Timing of Compaction and Inner Cell Allocation in Bovine Embryos Produced in Vivo after Superovulation1

Soom, Ann Van; Boerjan, Marleen; Bols, P.E.J.; Vanroose, G.; Lein, A; Coryn, M.; Kruif, Aart de

doi:10.1095/biolreprod57.5.1041

Cited by 147 publications

(48 citation statements)

References 35 publications

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“…Data from in vivo-produced bovine embryos indicate that an ICM/TCN proportion between 20 and 40% is within the normal range (Van Soom et al 1997, Koo et al 2002, Rho et al 2007. In this study, a significant percentage of embryos treated with supraphysiological concentrations of IGF1 developed a high ICM/TCN proportion (O40%).…”

Section: Discussionsupporting

confidence: 47%

Increased apoptosis in bovine blastocysts exposed to high levels of IGF1 is not associated with downregulation of the IGF1 receptor

Velazquez¹,

Hermann²,

Kues³

et al. 2011

Reproduction

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The hypothesis that high concentrations of IGF1 can impair embryo development was investigated in a bovine in vitro model to reflect conditions in polycystic ovary syndrome (PCOS) patients. Embryos were either cultured in the absence or presence of a physiological (100 ng/ml) or supraphysiological (1000 ng/ml) IGF1 concentration. Cell allocation, apoptosis, transcript and protein expression of selected genes involved in apoptosis, glucose metabolism and the IGF system were analysed. Supraphysiological IGF1 concentration did not improve blastocyst formation over controls, but induced higher levels of apoptosis, decreased TP53 protein expression in the trophectoderm and increased the number of cells in the inner cell mass (ICM). The increase in ICM cells corresponded with an increase in IGF1 receptor (IGF1R) protein in the ICM. A small, but significant, percentage of blastocysts displayed a hypertrophic ICM, not observed in controls and virtually absent in embryos treated with physiological concentrations of IGF1. Physiological IGF1 concentrations increased total IGF1R protein expression and upregulated IGFBP3 transcripts leading to an increase in blastocyst formation with no effects on cell number or apoptosis. In conclusion, the results support the hypothesis of detrimental effects of supraphysiological IGF1 concentrations on early pregnancy. However, our results do not support the premise that increased apoptosis associated with high levels of IGF1 is mediated via downregulation of the IGF1R as previously found in preimplantation mouse embryos. This in vitro system with the bovine preimplantation embryo reflects critical features of fertility in PCOS patients and could thus serve as a useful model for in-depth mechanistic studies.

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Section: Discussionsupporting

confidence: 47%

Increased apoptosis in bovine blastocysts exposed to high levels of IGF1 is not associated with downregulation of the IGF1 receptor

Velazquez¹,

Hermann²,

Kues³

et al. 2011

Reproduction

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“…It is generally believed that a large number of cells in blastocyst indicates improved embryo viability [24], and the ratio of ICM in the blastocyst is thought to be crucial for postimplantation development and live offspring [25]. In order to improve the quality of embryos cultured in vitro, addition of growth factors, cytokines, vitamins or amino acids to in vitro culture medium have been stud- Values with different superscripts in the same column are significantly different (P<0.05).…”

Section: Discussionmentioning

confidence: 99%

Stage-dependent Effect of Leptin on Development of Porcine Embryos Derived from Parthenogenetic Activation and Transgenic Somatic Cell Nuclear Transfer

Wei

Zhang

et al. 2009

Journal of Reproduction and Development

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Abstract. Accumulating evidence suggests that leptin may play important roles in preimplantation embryonic development, although this remain controversial, and little is known about whether leptin has a stage-dependent regulatory effect on development of porcine embryos derived by parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT). The objective of this study was to investigate the effects of addition of leptin to in vitro culture (IVC) medium on development of porcine embryos derived by PA and SCNT. We found that addition of 50 ng/ml human recombinant leptin improved the rate of PA embryos reaching the blastocyst stage and increased the total cell number of blastocysts compared with the control group. The maximal blastocyst rate of SCNT embryos was achieved at 50 ng/ml, and the total cell number of blasocysts was increased significantly at 500 ng/ml leptin concentration. However, the ratio of the inner cell mass (ICM) to total cell number was not affected in any of the groups. Supplementation of leptin (50 ng/ml) from day 3, approximately the 4-8-cell stage, as in the case of the positive control, significantly increased the blatocyst rate of PA embryos compared with the negative control and inhibited cell apoptosis. There were no beneficial effects on embryonic development when 50 ng/ml leptin was added to the culture medium from day1 to day 3 or from day 4 to day 6. These results indicate that leptin could improve the development and the quality of PA and SCNT embryos; and 50 ng/ml leptin performs its primary stimulatory effect at 4-8-cell stage and that leptin may have no effect on the maternal-zygote transition (MZT) of porcine PA and SCNT embryos. Key words: Embryo development, Leptin, Parthenogenetic activation, Pig, Somatic cell nuclear transfer (SCNT) (J. Reprod. Dev. 55: [99][100][101][102][103][104] 2009) uccessful production of cloned pigs and many other mammalian species by SCNT not only strongly establishes that differentiated somatic cells still contain complete genetic information which thereby can be dedifferentiated and redifferentiated, but also provides a revolutionary tool for studies on embryonic stem cells, transgenesis or gene targeting and artificial reproductive technologies in such species [1,2]. Although SCNT is of great significance in agriculture, medicine and basic research, widespread application of SCNT is still very limited due to its poor efficiency. It is believed that its lower efficiency is the result of errors in reprogramming, especially incomplete epigenetic reprogramming [1], which could be improved, to some extent, by modifications of donor preparation, oocyte maturation, activation and embryo culture systems. It has been shown that alteration of oxygen tension, basic culture media or supplementation of certain kinds of growth factors, cytokines, vitamins or amino acids can enhance preimplantational development or quality of cloned embryos [3][4][5][6]. Leptin, a 16KD reproductive hormone and product of the obese gene (ob), which is synthesized ...

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“…In cattle, polarisation, as determined by the distribution of surface microvilli using scanning electron microscopy, occurs one cell division later than in mice, that is at the 16-cell (early morula) stage (Koyama et al 1994). Importantly, compaction -concomitant with E-cadherin depletion in the apical regions of outer cells (Barcroft et al 1998) occurs only at the 32-cell stage (Betteridge & Flechon 1988, Van Soom et al 1997. This is distinctly later than polarisation and well after blastomeres have started adopting the inner and outer positions (Betteridge & Flechon 1988, Van Soom et al 1997.…”

Section: Specification Of the Trophoblast Lineagementioning

confidence: 99%

“…Importantly, compaction -concomitant with E-cadherin depletion in the apical regions of outer cells (Barcroft et al 1998) occurs only at the 32-cell stage (Betteridge & Flechon 1988, Van Soom et al 1997. This is distinctly later than polarisation and well after blastomeres have started adopting the inner and outer positions (Betteridge & Flechon 1988, Van Soom et al 1997. Cattle may be an interesting alternate model for TE specification because the relative timing of morphological events is different from the mouse.…”

Section: Specification Of the Trophoblast Lineagementioning

confidence: 99%

Trophoblast development

Pfeffer¹,

Pearton²

2012

Reproduction

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This review summarises current knowledge about the specification, commitment and maintenance of the trophoblast lineage in mice and cattle. Results from gene expression studies, in vivo loss-of-function models and in vitro systems using trophoblast and embryonic stem cells have been assimilated into a model seeking to explain trophoblast ontogeny via gene regulatory networks. While trophoblast differentiation is quite distinct between cattle and mice, as would be expected from their different modes of implantation, recent studies have demonstrated that differences arise much earlier during trophoblast development.

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Timing of Compaction and Inner Cell Allocation in Bovine Embryos Produced in Vivo after Superovulation1

Cited by 147 publications

References 35 publications

Increased apoptosis in bovine blastocysts exposed to high levels of IGF1 is not associated with downregulation of the IGF1 receptor

Increased apoptosis in bovine blastocysts exposed to high levels of IGF1 is not associated with downregulation of the IGF1 receptor

Stage-dependent Effect of Leptin on Development of Porcine Embryos Derived from Parthenogenetic Activation and Transgenic Somatic Cell Nuclear Transfer

Trophoblast development

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