The TAF10-containing TFIID and SAGA transcriptional complexes are dispensable for early somitogenesis in the mouse embryo

Abstract

AbstractDuring development, tightly regulated gene expression programs control cell fate and patterning. A key regulatory step in eukaryotic transcription is the assembly of the pre-initiation complex (PIC) at promoters. The PIC assembly has mainly been studiedin vitro, and little is known about its composition during development.In vitrodata suggests that TFIID is the general transcription factor that nucleates PIC formation at promoters. Here we show that TAF10, a subunit of TFIID and of the transcriptional co-activator SAGA, is required for the assembly of these complexes in the mouse embryo. We performedTaf10conditional deletions during mesoderm development and show thatTaf10loss in the presomitic mesoderm (PSM) does not prevent cyclic gene transcription or PSM segmental patterning, while lateral plate differentiation is profoundly altered. During this period, global mRNA levels are unchanged in the PSM, with only a minor subset of genes dysregulated. Together, our data demonstrate that the TAF10-containing canonical TFIID and SAGA complexes, are dispensable for early paraxial mesoderm development, arguing against the generic role in transcription proposed for these fully assembled holo complexes.