Early Transcription Products Research Articles

Effects of 5-bromodeoxyuridine on rat embryo cell cultures.

Maxillary and mandibular tooth germs from 16-day old Wistar/Furth rat embryos were enzymically separated into epithelium and mesenchyme. The two germ layers were grownin-vitro separately as cell monolayers, and treated with 10 μg/ml of 5-bromodeoxyuridine (BrdU) for 24 h. The epithelioid cell monolayers adapted poorly toin-vitro conditions. The mesenchymal cells proliferated regardless of BrdU treatment. Typical C-type virus particles were released from mesenchymal cell cultures as early as 2 days following BrdU removal. Approximately 85% of thymine sequences were initially replaced by bromouracil, and decreased to less than 20% 10 days later. Whole-cell RNA synthesis gradually diminished following BrdU treatment, unlike the production of poly (A)-containing early transcription products. These findings suggest highly specific interactions between the analog and macromolecular biosynthesis.