Changes in the DNA polymerase beta gene expression during development of lung, brain, and testis suggest an involvement of the enzyme in DNA recombination.

Changes in the expression pattern of DNA polymerase beta gene during rat lung, brain, and testis development have been investigated. A decrease in the level of beta-pol mRNA was observed during postnatal development of lung and brain. By contrast, an almost 20-fold increase in the level of beta-pol mRNA was observed during spermatogenesis. For most adult rat tissues the abundance of beta-pol mRNA was low compared with that of beta-actin mRNA. Northern blot analysis revealed four distinct transcripts hybridizing to beta-pol probes. At least two of them, 1.4 kb and 4.0 kb, were products of a beta-polymerase gene. The changes in the expression pattern during lung and brain development, and during spermatogenesis, suggest involvement of DNA polymerase beta in gap-filling DNA synthesis during recombination.