Chick embryos tracing

GreenVA. 1970. Effects of pesticides on rat and chick embryo. Trace Substances in Environmental Health - III, 183-209. 

Using Fluorescent Dyes for Fate Mapping, Lineage Analysis, and Axon Tracing in the Chick Embryo... 

The metabolic pathways discussed above were based on experiments performed on adult animals. It was recently shown that tissues of chick and calf embryo exhibit certain peculiarities of sulfur metabolism which distinguish them from tissues of adult animals. Chapeville and Fromageot (36) observed that chick embryos in vivo rapidly utilize the S of SOs for the formation of taurine. It was shown that in the embryo hypotaurine is not a precursor of taurine and only yields traces of S04, while cysteate is rapidly decarboxylated to taurine. This pathway differs from that of adult animals where hypotaurine is readily degraded to SO4 (36). Further work of Chapeville et al. (37) suggests that the enzymic mechanism of this process in the embryo is compatible with the following reactions ... 

Chick edema disease became a serious economic problem by the mid-1950s, by which time millions of broilers had succumbed to it in the U.S. The problem was traced to toxic components in the unsaponifiable fraction of certain low cost feed fats Introduced into the chick diet to increase the caloric intake (ref. 121c). Symptoms included fluid in the heart sack and abdominal cavity, subcutaneous edema and liver necrosis. Injection of purified chick edema factor into fertile eggs resulted in lower hatch yield, embryonic deformities and edema. Unhatched embryos exhibited a variety of defects (malformed beaks, leg deformities, no development of the right mesencephalon, and eye defects). Hatched embryos were growth-retarded, with sparse and defective feathers. The isolated toxin was ultimately identified as 1.2,3,7.8,9-... 

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