DNA-dependent RNA-polymerases from Artemia embryos. characterization of polymerases I and II from nauplius larvae.

Partial purification and characterization of DNA-dependent RNA-polymerases from nauplius larvae of the brine shrimp, Artemia salina, are described. Fractionation of solubilized RNA-polymerases on columns of DEAE-cellulose yielded partially purified preparations of RNA polymerases I and II. The properties of these enzymes were found to be similar to properties of corresponding enzymes from other animal sources. A significant change in the relative amounts of polymerases I and II occurs between 36 and 72 hr of development. Polymerase activity obtained from 36-hr nauplii consisted of approximately equal amounts of polymerases I and II, whereas polymerase II accounted for more than 80% of the activity recovered from 72-hr nauplii. Total polymerase activity was lower at 72 than at 36 hr. The significance of these changes in relation to the decrease in RNA synthesis in vivo that occurs after 36 hr is discussed.