Genetics in the Third Millennium
Volume:10 Issue: 4, 2013

Thalassemia is the most common hereditary anemia. In most cases، it affects genes of alpha and beta globin chains and leads to the reduction of affected chains. About 5% of the world population has one genetic variant in their globin genes، but only 1. 7% of them exhibit alpha and beta thalassemia minor. Recognition of frequent mutations in beta thalassemia minor will be helpful in devising preventive measures and therapeutic programs among carriers of special genotypes. In this descriptive and cross sectional study، data was obtained from patients admitted to the Genetic Laboratory of Shefa Hospital for the diagnosis of thalassemia in 2010. The total number of the patients diagnosed with thalassemia minor was 707. ARMS-PCR was used to diagnose point mutations and RFLP was done to detect deletions in beta globin genes. The data was analyzed with SPSS version 14. Based on race، our beta thalassemic minor patients were Arab (358 cases)، Bakhtiari (n = 164)، Fars (77 cases)، Kurd (20 people)، and Lur (88 cases). Out of 39 identified mutations and deletions، the most prevalent mutations were Cd 36/37 (- T) with 156 carriers، IVSII-1 (G> A) with 129 carriers، and IVSI-110 (G> A) with 66 carriers. Based on race، the most frequent mutation seen in Arab and Bakhtiari populations was Cd 36/37 (- T) [66 and 71 cases respectively]. In Fars، Kurd and Lur populations، the most frequent mutation was IVSII-1 (G> A) [17، 8 and 28 cases، respectively]. The prevalence of mutations causing beta-thalassemia in Khuzestan Province is very diverse، but shows close similarities in some races due to genetic similarities in the whole population. Considering the increasing trend of communication among different races، our findings are highly applicable in prediction of mutations as well as in screening and pre natal diagnosis.

Air pollution plays an important role in the development of some diseases such as cardio-vascular disorders and cancer. Previous studies have shown that air pollution is associated with an increase in the level of Reactive Oxygen Species (ROS) which can lead to oxidative DNA damage. 8-Hydroxy-2’-deoxyguanosine (8-OHdG) is a biomarker of oxidative DNA damage associated with occupational and environmental exposures. Although many studies have demonstrated a correlation between air pollution and increased 8-OHdG، no study has been conducted in Tehran. Therefore، in the present study، 8-OHdG level as an indicator of oxidative DNA damage was examined in 40 subjects living in air polluted areas of Tehran and 40 office workers in the North of Iran. Samples were evaluated by ELISA assay. There was no significant difference in the level of 8-OHdG between the two groups (p=0. 5677). Some studies have shown that genetic polymorphisms of the genes involved in metabolism and detoxification، antioxidant and physical status and different physical activities can decrease or increase the 8-OHdG level. Moreover، it is better to conduct more in-depth studies with larger sample sizes to evaluate the correlation of air pollution and oxidative DNA damage and if possible، genetic background، antioxidant and physical status of individuals should be considered in future studies.

Shigella dysenteriae is an important pathogen that induces acute enteric infection in human. IpaD antigen، play an important role in the creation and induction of infection by Shigella. The challenges of use ipad in design mucosal vaccines against Shigella is limited potency and non transferred to mucosal tissues. by linking IpaD antigen to Ricin toxin B Subunit as carrier and adjuvant we can eliminate challenges of production of mucosal vaccines. This study aimed to construct a gene cassette containing the N-terminal region of ipaD gene which was connected to the RTB gene as a new approach generating of mucosal vaccines against Shigella. genomic DNA of Ricins communis was extracted by CTAB method. Using specific primers، the fragment of 819 nucleotide of RTB gene with linker were amplified. PCR reactions for amplification of the ipaD gene were carried out. Each of the amplified fragments was cloned into the pGEM-T vector. In order to construct a gene cassette، ipaD was ejected from the vector pGEM-ipaD with enzymes XhoI / HindIII. Subsequently، the recombinant plasmid pGEM-RTB was cut with XhoI / HindIII enzymes. During the process of ligation، ipaD was inserted into the pGEM-RTB recombinant plasmid to construct RTB-ipaD gene cassette، and then the gene cassette was sequenced by the sequencer. after confirming the cloning of N-terminal region of ipaD and RTB genes، accurate construction of the gene cassette was confirmed by PCR، Nested-PCR، restriction enzyme and sequencing. Base on the last information، this study is a first report of design، construction of RTB-ipaD gene cassette، that can use for generating of a suitable candidate mucosal vaccine for shigellosis. This study also creates a strategic direction for the production of fusion proteins and immunological studies.

Various tools have been developed to deliver genes into eukaryotic cells; among them، the efficiency of RNA-containing viruses belonging to the family of Retroviridae is higher than other viruses because integrate their genomes into the target cell chromosomes. The Murine Leukemia Virus (MLV) is the most prominent member of orthoretrovirinae genus of gammaretroviruses. An MLV-based retroviral vector can only express transgenes in cells undergoing mitosis، indicating its suitability as a delivery vehicle for cancer gene therapy. In this study، an MLV-based viral vector was produced in the HEK293T cell line by transient cotransfection of three plasmids including pBABE-GFP (plasmid expressing GFP reporter gene)، pBS–CMV–gagpol (plasmid consisting of Gag-Pol genes) and pMD2. G (plasmid expressing VSVG gene). The produced viral vector was concentrated by ultracentrifuge and poly ethylene glycol methods. Serial dilutions were prepared from concentrated virus and virus titer was calculated according to infectious unit per milliliter (21×106 infectious particles per milliliter in both methods). Then، the transduction efficiency of cancerous cell lines (A549 and Hela) and non- cancerous cell lines (HEK and Vero) was compared by the produced viral vector. The results showed that efficiency of the generated vector to infect cancer cells in comparison with other cells was higher and thus was more suitable for gene transfer into cancer cell lines.

Fndc5، also known as PEP، encodes a protein with 209 amino acids. Fndc5 is mainly expressed in the heart، skeletal muscle، and brain tissues. This experiment was carried out to elucidate the temporal expression of this gene during the process of cardiac cell differentiation of mouse embryonic stem cells. Mouse embryonic stem cells were induced to differentiate to beating bodies under ascorbic acid treatment. The expression pattern of PEP was investigated under distinct steps of differentiation by real-time PCR. Our results demonstrated that expression of PEP transcripts was markedly increased at matured cardiomyocyte. Thus، PEP might be involved in late cardiac cell differentiation، which needs further verification، implying a possible role in this process.

PROP1 (Prophet of POU1F1) is specifically expressed in the pituitary gland. The PROP1 gene organizes three exons encoding for the 226 amino acids in humans and domestic animals; this gene is localized on chromosome 1 and regulates growth hormone، prolactin، and thyroid. The aim of this research was to study the polymorphisms of the PROP1 gene in Zel، Lori-Bakhtiari and Zel-Atabay crossbred sheep breeds، using PCR–RFLP. Blood samples from 90 Lori-Bakhtiari (research station)، 60 Lori-Bakhtiari (slaughterhouse)، 90 Zel (research station) and 40 Zel-Atabay crossbred (slaughterhouse) sheep were collected. DNA was extracted using the salting out method and the desired fragment was amplified using PCR. The genotypic frequency of GG and GA in Lori-Bakhtiari (research station)، Lori-Bakhtiari (slaughterhouse)، Zel (research station) and Zel-Atabay crossbred sheep were 0. 98%، 0. 02%، 0. 86%، 0. 14%، 0. 96%، 0. 04%، 0. 89%، and 0. 11%، respectively. The genotypic frequency of AA and AB in Lori-Bakhtiari (research station)، Lori-Bakhtiari (slaughterhouse)، Zel (research station) and Zel-Atabay crossbred sheep were 0. 70%، 0. 30%، 0. 78%، 0. 22%، 0. 68%، 0. 32%، 0. 84%، and 0. 16%، respectively. It can be concluded that polymorphism of this gene can be used as a candidate gene for some biometric traits.

MicroRNAs (miRNAs) are a group of short non-coding RNAs which regulate protein-coding gene expression and often actbypairing withcomplementarysequences in the 3’ UTR of multiple target mRNA. MicroRNAs were discovered in 1993 and play very important and broad roles in different organisms. It was initially thought that the genes encoding miRNAswere located in intergenic regions. However، recent analyses of miRNA gene locations showed that the most of mammalian miRNA genes are located in defined transcription units (TUs) and transcribed by RNA polymerase II. Transcription product must be processed to become mature miRNA and ultimately effectson gene expression. The miRNA deregulation in breast cancer was first reported in 2005. Epigenetic، chromosomal changes، polymorphismsoradefect inproteinprocessing are the mechanismsthat maybecausingthelack ofproperexpression of mi RNA in cancers. In fact، these RNAs may act as oncogene or tumor suppressor. Scientistsarenow tryingtomakethediagnosis andclassificationofcancer usingmiRNA، and arealso usedinthe treatment. They have alsoachievedinthesefieldsto succeed.

Cloning of large DNA fragments is necessary for more accurate analysis of cloned fragments. Therefore، there have been many attempts for cloning of large DNA fragments and whole genome. Earlier studies have showed that cloning of large DNA fragments and whole genome of organelles، bacteria and viruses is possible by using standard molecular biology techniques such as overlapping DNA fragments and whole genome cloning techniques. Genomic fragments can be inserted into the specific vectors by several strategies، such as inchworm elongation process and simultaneous homologous recombination at two small flanking DNAs called landing pad sequences (LPS)، or direct recombination and transformation into the host genome. Also، whole continuous genomes can be inserted to the host genome by specific designed vectors. For achieve this purpose، common processes in live organism such as recombination، gene conversion، and also transposons and insertion sequences capabilities can be benefitted from in this regard، using suitable specific vectors.

Steroid receptors (SRs) are ligand-dependent transcription factors. These receptors are subfamilies of nuclear receptors (NRs) superfamily. It is believed that NRs are derived from one common ancestor through evolution, and all harbor a common structure containing five main regions. These receptors may be classified into two groups according to their mechanism of action: homodimer and heterodimer receptors. The receptors are activated through different pathways based on their position in the nucleus or cytoplasm. Recent studies demonstrate that SRs regulate miRNAs, and in turn, miRNAs can regulate SR expression and function. In the present study, the molecular mechanisms of steroid receptors, their relationships with miRNA and genetic disease have been reviewed.