Complete preimplantation development in culture of parthenogenetic mouse embryos

Development ◽  
1976 ◽  
Vol 35 (1) ◽  
pp. 179-190
Author(s):  
Matthew H. Kaufman ◽  
Leo Sachs

The present experiments were undertaken to determine whether, in parthenogenesis, heterozygous embryos develop better than homozygous embryos. Such experiments may provide an approach to elucidating whether fertilized embryos develop better than parthenogenetic ones because of heterozygosity, or if the sperm provides another contribution necessary for complete embryonic development. The parthenogenetic embryos studied included uniform haploids after extrusion of the second polar body, mosaic haploids in which each blastomere contained a genetically different haploid nucleus, and heterozygous diploid mouse embryos. Eggs were activated and cultured in a chemically denned medium. About three times as many mosaic haploid or heterozygous diploid eggs developed beyond the 4-cell stage after 98–100 h and to the blastocyst stage after 120 h in culture, than uniform haploid eggs. This indicates that the development of parthenogenetic embryos is probably under genetic control and that there was a better development of the heterozygous embryos. Mosaic haploid embryos showed the same high frequency of development as heterozygous diploids. The results therefore indicate that heterozygosity provided a developmental advantage even when distributed between two genetically different clones of cells in the same embryo.

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 645-655
Author(s):  
Matthew H. Kaufman ◽  
Leo Sachs

The early development of parthenogenetically activated oocytes has been studied in C57BL × CBA-T6T6 (F1T6) translocation heterozygote mice and C57BL × CBA-LAC (F1LAC) mice. All F1T6 oocytes had either a quadrivalent or a univalent-trivalent configuration at meiosis I; no such chromosome configurations were observed in the F1LAC oocytes. At ovulation 36·5 % of the F1T6 oocytes had 19 or 21 chromosomes, whereas 97 % of the F1LAC had the normal haploid chromosome number of 20. After parthenogenetic activation, chromosome counts at metaphase of the first cleavage mitosis were made of the eggs with a single pronucleus following extrusion of the second polar body. These activated eggs had similar frequencies of 19, 20 and 21 chromosomes as had the oocytes at ovulation. The activated 1-cell eggs were transferred to the oviducts of pseudopregnant recipients and the embryos recovered 3 days later. At this stage of development, most of the F1T6 embryos with 19 chromosomes were no longer found, but the frequency of 21-chromosome embryos was similar to the frequency of 21-chromosome oocytes and activated eggs. There was a similar mean number of cells in the embryos with 20 and 21 chromosomes. The results indicate that nearly all the embryos with 19 chromosomes failed to develop, probably beyond the 2-cell stage, whereas oocytes with 21 chromosomes had a similar development to oocytes with 20 chromosomes up to the morula stage.


2018 ◽  
Vol 14 (4) ◽  
pp. 512-514
Author(s):  
Nor Shahida Abdul Rahman ◽  
Mimi Sophia Sarbandi ◽  
Wan Hafizah Wan Jusof ◽  
Zolkapli Eshak ◽  
Salina Othman ◽  
...  

The timing of the first zygotic cleavage is an accurate predictor of embryo quality. Embryos that cleaved early have higher developmental viability compared to their late counterparts. During embryonic development, cleavage is affected by cellular metabolic processes performed by mitochondria and its synergistic interaction with endoplasmic reticulum (ER). However, in depth study on differences of mitochondria and ER ultrastructures in early- cleaving (EC) versus late- cleaving (LC) embryos is limited. This study compares mitochondria and ER ultrastructures of EC versus LC embryos using Confocal Laser Scanning Microscopy (CLSM) and Transmission Electron Microscopy (TEM). Embryos were obtained from female ICR superovulated mice, 28-30 hours post hCG. Two-cell embryos were categorized as early-cleaving (EC), while zygotes with the second polar body and two pronuclei present were categorized as late-cleaving (LC). The LC embryos were cultured in vitro until the 2- cell stage. In EC embryos, mitochondria were mostly found at the perinuclear region and closely associated with dense ER. Meanwhile, mitochondria of LC embryos were distributed uniformly within the cytoplasm. Mitochondrial fluorescence intensity was significantly higher in EC versus LC [(18.7 ± 0.4) versus (14.6 ± 0.4)] x 105 pixel, (p<0.01). Development to the blastocyst stage was also significantly higher in EC compared to LC embryos (96.7% versus 60.9%) (p<0.01). Higher viability of EC embryos is attributed to the close association of their mitochondria to ER. This contributed to better mitochondrial fission, resulting in enhanced energy generating processes and preimplantation development. 


Zygote ◽  
1993 ◽  
Vol 1 (3) ◽  
pp. 237-242 ◽  
Author(s):  
Marek Maleszewski ◽  
Anna Bielak

SummaryMouse oocytes activated parthenogenetically do not generate a plasma membrane block against spermatozoa over the first three cell cycles. We show that they lose this fusibility spontaneously at the 8-cell stage. Insemination of 1-cell parthenogenetic embryos induces loss of fusibility earlier, at the 2-cell stage. This observation suggests that incorporation of the sperm cell membrane components into the oolemma may be responsible for the development of the membrane block.


Development ◽  
1991 ◽  
Vol 111 (3) ◽  
pp. 763-769 ◽  
Author(s):  
J. Kubiak ◽  
A. Paldi ◽  
M. Weber ◽  
B. Maro

The microfilament inhibitor cytochalasin D inhibits extrusion of the first polar body when present during the first meiotic division of mouse oocytes; however, it does not interfere with anaphase movement of chromosomes, and thus induces the formation of tetraploid oocytes. After the separation of chromosomes in anaphase, two spindles start to assemble. However, they merge rapidly and a single meiotic spindle forms. During the transition between metaphase I and metaphase II, in the presence of cytochalasin D, a drop in histone kinase activity takes place demonstrating a transitional decrease in the activity of the maturation promoting factor. These oocytes can be activated parthenogenetically a few hours after washing out the inhibitor. After completion of the second meiotic division and extrusion of a polar body, they contain a diploid number of chromosomes. They are genetically identical to each other and to their mother. Such eggs develop to the blastocyst stage and can implant in the uteri of foster mothers. Most of these fetuses die before the 9th day of gestation, as do diploid control fetuses treated with cytochalasin D during the second meiotic division. The heterozygous state of the experimental embryos obtained after activation of eggs recovered from heterozygous females and treated with cytochalasin D during the first meiotic division was confirmed using a glucose-phosphate isomerase assay. This technique allows the production of genetic clones of parthenogenetic embryos by simple means.


Development ◽  
1976 ◽  
Vol 35 (1) ◽  
pp. 25-39
Author(s):  
Hanna Bałakier ◽  
Andrzej K. Tarkowski

Swiss albino and C57BL/10 eggs from induced ovulations, and spontaneously ovulated A eggs, were activated in vitro by a heat shock of 44 °C for 5 or 7·5 min and cultured in the presence of 10 μg/ml of Cytochalasin B (CB) for 5–8 h. The activation rate was about 70 % in Swiss albino, 40 % in C57BL and 90 % in A eggs. CB suppressed second polar body (2P.B.) formation in over 90 % of activated eggs, with the majority containing two pronuclei. When eggs were placed in CB-free medium their surface became wrinkled and they formed protrusions of various sizes, which in some eggs detached to form enucleate or pronucleate cytoplasmic fragments; some eggs broke down completely into fragments. In most eggs, however, the surface smoothed out in a few hours and suppression of 2P.B. appeared to be permanent. The rate of development of these eggs after transplantation to the oviduct was delayed in terms both of cell divisions and of the time of blastocyst formation. Out of 41 implants collected on the 8th–10th day of pregnancy only two healthy looking egg-cylinders were found on the 8th and 9th day; both were retarded, at the stage characteristic for the 7th day of normal development. The reasons for delayed preimplantation development and low implantation rate are discussed. The present experiments corroborate earlier observations that parthenogenetic mouse embryos, even if diploid, rarely survive in the uterus beyond the egg-cylinder stage.


Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 635-642
Author(s):  
M. H. Kaufman ◽  
R. L. Gardner

Parthenogenetic mouse embryos were selected following in vitro activation, and transferred to the oviducts of pseudopregnant recipients. Decidua was evoked by 50–56% of diploid parthenogenones compared to 35·1% of haploid embryos with a single pronucleus, 37·5% of immediate cleavage eggs and 77% of fertilized eggs (controls). On day 4, 58·7% of diploid parthenogenones were morphologically normal morulae or blastocysts; over 90% of these ‘normal’ embryos evoked decidua when retransferred to recipients compared to 8·9% of abnormal embryos flushed from the ‘transfer’ sides, suggesting that only ‘normal’ embryos could evoke decidua. Potentially diploid parthenogenones remained diploid on chromosomal examination on day 4.


2005 ◽  
Vol 17 (2) ◽  
pp. 210
Author(s):  
A. Suwinska ◽  
M. Waksmundzka ◽  
W. Ozdzenski ◽  
A.K. Tarkowski

A chimaera is an organism composed of cells derived from two (or more) zygotes. Spontaneously originated diploid-triploid (2n-3n) chimaeric embryos and adults have been described in many species of mammals. In man, between 1960 and 2002 over 30 cases of chimaerism were discovered (van de Laar I et al. 2002 Clin. Genet. 62(5), 376–382). A deeper insight into the developmental consequences of this rare and odd phenomenon requires experimental production of 2n-3n embryos and animals. The present study is the first and successful attempt to produce diploid-triploid chimaeric embryos, fetuses, and postnatal animals in the mouse. Diploid embryos originated from BAMIZ females crossed with BAMIZ males. The zygotes that were the source of triploid embryos were obtained from females F1 (C57Bl/6 × CBA/H) crossed with F1 males as a result of “delayed mating.” The triploidy was induced by suppression of the extrusion of the second polar body with cytochalasin D (1 μg mL−1, 5 h). Diploid-triploid chimaeric embryos were created by aggregation of diploid embryos with triploid embryos at 4–8 cell stage. In chimaeras created according to this procedure, the triploid component was agouti and produced the 1B1B isoform of glucose phosphate isomerase (GPI) and the diploid component was albino and produced the GPI-1A1A isoform. Electrophoresis of GPI was performed in order to determine the contribution of both populations of cells in tissues of embryos and individuals. Over a thousand oocytes were subjected to triploidization. A total number of 201 diploid-triploid aggregates developed into blastocysts and were transplanted to the oviducts of 30 recipients. Our experiment yielded 23 living and 6 dead embryos (age: 8th–19th day) out of which 22 proved to be chimaeric and 3 were adults. Two of these animals were albino but had the triploid component in several internal tissues; both were fertile. The third animal, a male, was an overt chimaera. It turned out to be infertile (no sperm in the ejaculate; testes small and deprived of germ cells). The infertility of this individual is puzzling because the FISH studies with the help of X and Y chromosome painting probes proved that the diploid component was XY and the triploid component was XXX. The results of our study indicate that the rate of postimplantation development of 2n-3n chimaeric embryos is normal or only slightly retarded. Developmental stage of chimaeric embryos was assessed by comparison of their external morphology with normal diploid embryos of equivalent post-coital age according to the descriptions given by Theiler K (1972 The House Mouse, Springer-Verlag, Berlin). With the exception of one embryo lacking both eyes (but otherwise looking quite normal) no other morphological abnormalities were observed. Comparison of the contribution of both components to the fetal and extra-embryonic tissues at the consecutive foetal stages has shown that participation of triploid cells slightly but steadily decreased in all tissues examined. However, the presence of triploid cells in mouse chimaeras was compatible with their normal postnatal development to adulthood.


1996 ◽  
Vol 8 (8) ◽  
pp. 1193 ◽  
Author(s):  
B Mognetti ◽  
D Sakkas

Diploid parthenogenetic mouse embryos (which possess two maternally-derived genomes) can develop only as far as the 25-somite stage when transferred in utero and exhibit a substantial reduction in trophoblast tissue. The loss of cultured parthenogenetic embryos during postimplantation indicates that a defect in cell lineage may be evident as early as the blastocyst stage. The possibility that a defect may already be reflected at the preimplantation stage was investigated by examining the allocation of cells to the trophectoderm (trophoblast progenitor cells) and the inner cell mass of haploid and diploid parthenogenetic mouse blastocysts. Utilizing a differential labelling technique for counting cells, diploid parthenogenetic blastocysts were found to have fewer inner cell mass cells and trophectoderm cells than their haploid counterparts and normal blastocysts. In addition, both haploid and diploid parthenogenetic blastocysts had a lower inner cell mass: trophectoderm ratio than normal blastocysts. Thus, the relatively poor development of the trophectoderm lineage at the postimplantation stage is not reflected by a reduction in its allotment of cells at its first appearance. Nevertheless, the findings indicate that parthenogenetic development is already compromised at the blastocyst stage, and provide evidence that the expression of imprinted genes has significance for the development of the embryo at the preimplantation stage.


2008 ◽  
Vol 20 (1) ◽  
pp. 168
Author(s):  
L. Magnani ◽  
R. Cabot

Parthenogenetic embryos obtained by electroactivation of mature oocytes have been used as models in developmental studies. The correct gene expression in early cleavage embryos is essential to sustain embryo development. The precise regulation of genes involved in pluripotency (Oct-4, Sox-2, and Nanog) is crucial to the formation of inner cell mass and trophoblast cells. Failure to do so can contribute to impaired development. We hypothesized that porcine embryos produced by fertilization in vitro and parthenogensis would possess a similar pattern of expression of Oct-4, Nanog, and Sox-2 during cleavage development. The objective of this study was to determine the developmental expression pattern of these three transcription factors in porcine oocytes and cleavage-stage embryos produced by either fertilization or parthenogenesis. Messenger RNAwas isolated from pools of 40-150 germinal vesicle (GV)- and MII-arrested oocytes and pools of 2-cell (2c), 4-cell (4c), 8-cell (8c), and blastocyst-stage embryos produced by in vitro fertilization (IVF) or electroactivation. Quantitative real-time PCR was performed following cDNA synthesis. Transcripts for Oct-4, Nanog, Sox-2, andYWHAG (housekeeping gene control) were amplified in duplicate across three to five experimental replicates. Transcripts were quantified using the comparative CT method using YWHAG as internal control and GV stage as normalizing stage. Fold activation and repression were analyzed with ANOVA and Tukey's post-hoc test. Our results show that porcine embryos produced by either IVF or electroactivation possess a similar pattern of pluripotent gene expression during cleavage-stage development. Oct-4 was found to be present in high abundance in the 2-cell parthenogenetic embryos and then repressed at the 8-cell stage (10-fold; P < 0.05, 2c v. 8c). In IVF embryos, Oct-4 was found in significantly higher amount at the 2-cell stage (35-fold; P < 0.05, 2c v. GV). Nanog transcripts were present at low levels from the GV oocyte until the 4-cell stage in both IVF and parthenogenetic embryos and then upregulated 10 000-fold at the 4-cell stage (P < 0.0001, GV v. 4c); at the blastocyst stage, Nanog transcript levels were similar to the levels found in the GV stage oocytes. Sox-2 transcripts were lower in MII oocytes and were significantly upregulated in 8-cell-stage embryos produced by either IVF or electroactivation (9- and 20-fold; P < 0.01, P < 0.0001, MII v. 8c, respectively). In addition, Sox-2 transcripts were significantly higher in parthenogenetic blastocysts compared to IVF-derived blastocysts (P < 0.05). This work demonstrates that cleavage-stage porcine embryos, produced by either electroactivation or IVF, undergo a similar pattern of activation of key regulatory genes; however, the activation method can have an influence on the transcript abundance of specific genes at defined stages.


2011 ◽  
Vol 49 (No. 3) ◽  
pp. 93-98 ◽  
Author(s):  
I. Petrová ◽  
M. Sedmíková ◽  
E. Chmelíková ◽  
D. Švestková ◽  
R. Rajmon

Porcine oocytes matured in vitro develop in various ways if they are further cultivated. In our studies these oocytes were cultivated for 1 to 5 days (in vitro aging). During the 1st day of aging, most of them remained at the stage of metaphase II (98%). Then many oocytes underwent the spontaneous parthenogenetic activation. The portion of activated oocytes reached its peak after 2 or 3 days of aging in vitro (39 or 45%). The portion of fragmented oocytes peaked at the same time (28%). During subsequent aging in vitro (i.e. day 4 or 5 of aging), the portion of lysed oocytes significantly increased (30 or 37%). The highest portion of spontaneously activated parthenogenetic embryos at a pronuclear stage (35%) was observed during the 2nd day of aging in vitro. These pronuclear embryos had mainly one polar body with two pronuclei (47% of all pronuclear embryos) or two polar bodies with one pronucleus (38% of all pronuclear embryos). During the 3rd and 5th day of in vitro aging, there was a significant increase in the portion of parthenogenetic embryos cleaved to the 2-cell or 3-cell stage. When considering the prolonged in vitro culture of porcine oocyte, only the first day of aging should be taken into account, since beyond this time significant changes, i.e. parthenogenesis, fragmentation or lysis, occurred in oocytes under in vitro conditions. &nbsp;


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