The importance of growth factors for preimplantation embryo development and in-vitro culture

Human reproduction, like all biological systems, is characterised by a large level of variability. In this field, the variability is observed as a large difference in implantation potential of human embryos developing in vitro, despite similarities in observable parameters such as rate of development and morphology of these embryos. One of the underlying factors that determines developmental potential in these embryos is the availability of energy in the form of ATP for development. Here, we suggest that, despite the evidence suggesting that mitochondrial metabolism is relatively inactive during preimplantation embryo development, aerobic (mitochondrial) metabolism contributes a major role in the supply of ATP. A second pathway, anaerobic respiration, is also active and the two pathways work in synchrony to supply all the ATP necessary. We discuss the differences in the two forms of energy production and suggest that, although anaerobic respiration can supplement deficiencies in the energy supply in the short term, this is not sufficient to substitute for aerobic respiration over long periods. Therefore, we suggest that deficiencies in the levels of aerobic respiration can explain variability in the implantation potential of apparently equivalent embryos.

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In vitro fertilization and preimplantation embryo development of African green monkeys (Cercopithecus aethiops)

American Journal of Primatology ◽

10.1002/(sici)1098-2345(1997)43:1<43::aid-ajp3>3.0.co;2-y ◽

1997 ◽

Vol 43 (1) ◽

pp. 43-50 ◽

Cited By ~ 11

Author(s):

T. Sankai ◽

F. Cho ◽

Y. Yoshikawa

Keyword(s):

In Vitro Fertilization ◽

Embryo Development ◽

Preimplantation Embryo ◽

Cercopithecus Aethiops ◽

Vitro Fertilization ◽

Preimplantation Embryo Development ◽

Green Monkeys

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Deadly decisions: the role of genes regulating programmed cell death in human preimplantation embryo development

Reproduction ◽

10.1530/rep.1.00241 ◽

2004 ◽

Vol 128 (3) ◽

pp. 281-291 ◽

Cited By ~ 78

Author(s):

Andrea Jurisicova ◽

Beth M Acton

Keyword(s):

Gene Expression ◽

Cell Death ◽

Cell Fate ◽

Embryo Development ◽

Preimplantation Embryo ◽

Culture Media ◽

Culture Conditions ◽

Early Embryo ◽

Preimplantation Embryo Development

Human preimplantation embryo development is prone to high rates of early embryo wastage, particularly under currentin vitroculture conditions. There are many possible underlying causes for embryo demise, including DNA damage, poor embryo metabolism and the effect of suboptimal culture media, all of which could result in an imbalance in gene expression and the failed execution of basic embryonic decisions. In view of the complex interactions involved in embryo development, a thorough understanding of these parameters is essential to improving embryo quality. An increasing body of evidence indicates that cell fate (i.e. survival/differentiation or death) is determined by the outcome of specific intracellular interactions between pro- and anti-apoptotic proteins, many of which are expressed during oocyte and preimplantation embryo development. The recent availability of mutant mice lacking expression of various genes involved in the regulation of cell survival has enabled rapid progress towards identifying those molecules that are functionally important for normal oocyte and preimplantation embryo development. In this review we will discuss the current understanding of the regulation of cell death gene expression during preimplantation embryo development, with a focus on human embryology and a discussion of animal models where appropriate.

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