The maize INDETERMINATE1 flowering time regulator defines a highly conserved zinc finger protein family in higher plants

BACKGROUND: The maize INDETERMINATE1 gene, ID1, is a key regulator of the transition to flowering and the founding member of a transcription factor gene family that encodes a protein with a distinct arrangement of zinc finger motifs. The zinc fingers and surrounding sequence make up the signature ID domain (IDD), which appears to be found in all higher plant genomes. The presence of zinc finger domains and previous biochemical studies showing that ID1 binds to DNA suggests that members of this gene family are involved in transcriptional regulation. RESULTS: Comparison of IDD genes identified in Arabidopsis and rice genomes, and all IDD genes discovered in maize EST and genomic databases, suggest that ID1 is a unique member of this gene family. High levels of sequence similarity amongst all IDD genes from maize, rice and Arabidopsis suggest that they are derived from a common ancestor. Several unique features of ID1 suggest that it is a divergent member of the maize IDD family. Although no clear ID1 ortholog was identified in the Arabidopsis genome, highly similar genes that encode proteins with identity extending beyond the ID domain were isolated from rice and sorghum. Phylogenetic comparisons show that these putative orthologs, along with maize ID1, form a group separate from other IDD genes. In contrast to ID1 mRNA, which is detected exclusively in immature leaves, several maize IDD genes showed a broad range of expression in various tissues. Further, Western analysis with an antibody that cross-reacts with ID1 protein and potential orthologs from rice and sorghum shows that all three proteins are detected in immature leaves only. CONCLUSION: Comparative genomic analysis shows that the IDD zinc finger family is highly conserved among both monocots and dicots. The leaf-specific ID1 expression pattern distinguishes it from other maize IDD genes examined. A similar leaf-specific localization pattern was observed for the putative ID1 protein orthologs from rice and sorghum. These similarities between ID1 and closely related genes in other grasses point to possible similarities in function

Seismic analysis of Fujian Hakka Tulous

The overall earthquake response of Hakka Tulous, traditional earth constructions of the Fujian Province (China) and listed among the UNESCO World Heritage buildings, is investigated. Non-linear static analysis (pushover) with the equivalent frame approach is used. Although some rough approximations are assumed, this approach is well suited to model complex masonry structures, like Tulous. In fact, nonlinear analysis implemented by finite elements or by discrete elements would involve complex models hard to converge and needing long computational time. After carrying out seismic analysis of a Tulou prototype, its failure modes and overall seismic response were evaluated. The Tulou has shown to have good earthquake resistance with respect to the maximum seismic action that can be expected in the Fujian Province

Monte-Carlo Simulations of the Suzaku-XRS Residual Background Spectrum

Cryogenic micro-calorimeters are suitable to detect small amounts of energy deposited by electromagnetic and nuclear interactions, which makes them attractive in a variety of applications on ground and in space. The only X-ray microcalorimeter that operated in orbit to date is the X-Ray Spectrometer on-board of the Japanese Suzaku satellite. We discuss the analysis of the components of its residual background spectrum with the support of Monte-Carlo simulations

Pain Behavior Changes Following Disc Puncture Relate to Nucleus Pulposus Rather than to the Disc Injury Per Se: An Experimental Study in Rats

It has previously been demonstrated that disc puncture in the rat induced changes in grooming and wet dog shakes, two behavioral changes that may be linked to discomfort and neuropathic pain. In this study the aim was to separate the effects of disc injury and the epidural presence of nucleus pulposus. Following anesthesia, the L4-5 disc was exposed using a dorsal approach. Ten rats received a superficial disc injury without nucleus pulposus leakage and ten rats received nucleus pulposus from a donor rat without disc injury. In ten animals the L4-5 disc was punctured using a ventral approach, with 10 corresponding controls. Spontaneous behavior was assessed after surgery. The data was matched to historical control of dorsal sham surgery and disc puncture. The study showed that the effects of nucleus pulposus were more pronounced than the effects induced by the disc injury. Ventral disc puncture did not induce any behavioral changes different from sham exposure. In conclusion, the data from the study indicate that behavioral changes induced by disc puncture are more likely to relate to the epidural presence of nucleus pulposus than the disc injury per se

Long-range effects of histone point mutations on DNA remodeling revealed from computational analyses of SIN-mutant nucleosome structures

The packaging of DNA into nucleosomes impedes the binding and access of molecules involved in its processing. The SWI/SNF multi-protein assembly, found in yeast, is one of many regulatory factors that stimulate the remodeling of DNA required for its transcription. Amino-acid point mutations in histones H3 or H4 partially bypass the requirement of the SWI/SNF complex in this system. The mechanisms underlying the observed remodeling, however, are difficult to discern from the crystal structures of nucleosomes bearing these so-called SIN (SWI/SNF INdependent) mutations. Here, we report detailed analyses of the conformations and interactions of the histones and DNA in these assemblies. We find that the loss of direct protein–DNA contacts near point-mutation sites, reported previously, is coupled to unexpected additional long-range effects, i.e. loss of intermolecular contacts and accompanying DNA conformational changes at sequentially and spatially distant sites. The SIN mutations seemingly transmit information relevant to DNA binding across the nucleosome. The energetic cost of deforming the DNA to the states found in the SIN-mutant structures helps to distinguish the mutants that show phenotypes in yeast from those that do not. Models incorporating these deformed dimer steps suggest ways that nucleosomal DNA may be remodeled during its biological processing

Effects of tryptophan depletion and tryptophan loading on the affective response to high-dose CO2 challenge in healthy volunteers

It has been reported that in panic disorder (PD), tryptophan depletion enhances the vulnerability to experimentally induced panic, while the administration of serotonin precursors blunts the response to challenges. Using a high-dose carbon dioxide (CO2) challenge, we aimed to investigate the effects of acute tryptophan depletion (ATD) and acute tryptophan loading (ATL) on CO2-induced panic response in healthy volunteers. Eighteen healthy volunteers participated in a randomized, double-blind placebo-controlled study. Each subject received ATD, ATL, and a balanced condition (BAL) in separate days, and a double-breath 35% CO2 inhalation 4.5 h after treatment. Tryptophan (Trp) manipulations were obtained adding 0 g (ATD), 1.21 g (BAL), and 5.15 g (ATL) of l-tryptophan to a protein mixture lacking Trp. Assessments consisted of a visual analogue scale for affect (VAAS) and panic symptom list. A separate analysis on a sample of 55 subjects with a separate-group design has also been performed to study the relationship between plasma amino acid levels and subjective response to CO2. CO2-induced subjective distress and breathlessness were significantly lower after ATD compared to BAL and ATL (p <0.05). In the separate-group analysis, Delta VAAS scores were positively correlated to the ratio Trp:I LNAA pound after treatment (r = 0.39; p <0.05). The present results are in line with preclinical data indicating a role for the serotonergic system in promoting the aversive respiratory sensations to hypercapnic stimuli (Richerson, Nat Rev Neurosci 5(6):449-461, 2004). The differences observed in our study, compared to previous findings in PD patients, might depend on an altered serotonergic modulatory function in patients compared to healthy subjects

Localization of an accessory helicase at the replisome is critical in sustaining efficient genome duplication

Genome duplication requires accessory helicases to displace proteins ahead of advancing replication forks. Escherichia coli contains three helicases, Rep, UvrD and DinG, that might promote replication of protein-bound DNA. One of these helicases, Rep, also interacts with the replicative helicase DnaB. We demonstrate that Rep is the only putative accessory helicase whose absence results in an increased chromosome duplication time. We show also that the interaction between Rep and DnaB is required for Rep to maintain rapid genome duplication. Furthermore, this Rep–DnaB interaction is critical in minimizing the need for both recombinational processing of blocked replication forks and replisome reassembly, indicating that colocalization of Rep and DnaB minimizes stalling and subsequent inactivation of replication forks. These data indicate that E. coli contains only one helicase that acts as an accessory motor at the fork in wild-type cells, that such an activity is critical for the maintenance of rapid genome duplication and that colocalization with the replisome is crucial for this function. Given that the only other characterized accessory motor, Saccharomyces cerevisiae Rrm3p, associates physically with the replisome, our demonstration of the functional importance of such an association indicates that colocalization may be a conserved feature of accessory replicative motors

Blunted endogenous opioid release following an oral amphetamine challenge in pathological gamblers

Pathological gambling is a psychiatric disorder and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher mu-opioid receptor (MOR) availability reported in alcohol, cocaine and opiate addiction. Impulsivity, a risk factor across the addictions, has also been found to be associated with higher MOR availability. The aim of this study was to characterize baseline MOR availability and endogenous opioid release in pathological gamblers (PG) using [(11)C]carfentanil PET with an oral amphetamine challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two [(11)C]carfentanil PET scans, before and after an oral administration of 0.5 mg/kg of d-amphetamine. The change in [(11)C]carfentanil binding between baseline and post-amphetamine scans (ΔBPND) was assessed in 10 regions of interest (ROI). MOR availability did not differ between PG and HV groups. As seen previously, oral amphetamine challenge led to significant reductions in [(11)C]carfentanil BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted amphetamine-induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions