Embryogenesis deficiency

Donehower, L. A., M. Harvey, B. L. Slagle, M. J. McArthur, C. A. Montgomery, J. S. Butel, and A. Bradley, Mice deficient for p53 are developmentally normal but susceptible to spontaneous tumours. Nature 356 215-221, 1992. A remarkable new technique for obtaining null mutations demonstrates that embryogenesis is normal in the absence of p53. However, animals develop a variety of neoplasms in the first 6 months when p53 is lacking. 

Cui J, O Shea KS, Purkayastha A et al. (1996) Fatal haemorrhage and incomplete block to embryogenesis in mice lacking coagulation factor V. Nature 384 66-68 Yang TL, Cui J, Taylor JM et al. (2000) Rescue of fatal neonatal hemorrhage in factor V deficient mice by low level transgene expression. Thromb Haemost 83 70-77... 

Connolly AJ, Ishihara H, Kahn ML et al. (1996) Role of the thrombin receptor in development and evidence for a second receptor. Nature 381 516-519 Cui J, O Shea KS, Purkayastha A et al. (1996) Fatal haemorrhage and incomplete block to embryogenesis in mice lacking coagulation factor V. Nature 384 66-68 Denis C, Methia N, Frenette PS et al. (1998) A mouse model of severe von Willebrand disease defects in hemostasis and thrombosis. Proc Nad Acad Sci USA 95 9524-9529 Dewerchin M, Liang Z, Moons L et al. (2000) Blood coagulation factor X deficiency causes partial embryonic lethality and fatal neonatal bleeding in mice. Thromb Haemost 83 185-190... 

Iodine excess may cause thyroid dysfunction, such as hypothyroidism or hyperthyroidism, in humans. Although no direct developmental toxic effect of excess iodine was reported in humans, the body of evidence that maternal thyroid dysfunction may result in adverse pregnancy outcome is increasing. An in vitro study (Harakawa et al., 1989) investigated the effects of excess or deficiency of TH on early embryogenesis in rat embryo culture. The results showed that malformations, including open... 

Micronutrients Micronutrients play an important and sometimes a crucial role in normal plant growth and development. Deficiency symptoms arise in plants that are grown under sub-optimal levels of micronutrients. As such, the tissue culture media are also formulated with the inclusion of essential micronutrients. However, in depth studies of their influence on in vitro cell culture, particularly microspore embryogenesis, are limited. This neglect is in spite of their absolute requirement for many physiological and biochemical cellular processes, including the catalysis of enzymatic reactions. Two of the micronutrients that... 

Within cells, vitamin A (retinol, retinal, retinoic acid) functions mainly in vision, cellular differentiation, and embryogenesis. The adverse effects of vitamin A deficiency on complex physiological processes such as reproduction and the immvme response result primarily from defective cellular differentiation. 

---