Pascal Heitzler

Drosophila C-terminal binding protein, dCtBP is required for sensory organ prepattern and sharpens proneural transcriptional activity of the GATA factor Pnr

The peripheral nervous system is required for animals to detect and to relay environmental stimuli to central nervous system for the information processing. In Drosophila, the precise spatial and temporal expression of two proneural genes achaete (ac) and scute (sc), is necessary for development of the sensory organs. Here we present an evidence that the transcription co-repressor, dCtBP acts as a negative regulator of sensory organ prepattern. Loss of dCtBP function mutant exhibits ectopic sensory organs, while overexpression of dCtBP results in a dramatic loss of sensory organs. These phenotypes are correlated with mis-emerging of sensory organ precursors and perturbated expression of proneural transcription activator Ac. Mammalian CtBP-1 was identified via interaction with the consensus motif PXDLSX(K/R) of adenovirus E1A oncoprotein. We demonstrated that dCtBP binds directly to PLDLS motif of Drosophila Friend of GATA-1 protein, U-shaped and sharpens the adult sensory organ development. Moreover, we found that dCtBP mediates multivalent interaction with the GATA transcriptional activator Pannier and acts as a direct co-repressor of the Pannier-mediated activation of proneural genes. We demonstrated that Pannier genetically interacts with dCtBP-interacting protein HDAC1, suggesting that the dCtBP-dependent regulation of Pannier activity could utilize a repressive mechanism involving alteration of local chromatine structure.

The Rosa genome provides new insights into the domestication of modern roses

Roses have high cultural and economic importance as ornamental plants and in the perfume industry. We report the rose whole-genome sequencing and assembly and resequencing of major genotypes that contributed to rose domestication. We generated a homozygous genotype from a heterozygous diploid modern rose progenitor, Rosa chinensis ‘Old Blush’. Using single-molecule real-time sequencing and a meta-assembly approach, we obtained one of the most comprehensive plant genomes to date. Diversity analyses highlighted the mosaic origin of ‘La France’, one of the first hybrids combining the growth vigor of European species and the recurrent blooming of Chinese species. Genomic segments of Chinese ancestry identified new candidate genes for recurrent blooming. Reconstructing regulatory and secondary metabolism pathways allowed us to propose a model of interconnected regulation of scent and flower color. This genome provides a foundation for understanding the mechanisms governing rose traits and should accelerate improvement in roses, Rosaceae and ornamentals.High-quality genome assembly of diploid Rosa chinensis and resequencing of major genotypes highlights the origin of modern rose cultivars and provides insights into color biosynthesis and scent pathways.

01-P016 The Drosophila LIM-only, dLMO transcription factor that controls sensory organ and wing developments, is regulated by mir-9a

miRNA 5 end being fully complementary to the target mRNA, with binding of the 3 miRNA end varying. Many predictive algorithms have been produced to identify potential miRNA-target pairs. However many ignore full and near-full complementarity miRNA-mRNA pairs as they are considered unusual or potential false positives. However miRNA-mRNA pairs of this nature have been previously verified as functional in regulating a Hox gene (Yekta etal., 2004). Here we conducted a bioinformatics exploration of the possible full and near-full (to a maximum of 3 GU wobbles) miRNA-mRNA interactions across a number of different species (mouse, rat, human, chimp). We then assessed the candidate miRNA-mRNA pairs for their quality as probable targets with a specific focus in their possible involvement in developmental pathways.