Establishment of cell fate during early Drosophila embryogenesis requires transcriptional Mediator subunit dMED31.
During early Drosophila embryogenesis, formation of the anterior-posterior (A/P) axis depends on spatial gradients of maternal morphogens. It is well recognized that positional information is transmitted from these morphogens to the gap genes. However, how this information is being transmitted is largely unknown. The transcriptional Mediator complex is involved in the fine tuning of the signaling between chromatin status, transcription factors and the RNA polymerase II transcription machinery. We found that a mutation in the conserved subunit of the Mediator complex, dMED31, hampers embryogenesis prior to gastrulation and leads to aberrant expression of the gap genes knirps and Krüppel and the pair-rule genes fusi tarazu and even-skipped along the A/P axis. Expression of the maternal morphogens dorsal and hunchback was not affected in dMED31 mutants. mRNA expression of dMED31 exactly peaks between the highest expression levels of the maternal genes and the gap genes. Together, our results point to a role for dMED31 in guiding maternal morphogen directed zygotic gap gene expression and provide the first in vivo evidence for a role of the Mediator complex in the establishment of cell fate during the cellular blastoderm stage of Drosophila melanogaster.
Bosveld
Floris
F
Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Centre Groningen, University of Groningen, Ant. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
van Hoek
Sjoerd
S
Sibon
Ody C M
OC
D000818:Animals; D001756:Blastoderm / Q000166:cytology; D019521:Body Patterning; D002843:Chromatin / Q000378:metabolism; D004330:Drosophila / Q000166:cytology* / Q000196:embryology* / Q000235:genetics; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D004625:Embryo, Nonmammalian; D047108:Embryonic Development; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005786:Gene Expression Regulation; D017344:Genes, Insect; D005809:Genes, Regulator; D056892:Mediator Complex; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics; D012319:RNA Polymerase II / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019076:Transgenes
D002843:Chromatin; D029721:Drosophila Proteins; C526783:Med31 protein, Drosophila; D056892:Mediator Complex; D009687:Nuclear Proteins; C092281:PSI protein, Drosophila; D021122:Protein Subunits; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D012319:RNA Polymerase II; D016650:Fluorescein-5-isothiocyanate