Guilgur, Leonardo GastónPrudencio, PedroSobral, DanielLiszekova, DenisaRosa, AndreMartinho, Rui Goncalo2018-12-072018-12-072014-042050-084Xhttp://hdl.handle.net/10400.1/11124Drosophila syncytial nuclear divisions limit transcription unit size of early zygotic genes. As mitosis inhibits not only transcription, but also pre-mRNA splicing, we reasoned that constraints on splicing were likely to exist in the early embryo, being splicing avoidance a possible explanation why most early zygotic genes are intronless. We isolated two mutant alleles for a subunit of the NTC/Prp19 complexes, which specifically impaired pre-mRNA splicing of early zygotic but not maternally encoded transcripts. We hypothesized that the requirements for pre-mRNA splicing efficiency were likely to vary during development. Ectopic maternal expression of an early zygotic pre-mRNA was sufficient to suppress its splicing defects in the mutant background. Furthermore, a small early zygotic transcript with multiple introns was poorly spliced in wild-type embryos. Our findings demonstrate for the first time the existence of a developmental pre-requisite for highly efficient splicing during Drosophila early embryonic development and suggest in highly proliferative tissues a need for coordination between cell cycle and gene architecture to ensure correct gene expression and avoid abnormally processed transcripts.engSpliceosome activationGene-expressionMitotic-cyclesCell-cycleIn-vivoTranscriptionComplexNuclearRevealsEmbryogenesisjournal article10.7554/eLife.02181