Project description:We report the genome-wide analysis from chromatin immunoprecipitated DNA (ChIP-sequencing) at very high resolution of the DNA binding pattern of ParBF (SopB) either on the full length plasmid F or on E. coli chromosome carrying the parSF centromere sequence. We also varied the intracellular ParBF concentration to discriminate between the several proposed mechanism of partition complexes assembly.
Project description:We used an approach combining PacBio data and published Illumina reads to de novo assemble D. busckii contigs. We generated Hi-C data from D. busckii embryos to order these contigs into chromosome-length scaffolds. For D. virilis we generated Hi-C data to order and orient the published Dvir_caf1 scaffolds into chromosome-length assemblies. Furthermore, we compared Hi-C matrices from these two new assemblies with D. melanogaster with respect to synteny blocks and dosage compensation as a chromosome-wide gene-regulatory mechanism.
Project description:Nanopore Sequencing and assembly of Col-0 carrying seed coat expressed GFP and RFP transgenes flanking the centromere of chromosome 3 (CTL 3.9) - additionally, DNA methylation was derived using deepsignal-plant using these reads.
Project description:Condensin drives mitotic chromosome assembly by folding chromatin into loops and is enriched in the vicinity of highly expressed genes, but the significance of such proximity with respect to condensin activity has remained unclear. Here, by modulating the occupancy of RNA Pol II in vivo, we show that transcription plays no role in the steady state association of condensin with DNA. Rather, transcription stalls and even displaces condensin, hindering its ability to fold chromatin and to support chromosome segregation. Our results highlight a key aspect of the integrated functioning of condensin and suggest that a tight control of transcription underlies mitotic chromosome assembly.
Project description:The majority of bird species studied to date have molt schedules that are not concurrent with other energy demanding life history stages, an outcome assumed to arise from energetic trade-offs. Empirical studies reveal that molt is one of the most energetically demanding and perplexingly inefficient growth processes measured. Furthermore, small birds, which have the highest mass-specific basal metabolic rates (BMR(m)), have the highest costs of molt per gram of feathers produced. However, many small passerines, including white-plumed honeyeaters (WPHE; Lichenostomus penicillatus), breed in response to resource availability at any time of year, and do so without interrupting their annual molt. We examined the energetic cost of molt in WPHE by quantifying weekly changes in minimum resting metabolic rate (RMR(min)) during a natural-molt period in 7 wild-caught birds. We also measured the energetic cost of feather replacement in a second group of WPHEs that we forced to replace an additional 25% of their plumage at the start of their natural molt period. Energy expenditure during natural molt revealed an energy conversion efficiency of just 6.9% (±0.57) close to values reported for similar-sized birds from more predictable north-temperate environments. Maximum increases in RMR(min) during the molt of WPHE, at 82% (±5.59) above individual pre-molt levels, were some of the highest yet reported. Yet RMR(min) maxima during molt were not coincident with the peak period of feather replacement in naturally molting or plucked birds. Given the tight relationship between molt efficiency and mass-specific metabolic rate in all species studied to date, regardless of life-history pattern (Efficiency (%) ?=?35.720 x 10(-0.494BMRm); r²?=?0.944; p? =? or < 0.0001), there appears to be concomitant physiological costs entrained in the molt period that is not directly due to feather replacement. Despite these high total expenditures, the protracted molt period of WPHE significantly reduces these added costs on a daily basis.