Embryo patterns

FGF (22 members) FGFs require heparan sulfate to activate their receptors FGFR Four members expressed as a number of splice variants Proliferation of many cell types. Embryo patterning and organogenesis, bone development, angiogenesis... 

Supena, E.D.J. Winarto, B. Riksen, T. Dubas, E. van Lammeren, A. Offringa, R. Boutilier, K. Custers, J. (2008). Regeneration of zygotic-like microspore-derived embryos suggests an important role for the suspensor in early embryo patterning, foumal of Experimental Botany, Vol.59, No.4, (March 2008), pp. 803-814, ISSN 1460-2431... 

Microspore embryogenesis occurs in a pattern of morphogenesis akin to zygotic embryo development. Based on this similarity, embryo pattern regulators such as members of the gene family 14-3-3 of barley have been observed to be up regulated, both in time and space (Maraschin et al. 2003). 

Diflfiisive processes nonnally operate in chemical systems so as to disperse concentration gradients. In a paper in 1952, the mathematician Alan Turing produced a remarkable prediction [37] that if selective diffiision were coupled with chemical feedback, the opposite situation may arise, with a spontaneous development of sustained spatial distributions of species concentrations from initially unifonn systems. Turmg s paper was set in the context of the development of fonn (morphogenesis) in embryos, and has been adopted in some studies of animal coat markings. With the subsequent theoretical work at Brussels [1], it became clear that oscillatory chemical systems should provide a fertile ground for the search for experimental examples of these Turing patterns. 

Edgar, B. A., and O Farrell, P. H. (1989). Genetic control of cell division patterns in the Drosophila embryo. Cell 57 117-187. 

Candia, A. F., Hu, J Crosby, J Lalley, R A., Noclen, D Nadeau, J., and Wright, C. V. E (1992). Mox-1 and Mox-2 define a novel homeobox gene subfamily and are differentially expressed during early mesodermal patterning in mouse embryos. Development 116 1123-1136. 

Arora K, Niisslein-Volhard C 1992 Altered mitotic domains reveal fate map changes in Drosophila embryos mutant for zygotic dorsoventral patterning genes. Development 114 1003-1024... 

Diazinon adversely affects survival of developing mallard embryos when the eggshell surface is subjected for 30 seconds to concentrations 25 to 34 times higher than recommended field application rates. Mortality patterns were similar for solutions applied in water or in oil (Table 16.3). 

Toxicokinetics of PCBs in rodents were altered when administered in mixtures (de Jongh et al. 1992). PCBs 153, 156, and 169 produced biphasic elimination patterns in mice when administered in combinations, but single-phase elimination when administered alone. Elimination of all PCBs was more rapid after coadministration. Mixtures of PCBs 153 and 156 raised EROD activity and lengthened retention of each congener in liver however, a mixture of PCB 153 and 169 lowered EROD activity (de Jongh et al. 1992). Selected PCBs of low acute toxicity may increase the toxicity of compounds such as 2,3,7,8-TCDD (Bimbaum et al. 1985). Thus, PCB 153 or 157 at sublethal dosages (20 to 80 mg/kg BW) did not produce cleft palate deformities in mouse embryos. But a mixture of PCB 157 and 2,3,7,8-TCDD produced a tenfold increase in the incidence of palate deformities that were expected of 2,3,7,8-TCDD alone palate deformities did not increase with a mixture of PCB 153 and 2,3,7,8-TCDD. The widespread environmental occurrence of PCB-PCDD and PCB-PCDF combinations suggests a need for further evaluation of the mechanism of this interaction (Bimbaum et al. 1985). 

Fig. 5.5 Electrophoresis pattern of proteins in the allantoic fluid of chicken embryos. Lanes 1-3 intact fluid lanes 4-6 fluid after 6h of irradiation...

The genic pattern of a fertilized egg cell determines what the developing embryo is going to need during the course of its development. In certain species of mammals (e.g., rats), the over-all nutritional needs are qualitatively different from those of other species (e g., guinea pigs). In each individual within the human species, the needs are quantitatively different. 

Tanaka Y, Naruse I, Maekawa T, Masuya H, Shiroishi T, Ishu S (1997) Abnormal skeletal patterning in embryos lacking a single Cbp allele a partial similarity with Rubinstein-Taybi syndrome. Proc Natl... 

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