An intronic SNP of <i>PPARG</i> and its association with fat traits in four meat-type duck populations (Brief report)

Abstract. Modern strains of ducks exhibit excessive body fat deposition, which is one of the main problems encountered by duck industry today. Excess fat deposition has led commercial breeders to incorporate significant selection for reduced body fatness in breeding programs. Peroxisome proliferators-activated receptors (PPARs) belong to the nuclear receptor superfamily (SCHOONJANS et al., 1996). In particular peroxisome proliferators-activated receptor gamma, PPARG has been implicated in the regulation of lipid metabolism and, consequently, in diseases that involve disturbances in lipid metabolism (obesity, diabetes, atherosclerosis, cardiac failure) (VAN et al., 2002). Thus PPARG is a candidate gene for traits related to fat deposition.

The next generation of electron cyclotron emission imaging diagnostics (invited)

A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16x8 images of T(e) profiles and fluctuations on the TEXTOR tokamak. Electron cyclotron emission imaging (ECEI) is undergoing significant changes which promise to revolutionize and extend its capabilities far beyond what has been achieved to date. These include the development of a minilens array configuration with increased sensitivity antennas, a new local oscillator pumping scheme, enhanced electron cyclotron resonance heating shielding, and a highly flexible optical design with vertical zoom capability. Horizontal zoom and spot size (rf bandwidth) capabilities are also being developed with new ECEI electronics. An interface module is under development to remotely control all key features of the new ECEI instrument, many of which can be changed during a plasma discharge for maximum flexibility.

Fine scale genetic and physical mapping using interstitial deletion mutants of Lr34 /Yr18: a disease resistance locus effective against multiple pathogens in wheat

The Lr34/Yr18 locus has contributed to durable, non-race specific resistance against leaf rust (Puccinia triticina) and stripe rust (P. striiformis f. sp. tritici) in wheat (Triticum aestivum). Lr34/Yr18 also cosegregates with resistance to powdery mildew (Pm38) and a leaf tip necrosis phenotype (Ltn1). Using a high resolution mapping family from a cross between near-isogenic lines in the "Thatcher" background we demonstrated that Lr34/Yr18 also cosegregated with stem rust resistance in the field. Lr34/Yr18 probably interacts with unlinked genes to provide enhanced stem rust resistance in "Thatcher". In view of the relatively low levels of DNA polymorphism reported in the Lr34/Yr18 region, gamma irradiation of the single chromosome substitution line, Lalbahadur(Parula7D) that carries Lr34/Yr18 was used to generate several mutant lines. Characterisation of the mutants revealed a range of highly informative genotypes, which included variable size deletions and an overlapping set of interstitial deletions. The mutants enabled a large number of wheat EST derived markers to be mapped and define a relatively small physical region on chromosome 7DS that carried Lr34/Yr18. Fine scale genetic mapping confirmed the physical mapping and identified a genetic interval of less than 0.5 cM, which contained Lr34/Yr18. Both rice and Brachypodium genome sequences provided useful information for fine mapping of ESTs in wheat. Gene order was more conserved between wheat and Brachypodium than with rice but these smaller grass genomes did not reveal sequence information that could be used to identify a candidate gene for rust resistance in wheat. We predict that Lr34/Yr18 is located within a large insertion in wheat not found at syntenic positions in Brachypodium and rice.

The UL31 to UL35 gene sequences of Duck enteritis virus correspond to their homologs in herpes simplex virus 1

Five ORFs in the genome of Duck enteritis virus (DEV) corresponding to UL31, UL32, UL33, UL34, and UL35 genes of Herpes simplex virus 1 (HSV-1) were amplified by a modified "targeted gene walking" PCR, cloned, and sequenced. UL33, UL34, and UL35 genes were oriented from the left to the right of genome, while UL31 and UL32 had an opposite orientation. A comparison of deduced amino acid sequences of the DEV ORFs with their alphaherpesvirus homologs showed well-conserved regions except for the UL34 and UL35 genes. Phylogenetic analysis revealed that DEV was closer to the genus Mardivirus than to any other genus of the subfamily Alphaherpesvirinae. Based on this evidence, we proposed to assign DEV to the subfamily Alphaherpesvirinae.

Systemic oxytocin and vasopressin excite gastrointestinal motility through oxytocin receptor in rabbits

The aim of the present study was to investigate the effect of systemic oxytocin (OT) and vasopressin (VP) on the motility of stomach and duodenum. Two plastic balloons made of condom were inserted into stomach and duodenum to monitor the change of mean pressure. Intravenous injection of OT (0.1-0.8 microg kg(-1)) or VP (0.02-0.08 IU kg(-1)) dose-dependently increased the stomach and duodenum pressure. Pretreatment of atosiban (1 microg kg(-1)), the specific OT receptor (OTR) antagonist, attenuated the excitatory effect of OT or VP on the pressure of stomach and duodenum. Pretreatment of V1880 (1 microg kg(-1)), the specific V1 receptor blocker, did not influence this effect. So we conclude that both of OT and VP injected systemically increased the gastric and duodenum motility via OTR.

Practical aspects of planning, building, and interpreting tissue microarrays: The Cooperative Prostate Cancer Tissue Resource experience

This is a review of several new approaches developed at or adopted by the Cooperative Prostate Cancer Tissue Resource (CPCTR) to resolve issues involved in tissue microarray (TMA) construction and use. CPCTR developed the first needle biopsy TMA, allowing researchers to obtain 200 or more consecutive cancer sections from a single biopsy core. Using radiographs of original paraffin blocks to measure tissue thickness we developed a method to produce TMAs with a larger number of usable sections. The modular approach to plan TMA construction is also a novel concept wherein TMAs of different types, such as tumor grade TMAs, metastasis TMA and hormone refractory tumors TMA can be combined to form an ensemble of TMAs with expanded research utility, such as support for tumor progression studies. We also implemented an open access TMA Data Exchange Specification that allows TMA data to be organized in a self-describing XML document annotated with well-defined common data elements. It ensures inter-laboratory reproducibility because it offers information describing the preparation of TMA blocks and slides. There are many important aspects that may be missed by both beginners and experienced investigators in areas of TMA experimental design, human subjects protection, population sample size, selection of tumor areas to sample, strategies for saving tissues, choice of antibodies for immunohistochemistry, and TMA data management.

Wheat genome structure and function: genome sequence data and the International Wheat Genome Sequencing Consortium

Genome sequencing and the associated bioinformatics is now a widely accepted research tool for accelerating genetic research and the analysis of genome structure and function of wheat because it leverages similar work from other crops and plants. The International Wheat Genome Sequencing Consortium addresses the challenge of wheat genome structure and function and builds on the research efforts of Professor Bob McIntosh in the genetics of wheat. Currently, expressed sequence tags (ESTs; ~500 000 to date) are the largest sequence resource for wheat genome analyses. It is estimated that the gene coverage of the wheat EST collection is ~60%, close to that of Arabidopsis, indicating that ~40% of wheat genes are not represented in EST collections. The physical map of the D-genome donor species Aegilops tauschii is under construction (http://wheat.pw.usda.gov/PhysicalMapping). The technologies developed in this analysis of the D genome provide a good model for the approach to the entire wheat genome, namely compiling BAC contigs, assigning these BAC contigs to addresses in a high resolution genetic map, filling in gaps to obtain the entire physical length of a chromosome, and then large-scale sequencing.

Relationships among genotypes, virulence and clinical forms of Sporothrix schenckii infection

This study explored the relationships among genotypes, virulence and clinical forms of Sporothrix schenckii. Genomic DNA from isolates of S. schenckii, collected from different clinical forms of sporotrichosis, was amplified by randomly amplified polymorphic DNA (RAPD). Suspensions of different isolates of S. schenckii were inoculated into healthy BALB/c mice to compare their virulence, and the numbers and distribution of spores were determined by histological analysis. RAPD analysis indicated that the isolates from different clinical forms of sporotrichosis belonged to different genotypes. The mice inoculated with isolates from disseminated sporotrichosis showed an earlier onset of illness and more severe lesions than those inoculated with isolates from lymphocutaneous sporotrichosis, which, in turn, showed an earlier onset of illness and more severe lesions than those inoculated with isolates from fixed cutaneous sporotrichosis. Healthy BALB/c mice injected with isolates from disseminated sporotrichosis died within 10 days, whereas isolates from lymphocutaneous sporotrichosis and fixed cutaneous sporotrichosis failed to cause death. Histologically, mice inoculated with isolates from disseminated sporotrichosis had more spores than those inoculated with isolates from lymphocutaneous sporotrichosis and fixed cutaneous sporotrichosis. Thus, different genotypes may be associated closely with the virulence of different clinical forms of S. schenckii infection.

Effect of cardiac lymph flow obstruction on cardiac collagen synthesis and interstitial fibrosis

The effect of chronic cardiac lymphatic obstruction on the myocardial synthesis of collagen type I and III was investigated in a rabbit model. In the lymphatic obstruction group (n=16), plasma C-terminal propeptide type I procollagen (PICP) and N-terminal propeptide type III procollagen (PIIINP) were elevated at 7, 14 and 30 days after the operation (p<0.05). The elevated PICP and PIIINP returned to the pre-operation values 60 days after the operation. The myocardial expression of collagen type I and III mRNA were also enhanced in the lymphatic flow obstruction group. Plasma PICP, PIIINP and myocardial collagen type I and III mRNA remained unchanged in the control group (n=16). We concluded that chronic obstruction of cardiac lymph flow leads to enhanced myocardial collagen synthesis in rabbits. The enhanced collagen synthesis starts within seven days after lymphatic obstruction and subsides after 60 days.

The rapid formation of a large rotating disk galaxy three billion years after the Big Bang

Observations and theoretical simulations have established a framework for galaxy formation and evolution in the young Universe. Galaxies formed as baryonic gas cooled at the centres of collapsing dark-matter haloes; mergers of haloes and galaxies then led to the hierarchical build-up of galaxy mass. It remains unclear, however, over what timescales galaxies were assembled and when and how bulges and disks--the primary components of present-day galaxies--were formed. It is also puzzling that the most massive galaxies were more abundant and were forming stars more rapidly at early epochs than expected from models. Here we report high-angular-resolution observations of a representative luminous star-forming galaxy when the Universe was only 20% of its current age. A large and massive rotating protodisk is channelling gas towards a growing central stellar bulge hosting an accreting massive black hole. The high surface densities of gas, the high rate of star formation and the moderately young stellar ages suggest rapid assembly, fragmentation and conversion to stars of an initially very gas-rich protodisk, with no obvious evidence for a major merger.

Peroneal F-wave characteristics under submaximal stimulation

PURPOSE

F-wave studies are valuable tools in clinical neurophysiology. F-wave parameter estimation must be based on multiple F-wave traces due to their inherent variability. Repetitive supramaximal stimulation is uncomfortable for many patients. This study tested the hypothesis that submaximally stimulated nerves yield F-wave parameters equivalent to those obtained with supramaximal stimulation.

METHODS

Thirty-five peroneal nerves from 27 subjects were stimulated both supramaximally and submaximally. CMAP and F-wave responses from the extensor digitorum brevis muscle were recorded and analyzed offline. Automated algorithms were used to determine F-wave parameters.

RESULTS

Mean, minimum, maximum F-wave latencies, F-wave duration, and chronodispersion showed no statistically significant difference under the two stimulation conditions. F-wave persistence, amplitude, and subject's discomfort level, were lower with statistical significance. The correlation coefficient of submaximal and supramaximal mean F-wave latencies was 0.977 and their intraclass correlation coefficient was 0.976. The bias of the mean latencies was 0.21 ms and the 95% limits of agreement were less than 5% of the mean F-wave latency.

CONCLUSIONS

F-waves acquired with submaximal stimulation possess characteristics statistically equivalent to those obtained under supramaximal stimulation, as measured by the latency and duration parameters. Persistence and amplitude were lower. Reduction in discomfort level was also achieved.

Composition fluctuations in dilute nitride (Ga,In)(N,As)/GaAs heterostructures measured by low-loss electron energy-loss spectroscopy

We report on the investigation of composition fluctuations in epitaxially grown (Ga,In)(N,As) epilayers on GaAs(001) substrates by using electron energy-loss spectroscopy (EELS). The N and In concentrations are determined locally with a probe size of about 8 nm from the low-loss EELS measurements. We demonstrate that the small amount of N incorporating in dilute nitride alloys can be measured quantitatively by the plasmon energy shift with respect to a GaAs reference, and that the In content is analyzed simultaneously from the In 4d transitions, which have been isolated from the overlapping Ga 3d transitions. Our spatially resolved EELS results are utilized to discuss the origin of the inherent composition fluctuations and their influences on the morphological instabilities during epitaxial growth.