Project description:Chromatin loops are a major componant of 3D nuclear organization that appear as intense point-to-point interactions in Hi-C maps. Identification of these loops is an important part of Hi-C analysis. We present SIP, Significant Interaction Peak caller, a platform independent program to identify these loops in a time and memory efficient manner and which is resistant to noise and sequencing depth. We also present a companion tool, SIPMeta, to create more visually accurate average plots of Hi-C and HiChIP data. We then demonstrate that use of SIP and SIPMeta can lead to biological insight through characterizing the contribution of several transcription factors to CTCF loops in human cells. We then use SIP and SIPMeta to discover loops associated with condensin IDCC in C. elegans and confirm these loops by HiChIP. These loops form a network of interactions and likely explain the partial condensation of dosage compensated X chromosomes in hermaphrodites.
Project description:Polychlorinated dibenzo-p-dioxins and dibenzofurans are a group of chemcially-related pollutants categorically known as dioxins. We used Sphingomonas wittichii strain RW1 (RW1), one of the few strains able to grow on dioxin, to characterize its ability to respond to and degrade clay-bound dioxin. Strain RW1 grew on and completely degraded dioxin intercalated in smectite clay. To characterize the effects of sorption and bioavailability of dioxin on RW1, transcriptomes of RW1 either grown with dioxin intercalated to clay (DDSAP) or with free crystalline dioxin (DD) were sequenced using RNA-Seq. While either condition caused RW1 large-scale shifts in gene expression compared to succinate control (SUC), differences in gene expression between these two conditions were marked by a small number (86) of differentially expressed genes. The differences in gene expression may reflect the underlying adaptive mechanisms by which RW1 cells sense and deploy pathways to access dioxin intercalated in the clay.
Project description:Impact of aggregate size and clay content on the bacterial community structure in soil microaggregates and macroaggregates of a clay catena
Project description:In order to obtain a global view on the transcriptional changes induced by the sex-inducing pheromone released by Seminavis robusta mating type plus cells (SIP+), an RNA-seq experiment was conducted. Therefore, purified SIP+ from RP-UPLC/MS was added to MT- cultures, 15 min before light onset after a prolonged dark period. MT- cultures without extract addition constituted the control conditions. Samples were taken after 15 min, 1 h and 3 h of illumination. An additional, non-treated MT- culture was harvested before illumination.
