Functions of DNA Polymerases , , and in Neurons during Development

Abstract

The rapid rise of interest recently in the DNA polymerases of vertebrate and especially of mammalian cells has led to a good knowledge of the chemical, physical, and catalytic properties of three DNA polymerases, named α, β, and γ (Bollum 1975; Weissbach 1977; Falaschi and Spadari 1978). In contrast, identification of their respective functions has lagged behind. This is due to the lack of eukaryotic cell mutants defective in DNA replication. Contrary to prokaryotes (Kornberg 1974), where conditional mutants have allowed a direct correlation between functional deficiency and specific action of the DNA polymerases, the experimental strategy with eukaryotes has been to compare individual levels of DNA polymerase activities in dividing and resting cells, thus providing only indirect and suggestive evidence for the roles played by the various DNA polymerases. We have approached this question by using neurons of different developmental stages (Hübscher et al. 1978), where Nature has provided...