Human glucose-6-phosphate dehydrogenase gene carried on a yeast artificial chromosome encodes active enzyme in monkey cells

Yeast artificial chromosomes (YACs) permit the cloning of large tracts of human DNA. A YAC containing the human glucose-6-phosphate dehydrogenase gene is shown to encode active enzyme, supporting the inference that the YAC conserves the structure of the genomic DNA.     

Dietary valine requirement of Indian major carp, Labeo rohita (Hamilton) fry

Dietary valine requirement of Indian major carp, Labeo rohita Hamilton, fry (3.0 ± 0.02 cm, 0.16 ± 0.03 g) was determined using dose‐response method. Fishes were fed six isonitrogenous [40% crude protein (CP)] and isocaloric (4.28 kcal g^?1, Gross Energy (GE)) amino acid test diets containing casein, gelatin, and l ‐crystalline amino acids with graded levels of valine (0.75, 1.00, 1.25, 1.50, 1.75, and 2.00% dry diet) at 5% body weight for 6 weeks in triplicate groups twice a day at 07.00 and 17.30 hours. Live weight gain (158.52%), feed conversion ratio (FCR, 1.70), specific growth rate (SGR, 2.25), and protein efficiency ratio (PER, 1.46) were significantly (P < 0.05) higher in fish fed a diet containing 1.5% of the dietary valine (diet IV). Second‐degree polynomial regression analysis of the live weight gain and FCR data indicated the dietary valine requirement at 1.63 and 1.5% of the dry diet, corresponding to 4.0 and 3.75% of dietary protein. Maximum carcass protein, minimum moisture, and fat were recorded at 1.5% of the dietary valine level, except carcass ash, which remained constant throughout the treatments. No mortality was observed during the entire length of the feeding trial. On the basis of FCR and protein deposition data, it is recommended that dietary valine inclusion at 1.5% of dry diet, corresponding to 3.75% of dietary protein, is optimal for the growth of L. rohita fry.     

Taxonomic characterization of Lactobacillus delbrueckii subsp. bulgaricus isolates from a Cameroonian zebu's fermented raw milk

Atypical thermophilic homofermentative lactobacilli were isolated as one of the major microflora from Pindidam, an indigenous Cameroonian zebu's fermented raw milk. On the basis of their physiological characteristics, obtained isolates constituted a homogeneous group belonging to the species Lactobacillus delbrueckii. Nevertheless, their carbohydrate fermentation pattern was unusual and their identification to one of two subspecies Lact. delbrueckii subsp. bulgaricus (Lact. d. bulgaricus ) or Lact. delbrueckii subsp. lactis (Lact. d. lactis ) was rendered difficult. DNA-DNA hybridization confirmed that they belonged to the species Lact. delbrueckii and the electrophoretic mobility of the D-(—)-lactate dehydrogenase (LDH) furthermore precisely assigned them to Lact. d. bulgaricus. Whole-cell protein profiles were only able to weakly discriminate between these wild isolates and type strains of the species Lact. delbrueckii. The isolates from Pindidam were well adapted to their specific environmental conditions and demonstrated both high growth rates and ability to support elevated acidic levels in fermented milk.     

Fecundity of the freshwater catfishes mystus seenghala (sykes), mystus cavasius (ham), wallagonia attu (bloch) and heteropneustes fossilis (bloch) from the plains of Northern India

Fecundity of four species of catfishes, namely, Mystus seenghala (Sykes), Mystus cavasius (Ham), Wallagonia attu (Bloch) and Heteropneustes fossilis (Bloch), was studied. The fecundity of Mystus seenghala and Mystus cavasius varied between 20064 to 46443 and 3314 to 63135 respectively. In Wallagonia attu and Heteropneustes fossilis it varied between 66070 to 453148 and 1375 to 46737 respectively. In all the four species fecundity has a linear relationship with body weight and gonad weight, and a parabolic relationship with length in all the fishes excepting Mystus seenghala, where it is linear. By subjecting the data to multiple regression analysis, it is observed that the fecundity of each species can be most accurately determined by taking two variables together. In all the fishes studied the relative fecundity (Egg/body wt.) does not change significantly either with length or body weight.     

Blue light effects on rose photosynthesis and photomorphogenesis

Through its impact on photosynthesis and morphogenesis, light is the environmental factor that most affects plant architecture. Using light rather than chemicals to manage plant architecture could reduce the impact on the environment. However, the understanding of how light modulates plant architecture is still poor and further research is needed. To address this question, we examined the development of two rose cultivars, Rosa hybrida‘Radrazz’ and Rosa chinensis‘Old Blush’, cultivated under two light qualities. Plants were grown from one‐node cuttings for 6 weeks under white or blue light at equal photosynthetic efficiencies. While plant development was totally inhibited in darkness, blue light could sustain full development from bud burst until flowering. Blue light reduced the net CO₂ assimilation rate of fully expanded leaves in both cultivars, despite increasing stomatal conductance and intercellular CO₂ concentrations. In ‘Radrazz’, the reduction in CO₂ assimilation under blue light was related to a decrease in photosynthetic pigment content, while in both cultivars, the chl a/b ratio increased. Surprisingly, blue light could induce the same organogenetic activity of the shoot apical meristem, growth of the metamers and flower development as white light. The normal development of rose plants under blue light reveals the strong adaptive properties of rose plants to their light environment. It also indicates that photomorphogenetic processes can all be triggered by blue wavelengths and that despite a lower assimilation rate, blue light can provide sufficient energy via photosynthesis to sustain normal growth and development in roses.     

Preferential recognition of epitopes on peroxynitrite-modified alpha-2-macroglobulin by circulating autoantibodies in rheumatoid arthritis patients

Abstract

Autoimmune responses against post-translationally modified antigens are a hallmark of several autoimmune diseases. In this work, we have studied the changes in alpha-2-macroglobulin (α₂M) upon modification by peroxynitrite. Furthermore, we have evaluated the immunogenicity of modified α₂M in experimental rabbits and rheumatoid arthritis (RA) patients. Peroxynitrite-modified α₂M showed disturbed microenvironment and altered aromatic residues under UV and fluorescence studies. Aggregation, reduction in β-sheet content, production of nitrotyrosine and shift in amide I and II bands were observed in the modified α₂M by polyacrylamide gel electrophoresis besides CD and FTIR spectroscopic analysis. The exposure of hydrophobic clusters and changes in contact positions were observed in ANS and ThT binding assays. Immunological studies using ELISA showed peroxynitrite-modified α₂M as highly immunogenic producing high titre of specific antibodies in immunized rabbits. Cross-reactivity studies revealed the polyspecificity of the elicited antibodies. Direct binding ELISA and competitive inhibition studies confirmed the presence of circulating antibodies in the sera of RA patients having high specificity towards the peroxynitrite-modified α₂M as compared to the native α₂M. Sera from healthy (normal) human subjects showed lower binding with the native and modified protein. This study confirms that peroxynitrite induces structural modifications in α₂M and makes it immunogenic. The presence of neo-antigenic determinants on modified α₂M with enhanced binding for circulating autoantibodies in RA patients could offer new possibilities for diagnosis and etiopathology of the disease.

Communicated by Ramaswamy H. Sarma     

Tobacco cigarette smoking exacerbates aortic calcification in an early stage of myocardial infarction in a female mouse model

Despite increased social awareness, marketing restraints, tobacco taxation, and available smoking cessation rehab programs, active and passive smoking remain a worldwide challenging epidemic and a key risk factor for cardiovascular diseases development. Although cardiovascular (CV) protection is more pronounced in women than in men due to estrogenic effects, tobacco cigarette smoking exposure seems to alter this protection by modulating estrogen actions via undefined mechanisms. Premenopausal cigarette smoking women are at higher risk of adverse CV effects than non-smokers. In this study, we investigated the impact of cigarette smoking on early CV injury after myocardial infarction (MI) in non-menopausal female mice. Aortic arch calcification, fibrosis, reactive oxygen species, and gene expression of inflammatory and calcification genes were exaggerated in mice exposed to cigarette smoke (CS). These findings suggest that aortic injury following MI, characterized by vascular smooth muscle cells transdifferentiation, calcification, inflammation, and collagen deposition but not cardiac dysfunction is exacerbated with CS exposure. The novel findings of this study highlight the importance of aortic injury on short and long-term prognosis in CS-exposed MI females. Linking those findings to estrogen alteration is probable and entails investigation.     

Analysis of CLDN14 gene in deaf Moroccan patients with non-syndromic hearing loss

Mutations in the CLDN14 gene, encoding the tight junction claudin 14 protein has been reported to date in an autosomal recessive form of isolated hearing loss DFNB29. In order to identify the contribution of CLDN14 to inherited deafness in Moroccan population, we performed a genetic analysis of this gene in 80 Moroccan familial cases. Our results show the presence of 7 mutations: 6 being conservative and one leading to a missense mutation (C11T) which was found at heterozygous and homozygous states, with a general frequency of 6.87%. The pathogenicity of the resulting T4M substitution is under discussion.     

Multilocus loss of DNA methylation in individuals with mutations in the histone H3 Lysine 4 Demethylase KDM5C

Background

A number of neurodevelopmental syndromes are caused by mutations in genes encoding proteins that normally function in epigenetic regulation. Identification of epigenetic alterations occurring in these disorders could shed light on molecular pathways relevant to neurodevelopment.

Results

Using a genome-wide approach, we identified genes with significant loss of DNA methylation in blood of males with intellectual disability and mutations in the X-linked KDM5C gene, encoding a histone H3 lysine 4 demethylase, in comparison to age/sex matched controls. Loss of DNA methylation in such individuals is consistent with known interactions between DNA methylation and H3 lysine 4 methylation. Further, loss of DNA methylation at the promoters of the three top candidate genes FBXL5, SCMH1, CACYBP was not observed in more than 900 population controls. We also found that DNA methylation at these three genes in blood correlated with dosage of KDM5C and its Y-linked homologue KDM5D. In addition, parallel sex-specific DNA methylation profiles in brain samples from control males and females were observed at FBXL5 and CACYBP.

Conclusions

We have, for the first time, identified epigenetic alterations in patient samples carrying a mutation in a gene involved in the regulation of histone modifications. These data support the concept that DNA methylation and H3 lysine 4 methylation are functionally interdependent. The data provide new insights into the molecular pathogenesis of intellectual disability. Further, our data suggest that some DNA methylation marks identified in blood can serve as biomarkers of epigenetic status in the brain.     

Influence of age on the bioaccumulation of heavy metals in Apodemus sylvaticus at Merja Zerga lagoon,Morocco

The influence of age and sex on the bioaccumulation of heavy metals in Apodemus sylvaticus was studied in Merja Zerga lagoon in northern Morocco. Five trace metal elements (Zn, Pb, Cr, Cu and Fe) were quantitatively analyzed by Varian AA 240 atomic absorption spectroscopy with graphite furnace in three organs (Liver, Kidney and Heart) from animals of different age and sex. The maximum metal level of the analyzed samples was recorded in adults and was limited to 46.62 μg/g for Pb and 35.1 μg/g for Cu, while it reached 22.69 μg/g, 7.59 μg/g and 6.78 μg/g for Cr, Zn and Fe, respectively. Highly significant differences were found for bioaccumulation of heavy metals according to animal ages and no significant differences were observed between the two sexes among the studied animals. Our results revealed also the existence of a strong correlation (r > 0.65) between the majority of biometric parameters and the trace element concentrations. In general, we found that age is a critical factor in estimating the level of heavy metal pollution. Other characteristics such as habitat, feeding habits and anti-predator behavior of the species need to be studied.