucose phosphate isomerase (GPI). A single 11-day embryo delayed to day 8 proved chimeric by expressing both donor isozyme GPI-1B and recipient GPI-1A. Similar chimerism was found in the extraembryonic lineage of 11% of embryos by day 12. Starting from day 11 onwards, in 32% of normal embryos and in 57% of foetal membranes, hybrid GPI-1AB isozyme, as well as recipient isozyme, was present. Hybrid GPI-1AB can only be produced in hybrid cells derived by cell fusion, therefore, we suggest that during postimplantation development, FFs are rescued by fusion with recipient cells. In the mice born, hybrid isozyme was found in several tissues, including brain, lung, gut and kidney. We conclude that somatic cells (FFs) can proliferate in earlyembryonic environment until early postimplantation stages. Foetuses and the mice born are chimeras between recipient cells and hybrid cells with contributions from the donor FFs. Transdifferentiation as opposed to reprogramming by cell fusion can be considered as underlying cellular processes in these chimeras.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marino Maemura ◽  
Hiroaki Taketsuru ◽  
Yuki Nakajima ◽  
Ruiqi Shao ◽  
Ayaka Kakihara ◽  
...  

AbstractIn multicellular organisms, oocytes and sperm undergo fusion during fertilization and the resulting zygote gives rise to a new individual. The ability of zygotes to produce a fully formed individual from a single cell when placed in a supportive environment is known as totipotency. Given that totipotent cells are the source of all multicellular organisms, a better understanding of totipotency may have a wide-ranging impact on biology. The precise delineation of totipotent cells in mammals has remained elusive, however, although zygotes and single blastomeres of embryos at the two-cell stage have been thought to be the only totipotent cells in mice. We now show that a single blastomere of two- or four-cell mouse embryos can give rise to a fertile adult when placed in a uterus, even though blastomere isolation disturbs the transcriptome of derived embryos. Single blastomeres isolated from embryos at the eight-cell or morula stages and cultured in vitro manifested pronounced defects in the formation of epiblast and primitive endoderm by the inner cell mass and in the development of blastocysts, respectively. Our results thus indicate that totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage.


Development ◽  
1975 ◽  
Vol 33 (4) ◽  
pp. 979-990
Author(s):  
J. Rossant

Inner cell masses (ICMs) were dissected from 3½- and 4½-day blastocysts and cultured in contact with 2½-day morulae. Blastocysts and morulae were homozygous for different electrophoretic variants of the enzyme glucose phosphate isomerase (GPI). Aggregation of ICMs and morulae was observed, and such aggregates were able to form blastocysts in vitro and morphologically normal foetuses in utero. GPI analysis of these conceptuses revealed that most were chimaeric. However, donor ICM-type isozyme was only detected in the embryonic and extra-embryonic fractions of the chimaeras and never in the trophoblastic fraction. Thus, ICM cells appear unable to form trophoblast derivatives even when exposed to ‘outside’ conditions as experienced by developing trophoblast cells. This is evidence that ICM cells, although not overtly differentiated, are determined by 3½ days.


Development ◽  
1973 ◽  
Vol 29 (3) ◽  
pp. 601-615
Author(s):  
M. H. L. Snow

Mouse embryos were grown in vitro from the 2-cell stage to blastocysts in the presence of [3H]thymidine. Methyl-T-thymidine and thymidine-6-T(n) were used and both forms found to be lethal at concentrations above 0·1 μCi/ml. Both forms of [3H]Tdr at concentrations between 0·01 and 0·1 μCi/ml caused a highly significant (P < 0·001) reduction in blastocyst cell number. The reduction in cell number, which was positively correlated with specific activity and tritium concentration, was associated with cell damage typical of radiation damage caused by tritium disintegration. Thymidine-6-T(n) also significantly reduced the number of 2-cell embryos forming blastocysts whereas methyl-T-Tdr did not. This difference in effect is assumed to be caused by contamination of one form of [3H]Tdr with a by-product of the tritiation process. A study of the cleavage stages showed that almost all the reduction in cell numbers could be accounted for by selective cell death occurring at the 16-cell stage. Cells which survive that stage cleave at a normal rate. The cells that are most susceptible to [3H]Tdr damage were found to normally contribute to the inner cell mass. The [3H]Tdr-resistant cells form the trophoblast. It is possible to grow blastocysts in [3H]Tdr such that they contain no inner cell mass but are composed entirely of trophoblast. Comparatively short (12 h) incubation with [3H]Tdr at any stage prior to the 16-cell stage will cause this damage. Possible reasons for this differential effect are discussed, and also compared with damage caused by X-irradiation.


1995 ◽  
Vol 29 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Th. Rülicke ◽  
P. Autenried

Approximately 18% of cryopreserved 2-cell mouse embryos of 26 different batches showed various degrees of morphological damage after the freeze-thaw process. Normal and damaged morphology were assessed by light microscopy and the ability of an embryo to develop in vitro to a blastocyst, or to develop to term, after transfer to foster mothers. Using vital stains such as Fluorescein-diacetate (FDA) and 4',6-Diamidino-2-Phenylindole (DAPI) it was found that in approximately 82% of the cases, both of the 2 blastomeres of the cryopreserved embryos survived the freeze-thaw process; in 10% only one cell survived the process; and in 8% none survived. Normally, only intact 2-cell embryos are considered for transfer. Here it was shown that over 60% of the partially damaged embryos developed in vitro to the blastocyst stage and, of those, 26% developed to term after transfer to suitable foster mothers. Although the inner cell mass (ICM) appeared to remain smaller during culture after the transfer of partially damaged 2-cell stage embryos, no difference during gestation period was found compared with intact embryos.


Development ◽  
1982 ◽  
Vol 67 (1) ◽  
pp. 51-58
Author(s):  
L. Izquierdo ◽  
M. I. Becker

Two-cell mouse embryos were cultured in vitro for different periods in a medium in which NaCl was partially replaced by LiCl at concentrations ranging from 1 to 30 mm. The relative cell number diminished according to increasing LiCl concentrations but the onset of blastulation was not affected, thus resulting in blastulae with fewer cells than normal and with a reduced or absent inner cell mass. Results are discussed in terms of the possible mechanisms involved and are related with the vegetalization induced by Li+ on early embryos of echinoderms and amphibia.


2004 ◽  
Vol 24 (15) ◽  
pp. 6710-6718 ◽  
Author(s):  
Mirei Murakami ◽  
Tomoko Ichisaka ◽  
Mitsuyo Maeda ◽  
Noriko Oshiro ◽  
Kenta Hara ◽  
...  

ABSTRACT TOR is a serine-threonine kinase that was originally identified as a target of rapamycin in Saccharomyces cerevisiae and then found to be highly conserved among eukaryotes. In Drosophila melanogaster, inactivation of TOR or its substrate, S6 kinase, results in reduced cell size and embryonic lethality, indicating a critical role for the TOR pathway in cell growth control. However, the in vivo functions of mammalian TOR (mTOR) remain unclear. In this study, we disrupted the kinase domain of mouse mTOR by homologous recombination. While heterozygous mutant mice were normal and fertile, homozygous mutant embryos died shortly after implantation due to impaired cell proliferation in both embryonic and extraembryonic compartments. Homozygous blastocysts looked normal, but their inner cell mass and trophoblast failed to proliferate in vitro. Deletion of the C-terminal six amino acids of mTOR, which are essential for kinase activity, resulted in reduced cell size and proliferation arrest in embryonic stem cells. These data show that mTOR controls both cell size and proliferation in early mouse embryos and embryonic stem cells.


2015 ◽  
Vol 27 (1) ◽  
pp. 160
Author(s):  
A. C. Taskin ◽  
A. Kocabay ◽  
M. Yucel

Leptin is a hormone-like protein of 167 amino acids. As an adipocyte-related hormone it has an important role in weight regulation and physical fitness but also has effects on reproductive and other physiological mechanisms. The aim of the present study was to investigate the effects of different concentrations of leptin added to the culture media, the quality, in vitro development rate, and in vivo rate of mouse embryos. Superovulated CB6F1 (C57BL/6XBalb/c) hybrid female mice (5–6 weeks of age) were killed ~18 to 20 h after hCG administration. Single-cell embryos were flushed from the oviducts of the dead mice with human tubal fluid medium supplemented with HEPES and 3 mg mL–1 of BSA. They were cultured in Quinn's cleavage medium supplemented with 4 mg mL–1 of BSA in 5% CO2, 37°C until reaching 2-cell stage. The 2-cell embryos were randomly divided into 4 groups and cultured in Quinn's blastocyst medium supplemented with 4 mg mL–1 BSA + 0, 10, 50, and 100 ng mL–1 leptin (L0, L10, L50, and L100) in 5% CO2, 37°C until the blastocyst stage. Some of the developing blastocysts were used for differential staining for the inner cell mass and trophectoderm (TE) cells [Mallol et al. 2013 Syst. Biol. Reprod. Med. 59,117–122]. Some of them were transferred into pseudopregnant females (CD1) on the 2.5 to 3.5th days and kept until the 13.5th day of pregnancy for the in vivo development rate. The results were evaluated using one-way ANOVA with Bonferroni post-hoc test in SPSS 22.0. The P-values <0.05 were considered statistically significant. Each experiment was repeated at least 4 times. The blastocyst development rates of L0, L10, L50, and L100 were 92.57% (162/175), 97.16% (205/211), 97.80% (178/182), and 97.85% (182/186), respectively. The in vitro development rates were significantly higher in the L10, L50, and L100 compared with L0 (P < 0.05). The inner cell mass cells of L0, L10, L50, and L100 were 13.17, 14, 16, and 15.43. There was no significant difference between the groups in terms of inner cell mass cells (P > 0.05). The TE cells of L0, L10, L50, and L100 were 47, 56.4, 53.7, and 58.57, respectively. The TE numbers were significantly increased in the presence of L10 and L100 compared with L0 (P < 0.05). The in vivo development rates of L0, L10, L50, and L100 were 13.51% (5/37), 48.72% (19/39), 15.38% (6/39), and 41.03% (16/39), respectively. The in vivo development rates of L10 and L100 were significantly higher than for L0 and L50 (P < 0.05). The resorption rates of L0, L10, L50, and L100 were 10.8% (4/37), 30.8% (12/39), 12.8% (5/39), and 20.5% (8/39), respectively. There was no significant difference between the groups in terms of the resorption rates (P > 0.05). This study found that L10, L50, and L100 were supporting the development of the embryos in the in vitro culture. The L10, L50, and L100 significantly increased the total cell numbers. The L10 and L100 were particularly effective on the number of the TE cells. In conclusion, 10 and 100 ng mL–1 leptin have a positive effect on the in vitro, quality and in vivo development of the mouse embryo. Therefore, leptin seems to play an important role on the embryo development and in vivo development. Research supported by TUBITAK-113O223.


Author(s):  
Manuel Belli ◽  
Paolo Rinaudo ◽  
Maria Grazia Palmerini ◽  
Elena Ruggeri ◽  
Sevastiani Antonouli ◽  
...  

Assisted Reproductive Technologies routinely utilize different culture media and oxygen (O2) concentrations to culture human embryos. Overall, embryos cultured under physiological O2 tension (5%) have improved development compared to embryos cultured under atmospheric O2 conditions (20%). The mechanisms responsible for this remain unclear. This study aimed to evaluate the effect of physiologic (5%) or atmospheric O2 (20%) tension on the microscopic ultrastructure of pre-implantation mouse embryos using Transmission Electron Microscopy (TEM). Embryos flushed out of the uterus after natural mating were used as the control. For use as the control, 2-cells, 4-cells, morulae, and blastocysts were flushed out of the uterus after natural fertilization. In vitro fertilization (IVF) was performed using potassium simplex optimized medium (KSOM) under different O2 tensions (5% and 20%) until the blastocyst stage. After collection, embryos were subjected to the standard preparative for light microscopy (LM) and TEM. We found that culture in vitro under 5% and 20% O2 results in an increase of vacuolated shaped mitochondria, cytoplasmic vacuolization and presence of multi-vesicular bodies at every embryonic stage. In addition, blastocysts generated by IVF under 5% and 20% O2 showed a lower content of heterochromatin, an interruption of the trophectodermal and inner cell mass cell membranes, an increased density of residual bodies, and high levels of glycogen granules in the cytoplasm. In conclusion, this study suggests that in vitro culture, particularly under atmospheric O2 tension, causes stage-specific changes in preimplantation embryo ultrastructure. In addition, atmospheric (20%) O2 is associated with increased alterations in embryonic ultrastructure; these changes may explain the reduced embryonic development of embryos cultured with 20% O2.


2012 ◽  
Vol 19 (3) ◽  
pp. 243-252 ◽  
Author(s):  
G. Giritharan ◽  
L. Delle Piane ◽  
A. Donjacour ◽  
F. J. Esteban ◽  
J. A. Horcajadas ◽  
...  

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