Correlative scanning electron, transmission electron, and light microscopic studies of the in vitro development of mouse embryos on a plastic substrate at the implantation stage

Development ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 23-39
Author(s):  
Matthew A. Gonda ◽  
Yu-Chih Hsu

Correlative scanning electron, transmission electron, and light microscopy were utilized to study the morphogenic events occurring during mouse blastocyst outgrowth and earlyegg- cylinder development in vitro. After hatching and attachment of blastocysts on theplastic surface, the blastocoelic cavity collapses as the mural trophoblasts spread and migrate outward. The inner cell mass is covered with a differentiated endoderm on the blastocoelic cavity side and by the polar trophoblasts on the medium sideat this stage. As the endodermcovered inner cell mass proliferates, being physically restricted from further downward expansion by the plastic coverslip and by lack of space in the collapsed blastocoelic cavity, it migrates upward and protrudes into the culture medium in a breakbetween the polar and mural trophoblast cells. Polar trophoblast cellsapposed to the base of the egg cylinder continue to proliferate forming the ectoplacental cone. Thus, the early egg cylinder lacking a trophoblast barrier begins inverting its growth pattern from towards the culture dish surface to a more upright position. Egg-cylinder development in vitro from the inner cell mass and polar trophoblast cells closely paralleled in vivo. The functional nature of variousembryonic cell types observed in these embryos was revealed by scanning electron microscopy. These studies as well as those of Wiley and Pedersen (1977) suggest that blastocysts can serve as a source of in vitro developing early mouse egg cylinders that appear to resemble their in vivo counterparts and can be used in experimental studies of mouse embryogenesis.

1995 ◽  
Vol 43 (1) ◽  
pp. 304 ◽  
Author(s):  
D. Rath ◽  
H. Niemann ◽  
T. Tao ◽  
M. Boerjan

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.


2009 ◽  
Vol 21 (1) ◽  
pp. 235 ◽  
Author(s):  
M. D. Goissis ◽  
F. R. O. de Barros ◽  
M. G. Marques ◽  
C. M. Mendes ◽  
M. P. Milazzotto ◽  
...  

Establishment of embryonic stem cell (ESC) culture in pigs has not been achieved. Verification of pluripotency markers is necessary for validation of a pluripotent cell line. Not all markers observed in ESC from other species are characterized in swine embryos. The objective of this study was to characterize CD9 and α6-integrin expression in porcine blastocysts and to derive porcine ESC using Matrigel. In vitro or in vivo porcine blastocysts were submitted to total RNA extraction for RT-PCR, fixation for immunocytochemistry or immunosurgery for culture of inner cell mass. Expression of Oct-4, CD9, and α6-integrin was detected by PCR. CD9 and α6-integrin PCR products had their nucleotide sequence assessed and compared with public nucleotide database. CD9 product was identical to CD9 porcine sequences and α6-integrin product was similar to human and equine α6-integrin. Immunocytochemistry revealed Oct-4 expression in cytoplasm of the inner cell mass (ICM) and trophoblast cells. CD9 and α6-integrin were observed preferentially on trophoblast cells. No ESC colonies were obtained using co-culture on mouse embryonic fibroblasts (MEF) or on Matrigel. This study describes for the first time expression of CD9 and α6-integrin in porcine blastocysts. Financial support: Fapesp 05/57314-0.


Development ◽  
1975 ◽  
Vol 33 (1) ◽  
pp. 177-185
Author(s):  
J. D. Ansell ◽  
M. H. L. Snow

When intact mouse blastocysts are cultured in vitro in medium supplemented with foetal calf serum, trophoblast cells proliferate and undergo giant cell transformation such as occurs in vivo. If the amount of inner cell mass in the blastocyst is decreased by culture with [3H]-thymidine then giant cell transformation occurs normally but proliferation is reduced. In the absence of inner cell mass no proliferation occurs, and giant cell transformation is more rapid than in undamaged blastocysts.


Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 793-803 ◽  
Author(s):  
V.E. Papaioannou ◽  
K.M. Ebert

Total cell number as well as differential cell numbers representing the inner cell mass (ICM) and trophectoderm were determined by a differential staining technique for preimplantation pig embryos recovered between 5 and 8 days after the onset of oestrus. Total cell number increased rapidly over this time span and significant effects were found between embryos of the same chronological age from different females. Inner cells could be detected in some but not all embryos of 12–16 cells. The proportion of inner cells was low in morulae but increased during differentiation of ICM and trophectoderm in early blastocysts. The proportion of ICM cells then decreased as blastocysts expanded and hatched. Some embryos were cultured in vitro and others were transferred to the oviducts of immature mice as a surrogate in vivo environment and assessed for morphology and cell number after several days. Although total cell number did not reach in vivo levels, morphological development and cell number increase was sustained better in the immature mice than in vitro. The proportion of ICM cells in blastocysts formed in vitro was in the normal range.


Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 405-418
Author(s):  
E. B. Ilgren

The growth of mouse trophectoderm depends upon the presence of the inner cell mass. Whether this applies to other species of mammals is not known. To investigate this problem, the guinea pig was selected for two reasons. Firstly, the growth of guinea-pig trophoblast resembles that of man. Secondly, earlier studies suggest that the proliferation of guinea-pig trophectoderm may not be under ICM control. Therefore, in the present study, the guinea-pig blastocyst was cut microsurgically to yield two tissue fragments. These contained roughly equal numbers of trophectodermal cells, one fragment being composed only of trophectoderm and the other containing ICM tissue as well. Subsequently, the growth of these mural and polar fragments was followed in vitro since numerous technical difficulties make an in vivo analysis of this problem impracticable. In a manner similar to the mouse, the isolated mural trophectoderm of the guinea pig stopped dividing and became giant. In contrast, guinea-pig polar fragments formed egg-cylinder-like structures. The latter contained regions structurally similar to two presumptive polar trophectodermal derivatives namely the ectoplacental and extraembryonic ectodermal tissues. These findings suggest that guinea-pig trophectodermal growth may occur in a manner similar to the mouse and thus be under ICM control.


Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 597-604 ◽  
Author(s):  
K. Hardy ◽  
A.H. Handyside ◽  
R.M. Winston

The development of 181 surplus human embryos, including both normally and abnormally fertilized, was observed from day 2 to day 5, 6 or 7 in vitro. 63/149 (42%) normally fertilized embryos reached the blastocyst stage on day 5 or 6. Total, trophectoderm (TE) and inner cell mass (ICM) cell numbers were analyzed by differential labelling of the nuclei with polynucleotide-specific fluorochromes. The TE nuclei were labelled with one fluorochrome during immunosurgical lysis, before fixing the embryo and labelling both sets of nuclei with a second fluorochrome (Handyside and Hunter, 1984, 1986). Newly expanded normally fertilized blastocysts on day 5 had a total of 58.3 +/− 8.1 cells, which increased to 84.4 +/− 5.7 and 125.5 +/− 19 on days 6 and 7, respectively. The numbers of TE cells were similar on days 5 and 6 (37.9 +/− 6.0 and 40.3 +/− 5.0, respectively) and then doubled on day 7 (80.6 +/− 15.2). In contrast, ICM cell numbers doubled between days 5 and 6 (20.4 +/− 4.0 and 41.9 +/− 5.0, respectively) and remained virtually unchanged on day 7 (45.6 +/− 10.2). There was widespread cell death in both the TE and ICM as evidenced by fragmenting nuclei, which increased substantially by day 7. These results are compared with the numbers of cells in morphologically abnormal blastocysts and blastocysts derived from abnormally fertilized embryos. The nuclei of arrested embryos were also examined. The number of TE and ICM cells allocated in normally fertilized blastocysts appears to be similar to the numbers allocated in the mouse. Unlike the mouse, however, the proportion of ICM cells remains higher, despite cell death in both lineages.


Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1333-1339 ◽  
Author(s):  
P. Bhatnagar ◽  
V.E. Papaioannou ◽  
J.D. Biggers

The effects of macrophage colony stimulating factor on the development of the zygote to the blastocyst stage of an outbred strain of mouse have been studied in KSOM, an improved medium that supports a high rate of in vitro development. Macrophage colony stimulating factor accelerates the formation of the blastocyst cavity by day 4 (96 hours post-hCG). It also increases overall embryonic cell number through a differential increase in the number of trophoblast cells, with no significant effect on the number of inner cell mass cells. By day 5 of culture (120 hours post-hCG), colony stimulating factor-treated embryos have about 20 more trophoblast cells than control embryos, an increase of about 30 percent of the total number of cells in a control blastocyst. The maximum response of embryos was obtained at a concentration around 540 U ml-1 colony stimulating factor (identical to 918 Stanley units ml-1), and the cytokine can produce the same effects even if it is present in the medium for only part of the culture period. This in vitro stimulation of preimplantation development with macrophage colony stimulating factor is compatible with continued normal fetal development in vivo.


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.


2010 ◽  
Vol 88 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Guoliang Meng ◽  
Shiying Liu ◽  
Xiangyun Li ◽  
Roman Krawetz ◽  
Derrick E. Rancourt

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the blastocyst. Because of their ability to differentiate into a variety of cell types, human embryonic stem cells (hESCs) provide an unlimited source of cells for clinical medicine and have begun to be used in clinical trials. Presently, although several hundred hESC lines are available in the word, only few have been widely used in basic and applied research. More and more hESC lines with differing genetic backgrounds are required for establishing a bank of hESCs. Here, we report the first Canadian hESC lines to be generated from cryopreserved embryos and we discuss how we navigated through the Canadian regulatory process. The cryopreserved human zygotes used in this study were cultured to the blastocyst stage, and used to isolate ICM via microsurgery. Unlike previous microsurgery methods, which use specialized glass or steel needles, our method conveniently uses syringe needles for the isolation of ICM and subsequent hESC lines. ICM were cultured on MEF feeders in medium containing FBS or serum replacer (SR). Resulting outgrowths were isolated, cut into several cell clumps, and transferred onto fresh feeders. After more than 30 passages, the two hESC lines established using this method exhibited normal morphology, karyotype, and growth rate. Moreover, they stained positively for a variety of pluripotency markers and could be differentiated both in vitro and in vivo. Both cell lines could be maintained under a variety of culture conditions, including xeno-free conditions we have previously described. We suggest that this microsurgical approach may be conducive to deriving xeno-free hESC lines when outgrown on xeno-free human foreskin fibroblast feeders.


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