The relationship between chromosomal abnormality in the human preimplantation embryo and development in vitro

1996 ◽  
Vol 8 (2) ◽  
pp. 235 ◽  
Author(s):  
PA Almeida ◽  
VN Bolton

The relationship between the survival of the human preimplantation embryo in vitro and chromosomal abnormality was investigated by cytogenetic analysis of a total of 250 embryos of varying morphology between the pronucleate stage and the 8-cell stage. The overall incidence of chromosomal abnormality among these embryos was 49%. At the pronucleate stage (n = 46) the incidence was 65.2%, at the 2-4-cell stage (n = 126) it was 54.6%, and at the 5-8-cell stage (n = 78) it was 27.4%. Cleavage-stage embryos with poor morphology (irregular shaped blastomeres with severe extracellular fragmentation) showed a higher incidence of chromosomal abnormality (62%; 54 of 87 analysed) than those with good morphology (22.2%; 26 of 117 analysed). This study demonstrates: (i) that there is progressive loss of chromosomally-abnormal embryos during preimplantation development; and (ii) that there is an association between chromosomal abnormality and embryo morphology.


1998 ◽  
Vol 10 (6) ◽  
pp. 505 ◽  
Author(s):  
Paula A. Almeida ◽  
Virginia N. Bolton

The relationship between chromosomal abnormalities in the human preimplantation embryo and developmental arrest in vitro was investigated. Cytogenetic analysis of 171 embryos that had arrested between the pronucleate and the 8-cell stages demonstrated that the overall incidence of chromosomal abnormality among these embryos was 63.4%. Of the embryos that arrested at the pronucleate stage (n = 48), 47.9% were chromosomally abnormal, compared with 59.5% of those that arrested between the 2- and 4-cell stages (n = 50), and 82.8% of those arrested between the 5- and 8-cell stage (n = 73). The rate of abnormality in embryos with poor morphology (irregular shaped blastomeres and considerable extracellular fragmentation) was significantly higher (86.8%; n = 33) than those with good morphology (60%; n = 51; P<0.005). These results suggest that there is an association between chromosomal abnormality, developmental arrest in vitro, and poor morphology.



2018 ◽  
Vol 30 (5) ◽  
pp. 779 ◽  
Author(s):  
N.-Y. Rho ◽  
F. A. Ashkar ◽  
T. Revay ◽  
P. Madan ◽  
G.-J. Rho ◽  
...  

Thyroid hormone receptor (THR) α and THRβ mediate the genomic action of thyroid hormones (THs) that affect bovine embryo development. However, little is known about THRs in the preimplantation embryo. The aim of the present study was to investigate the importance of THRs in in vitro preimplantation bovine embryos. THR transcripts and protein levels were detected in developing preimplantation embryos up to the blastocyst stage. Embryonic transcription of THRs was inhibited by α-amanitin supplementation, and both maternal and embryonic transcription were knocked down by short interference (si) RNA microinjection. In the control group, mRNA and protein levels of THRs increased after fertilisation. In contrast, in both the transcription inhibition and knockdown groups there were significant (P < 0.05) decreases in mRNA expression of THRs from the 2-cell stage onwards. However, protein levels of THRs were not altered at 2-cell stage, although they did exhibit a significant (P < 0.05) decrease from the 4-cell stage. Moreover, inhibition of de novo transcripts of THRs using siRNA led to a significant (P < 0.01) decrease in the developmental rate and cell number, as well as inducing a change in embryo morphology. In conclusion, THRs are transcribed soon after fertilisation, before major activation of the embryonic genome, and they are essential for bovine embryo development in vitro.



Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 581
Author(s):  
Adel R. Moawad ◽  
Ali Salama ◽  
Magdy R. Badr ◽  
Mohamed Fathi

This study aimed to investigate the effect of L-Carnitine (LC) supplementation during in vitro maturation (IVM) of canine oocytes on nuclear maturation, fertilization status, and preimplantation development. Cumulus–oocyte complexes (COCs) collected from the ovaries of ovariohysterectomized female dogs were matured in vitro for 72 h in a TCM-199 medium supplemented with (0.1, 0.3, 0.6, 1.0, or 2.0 mg/mL) or without (0.0 mg/mL) LC. Matured oocytes were fertilized in vitro with frozen–thawed spermatozoa, and zygotes were cultured in a SOF medium for 7 days. IVM rates were higher (p ≤ 0.05) in 0.3 and 0.6 mg/mL LC supplemented groups than in the control (0.0 mg/mL LC) and other LC groups. Fertilization (18 h postinsemination (pi)) and cleavage (2–16-cell stage at day 3 pi) rates were higher (p ≤ 0.05) in the 0.6 mg/mL LC group than in the control and 0.1, 1.0, and 2 mg/mL LC supplemented groups. Interestingly, 4.5% of fertilized oocytes developed to morula (day 5 pi) in the 0.6 mg/mL LC group, which was higher (p ≤ 0.05) than those developed in the 0.3 mg/mL group (1.0%). No cleaved embryos developed to morula in other groups. In conclusion, LC supplementation at 0.6 mg/mL during IVM of canine oocytes improved their maturation, fertilization, and preimplantation embryo development rates following IVF and in vitro culture (IVC).



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karina Cañón-Beltrán ◽  
Yulia N. Cajas ◽  
Serafín Peréz-Cerezales ◽  
Claudia L. V. Leal ◽  
Ekaitz Agirregoitia ◽  
...  

AbstractIn vitro culture can alter the development and quality of bovine embryos. Therefore, we aimed to evaluate whether nobiletin supplementation during EGA improves embryonic development and blastocyst quality and if it affects PI3K/AKT signaling pathway. In vitro zygotes were cultured in SOF + 5% FCS (Control) or supplemented with 5, 10 or 25 µM nobiletin (Nob5, Nob10, Nob25) or with 0.03% dimethyl-sulfoxide (CDMSO) during minor (2 to 8-cell stage; MNEGA) or major (8 to 16-cell stage; MJEGA) EGA phase. Blastocyst yield on Day 8 was higher in Nob5 (42.7 ± 1.0%) and Nob10 (44.4 ± 1.3%) for MNEGA phase and in Nob10 (61.0 ± 0.8%) for MJEGA phase compared to other groups. Mitochondrial activity was higher and lipid content was reduced in blastocysts produced with nobiletin, irrespective of EGA phase. The mRNA abundance of CDK2, H3-3B, H3-3A, GPX1, NFE2L2 and PPARα transcripts was increased in 8-cells, 16-cells and blastocysts from nobiletin groups. Immunofluorescence analysis revealed immunoreactive proteins for p-AKT forms (Thr308 and Ser473) in bovine blastocysts produced with nobiletin. In conclusion, nobiletin supplementation during EGA has a positive effect on preimplantation bovine embryonic development in vitro and corroborates on the quality improvement of the produced blastocysts which could be modulated by the activation of AKT signaling pathway.



2021 ◽  
Vol 350 ◽  
pp. S169-S170
Author(s):  
I. Hallberg ◽  
M. Moberg ◽  
M. Olovsson ◽  
P. Damdimopoulou ◽  
J. Rüegg ◽  
...  


2005 ◽  
Vol 229 (1-2) ◽  
pp. 141-147 ◽  
Author(s):  
Jesse A. Craig ◽  
Hai Zhu ◽  
Paul W. Dyce ◽  
Lihua Wen ◽  
Julang Li


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.



Reproduction ◽  
2001 ◽  
pp. 957-963 ◽  
Author(s):  
A Nishikimi ◽  
T Matsukawa ◽  
K Hoshino ◽  
S Ikeda ◽  
Y Kira ◽  
...  

Changes in the activities of nitric oxide synthase (NOS) during embryonic development, and the distribution of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) isoforms were examined in unfertilized mouse oocytes at the second meiotic metaphase (MII) stage and in fertilized mouse embryos during preimplantation development. In addition, the effects of NOS inhibitors on mouse preimplantation development in vitro were investigated. The activities of NOS in MII oocytes and fertilized embryos during the preimplantation period were determined by NADPH-diaphorase staining. Although NOS activity was detected in unfertilized MII oocytes, the intensity of staining was much weaker than that of fertilized embryos at the one-cell stage. There was a decrease in NOS activity in embryos from the four-cell to the eight-cell stage; however, NOS activity increased again in embryos at the morula stage, particularly in the inner cell population. In the expanded blastocysts, staining was confined to the inner cell mass. Immuno-cytochemical staining showed that eNOS and iNOS were expressed in the cytoplasm of oocytes and embryos during the preimplantation period, and eNOS was also distributed in the nuclei of the embryos. When one-cell embryos were treated with 1 mmol N(omega)-nitro-L-arginine methyl ester (L-NAME) l(-1), their development in vitro was arrested at the two-cell stage. This inhibition of development was overcome by the addition of 1 mmol L-arginine l(-1) to the medium. These observations indicate that nitric oxide plays an important role as a diffusible regulator of cell proliferation and differentiation, especially at the developmental transition from the two-cell to the four-cell stage during preimplantation development of mice.



2009 ◽  
Vol 21 (1) ◽  
pp. 203
Author(s):  
Y. J. Kim ◽  
Y. P. Jeon ◽  
S. H. Hyun

Porcine embryos could be a valuable tool to study preimplantation development, implantation, and pregnancy, but to do this it is necessary to establish an efficient in vitro embryo production system. Because the cause of high mortality in embryos during preimplantation development is not clear, a noninvasive method of determining the developmental potential of cleavage-stage embryos is needed. The objective was to evaluate the developmental potential of Day 2 embryos in a porcine in vitro fertilization (IVF) system. Specifically, this study was conducted to examine the relationship between embryo morphology 48 h after IVF on rates of blastocyst formation 5 days later. To prepare in vitro maturation (IVM) of porcine oocytes, cumulus–oocyte complexes were obtained from slaughterhouse-derived ovaries and matured in M-199 medium supplemented with 10% pig follicular fluid and 0.57 mm cysteine for 44 h and then freed from cumulus cells. After IVM, cumulus-free oocytes were coincubated with frozen–thawed sperm (2 × 106 cells mL–1) and 2 mm caffeine for 6 h. Inseminated embryos were cultured in NCSU-23 medium that was supplemented with 0.5 mm pyruvate and 0.5 mm lactate. Data were analyzed by ANOVA and Duncan’s test (P < 0.05). Morphology data on a total of 919 embryos were analyzed retrospectively. Forty-eight hours after insemination, embryos were classified into the following 5 groups based on the cleavage state: 1 cell, 2 cells, 4 cells, 5 to 8 cells, and fragmentation. These groups were cultured another 120 h and then evaluated for blastocyst formation. Blastocyst formation rates were significantly higher in the 4-cell (38.07%) and 5- to 8-cell (40.65%) cleaving groups than in the other groups (P < 0.05). In contrast, the 2-cell and fragmentation groups produced 7.5 and 2.9% blastocysts, respectively. Data suggest that embryos reaching 4 cells and 5 to 8 cells by 48 h after insemination have high developmental competence, and this parameter may be useful to predict the development of preimplantation embryos and their ability to establish pregnancy. This work was supported by a grant (No. 20070301034040) from the BioGreen 21 program, Rural Development Administration, Republic of Korea.



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