RFLP linkage analysis and mapping genes controlling the fatty acid profile of <Emphasis Type="Italic">Brassica juncea</Emphasis> using reciprocal DH populations

An RFLP linkage map, comprising 300 linked and 16 unlinked loci, was constructed using reciprocal DH populations of Brassica juncea. The linked loci were organized into 18 linkage groups and seven unlinked segments, covering a total map distance of 1,564 cM. The A and B genomes were identified. The chi(2) test showed that 96.1% of the common intervals in the two populations differed non-significantly for recombination fractions, thus strongly suggesting the absence of sex-based differences for recombination fractions in B. juncea. Two QTLs, E(1a) and E(1b), significantly affected erucic acid content, and individually explained 53.7% and 32.1%, respectively, and collectively 85.8% of the phenotypic variation in the population. The QTLs E(1a) and E(1b) showed epistasis, and the full model including epistasis explained nearly all of the phenotypic variation in the population. The QTLs E(1a) and E(1b) were also associated with contents of oleic, linoleic and linolenic acids. Three additional QTLs (LN(2), LN(3) and LN(4)) significantly influenced linolenic acid content. The QTL LN(2) accounted for 35.4% of the phenotypic variation in the population. Epistatic interactions were observed between the QTLs E1a and LN(2). The stability of the detected QTLs across years and locations, and breeding strategies for improving the fatty acid profile of B. juncea, are discussed.     

The molecular basis of water transport in the brain

Brain function is inextricably coupled to water homeostasis. The fact that most of the volume between neurons is occupied by glial cells, leaving only a narrow extracellular space, represents an important challenge, as even small extracellular volume changes will affect ion concentrations and therefore neuronal excitability. Further, the ionic transmembrane shifts that are required to maintain ion homeostasis during neuronal activity must be accompanied by water. It follows that the mechanisms for water transport across plasma membranes must have a central part in brain physiology. These mechanisms are also likely to be of pathophysiological importance in brain oedema, which represents a net accumulation of water in brain tissue. Recent studies have shed light on the molecular basis for brain water transport and have identified a class of specialized water channels in the brain that might be crucial to the physiological and pathophysiological handling of water.     

The intercellular adhesion molecule-1 K469E polymorphism in type 1 diabetes

Type 1 (insulin-dependent) diabetes is a complex trait. The region harboring the ICAM1 gene on 19p13 links to type 1 diabetes, and a growing body of evidence indicates that intercellular adhesion molecule-1 (ICAM-1) could play a role in type 1 diabetes development. Recently, association studies of an ICAM-1 K469E polymorphism in type 1 diabetes populations have reported conflicting results. Hence, we performed a transmission disequilibrium test analysis of the ICAM-1 K469E variations in 253 Danish type 1 diabetes families. Linkage and association was not found between the ICAM-1 K469E variation and type 1 diabetes in Danish patients (P(tdt)> or =0.48), and our data did not indicate an interaction between ICAM1 and IDDM1 in predisposition to type 1 diabetes in Danes (P=0.78). We did not observe significant association with late-onset type 1 diabetes (P(tdt)> or =0.12) or differences in transmission patterns between groups of affected offspring stratified for age at onset (P> or =0.19), as suggested in Japanese patients. Combined analysis of the present and previously reported transmission data comprising 728 affected offspring of Romanian, Finnish, and Danish ancestry suggested association between the ICAM-1 E469 allele and type 1 diabetes (P(tdt)=0.013), but association was not found in the combined Scandinavian material. In conclusion, we found no association of the ICAM-1 K469E polymorphism with type 1 diabetes or its subsets stratified for age at onset and HLA risk in Danish patients. Analysis of ICAM-1 K469E transmissions reported in three populations suggested association to type 1 diabetes, but also demonstrated heterogeneity between populations.     

Mechanisms of maternal aneuploidy: FISH analysis of oocytes and polar bodies in patients undergoing assisted conception

We have examined unfertilised oocytes and their first polar bodies (PBs) to determine the way in which the frequency of whole chromosome imbalance compares with that involving single chromatids and whether the precocious separation of chromatids prior to anaphase I affects all pairs of chromosomes. We have applied the technique of fluorescent in situ hybridisation in a three-stage method by using locus-specific probes for chromosomes 13 and 21 and alpha-satellite probes for chromosomes 1, 9, 16, 18 and X to determine the chromosome status of oocytes and their PBs. We obtained analysable results from 127 oocytes and 57 PBs from 72 patients of average age 33 years. Six oocytes and three PBs had extra signals but, of these, three were derived from a single patient, aged 26. Anomalies were seen in chromosomes 13, 16, 18, X and, notably, 21 but none were observed in chromosomes 1 and 9. Half of the anomalies involved additional chromatids rather than whole chromosomes. Since particular chromatids were found to be prematurely separated in the metaphase II oocyte, this may provide further evidence for an additional mechanism of maternal aneuploidy that operates at anaphase II. Detailed analyses of both oocytes and PBs have elucidated possible mechanisms leading to aneuploid gametes in this group of patients with fertility problems.     

Adaptive response to low dose of EMS or MMS in human peripheral blood lymphocytes

Human peripheral blood lymphocytes stimulated in vitro for 6 hr were exposed to a low (conditioning) dose of ethyl methanesulfonate (EMS; 1.5 x 10(-4) M) or methyl methanesulfonate (MMS; 1.5 x 10(-5) M). After 6 hr, the cells were treated with a high (challenging) concentration of the same agent (1.5 x 10(-3) M EMS or 1.5 x 10(-4) M MMS). The cells that received both conditioning and challenging doses became less sensitive to the induction of sister chromatid exchanges (SCEs) than those which did not receive the pretreatment with EMS or MMS. They responded with lower frequencies of SCEs. This suggests that conditioning dose of EMS or MMS has offered the lymphocytes to have decreased SCEs. This led to the realization that pre-exposure of lymphocytes to low dose can cause the induction of repair activity. This is a clear indication of the existence of adaptive response induced by alkylating agents whether it is ethylating or methylating in human lymphocytes in vitro.     

Partial purification and kinetic properties of three different d-glucosamine 6-P:N-acetyltransferase forms from human placenta

Three distinct forms of -glucosamine 6-P (Gm 6-P):N-acetyltransferases (EC 2.3.1.4) were partially purified from human placental homogenates by carboxy methyl-Sephadex chromatography. Purification of forms I and II were 13.5-fold, while that of form III was 114-fold. All three forms had a pH optimum value of 9.7 in glycine–NaOH buffer. Enzymes II and III had a K_m value for Gm 6-P of 3.0 mM, which was less than half of that observed for form I (7.1 mM). The corresponding K_m values for acetyl CoA were 0.157 (form I), 0.187 (form II) and 0.280 mM (form III), respectively. Activities of all three forms were inhibited at high concentrations of either substrate. These enzymes were inhibited from 82 to 92% by 2.5 mM p-chloromercuribenzoate. The inhibition was largely reversible by inclusion of 2.5 mM dithiothreitol in the incubation mixtures. There was no requirement for divalent cations, as demonstrated by lack of inhibition of enzyme activity by ethylene diamine tetraacetate. The results are discussed in terms of differences among the enzyme properties of human placental, rodent and porcine liver forms.     

16.1% Efficient Hysteresis‐Free Mesostructured Perovskite Solar Cells Based on Synergistically Improved ZnO Nanorod Arrays

Significant efficiency improvements are reported in mesoscopic perovskite solar cells based on the development of a low‐temperature solution‐processed ZnO nanorod (NR) array exhibiting higher NR aspect ratio, enhanced electron density, and substantially reduced work function than conventional ZnO NRs. These features synergistically result in hysteresis‐free, scan‐independent, and stabilized devices with an efficiency of 16.1%. Electron‐rich, nitrogen‐doped ZnO (N:ZnO) NR‐based electron transporting materials (ETMs) with enhanced electron mobility produced using ammonium acetate show consistently higher efficiencies by one to three power points than undoped ZnO NRs. Additionally, the preferential electrostatic interaction between the ­nonpolar facets of N:ZnO and the conjugated polyelectrolyte polyethylenimine (PEI) has been relied on to promote the hydrothermal growth of high aspect ratio NR arrays and substantially improve the infiltration of the perovskite light absorber into the ETM. Using the same interactions, a conformal PEI coating on the electron‐rich high aspect ratio N:ZnO NR arrays is ­successfully applied, resulting in a favorable work function shift and altogether leading to the significant boost in efficiency from <10% up to >16%. These results largely surpass the state‐of‐the‐art PCE of ZnO‐based perovskite solar cells and highlight the benefits of synergistically combining mesoscale control with doping and surface modification.     

Steroidal dihydrocarbothioic acid amido pyrazoles: synthesis,characterization, cytotoxicity and genotoxicity studies

A new series of steroidal dihydrocarbothioic acid amido pyrazole analogues were synthesized, and after characterization, evaluation for cytotoxicity, comet assay and western blotting was carried out. The synthesis of these analogues is convenient and involves two steps, i.e. aldol condensation as first step followed by nucleophilic addition of thiosemicarbazide across α, β-unsaturated carbonyl as a later step. Quantitative yields of more than 80 % are obtained in both the steps. After characterization by IR, ¹H NMR, ¹³C NMR, MS and analytical data, all the compounds of both series were tested for cytotoxic activity against a panel of different human cancer cell lines by MTT assay, during which compound 3e, 3f, 4e, 4f and 4h are very potent especially against HepG2 and MCF-7 cancer cell lines. Cell cycle analysis depicted the cell death in S-phase while as annexin V-FITC/PI analysis showed that compounds effectively induce apoptosis. Apoptotic degradation of DNA of MCF-7 cells in the presence of different steroidal derivatives was analysed by agarose gel electrophoresis and visualized by ethidium bromide staining (comet assay). In western blotting analysis, the relative expressions of relevant apoptotic markers depicted an apoptosis by steroidal dihydropyrazole in MCF-7 cancer cells.     

APOA2 ?256T>C polymorphism interacts with saturated fatty acids intake to affect anthropometric and hormonal variables in type 2 diabetic patients

Recent studies have established the interaction between APOA2 −256T>C polymorphism and dietary saturated fatty acids intake in relation to obesity on healthy individuals. In the current study, we investigate the effects of this interaction on anthropometric variables and serum levels of leptin and ghrelin in patients with type 2 diabetes. In this cross-sectional study, 737 patients with type 2 diabetes mellitus (290 males and 447 females) were recruited from diabetes clinics in Tehran. The usual dietary intake of all participants during the last year was obtained by validated semiquantitative food frequency questionnaire. APOA2 genotyping was performed by real-time PCR on genomic DNA. No significant relation was obtained by univariate analysis between anthropometric variables and APOA2 genotypes. However, after adjusting for age, gender, physical activity and total energy intake, we identified a significant interaction between APOA2-saturated fatty acids intake and body mass index (BMI). After adjusting for potential confounders, serum levels of ghrelin in CC genotype patients were significantly higher than T allele carriers (p = 0.03), whereas the case with leptin did not reveal a significant difference. The result of this study confirmed the interaction between APOA2 −256T>C polymorphism and SFAs intake with BMI in type 2 diabetic patients. In fact, homozygous patients for the C allele with high saturated fatty acids intake had higher BMI. The APOA2 −256T>C polymorphism was associated with elevated levels of serum ghrelin.