With a few notable exceptions, mammalian preimplantation embryos grown in vitro are likely to exhibit sub-optimal or retarded development. This may be manifested in different ways, depending on the species and on the stage(s) of embryonic development that are being examined. For example, bovine embryos often experience difficulty in cleaving under in vitro conditions, and usually cease development at about the 8-cell stage (Wright and Bondioli, 1981). The block to development is stage-dependent; embryos cultured for 24 hr from the I-cell stage are much more capable of developing into viable blastocysts after transfer to oviducts than embryos cultured for 24 hr from the 4-cell stage prior to transfer (Eyestone et oZ. , 1985). Similar problems with in vitro embryo development are encountered in other species. Pig embryos can be grown up to the 4-cell stage in vitro but usually no further (Davis and Day, 1978). In the golden hamster, in the rat and in many outbred strains of mice, development of zygotes in vitro is blocked at the 2-cell stage (Yanagimachi and Chang, 1964; Whittingham, 1975).
Even with some inbred mouse strains, embryo development is reduced if very early cleavage stages are used as the starting point for in vitro culture (Spielmann et oZ. , 1980). A common finding is that embryos grown in vitro have reduced cell counts (Harlow and Quinn, 1982; Kane, 1985) and their viability is reduced (Bowman and McLaren, 1970; Papaioannou and Ebert, 1986) compared to equivalent developmental stages recovered from mated animals.
1 Pioneering Mammalian Embryo Culture.- 1. Introduction.- 2. Early Period Using Media Prepared From Biological Fluids.- 3. Successful Culture of a Rodent Preimplantation Embryo.- 4. Culture of Rabbit Embryos Revisited.- 5. Conclusion.- 6. References.- 2 Cell Polarity in the Preimplantation Mouse Embryo.- 1. Introduction.- 2. The Unfertilized Egg.- 3. The Fertilized Egg.- 4. 2-Cell and 4-Cell Stages.- 5. The 8-Cell Stage Embryo.- 6. Developmental Significance of Embryonic Polarities.- 7. References.- 3 Intercellular Communication during Mouse Embryogenesis.- 1. Introduction.- 2. Communication Via Cytoplasmic Bridges.- 3. Communication Via Intercellular Membrane Channels.- 4. Communication Via Cell Surface Interaction.- 5. On the Role of Intercellular Communication Pathways in Embryogenesis.- 6. References.- 4 Development of the Blastocyst: Role of Cell Polarity in Cavitation and Cell Differentiation.- 1. Introduction.- 2. Three Models for Cavitation: Cell Polarity and the Production of Nascent Blastocoele Fluid.- 3. Electrical Polarity of Outer Blastomeres from Mouse Morulae.- 4. Summary.- 5. References.- 5 In Vitro Assessment of Blastocyst Differentiation.- 1. Introduction - Overview of Blastogenesis.- 2. Oxidative Metabolism.- 3. Trans-Trophectodermal Sodium Transport.- 4. Protein Synthesis During Blastogenesis.- 5. Characterization of Blastocyst Plasma Membranes.- 6. Conclusions: Future Perspectives.- 7. References.- 6 Steroid Hormones in Early Pig Embryo Development.- 1. Introduction.- 2. Methodology.- 3. Progesterone: Embryonic Uptake and Its Specificity.- 4. In Vitro Culture of Morulae in the Presence of Supplementary Steroids.- 5. Estradiol-17 Beta: Embryonic Uptake and Its Specificity.- 6. Estradiol Withdrawal and In Vitro Development of Morula Stages.- 7. Further Considerations.- 8. References.- 7 Genetic Expression during Early Mouse Development.- 1. Introduction.- 2. Synthesis of Maternally-Derived Products.- 3. Activation of the Embryonic Genome.- 4. Are Maternally-Derived Products Important for Development Beyond the 2-Cell Stage?.- 5. Both the Maternal and Paternal Genomes Are Required for Normal Development.- 6. Is It Possible To Clone Mammals by Nuclear Transfer?.- 7. Mutations and Chromosomal Abnormalities That Affect the Preimplantation Mouse Embryo.- 8. Genetic Control of Early Mammalian Development: Future Approaches.- 9. Summary.- 10. References.- 8 Defining the Roles of Growth Factors during Early Mammalian Development.- 1. Introduction.- 2. Preimplantation Mouse Embryos Cultured In Serum-Supplemented Media.- 3. Mouse Embryos Cultured in Serum-Free Media.- 4. Design of Serum-Free Media for Mouse Blastocysts.- 5. Production of Growth Factors by Early Embryos.- 6. Possible Roles of Growth Factors During Early Postimplantation Development.- 7. Possible Effects of Growth Factors on the Process of Differentiation.- 8. Conclusions.- 9. Appendix.- 10. References.- 9 Interaction of Trophoblastic Vesicles with Bovine Embryos Developing in Vitro.- 1. Introduction.- 2. Working With Trophoblastic Vesicles.- 3. Effect of Trophoblastic Vesicles on Early Stage Embryo Development In Vitro.- 4. Evidence for Release by Trophoblastic Vesicles of Signals For Corpus Luteum Function.- 5. Conclusions.- 6. References.- 10 In Vitro Growth of Preimplantation Rabbit Embryos.- 1. Introduction.- 2. Relevance of Rabbit Embryo Culture to Studies of Embryonic Development.- 3. How Does Growth of Cultured Rabbit Embryos Compare With Growth In Vivo?.- 4. In Vitro Growth Requirements of Rabbit Embryos.- 5. Methodological Considerations.- 6. Evaluation of Embryos.- 7. Conclusions.- 8. References.- 11 Studies on the Developmental Blocks in Cultured Hamster Embryos.- 1. Introduction.- 2. Technical Procedures.- 3. The 2-Cell Block to Development.- 4. Growth of 8-Cell Embryos In Vitro.- 5. Conclusions.- 6. References.- 12 Growth of Domesticated Animal Embryos in Vitro.- 1. Introduction.- 2. Media, Supplements and Antibiotics.- 3. Glucose Metabolism During Embryo Development.- 4. Embryo Co-Culture.- 5. References.- 13 In Vitro Growth of Non-Human Primate Pre- and Peri- Implantation Embryos.- 1. Introduction.- 2. Technical Considerations.- 3. Supply of In Vivo Fertilized Embryos.- 4. In Vitro Fertilized Embryos.- 5. Embryo Growth Characteristics.- 6. Assessment of Embryonic Normalcy after In Vitro Culture.- 7. Conclusions.- 8. Appendix: Culture Media.- 9. References.- 14 Analysis of Embryotoxic Effects in Preimplantation Embryos.- 1. Introduction.- 2. Sensitive Toxicological Endpoints.- 3. Exposure of Embryos In Vitro.- 4. Exposure of Embryos In Vivo.- 5. Conclusions.- 6. References.- 15 Applications of Animal Embryo Culture Research to Human IVF and Embryo Transfer Programs.- 1. Introduction.- 2. Studies on Animal IVF, Embryo Culture and Transfer.- 3. Present Status and Prospects of Human IVF-ET.- 4. Conclusions.- 5. References.- Appendix I.- 1. Introduction.- 2. Conditions for Embryo Culture.- 3. Equipment.- 4. Experimental Design.- 5. Evaluation of Responses to Embryo Culture.- 6. Blocks to Development.- 7. References.- Appendix II.- 1. Supplies for Embryo Culture Experiments.- 2. Equipment.- 3. Manufacturers and Distributors of Supplies and Equipment.