Postimplantation development of tetraploid mouse embryos produced by electrofusion

Development ◽  
1990 ◽  
Vol 110 (4) ◽  
pp. 1121-1132
Author(s):  
M.H. Kaufman ◽  
S. Webb

Despite the fact that a variety of experimental techniques have been devised over the years to induce tetraploid mammalian embryonic development, success rates to date have been limited. Apart from the early study by Snow, who obtained development to term of a limited number of cytochalasin B-induced tetraploid mouse embryos, no other researchers have achieved development of tetraploid embryos beyond the early postimplantation period. We now report advanced postimplantation development of tetraploid mouse embryos following electrofusion of blastomeres at the 2-cell stage, and subsequent transfer of these 1-cell ‘fused’ embryos to appropriate recipients. Cytogenetic analysis of the extraembryonic membranes of all of the postimplantation embryos encountered in the present study has provided an unequivocal means of confirming their tetraploid chromosome constitution. A preliminary morphological and histological analysis of the tetraploid embryos obtained by this technique has revealed that characteristic craniofacial abnormalities particularly involving the forebrain and eyes were consistently observed, and these features were often associated with abnormalities of the vertebral axis and heart. The most advanced viable embryo in this series was recovered on the 15th day of gestation, and its morphological features suggest that it was developmentally equivalent to a normal embryo of about 13.5-14 days p.c.

Development ◽  
1987 ◽  
Vol 99 (3) ◽  
pp. 411-416
Author(s):  
J.R. Mann ◽  
R.H. Lovell-Badge

Diploid gynogenetic embryos, which have two sets of maternal and no paternal chromosomes, die at or soon after implantation. Since normal female embryos preferentially inactivate the paternally derived X chromosome in certain extraembryonic membranes, the inviability of diploid gynogenetic embryos might be due to difficulties in achieving an equivalent inactivation of one of their two maternally derived X chromosomes. In order to investigate this possibility, we constructed XO gynogenetic embryos by nuclear transplantation at the 1-cell stage. These XO gynogenones showed the same mortality around the time of implantation as did their XX gynogenetic counterparts. This shows that the lack of a paternally derived autosome set is sufficient to cause gynogenetic inviability at this stage. Autosomal imprinting and its possible relation to X-chromosome imprinting is discussed.


1975 ◽  
Vol 45 (2) ◽  
pp. 372-377 ◽  
Author(s):  
Margaret M. Perry ◽  
M.H.L. Snow

1992 ◽  
Vol 60 (3) ◽  
pp. 185-194 ◽  
Author(s):  
Roberta M. James ◽  
Matthew H. Kaufman ◽  
Sheila Webb ◽  
John D. West

SummarySome previous attempts to produce tetraploids experimentally have resulted in a proportion of treated embryos becoming 2n/4n mosaics at a frequency which may be as high as 20%, when using cytochalasin B as a fusigenic stimulus and cytogenetic techniques to identify putative tetraploid embryos. To investigate the possible occurrence of 4n/2n mosaicism, tetraploid embryos were produced by electrofusion, a process which allows adjacent blastomeres at the 2-cell stage to fuse following exposure to electric field pulses. Embryos used for electrofusion were hemizygous for a transgene consisting of approximately 1000 copies of the mouse β-globin gene. After in situ hybridization, one hybridization signal is expected per diploid genome. Tetraploid cells in 7·5-, 8·5-, 9·5- and 10·5-day-old conceptuses were distinguished from diploid cells by performing in situ hybridization on histological sections. The frequency of nuclei with two hybridization signals in the ‘hemizygous’ tetraploid embryos was compared to diploid embryos which were either hemizygous or homozygous for the β-globin transgene. Comparison of the frequency of nuclei with two hybridization signals between tissues of ‘hemizygous’ tetraploid conceptuses and homozygous diploid conceptuses showed no significant difference, which implies that the tissues in the tetraploid conceptuses were uniformly tetraploid. No evidence was found to suggest that electrofusion results in 2n/4n mosaicism.


Author(s):  
D. G. Chase ◽  
W. Winters ◽  
L. Piko

Although the outlines of human adenovirus entry and uncoating in HeLa cells has been clarified in recent electron microscope studies, several details remain unclear or controversial. Furthermore, morphological features of early interactions of human adenovirus with non-permissive mouse cells have not been extensively documented. In the course of studies on the effects of human adenoviruses type 5 (AD-5) and type 12 on cultured preimplantation mouse embryos we have examined virus attachment, entry and uncoating. Here we present the ultrastructural findings for AD-5.AD-5 was grown in HeLa cells and purified by successive velocity gradient and equilibrium density gradient centrifugations in CsCl. After dialysis against PBS, virus was sedimented and resuspended in embryo culture medium. Embryos were placed in culture at the 2-cell stage in Brinster's medium.


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.


2021 ◽  
Vol 22 (1) ◽  
pp. 460
Author(s):  
Huan Ou-Yang ◽  
Shinn-Chih Wu ◽  
Li-Ying Sung ◽  
Shiao-Hsuan Yang ◽  
Shang-Hsun Yang ◽  
...  

The maternal-to-zygotic transition (MZT), which controls maternal signaling to synthesize zygotic gene products, promotes the preimplantation development of mouse zygotes to the two-cell stage. Our previous study reported that mouse granzyme g (Gzmg), a serine-type protease, is required for the MZT. In this study, we further identified the maternal factors that regulate the Gzmg promoter activity in the zygote to the two-cell stage of mouse embryos. A full-length Gzmg promoter from mouse genomic DNA, FL-pGzmg (−1696~+28 nt), was cloned, and four deletion constructs of this Gzmg promoter, Δ1-pGzmg (−1369~+28 nt), Δ2-pGzmg (−939~+28 nt), Δ3-pGzmg (−711~+28 nt) and Δ4-pGzmg (−417~+28 nt), were subsequently generated. Different-sized Gzmg promoters were used to perform promoter assays of mouse zygotes and two-cell stage embryos. The results showed that Δ4-pGzmg promoted the highest expression level of the enhanced green fluorescent protein (EGFP) reporter in the zygotes and two-cell embryos. The data suggested that time-specific transcription factors upregulated Gzmg by binding cis-elements in the −417~+28-nt Gzmg promoter region. According to the results of the promoter assay, the transcription factor binding sites were predicted and analyzed with the JASPAR database, and two transcription factors, signal transducer and activator of transcription 3 (STAT3) and GA-binding protein alpha (GABPα), were identified. Furthermore, STAT3 and GABPα are expressed and located in zygote pronuclei and two-cell nuclei were confirmed by immunofluorescence staining; however, only STAT3 was recruited to the mouse zygote pronuclei and two-cell nuclei injected with the Δ4-pGzmg reporter construct. These data indicated that STAT3 is a maternal transcription factor and may upregulate Gzmg to promote the MZT. Furthermore, treatment with a STAT3 inhibitor, S3I-201, caused mouse embryonic arrest at the zygote and two-cell stages. These results suggest that STAT3, a maternal protein, is a critical transcription factor and regulates Gzmg transcription activity in preimplantation mouse embryos. It plays an important role in the maternal-to-zygotic transition during early embryonic development.


1992 ◽  
Vol 37 (1) ◽  
pp. 246
Author(s):  
L.Y. Li ◽  
R.S. Denniston ◽  
W. hansel ◽  
R.A. Godke

2007 ◽  
Vol 1 (5) ◽  
pp. 399-403
Author(s):  
D. V. Goldshtein ◽  
V. N. Pogorelova ◽  
A. G. Pogorelov
Keyword(s):  

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 343-354
Author(s):  
J. R. Whittaker

This research shows that myoplasmic crescent material of the ascidian egg has both functional autonomy and functional specificity in establishing the differentiation pathway of muscle lineage cells. The cytoplasmic segregation pattern in eggs of Styela plicata was altered by compression of the embryos during third cleavage. This caused a meridional division instead of the normal equatorial third cleavage; first and second cleavages are meridional. Since eggs of S. plicata have a pronounced yellow myoplasmic crescent, one observes directly that third cleavage under compression resulted in a flat 8-cell stage with four cells containing yellow myoplasm instead of the two myoplasm-containing cells that would be formed by normal equatorial division at third cleavage. If such altered 8-cell-stage embryos were released from compression and kept from undergoing further divisions by continuous treatment with cytochalasin B, some embryos eventually developed histospecific acetylcholinesterase in three and four cells instead of in just the two muscle lineage cells found in cleavage-arrested normal 8-cell stages. The wider myoplasmic distribution effected by altering the division plane at third cleavage apparently caused a change in developmental fate of the extra cells receiving myoplasm. This meridional third cleavage also resulted in a changed nuclear lineage pattern. Two nuclei that would ordinarily be in ectodermal lineage cells after third cleavage were now associated with yellow myoplasm. Acetylcholinesterase development in these cells demonstrates that nuclear lineages are not responsible for muscle acetylcholinesterase development in the ascidian embryo.


Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 37-51
Author(s):  
S. J. Kelly ◽  
J. G. Mulnard ◽  
C. F. Graham

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.


Sign in / Sign up

Export Citation Format

Share Document