Abstract
Tau protein is a collection of closely related polypeptides that associate with microtubules in vivo and stimulate their assembly in vitro. Using an affinity-purified antiserum against bovine brain tau protein, it was found that the number and amount of tau polypeptides changes dramatically during mouse brain development. The different forms appear to result from changes in tau mRNA since in vitro translation products reflect the qualitative and quantitative changes found in vivo. To study the mRNA and genomic complexity of tau protein, tau mRNA, purified from polysomes with tau antiserum, was used to isolate embryonic mouse tau complementary DNA clones. With these probes it was determined that embryonic tau protein is translated from a 6-kb [kilobase] mRNA that persists throughout brain development.