Immunological detection of a DNA polymerase-β polypeptide in embryonic cysts and larvae of the brine shrimp Artemia

Abstract

1. 1. When embryonic cysts and larvae of Artemia were extracted under various conditions, no enzyme activity with properties characteristic of DNA polymerase-β could be detected either by glycerol density gradient analysis or by electrophoresis in “SDS-activity gels”. 2. 2. However when nitrocellulose blots of electrophoretically separated polypeptides were probed with an antibody raised against chick embryo DNA polymerase-β a polypeptide of M r ∼ 48,000 was detected in the cytoplasmic fraction of cysts and nauplius larvae but not at later stages of development. 3. 3. Either the Artemia DNA polymerase-β is extremely labile to extraction or it exists in an inactive cytoplasmic form in cysts and larvae.