Huntingtin interacting protein HYPK is intrinsically unstructured

To characterize HYPK, originally identified as a novel huntingtin (Htt) interacting partner by yeast two hybrid assay, we used various biophysical and biochemical techniques. The molecular weight of the protein, determined by gel electrophoresis, was found to be about 1.3-folds ( approximately 22 kDa) higher than that obtained from mass spectrometric analysis (16.9 kDa). In size exclusion chromatography experiment, HYPK was eluted in three fractions, the hydrodynamic radii for which were calculated to be approximately 1.5-folds (23.06 A) higher than that expected for globular proteins of equivalent mass (17.3 A). The protein exhibited predominantly (63%) random coil characteristics in circular dichroism spectroscopy and was highly sensitive to limited proteolysis by trypsin and papain, indicating absence of any specific domain. Experimental evidences with theoretical analyses of amino acids composition of HYPK and comparison with available published data predicts that HYPK is an intrinsically unstructured protein (IUP) with premolten globule like conformation. In presence of increasing concentration of Ca(2+), HYPK showed conformational alterations as well as concomitant reduction of hydrodynamic radius. Even though any link between the natively unfolded nature of HYPK, its conformational sensitivity towards Ca(2+) and interaction with Htt is yet to be established, its possible involvement in Huntington's disease pathogenesis is discussed.     

Inheritance of fertility in broiler chickens

Background

The fertility of a chicken''s egg is a trait which depends on both the hen that lays the egg and on her mate. It is also known that fertility of an individual changes over the laying period.

Methods

Longitudinal models including both random genetic and permanent environmental effects of both the female and her male mate were used to model the proportion of fertile eggs in a pedigree broiler population over the ages 29-54 weeks.

Results

Both the male and the female contribute to variation in fertility. Estimates of heritability of weekly records were typically 7% for female and 10% for male contributions to fertility. Repeatability estimates ranged from 24 to 33%, respectively. The estimated genetic variance remained almost constant for both sexes over the laying period and the genetic correlations between different ages were close to 1.0. The permanent environment components increased substantially towards the end of the analyzed period, and correlations between permanent environment effects at different ages declined with increasing age difference The heritability of mean fertility over the whole laying period was estimated at 13% for females and 17% for males. A small positive correlation between genetic effects for male and female fertility was found.

Conclusion

Opportunities to improve fertility in broiler stocks by selection on both sexes exist and should have an impact throughout the laying period.     

Momordica charantia trypsin inhibitor II inhibits growth and development of Helicoverpa armigera

Abstract  Bitter gourd ( Momordica charantia L.) seeds contain several squash-type serine proteinase inhibitors (PIs), which inhibit the digestive proteinases of the polyphagous insect pest Helicoverpa armigera . In the present work isolation of a DNA sequence encoding the mature peptide of a trypsin inhibitor McTI-II, its cloning and expression as a recombinant protein using Pichia pastoris have been reported. Recombinant McTI-II inhibited bovine trypsin at 1: 1 molar ratio, as expected, but did not inhibit chymotrypsin or elastase. McTI-II also strongly inhibited trypsin-like proteinases (81% inhibition) as well as the total proteolytic activity of digestive proteinases (70% inhibition) from the midgut of H. armigera larvae. The insect larvae fed with McTI-II-incorporated artificial diet suffered over 70% reduction in the average larval weight after 12 days of feeding. Moreover, ingestion of McTI-II resulted in 23% mortality in the larval population. The strong antimetabolic activity of McTI-II toward H. armigera indicates its probable use in developing insect tolerance in susceptible plants.     

Genetic heterogeneity of residual variance in broiler chickens

Aims were to estimate the extent of genetic heterogeneity in environmental variance. Data comprised 99 535 records of 35-day body weights from broiler chickens reared in a controlled environment. Residual variance within dam families was estimated using ASREML, after fitting fixed effects such as genetic groups and hatches, for each of 377 genetically contemporary sires with a large number of progeny (> 100 males or females each). Residual variance was computed separately for male and female offspring, and after correction for sampling, strong evidence for heterogeneity was found, the standard deviation between sires in within variance amounting to 15–18% of its mean. Reanalysis using log-transformed data gave similar results, and elimination of 2–3% of outlier data reduced the heterogeneity but it was still over 10%. The correlation between estimates for males and females was low, however. The correlation between sire effects on progeny mean and residual variance for body weight was small and negative (-0.1). Using a data set bigger than any yet presented and on a trait measurable in both sexes, this study has shown evidence for heterogeneity in the residual variance, which could not be explained by segregation of major genes unless very few determined the trait.     

Ecological and human health risk assessment of agricultural soils based on heavy metals in mining areas of Singhbhum copper belt,India

Risk characterization of agricultural soils in the mining areas of Singhbhum copper belt was done by determining the total concentrations of metals using inductively coupled plasma-mass spectrometry and assessing the potential ecological and human health risks. The concentrations were above the average shale values for most of the metals. Principal component analysis showed anthropogenic contributions of Cu, Ni, Co, Mn, Pb, and Cr in the soils. Ecological risk assessment revealed that 50% of the soil samples were at moderate to very high ecological risk. Health risks for adults and children were calculated using hazard quotients (HQs), hazard index (HI), and Cancer risks for the oral, dermal, and inhalation pathways. The HQs for all the metals except As and Co were below 1, which suggested that non-carcinogenic risks due to metal exposure through soils were within the safe limit. However, considering all the metals and pathways, the HI for adults and children was 0.71 and 5.61, respectively, suggesting appreciable risk to local residents. The carcinogenic risks due to As and Cr in the soils were within the acceptable value of 1E–04. For both carcinogenic and non-carcinogenic risks, oral ingestion appeared to be the primary pathway followed by dermal and inhalation pathways.     

Genetic Diversity and Differentiation in Hedychium spicatum, a Valuable Medicinal Plant of Indian Himalaya

Hedychium spicatum, a perennial rhizomatous medicinal plant distributed in subtropical and temperate parts, is considered nearly endemic to the Himalayan region.In this study allozyme markers were utilized to assess genetic variations and relationships among 12 distinct populations of this species from the West Himalaya of India. A high level of genetic diversity was found among the populations. Of the 13 loci generated using eight enzymes, 12 (92%) were polymorphic. F-statistics suggested a prevalence of a high heterozygote excess among populations (F(IS) = -0.51). Gene flow estimates and geographic distances between populations did not correlate significantly (r = -0.0258, P < 0.3550). The excess heterozygosity may be attributed to high pollinator mobility and inbreeding coefficient within the subpopulation, relative to the total F(IS) value. High frequencies of several alleles at different loci probably reflect the breeding pattern, as the species propagates clonally as well as through seeds. We also discuss conservation implications for the target species.     

Dynamics of epileptiform activity in mouse hippocampal slices

Increase of the extracellular K⁺ concentration mediates seizure-like synchronized activities in vitro and was proposed to be one of the main factors underlying epileptogenesis in some types of seizures in vivo. While underlying biophysical mechanisms clearly involve cell depolarization and overall increase in excitability, it remains unknown what qualitative changes of the spatio-temporal network dynamics occur after extracellular K⁺ increase. In this study, we used multi-electrode recordings from mouse hippocampal slices to explore changes of the network activity during progressive increase of the extracellular K⁺ concentration. Our analysis revealed complex spatio-temporal evolution of epileptiform activity and demonstrated a sequence of state transitions from relatively simple network bursts into complex bursting, with multiple synchronized events within each burst. We describe these transitions as qualitative changes of the state attractors, constructed from experimental data, mediated by elevation of extracellular K⁺ concentration.     

Biotransformations using plant cells, organ cultures and enzyme systems: current trends and future prospects

Plants are valuable sources of a variety of chemicals including drugs, flavours, pigments and agrochemicals. Some of the biochemical reactions occurring in plant cells are complex and cannot be achieved by synthetic routes. In vitro plant cell and organ cultures and plant enzymes act as suitable biocatalysts to perform these complex reactions. A wide variety of chemical compounds including aromatics, steroids, alkaloids, coumarins and terpenoids can undergo biotransformations using plant cells, organ cultures and enzymes. The biocatalyst-mediated reactions are regiospecific and stereospecific. Reaction types include oxidations, reductions, hydroxylations, methylations, acetylations, isomerizations, glycosylations and esterfications. Genetic manipulation approaches to biotransformation offer great potential to express heterologous genes and to clone and overexpress genes for key enzymes. Biotransformation efficiencies can further be improved using molecular techniques involving site-directed mutagenesis and gene manipulation for substrate specificity.     

Asynchronous remodeling is a driver of failed regeneration in Duchenne muscular dystrophy

We sought to determine the mechanisms underlying failure of muscle regeneration that is observed in dystrophic muscle through hypothesis generation using muscle profiling data (human dystrophy and murine regeneration). We found that transforming growth factor β–centered networks strongly associated with pathological fibrosis and failed regeneration were also induced during normal regeneration but at distinct time points. We hypothesized that asynchronously regenerating microenvironments are an underlying driver of fibrosis and failed regeneration. We validated this hypothesis using an experimental model of focal asynchronous bouts of muscle regeneration in wild-type (WT) mice. A chronic inflammatory state and reduced mitochondrial oxidative capacity are observed in bouts separated by 4 d, whereas a chronic profibrotic state was seen in bouts separated by 10 d. Treatment of asynchronously remodeling WT muscle with either prednisone or VBP15 mitigated the molecular phenotype. Our asynchronous regeneration model for pathological fibrosis and muscle wasting in the muscular dystrophies is likely generalizable to tissue failure in chronic inflammatory states in other regenerative tissues.