TBP-like factor is required for embryonic RNA polymerase II transcription in C-elegans

Recently, a novel family of TATA binding protein (TBP)like factors (TLFs) h ave been described in metazoan organisms; however, their function has not y et been elucidated. Using Caenorhabditis elegans (Ce) as a model, we demons trate that CeTLF is required in vivo for zygotic transcription during embry ogenesis. Elimination of CeTLF expression by RNA interference caused embryo nic lethality either due to the lack of expression of early patterning gene s or to their ectopic expression. Moreover, the absence of CeTLF in vivo pr evented the correct soma-specific phosphorylation of RNA polymerase II (Pol II). Thus, CeTLF may positively or negatively regulate Pol II transcriptio n, depending on the developmental stage of the embryo.