Carbonic Anhydrase Activity in Early Developing Chick Embryos
Changes in tension of environmental CO2 gas have been shown to affect cellular differentiation. In the presence of increased partial pressure of dissolved CO2(pCO2) Loomis (1957) has demonstrated an increase in sexual differentiation of hydra and Flickinger (1958) has caused explanted frog ectoderm to differentiate into neural tissue. Loomis was able to show that the substance which stimulates sexual differentiation in crowded cultures of Hydra littoralis is dissolved CO2 gas. Flickinger could produce a definite increase of neural tissue induction by bubbling CO2 gas through the culture media for a 10–20-minute period. Trinkaus & Drake (1959) have reported an analysis of the stimulating effect of PCO2 on development of the embryo of Fundulus heteroclitus. For these reasons it seemed important to study an enzyme which utilizes CO2 as a substrate. The appearance of carbonic anhydrase activity in early developing embryos which are producing CO2 might lead to a reduced CO2 tension (H2O+CO2⇆H2CO3).
The Wavy Erythropoiesis of Developing Chick Embryos. Isolation of Each Wave by a Differential Lysis and Identification of the Constituent Erythroid Types. (chick embryos/carbonic anhydrase activity/erythropoietic organs/ wave of erythropoiesis)
