Interrelationships between Lysine and ac - Diaminopimelic Acid and their Derivatives and Analogues in Mutants of Escherichia coli

1. An increase ofglutamic dehydrogenase (GDH) activity in yolk of the hen's egg has been shown to occur in the mid-incubation period. 2. Generally, the levels of GDH in embryonic tissues are less than those of tissues ofthe hen except for the blastoderm and 2-day-old embryo, which have GDH levels as high as those ofsomehen tissues. 3. GDHhasbeenfoundtoincreaseparipa88uwith total protein in the whole embryo and yolk sac from the fourth and sixth day of incubation respectively. 4. GDH activity in the chick embryo and its extra-embryonic tissues during development has been shown to have similarities with certain other enzyme activities. 5. In certain tissues of chick embryos during later developmental stages considerable surges of activity are found to occur which may be associated with functional differentiation.