The next step of neurogenesis in the context of Alzheimer’s disease

Molecular Biology Reports - Among different pathological mechanisms, neuronal loss and neurogenesis impairment in the hippocampus play important roles in cognitive decline in Alzheimer’s...     

Serum Iron,Zinc, and Copper Concentration in Premature Graying of Hair

Premature graying of hair with unclear etiology, which is known as premature canities, is a common cause of referrals to the dermatologists. We assessed the relationship between serum iron, copper, and zinc concentrations with premature canities. This study was conducted on patients under 20 years old suffering from premature canities, having a minimum of ten gray hair fibers, and referring to university hospitals of Isfahan (Iran). The results were compared with age–sex-matched controls. Demographic data and disease characteristics were recorded for two groups. We studied serum iron, copper, and zinc concentrations of 66 patients and 66 controls using atomic absorption and Ferrozine methods. The mean age of studied cases was 17.8 ± 2.0 years, and the mean age of the onset of canities was 15.5 ± 3.2 years with no significant difference between males and females (P > 0.05). Serum copper concentration was significantly lower in patients compared with controls (90.7 ± 37.4 vs. 105.3 ± 50.2 μg/dL, P = 0.048), but serum iron concentration was significantly lower in controls compared to patients (88.8 ± 39.5 vs. 108.3 ± 48.4 μg/dL, P = 0.008). Also, there was no significant difference between patients and controls in serum zinc concentration (114.8 ± 67.8 vs. 108.2 ± 49.9 μg/dL, P = 0.285). According to these results, among copper, zinc, and iron, a low serum copper concentration may play a role in premature graying of hairs in our society. Further studies are needed to find the underlying mechanism of this relationship.     

Genetic relatedness among some wild cherry (<Emphasis Type="Italic">Prunus</Emphasis> subgenus <Emphasis Type="Italic">Cerasus</Emphasis>) genotypes native to Iran assayed by morphological traits and random amplified polymorphic DNA analysis

Subgenus Cerasus species are useful genetic resources for cherry breeding programs. A total of 17 morphological traits together with 19 random amplified polymorphic DNA (RAPD) primers were used to study 39 accessions including 34 wild Cerasus subgenus genotypes belonging to Prunus avium L., P. cerasus L., P. mahaleb L., P. microcarpa Boiss., P. incana Pall., and P. brachypetala Boiss. species, along with an unknown wild Cerasus sample, two advanced cherry cultivars (‘Lambert’ and ‘Bulgar’), and two rootstocks (‘Colt’ and ‘Gisela 6’). Genotypes were separated into different groups according to their species and collection sites using cluster analysis performed by Ward’s clustering method based on morphological data. Nineteen RAPD primers from 60 screened produced 304 polymorphic reproducible bands (98.15% polymorphism). According to the similarity matrix, the lowest similarity was obtained between P. avium and P. microcarpa samples. A dendrogram was prepared by the unweighted pair-group method with arithmetic average (UPGMA), and the accessions were separated according to their species and geographic origin. In both morphological and molecular results, the advanced cultivars and rootstocks were separated from wild genotypes, and the unknown genotype was grouped with P. mahaleb accessions. Grouping by morphological characteristics was compared with the results of RAPD analysis, with no significant correlations between morphological and molecular data being found. This is the first report of molecular (RAPD) genetic diversity study in wild Cerasus subgenus genotypes from Iran, and the results demonstrate the high potential of RAPD analysis for discrimination of Cerasus subgenus genotypes.     

Delay expression of limonoid UDP-glucosyltransferase makes delayed bitterness in citrus

Genes encoding limonoid UDP-glucosyltransferase from albedo of six Citrus species with different levels of delayed bitterness are isolated and cloned in vector pTZ57R/T. Our results indicate that gene sequence of sweet lime (with intense juice delayed bitterness) have complete identity with Satsuma mandarin (without distinctive juice delayed bitterness). Also gene sequence of Marsh seedless grapefruit, local orange and Thompson navel orange (with mild juice delayed bitterness) have very similarity with Satsuma mandarin. On the other hand, this gene started to express 60, 120, and 210 days after full blooming in albedo of Satsuma mandarin, sweet oranges and sour orange, and both grapefruit and sweet lime, respectively. Expression pattern of limonoid glucosyltransferase gene in leaves was quite different with albedo. Thus, we supposed the delayed bitterness in this species was related to delay in expression of limonoid glucosyltransferase gene in albedo and lower limonoid glucoside accumulation in fruits.     

New mononuclear mercury(II) complexes of a bifunctionalized ylide containing five-membered chelate ring: Spectral and structural characterization

The reaction of a new bifunctionalized ylide, Ph₂PCH₂PPh₂C(H)C(O)(C₆H₄Cl) (2) with mercury(II) halides in equimolar ratios using dry methanol as solvent yielded the P, C-chelated complexes, {HgX₂[Ph₂PCH₂PPh₂C(H)C(O)(C₆H₄Cl)]} where X = Cl (3), Br (4), I (5). The structures of complexes 4 and 5 have been characterized crystallographically. Single crystal X-ray analyses reveal the presence of mononuclear complexes containing Hg atom in a distorted tetrahedral environment. Characterization of the obtained compounds was also performed by elemental analysis, IR, ¹H, ³¹P, and ¹³C NMR. A theoretical study at DFT (B3LYP) level using standard CEP-31G basis set showed that the experimentally determined structure of the complex 5 is about 0.6-15.75 kcal mol⁻¹ more stable than its other bonding modes.     

Phenotypic and genotypic variation in Iranian sour and duke cherries

Phenotypic and genotypic variation and structure of 29 sour cherry (P. cerasus) and duke cherry (P. x gondouinii) genotypes from different regions of Iran were identified using random amplified polymorphic DNA (RAPD) markers and morphological characters. Furthermore, one Prunus mahaleb genotype was used as an outgroup for molecular analysis. For morphological analysis, 23 variables were recorded to detect similarities between and among studied sour and duke cherries. Most studied characteristics were showing a high degree of variability. Principal component analysis showed that the first three components explained a total of 73.87 % of the whole phenotypic variability. Based on the morphological cluster analysis, studied sour and duke cherry genotypes were placed into three main clusters. The first main cluster included 16 sour cherry genotypes. The second main cluster contained all duke cherry genotypes and eight sour cherry genotypes, while, only one sour cherry genotype was placed in third main cluster. For RAPD analysis, 17 primers generated a total of 233 discernible and reproducible bands across genotypes analyzed, out of which 214 (91.51 %) were polymorphic with varied band size from 300 to 3000 bp. According to the similarity matrix, the lowest similarity was obtained between P. mahaleb, as an outgroup, and sour cherry. Dendrogram based on molecular data separated genotypes according to their species and geographic origin. Low correlation was observed between the similarity matrices obtained based on morphological and RAPD data. The information obtained here could be valuable for devising strategies for conservation of Iranian sour and duke cherries.     

Estimation of genetic diversity in some Iranian wild Prunus subgenus Cerasus accessions using inter-simple sequence repeat (ISSR) markers

As Iran is one of the main origins of Prunus germplasm. In this study, ISSR markers were used for genetic diversity evaluation of 39 accessions of subgenus Cerasus belonging to six species i.e. Prunus avium L., Prunus cerasus L., Prunus mahaleb L., Prunus incana Pall., Prunus microcarpa Boiss., and Prunus brachypetala Boiss.. With 12 ISSR primers, 151 polymorphic bands were detected with polymorphism ratio range of 81.8%–100%. The lowest similarity (0.04) was found between P. avium and P. microcarpa genotypes and the mean of similarity between all genotypes was 0.28. Cluster analysis separated improved cultivars from wild accessions. Improved cherry cultivars and rootstocks were placed closer to the P. avium than the other species. The principal coordinate analysis (PCoA) supported the cluster analysis results. The wild accessions were separated according to their species and collection sites. ISSR markers are useful techniques for genetic diversity evaluation in Prunus subgenus Cerasus.     

S-allele diversity in Prunus L. Cerasus subgenus from Iran

In this study, S-allele diversity of eight wild and two commercial species of the Cerasus subgenus in Iran was investigated using two primer pairs. A high level of S-allele polymorphism was detected among and within the species evaluated. Furthermore, most of wild species showed 2–4 alleles based on S-allele primers and may be considered as tetraploid. Sweet cherry cultivars, Siah-Mashhad, Siah-Shabestar, Takdaneh-Mashhad, Siah-Daneshkadeh and Protiva showed S₃S₁₂, S₃S₁₂, S₃S₁₂, S₃S₅ and S₃S₄ combinations, respectively, allele S₃ showing the highest frequency. Three Iranian sweet cherry cultivars had the same allelic combination (S₃S₁₂) that the same ancestor in genealogy of these cultivars may explain the loss of diversity observed at the S-locus. Wild cherry (mazzard) accessions showed wide range of alleles such as S₁, S₂, S₇, S₁₄ and S₂₀ and unknown alleles, while sour cherries showed S₆, S₉, S₁₃ and S₂₇ alleles. In conclusion, the conservation of these highly diverse native species of Iranian wild Cerasus germplasm is recommended for future breeding activity.     

5-Aminolevulinic acid moderates environmental stress-induced bunch wilting and stress markers in date palm

Bunch wilting, a disorder of date palm (Phoenix dactylifera L.) and caused by climatic factors (low relative humidity along with high temperatures), critically damages its production in Iran. In this study, the effects of 5-aminolevulinic acid (5-ALA) as precursor of chlorophyll and elicitor of antioxidants applied to be involve directly or indirectly in stress tolerance mechanisms, bunch wilting severity, and other physiological aspects on 10–12 years old date palm in two locations. 5-ALA concentrations included 0 (control), 200, 240 and 280 ppm, applied as aqueous solution at biweekly intervals from fruit set until the beginning of fruit Kimri stage on leaves around the fruit bunches (for three times). Results showed that the yield of trees and bunch weight increased; hydrolytic enzymes activities in stalk and fruit decreased and activities of peroxidase, superoxide dismutase, and catalase, important enzymes of the antioxidative system were increased. The plants’ redox state changed as identified by decrease in H₂O₂ and proline of fruits. Microelement concentrations of leaves were changed at damage stage. Perhaps, due to mild environmental conditions in location A, lower bunch wilting and better physiological conditions of fruits recorded compared to location B. Foliar application of 5-ALA resulted to a coordinated action of the antioxidative system, affecting the defense-related enzymes. The treatment caused biosynthesis of chlorophyll and adjustments in H₂O₂ and proline compositions in leaf, stalk, and fruit. Bunch wilting was alleviated by 240 ppm 5-ALA, moderating the response of tree load to environmental stress conditions.