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 β gene during rat lung, brain, and testis development have been investigated. A decrease in the level of β-pol mRNA was observed during postnatal development of lung and brain. By contrast, an almost 20-fold increase in the level of β-pol mRNA was observed during spermatogenesis. For most adult rat tissues the abundance of β-pol mRNA was low compared with that of β-actin mRNA. Northern blot analysis revealed four distinct transcripts hybridizing to β-pol probes. At least two of them, 1.4 kb and 4.0 kb, were products of a β-polymerase gene. The changes in the expression pattern during lung and brain development, and during spermatogenesis, suggest involvement of DNA polymerase β in gap-filling DNA synthesis during recombination. © 1990.