The behaviour in vitro of epidermal cells from normal and pupoid foetus mutant mouse embryos

1985 ◽  
Vol 79 (1) ◽  
pp. 305-315
Author(s):  
S. Anderson ◽  
D.A. Ede
Keyword(s):  
Mutant Mouse ◽  
Cell Mass ◽  
Time Lapse ◽  
Epidermal Cells ◽  
Mouse Embryos ◽  
Sensory Nerves ◽  
Recessive Lethal Mutation ◽  
Mutant Mouse Embryos ◽  
Peripheral Sensory

Pupoid foetus (pf/pf) is a recessive lethal mutation of the mouse causing epidermal hypertrophy and disorganization of peripheral sensory nerves and mesoderm. The comparative behaviour of epidermal cells from normal and pupoid foetus mutant mouse embryos was studied in vitro. Epidermal explants from the snout region of 12.5- to 13-day embryos were grown in culture for periods of up to 2 weeks. Cultures from both phenotypes were filmed using time-lapse cinemicrography for up to 3 days following explantation. Paths of individual cells were traced as they migrated from the explant, and their rate of locomotion and directional persistence were calculated. Differences in these parameters between the two phenotypes were tested statistically. The overall morphology of the cultures, and the tendency of the cells to detach from the periphery of the cell mass were also compared. The results show that, between 25 and 60 h after explantation, epidermal cells from pupoid foetus embryos move consistently more slowly than normal cells, and follow a more erratic path. This situation is reversed, however, between 16 and 25 h. This suggests that the pf mutation causes an alteration in epidermal cells that affects their locomotion, and which is maintained for a minimum of 3 days in the absence of other influencing factors.

scholarly journals Totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marino Maemura ◽  
Hiroaki Taketsuru ◽  
Yuki Nakajima ◽  
Ruiqi Shao ◽  
Ayaka Kakihara ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Mouse Embryos ◽  
Primitive Endoderm ◽  
Cell Stage ◽  
Supportive Environment ◽  
Mouse Zygotes ◽  
Single Blastomeres ◽  
Multicellular Organisms

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.

scholarly journals Morphology, topology and dimensions of the heart and arteries of genetically normal and mutant mouse embryos at stages S21-S23

2017 ◽  
Vol 231 (4) ◽  
pp. 600-614 ◽  
Author(s):  
Stefan H. Geyer ◽  
Lukas F. Reissig ◽  
Markus Hüsemann ◽  
Cordula Höfle ◽  
Robert Wilson ◽  
...  
Keyword(s):  
Mutant Mouse ◽  
Mouse Embryos ◽  
Mutant Mouse Embryos

Abnormal development of pre-implantation mouse embryos grown in vitro with [3H]thymidine

Development ◽  
1973 ◽  
Vol 29 (3) ◽  
pp. 601-615
Author(s):  
M. H. L. Snow
Keyword(s):  
Specific Activity ◽  
Inner Cell Mass ◽  
Cell Damage ◽  
Cell Mass ◽  
Cell Number ◽  
Mouse Embryos ◽  
Abnormal Development ◽  
Tritium Concentration ◽  
Cell Stage

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.

6 ANEUPLOIDY TOLERANCE IN RHESUS MACAQUE PRE-IMPLANTATION EMBRYOS VIA MICRONUCLEI FORMATION, CELLULAR FRAGMENTATION, AND BLASTOMERE EXCLUSION

2017 ◽  
Vol 29 (1) ◽  
pp. 110 ◽  
Author(s):  
B. L. Daughtry ◽  
J. L. Rosenkrantz ◽  
N. Lazar ◽  
N. Redmayne ◽  
K. A. Nevonen ◽  
...  
Keyword(s):  
Rhesus Macaque ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Time Lapse ◽  
Confocal Imaging ◽  
Chromosomal Mosaicism ◽  
Human Embryos ◽  
Cleavage Stage ◽  
Chromosomal Breakage

A primary contributor to in vitro fertilization (IVF) failure is the presence of unbalanced chromosomes in pre-implantation embryos. Previous array-based and next-generation sequencing (NGS) studies determined that ~50 to 80% of human embryos are aneuploid at the cleavage stage. During early mitotic divisions, many human embryos also sequester mis-segregated chromosomes into micronuclei and concurrently undergo cellular fragmentation. We hypothesised that cellular fragmentation represents a response to mis-segregated chromosomes that are encapsulated into micronuclei. Here, we utilised the rhesus macaque pre-implantation embryo as a model to study human embryonic aneuploidy using a combination of EevaTM time-lapse imaging for evaluating cell divisions, single-cell/-fragment DNA-Sequencing (DNA-Seq), and confocal microscopy of nuclear structures. Results from our time-lapse image analysis demonstrated that there are considerable differences in the timing of the first and third mitotic divisions between rhesus blastocysts and those that arrested before this stage in development (P < 0.01; ANOVA). By examining the chromosome content of each blastomere from cleavage stage embryos via DNA-Seq, we determined that rhesus embryos have an aneuploidy frequency up to ~62% (N = 26) with several embryos exhibiting chromosomal mosaicism between blastomeres (N = 6). Certain blastomeres also exhibited reciprocal whole chromosomal gains or losses, indicating that these embryos had undergone mitotic non-disjunction early in development. In addition, findings of reciprocal sub-chromosomal deletions/duplications among blastomeres suggest that chromosomal breakage had occurred in some embryos as well. Embryo immunostaining for the nuclear envelope protein, LAMIN-B1, demonstrated that fragmented cleavage-stage rhesus embryos often contain micronuclei and that cellular fragments can enclose DNA. Our DNA-Seq analysis confirmed that cellular fragments might encapsulate whole and/or partial chromosomes lost from blastomeres. When embryos were immunostained with gamma-H2AX, a marker of chromatin fragility, we observed distinct foci solely in micronuclei and DNA-containing cellular fragments. This suggests that micronuclei may be ejected from blastomeres through the process of cellular fragmentation and, once sequestered, these mis-segregated chromosomes become highly unstable and undergo DNA degradation. Finally, we also observed that ~10% of embryos prevented cellular fragments or large blastomeres from incorporating into the inner cell mass or trophectoderm at the blastocyst stage (n = 5). Upon confocal imaging, multiple nuclei and intense gamma-H2AX foci were found in a large unincorporated blastomere in one of the blastocysts. Altogether, our findings demonstrate that the rhesus embryo responds to segregation errors by eliminating chromosome-containing micronuclei via cellular fragmentation and/or selecting against aneuploid blastomeres that fail to divide during pre-implantation development with significant implications for human IVF.

Potential of two-cell mouse embryos to develop to term despite partial damage after cryopreservation

1995 ◽  
Vol 29 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Th. Rülicke ◽  
P. Autenried
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Mouse Embryos ◽  
Cell Stage ◽  
Freeze Thaw ◽  
Foster Mothers ◽  
Vital Stains ◽  
Partial Damage

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.

scholarly journals Anterior neural plate regionalization in cripto null mutant mouse embryos in the absence of node and primitive streak

2003 ◽  
Vol 264 (2) ◽  
pp. 537-549 ◽  
Author(s):  
Giovanna L Liguori ◽  
Diego Echevarría ◽  
Raffaele Improta ◽  
Massimo Signore ◽  
Eileen Adamson ◽  
...  
Keyword(s):  
Mutant Mouse ◽  
Primitive Streak ◽  
Neural Plate ◽  
Mouse Embryos ◽  
Null Mutant ◽  
Mutant Mouse Embryos ◽  
Anterior Neural Plate ◽  
Null Mutant Mouse
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