Metabolic and evolutionary insights into the closely-related species Streptomyces coelicolor and Streptomyces lividans deduced from high-resolution comparative genomic hybridization

Whilst being closely related to the model actinomycete Streptomyces coelicolor A3(2), S. lividans 66 differs from it in several significant and phenotypically observable ways, including antibiotic production. Previous comparative gene hybridization studies investigating such differences have used low-density (one probe per gene) PCR-based spotted arrays. Here we use new experimentally optimised 104,000 × 60-mer probe arrays to characterize in detail the genomic differences between wild-type S. lividans 66, a derivative industrial strain, TK24, and S. coelicolor M145

Genome-wide inference of regulatory networks in Streptomyces coelicolor

Background: The onset of antibiotics production in Streptomyces species is co-ordinated with differentiation events. An understanding of the genetic circuits that regulate these coupled biological phenomena is essential to discover and engineer the pharmacologically important natural products made by these species. The availability of genomic tools and access to a large warehouse of transcriptome data for the model organism, Streptomyces coelicolor, provides incentive to decipher the intricacies of the regulatory cascades and develop biologically meaningful hypotheses. Results: In this study, more than 500 samples of genome-wide temporal transcriptome data, comprising wild-type and more than 25 regulatory gene mutants of Streptomyces coelicolor probed across multiple stress and medium conditions, were investigated. Information based on transcript and functional similarity was used to update a previously-predicted whole-genome operon map and further applied to predict transcriptional networks constituting modules enriched in diverse functions such as secondary metabolism, and sigma factor. The predicted network displays a scale-free architecture with a small-world property observed in many biological networks. The networks were further investigated to identify functionally-relevant modules that exhibit functional coherence and a consensus motif in the promoter elements indicative of DNA-binding elements. Conclusions: Despite the enormous experimental as well as computational challenges, a systems approach for integrating diverse genome-scale datasets to elucidate complex regulatory networks is beginning to emerge. We present an integrated analysis of transcriptome data and genomic features to refine a whole-genome operon map and to construct regulatory networks at the cistron level in Streptomyces coelicolor. The functionally-relevant modules identified in this study pose as potential targets for further studies and verification.

Molecular Study of Partial Deletions of AZFc Region of the Y Chromosome in Infertile Men

Abstract: Background & Aims: The most significant cause of infertility in men is the genetic deletion in the azoospermia factor (AZF) region that is caused by the process of intra- and inter-chromosomal homologous recombination in amplicons. Homologous recombination could also result in partial deletions in AZF region. The aim of this research was to determine the association between the partial AZFc deletions and infertility. Methods: The blood samples were taken from 100 infertile men‚ who referred to the Infertility Center of Isfahan‚ Iran. 100 healthy matched people were also selected as the control group. The five markers of sY1201‚ sY1206‚ sY1161‚ sY1291, and sY1191 were applied in order to study partial deletions. Partial deletions were analyzed in AZF region using the Multiplex–STS–PCR technique. The chi-square test was conducted to check the difference between pretest and posttest. Differences were considered significant if P < 0.05. Results: 9% of studied persons showed gr/gr deletion (in the patient group). Only one case of gr/gr deletion was observed in the control group. Five patients showed b2/b3 deletion. One b2/b3 deletion was seen in the control group. The b2/b4 deletion was observed in 3 patients. In conclusion‚ partial deletions were observed in 14% of the patients. The statistical analysis of the gr/gr deletion in the study indicates a meaningful difference, but b2/b3 deletion does not represent a meaningful difference. Conclusion: Our results suggest that gr/gr deletions are associated with spermatogenic failure, and there is no association between b2/b3 deletion and infertility. Keywords: Keywords: Infertility, Deleted azoospermia‚ Azoospermia factor‚ STS marke

Evaluation of anticancer peptide VEGF111b secretion in HEK293 human cells

Background: VEGF111b is a new isoform of vascular endothelial growth factor (VEGF) recently considered as a new anticancer drug. The aim of this study was to evaluate the VEGF111b secretion from HEK293 cell wall in order to commercial production of this recombinant factor. Materials and Methods: After the design of VEGF111b sequence using OLIGO software and NCBI gene bank data, it was cloned into the pBUD.cE4.1 vector. The pBUD.VEGF111b recombinant vector was transfected into HEK293 cells using lipofectamine kit. Forty-eight hours after the transfection the production of VEGF111b was estimated by Western blotting and Human anti VEGF antibody. The VEGF111b secretion into cell culture and cell lysate extract was measured using ELISA. Results: The correct cloning of VEGF111b into pBUD.cE4.1vector was confirmed using enzymatic digestion and gel electrophoresis. The observed production of recombinant peptide in HEK293 was confirmed with 12KDa band in cell lysate extract of Western blotting. The ELISA results at 450 nanometer absorbance for cell culture media and cell lysate extract were 19.20&plusmn;2.81 pg/ml and 32.87&plusmn;7.42 pg/ml, respectively. However, no VEGF111b expression was observed in negative controls. Conclusion: The findings of this study indicate the powerful ability of transformation and secretion of VEGF111b from HEK293 cell wall to cell culture media with no breaking and proteolytic digestion. It seems that the commercial production and purification of this therapeutic peptide from HEK293 cell culture would be possible with high efficiency

Rapid Isolation and Molecular Detection of Streptomycin-Producing Streptomycetes

Introduction: Streptomyces species are mycelial, aerobic gram-positive bacteria that are isolated from soil and produce a diverse range of antibiotics. Streptomyces griseus produces the antibiotic, streptomycin and forms spores even in a liquid culture. The gene cluster for the production of Streptomycin antibiotic contains strR gene that encodes StrR, a pathway-specific regulator. Then, this pathway-specific regulator induces transcription of other streptomycin production genes in the gene cluster. The overall aim of this work was rapid isolation and molecular detection of streptomycin-producing Streptomycetes, especially S. griseus, from Iranian soils in order to manipulate them for increased production of streptomycin. Methods: This research used new initiative half-specific medium for isolation of Streptomycetes from natural environments, called FZmsn. The fifty colonies of Streptomyces strains grown on the surface of FZmsn medium isolated from environmental samples were defined on the basis of their morphological characteristics and light microscope studies. A set of primers was designed to detect strR by OLIGO software. Results: In colony-PCR reactions followed by gel electrophoresis, 6 colonies from Streptomyces strains colonies were detected as S. griseus colonies. Conclusion: These native Streptomyces strains will be used for genetic manipulation of S. griseus in order to increase production levels of streptomycin

Study of Y Chromosome Microdeletion in AZF Region in Infertile Males of Isfahan Population

Abstract Background & aim: One of the main genetic factors of infertility is the deletions in the chromosome Y. Accordingly this study was conducted to determine the frequency of microdeletion of AZF region in infertile men of Isfahan, Iran. Methods: In this case-control study, 100 infertile men referred to the Infertility Center of Isfahan and 100 fertile men as controls were randomly selected. Genomic DNA was extracted from their blood and amplified by sequence tagged sites-polymerase chain reaction (STS-PCR) method. The presence of microdeletion in AZF locus was diagnosed. Results: No AZFa, AZFb or AZFc deletions were found in the control group. Microdeletions were observed in one patient in AZFb region, eight patients in AZFc region and two patients in AZFa region. Conclusion: The incidence of Yq microdeletions in Iranian population is similar to the international frequency. Our data agree with other studies regarding microdeletions of AZFc, but for microdeletions of AZFa (2%) our results show smaller frequency and differ significantly with many studies. Key words: Infertility, Y chromosome, Microdeletio

Evaluation of clinical and paraclinical findings of Kawazaki patients among children admitted in Kashan Shahid Beheshti hospital during 1998-2008

Background: Kawazaki is an acute febrile vasculitis accompanied by cardiovascular complications. This study was conducted for the evaluation of clinical and paraclinical findings of Kawasaki disease among the children admitted in Kashan Shahid Beheshti Hospital. Materials and Methods: This cross-sectional study was carried out on 69 children diagnosed as Kawasaki. Medical documents of all cases were reviewed during the years 1998-2008 and all of the registered patients were invited to perform echocardiographic and cardiologic studies. Results: Sixty-nine out of 44 Kawasaki patients (63.8) were male and the remaining 25 (36.2) were female. 37 of cases were admitted in spring. All patients had fever, 89.9 elevated ESR and 24.6 elevated LDH. Among the 71.20 of cases albumin was lower than the normal range and 51.2 and 40 had elevated ALT and AST, respectively. 18.8 of Kawasaki patients had unqualified Kawasaki. Among the 2 cases with cardiac complication the serum albumin was lower than the normal. An ascending trend for the incidence of Kawasaki was seen since1998 till 2008.Conclusion: Considering the rising incidence of Kawasaki in recent years, paying careful attention to the disease signs, specially unqualified cases of Kawasaki in terms of on-time prescribing of Intravenous Immunoglobulin (IVIG), prevention of complications and also the evaluation of serum albumin level seems very important