Project description:The natural world is filled with substrates of varying properties that challenge locomotor abilities. Birds appear to transition smoothly from aerial to terrestrial environments during take-offs and landings using substrates that are incredibly variable. It may be challenging to control movement on and off compliant (flexible) substrates such as twigs, yet birds routinely accomplish such tasks. Previous research suggests that birds do not use their legs to harness elastic recoil from perches. Given avian mastery of take-off and landing, we hypothesized that birds instead modulate wing, body and tail movements to effectively use compliant perches. We measured take-off and landing performance of diamond doves (Geopelia cuneata (N = 5) in the laboratory and perch selection in this species in the field (N = 25). Contrary to our hypothesis, doves do not control take-off and landing on compliant perches as effectively as they do on stiff perches. They do not recover elastic energy from the perch, and take-off velocities are thus negatively impacted. Landing velocities remain unchanged, which suggests they may not anticipate the need to compensate for compliance. Legs and wings function as independent units: legs produce lower initial velocities when taking off from a compliant substrate, which negatively impacts later flight velocities. During landing, significant stability problems arise with compliance that are ameliorated by the wings and tail. Collectively, we suggest that the diamond dove maintains a generalized take-off and landing behavior regardless of perch compliance, leading us to conclude that perch compliance represents a challenge for flying birds. Free-living diamond doves avoid the negative impacts of compliance by preferentially selecting perches of larger diameter, which tend to be stiffer.
Project description:modENCODE_submission_5986 This submission comes from a modENCODE project of Jason Lieb. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: The focus of our analysis will be elements that specify nucleosome positioning and occupancy, control domains of gene expression, induce repression of the X chromosome, guide mitotic segregation and genome duplication, govern homolog pairing and recombination during meiosis, and organize chromosome positioning within the nucleus. Our 126 strategically selected targets include RNA polymerase II isoforms, dosage-compensation proteins, centromere components, homolog-pairing facilitators, recombination markers, and nuclear-envelope constituents. We will integrate information generated with existing knowledge on the biology of the targets and perform ChIP-seq analysis on mutant and RNAi extracts lacking selected target proteins. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf EXPERIMENT TYPE: CHIP-seq. BIOLOGICAL SOURCE: Strain: N2; Developmental Stage: L3 Larva; Genotype: wild type; Sex: mixed Male and Hermaphrodite population; EXPERIMENTAL FACTORS: Developmental Stage L3 Larva; temp (temperature) 20 degree celsius; Strain N2; Antibody NURF-1 SDQ3525 (target is NURF-1)
Project description:Trithorax group (TrxG) proteins counteract Polycomb silencing by an as yet uncharacterized mechanism. A well-known member of the TrxG is the histone methyltransferase Absent, Small, or Homeotic discs 1 (ASH1). In Drosophila ASH1 is needed for the maintenance of Hox gene expression throughout development, which is tightly coupled to preservation of cell identity. In order to understand the molecular function of ASH1 in this process, we performed affinity purification of tandem-tagged ASH1 followed by mass spectrometry (AP-MS) and identified FSH, another member of the TrxG as interaction partner. Here we provide genome-wide chromatin maps of both proteins based on ChIP-seq. Our Dataset comprises of 4 ChIP-seq samples using chromatin from S2 cells which was immunoprecipitated, using antibodies against Ash1, FSH-L and FSH-SL.