Identification of the genes promoting awnedness in the Triticum Aestivum/Aegilops Umbellulata introgressive line

A genetic analysis of the Triticum aestivum/Aegilops umbellulata introgressive line for the ear awnedness trait was carried out. Based on the results obtained in the study of awnedness and microsatellite components in lines and hybrids, a digenic model was proposed for the control of this trait by two genes??inhibitor of awnedness B1 (5AL) and promoter of awnedness Awn1, which are both located on chromosome 6U of Aegilops umbellulata. Chromosome 5A of the awned line was rearranged with respect to the same chromosome of the Aurora genotype. The genetic distance between the SSR-locus Xwmc705-5AL and the rearranged fragment or locus B1/b1 was determined to be 15.5 cM.     

Improving the design and analysis of high-throughput screening technology comparison experiments using statistical modeling

Contemporary small-molecule drug discovery frequently involves the screening of large compound files as a core activity. Subsequently cost, speed, and safety become critical issues. In order to meet this need, numerous technologies have been developed to allow mix and measure approaches, facilitate miniaturization, and to increase speed and to minimize the use of potentially hazardous reagents such as radioactive materials. However, despite the on-paper advantages of these new technologies, risks can remain undefined. For example, the question of whether the novel method will facilitate identification of active chemical series in a way that is comparable with conventional methods arises. In order to address this question, we have taken the approach of carrying out experiments to directly compare the output of high-throughput screens using a given novel approach and a traditional method. The concordance between the screening methods can then be determined via comparison of the numbers and structures of the active molecules identified. This article describes the approach taken in our laboratory to minimize variability in such experiments and shows data that exemplifies the general result of lower than expected concordance. Statistical modeling was subsequently used to facilitate this interpretation. The model used beta-distribution function to generate a real-activity frequency relationship with added normal random error and occasional outliers to represent assay variability. Hence, the effect of assay parameters such as the threshold, the number of real actives, and the number of outliers and the standard deviation could readily be explored. The model was found to describe the data reasonably and moreover was found to be of great utility when it came to planning further optimal experiments. A key conclusion from the model was that concordance between screening methods could appear poor even when one approach is compared with itself. This occurs simply because the result is a function of assay threshold, standard deviation and the true compound % activity. In response to this finding we have adopted alternative experimental designs that more reliably measure the concordance between screening methods.     

Uncharged P-selectin blockers

The blocking potency of P- and L-selectin was studied for certain small molecule mannosides and their polyacrylamide (PAA, 30 kDa) conjugates in comparison to SiaLe(x) and fucoidan. Two experimental systems were used: (1) solid phase static assay based on recombinant selectins, and (2) P-selectin dependent rat peritoneal inflammation. betaMan-SC6H4NO2- p was four times more potent P-selectin inhibitor as compared to SiaLe(x). Docking of this molecule onto the P-selectin carbohydrate-binding site demonstrated that a nitro group enabled an electrostatic interaction with residue Lys 84, while the phenyl ring and the CH2 at C-6 contacted the CH2 groups of the same Lys residue. In vivo, betaMan-SC6H4NO2- p blocked experimental inflammation better than SiaLe(x), but significantly lower than fucoidan. In vitro Man-polyacrylic acid conjugates appeared to be very potent inhibitors comparable to fucoidan, uncharged Man-PAA proved rather active, comparable to SiaLe(x)-PAA both in vitro, and in vivo, whereas mannan did not display any P-selectin blocking effect.     

Peripheral metabolic responses to prolonged weight reduction that promote rapid, efficient regain in obesity-prone rats

Weight regain after weight loss is the most significant impediment to long-term weight reduction. We have developed a rodent paradigm that models the process of regain after weight loss, and we have employed both prospective and cross-sectional analyses to characterize the compensatory adaptations to weight reduction that may contribute to the propensity to regain lost weight. Obese rats were fed an energy-restricted (50-60% kcal) low-fat diet that reduced body weight by 14%. This reduced weight was maintained for up to 16 wk with limited provisions of the low-fat diet. Intake restriction was then removed, and the rats were followed for 56 days as they relapsed to the obese state. Prolonged weight reduction was accompanied by 1) a persistent energy gap resulting from an increased drive to eat and a reduced expenditure of energy, 2) a higher caloric efficiency of regain that may be linked with suppressed lipid utilization early in the relapse process, 3) preferential lipid accumulation in adipose tissue accompanied by adipocyte hyperplasia, and 4) humoral adiposity signals that underestimate the level of peripheral adiposity and likely influence the neural pathways controlling energy balance. Taken together, long-term weight reduction in this rodent paradigm is accompanied by a number of interrelated compensatory adjustments in the periphery that work together to promote rapid and efficient weight regain. These metabolic adjustments to weight reduction are discussed in the context of a homeostatic feedback system that controls body weight.     

Molecular biomarkers of the physiological state of mitten crab Eriocheir japonica (de Haan, 1835) in the estuarine zones of Peter the Great Bay (Sea of Japan)

The mitten crab Eriocheir japonica (de Haan, 1835) is used as an indicator species for the biochemical monitoring of different estuarine zones in Peter the Great Bay (Sea of Japan). The following molecular biomarkers are determined in the gills and hepatopancreas of the crabs: the activity of biotransformation of enzyme glutathione-S-transferase; antioxidative enzymes, superoxide dismutase, and catalase; and reduced glutathione concentration and lipid peroxidation level measured as malondialdehyde. The state of biochemical indicators testify to the good physiological condition of crabs from estuaries of Shkotovka and Sukhodol rivers and to a depressed physiological condition for crans from the Tesnya River. The latter crabs have lower activity of catalase but higher glutathione-S-transferase activity and lipid peroxidation level. Using the data of molecular-biomarker determination, the integral biochemical index was calculated, which made it possible to rank the estuaries by the extent of adverse effects on the biota. Researching the functional condition of the indicator species allows one to estimate and predict the biota state under anthropogenic impact.     

Opening a can of worms: unprecedented sympatric cryptic diversity within British lumbricid earthworms

Earthworms play a major role in many aspects of soil fertility, food web ecology and ecosystem functioning, and hence are frequently the subjects of, for example, ecological and toxicological research. Our aim was to examine the genetic structure of common earthworm species, to identify cryptic lineages or species that may be distinct ecotypes or biotypes (and hence confound current research based upon morphotypes) and to try to explain the massive cryptic diversity that eventually emerged. We demonstrated that species such as Allolobophora chlorotica, Aporrectodea longa, Aporrectodea rosea and Lumbricus rubellus all comprise highly divergent lineages with species-level divergence at the mitochondrial cytochrome oxidase I (COI) gene. In Allo. chlorotica alone, we found 55 haplotypes for COI, with 35 of these being found in pink and 20 in green morph worms. There were no cases of the two colour morphs sharing COI haplotypes. Phylogenetic analyses of mitochondrial COI and 16S genes showed the presence of five highly divergent lineages, suggesting the presence of multiple cryptic species within Allo. chlorotica. There was no clear geographical pattern to lineage distribution and many populations were polymorphic for both mitochondrial DNA lineage and colour morph. Amplified fragment length polymorphism results, based on two primer combinations, were broadly congruent with mitochondrial DNA results with one significant exception. Despite showing over 14% divergence at COI, amplified fragment length polymorphism markers showed that the two green morph lineages may be interbreeding and therefore represent a single taxon. The cryptic diversity revealed by these results has profound consequences for all areas of earthworm research.