Toward the identification and regulation of the Arabidopsis thaliana ABI3 regulon.

The plant-specific, B3 domain-containing transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3) is an essential component of the regulatory network controlling the development and maturation of the Arabidopsis thaliana seed. Genome-wide chromatin immunoprecipitation (ChIP-chip), transcriptome analysis, quantitative reverse transcriptase-polymerase chain reaction and a transient promoter activation assay have been combined to identify a set of 98 ABI3 target genes. Most of these presumptive ABI3 targets require the presence of abscisic acid for their activation and are specifically expressed during seed maturation. ABI3 target promoters are enriched for G-box-like and RY-like elements. The general occurrence of these cis motifs in non-ABI3 target promoters suggests the existence of as yet unidentified regulatory signals, some of which may be associated with epigenetic control. Several members of the ABI3 regulon are also regulated by other transcription factors, including the seed-specific, B3 domain-containing FUS3 and LEC2. The data strengthen and extend the notion that ABI3 is essential for the protection of embryonic structures from desiccation and raise pertinent questions regarding the specificity of promoter recognition.

Spatial Design of Guest Feeding Programs and Their Effects on Giraffe Participation and Social Interactions.

Guest-animal feeding programs (GFPs) in zoological institutions aim to foster human-animal connections. The growing establishment of animal welfare science emphasizes the assessment of GFPs as permanent environmental inputs to habitats that require analysis of behavioral output. This study assessed the role of space allocation on giraffe participation and interactions in GFPs in two Florida zoos.Analysis of social structure indicates that centrality and influence from affiliative network on exhibit shape sharing interactions at GFPs under varying management protocols and designs. Findings suggest that interactions and significant ties among conspecifics are context and potentially temporally dependent. We propose the use of multiple guest engagement stations to maximize space and facilitate feeding opportunities for central and peripheral members. This proposed shift would provide variable feeding opportunities that represent group composition following ecological theory while maximizing points of guest engagement. Results indicate that increasing space allocation for GFPs increased feeding bout length for individuals, percent of time sharing among conspecifics, and reduced average rate of displacement/minute. Cross-institutional comparisons indicate that guest programs with more space allocation have lower rates of conspecific displacement.

The effects of warm water immersion on blood pressure, heart rate and heart rate variability in people with chronic fatigue syndrome.

BACKGROUND: Chronic fatigue syndrome (CFS) is a central sensitisation syndrome with abnormalities in autonomic regulation of blood pressure (BP), heart rate (HR) and heart rate variability (HRV). Prior to exploring the effects of hydrotherapy as a treatment for this population, changes in BP, HR and HRV during warm water immersion need to be established. OBJECTIVES: The study aimed to determine the effects of warm water immersion on BP, HR and HRV in adults with CFS compared to matched-pair healthy adults. METHOD: A quasi-experimental, single-blinded study design was used with nine CFS participants and nine matched controls. Participants' BP, HR and HRV were measured before, after 5 minutes and post warm water immersion at the depth of the fourth intercostal space, using the Ithlete® System and Dräger BP monitor. RESULTS: There was a significant difference between groups in HRV prior to immersion (control group: 73 [55-74] vs. chronic fatigue syndrome group: 63 [50-70]; p = 0.04). There was no difference in HRV post-immersion. A significant difference in HR after immersion was recorded with the control group having a lower HR than those with CFS (78 [60-86] vs. 86 [65-112]; p = 0.03). The low HRV present in the CFS group prior to immersion suggests autonomic dysregulation. Individuals with CFS may have reduced vagal nerve activation post-immersion. During immersion, HRV of the CFS participants improved similar to that of the healthy controls. CONCLUSION: Prior to immersion, differences were present in the HRV of the participants with CFS compared to healthy controls. These differences were no longer present post-immersion. CLINICAL IMPLICATIONS: Warm water immersion appears safe and may be beneficial in the management of individuals with CFS.

On the value of intra-motif dependencies of human insulator protein CTCF.

The binding affinity of DNA-binding proteins such as transcription factors is mainly determined by the base composition of the corresponding binding site on the DNA strand. Most proteins do not bind only a single sequence, but rather a set of sequences, which may be modeled by a sequence motif. Algorithms for de novo motif discovery differ in their promoter models, learning approaches, and other aspects, but typically use the statistically simple position weight matrix model for the motif, which assumes statistical independence among all nucleotides. However, there is no clear justification for that assumption, leading to an ongoing debate about the importance of modeling dependencies between nucleotides within binding sites. In the past, modeling statistical dependencies within binding sites has been hampered by the problem of limited data. With the rise of high-throughput technologies such as ChIP-seq, this situation has now changed, making it possible to make use of statistical dependencies effectively. In this work, we investigate the presence of statistical dependencies in binding sites of the human enhancer-blocking insulator protein CTCF by using the recently developed model class of inhomogeneous parsimonious Markov models, which is capable of modeling complex dependencies while avoiding overfitting. These findings lead to a more detailed characterization of the CTCF binding motif, which is only poorly represented by independent nucleotide frequencies at several positions, predominantly at the 3' end.

Phylogenetic footprints in fern spore- and seed-specific gene promoters.

Spermatophyte seed-storage proteins have descended from a group of proteins involved in cellular desiccation/hydration processes. Conserved protein structures are found across all plant phyla and in the fungi and Archaea. We investigated whether conservation in the coding region sequence is paralleled by common gene regulatory processes. Seed- and spore-specific gene promoters of three phylogenetically diverse plants were analysed by transient and transgenic expression in Arabidopsis thaliana and tobacco. The transcription factors FUS3 and ABI3, which are central regulators of seed maturation processes, interact with cis-motifs of seed-specific promoters from distantly related plants. The promoter of a fern spore-specific gene encoding a seed-storage globulin-like protein exhibits strong seed-specific activity in both Arabidopsis and tobacco. The existence of phylogenetic footprints indicates good conservation of regulatory pathways controlling gene expression in fern spores and in gymnosperm and angiosperm seeds, reflecting the concerted evolution of coding and regulatory regions.