Distinct Roles for TBP and TBP-Like Factor in Early Embryonic Gene Transcription in Xenopus

The TATA-binding protein (TBP) is believed to function as a key component of the general transcription machinery. We tested the role of TBP during the onset of embryonic transcription by antisense oligonucleotide-mediated turnover of maternal TBP messenger RNA. Embryos without detectable TBP initiated gastrulation but died before completing gastrulation. The expression of many genes transcribed by RNA polymerase II and III was reduced; however, some genes were transcribed with an efficiency identical to that of TBP-containing embryos. Using a similar antisense strategy, we found that the TBP-like factor TLF/TRF2 is essential for development past the mid-blastula stage. Because TBP and a TLF factor play complementary roles in embryonic development, our results indicate that although similar mechanistic roles exist in common, TBP and TLF function differentially to control transcription of specific genes.