Genetics in the Third Millennium
Volume:11 Issue: 1, 2013

SLC26A4 gene mutations are the second currently identifiable genetic cause of autosomal recessive non-syndromic hearing loss (ARNSHL) after GJB2 mutations, which are nowadays being investigated in molecular diagnosis. In databases, several potential STR markers related to this region have been introduced. In this study, the identity and informativeness of D7S2420 CA repeat STR marker in 5 end of SLC26A4 gene region was examined in five ethnic groups of the Iranian population. The locus was genotyped in 165 unrelated healthy individuals of five different ethnics including Fars, Azari, Turkmen, Gilaki, and Arabs using polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (PAGE) and fluorescent capillary electrophoresis. In the present study, the results of fluorescent capillary electrophoresis were analyzed by GeneMarker HID Human STR Identity software. The allele frequency, degree of heterozygosity and Hardy-Weinberg equilibrium (HWE) for unrelated individuals were estimated with the GenePop program and polymorphism information content (PIC) values were computed by Microsatellite Tools software. Analysis of the allelic frequency revealed the presence of 11 alleles for D7S2420 marker in the Iranian population of which, the allele 288bp at the D7S2420 locus with 24% frequency was the most frequent. The observed heterozygosity in all investigated ethnic groups was above 70%, with the highest rate of 87.9% for the Fars ethnic origin. Analysis of deviations from Hardy-Weinberg equilibrium demonstrated that all the ethnic groups were in equilibrium (P>0.05) for the D7S2420 locus. Finally, analysis of PIC value revealed that the D7S2420 marker could be considered as a highly informative marker in each ethnicity of the Iranian population (PIC value above 0.7). Our data suggested that D7S2420 could be introduced as a highly informative marker in molecular diagnosis of SLC26A4 based ARNSHL in our population by linkage analysis.

In this study, we introduced a new method for analyzing gene characteristics that cause a certain disease or a particular property. Item Response Theory (IRT) was used to calibrate gene and person characteristics and estimate their parameters. We described how to estimate these parameters by data simulation. Software output is numerical values that can be used for building gene banks or predicting transcriptional activation by a person with a particular predisposition.

Nowadays, cDNA is widely used in biotechnology and various methods suggested obtaining this goal due to its numerous applications. There is always a need to easier, faster, more accurate and more cost-effective methods for recombinant cDNA synthesis of different genes. In this study, the involving exons of VEGF-111 isoform related to VEGF-A gene were amplified through separate PCR reactions and finally VEGF-111 cDNA was synthesized after digestion and ligation reactions. In this method, the bioinformatics study and specific primer designing by Oligo 7 is very important. VEGF-111 isoform doesn’t expressed in normal tissue and only expressed in UV-B and genotoxic agents treated cell lines; so VEGF-111 cDNA synthesis is of great significant. VEGF-111 is a promising therapeutic agent in ischemic disease according to its potent properties such as angiogenic and remarkable resistance to proteases.

Congenital anomalies are amongst the main challenges for the families. The aim of this study was to determine the prevalence rate of neonates congenital anomalies. This descriptive-cross-sectional study was done in Mehregan Hospital in Babol from 2007 to 2009. Neonates were examined by two pediatricians. Sex, gestational age, type of anomalies and neonates` discharge status was recorded in a questionnaire. One thousand sixty hundred eighty four neonates were examined, 884(52.6%) were males and 798(47.4%) were females. The mean gestational age was 38.61.1 weeks. Total prevalence of congenital anomalies was 5.1% (CI 95%: 5.09-5.11). Musculoskeletal anomalies prevalence was 2.4%.In each group of female and male, the prevalence of congenital anomalies were 5.7% and 5.4% respectively (p>0.05). According to our findings the prevalence of congenital anomalies especially the musculoskeletal anomalies is high. Thus, more medical attention to diagnosis and treatment them on early stages is needed. Furthermore, more studies for understanding and preventing of congenital anomalies are necessary.

Lipases (Triacylglycerol acylhydrolases; EC 3.1.1.3) catalyze the hydrolysis of triacylglycerol to glycerol and fatty acids at the interface between water and oil. These enzymes are versatile biocatalysts with a wide range of application in food, dairy, leather, paper, and pharmaceutical and detergent industries. In this study, mesophilic lipase gene from an indigenous Bacillus pumilus F3 was cloned and expressed in methylotrophic yeast Pichia pastoris. The lipase gene of 648bp with natural signal peptid sequence from B. pumilus F3 was amplified by PCR and inserted into the PGEM5Zf vector. The lipase gene was excised from the recombinant plasmid with BamHI and EcoRI enzymes and ligated to the pPIC9 linearized with the same enzymes. The recombinant plasmid was confirmed by the PCR and restriction enzyme digestion. The Bgl II linearized Ppic9 recombinant plasmid was introduced into the yeast P. pastoris GS115 by electroporation and confirmed by PCR. One of the lipase expressing P. pastoris transformants was cultivated in expression medium. The expression of the lipase gene was confirmed by p-nitrophenyl palmitate test and SDS-PAGE.

Different types of first cousins marriage may variously affect the incidence of multifactorial disorders. Based on the pattern of X chromosome transmission, it seems that parallel and cross - cousin matrilateral marriages can have higher risks of multifactorial disorders with susceptibility genes on X chromosome in comparison to parallel and cross - cousin patrilateral marriages. In this study, the data of patients with 10 multifactorial disorders were extracted from the pedigrees of 9964 genetic counseling files. The frequency of different types of first cousins marriages among the parents of female patients with three disorders - cleft lip/palate, cleft palate, and systemic lupus erythematosus - was compared to the control group. No significant difference was observed in the frequency of different types of first cousins marriages among female patients’ parents and the control group. It seems that more studies are required to compare the effects of different types of first cousins marriages.

Liver X Receptors (LXRs) belong to the transcription factors activated by ligands of nuclear hormonal of super receptors family (ligand-activated transcription factors of the nuclear receptor superfamily) which regulate the expression of involved genes in transferring of cholesterol between the cells through high-density lipoproteins. Isoforms of LXRα and LXRβ function by activating the heterodimers of the retinoid X receptors (RXR) and forming complex LXR/RXR to an element of response of LXR (LXR response element) connected to the promoter region of the target genes. Thus the main function of LXRs is to regulate the cholesterol metabolism. Natural products, including the oxidized cholesterol derivatives which are called Oxysterols could be considered as LXR agonists. In recent years, LXRs are known as important regulators for transcriptional metabolism of carbohydrate and lipid. LXRs act as sterol (or cholesterols) sensors through stimulation of the reverse cholesterol transport (RCT) and activation of the return of biliary (bile) acids into the liver. Furthermore, it prevents the overload of cellular cholesterol. These phenomena resulted in identifying the LXR agonists as anti-atherogenic agents in atherosclerosis mice. In this article, the structure and mechanism of LXRs activity, their agonists and antagonists, and LXR expression regulation, will be discussed to clear the role of these receptors in cholesterol metabolism. The aim of this paper is to summarize the basic information about LXR physiological and pathophysiological roles in cholesterol metabolism and the related disorders.

Telomeres or nucleoprotein compounds are complexes that located at the ends of eukaryotic linear chromosomes and have many vital functions such as, protect the ends of chromosomes, complete replication of chromosome, a criterion for cell viability, and proper organization of chromosomes in the nucleus, regulate the expression of some genes and etc. During each cell division due to the end replication problem, continuously telomere length reduced which will be causes cell cycle arrest. Therefore telomeres as an internal controller clock set the number of cell divisions. Telomerase is a ribonucleoprotein enzyme with reverse transcription activity which adds DNA sequence repeats to the 3' end of DNA strands in the telomere regions can be solve this problem. About 90% of cancers cells are high telomerase activity that causes the cells immortalization. Unlike these cells, somatic cells are not very active. Therefore, analysis of telomerase activity in cancer cells can be detected as a tool for this purpose.

Quorum sensing is a microbial cell-to-cell communication process. Microbial cells produce and release extracellular signalling molecules called autoinducers. Gram-negative and gram-positive bacteria use homoserine lactones and oligo-peptides as autoinducer to communicate, respectively. The regulation of gene expression occurs in response to the changes of autoinducer which depends on cell-population density. Microbial cells use quorum sensing to regulate many diverse physiological activities such as virulence, pigmentation, bioluminescence, sporulation, motility, secondary metabolites and antibiotics production, biofilm formation, etc.

Standard plasmids consist of two parts: a bacterial backbone and a eukaryotic expression cassette. Recent studies demonstrate that the bacterial backbone in plasmids results in immunity problems and reduction of transgene expression. Based on this fact, minicircle DNA vectors were constructed. Minicircle vectors lack the bacterial backbone and only contain the eukaryotic expression cassette (transgene coding DNA sequence, promoter and poly A signal). Minicircle vectors are constructed by a recombinase–mediated intramolecular recombination. In this way, recombinase identifies its recognition sites at two sides of the eukaryotic expression cassette and by a recombination performance caused in segregation of eukaryotic expression cassette as a circle (minicircle). Up to now, minicircle vectors are produced by recombinases such as: λ integrase, ф C31 integrase, C rerecombinase and FLP recombinase, with specific advantages and disadvantages. Several studies have demonstrated that minicircles are safe and episomal vectors that enhance transgene expression extentand duration of tansgene expression in vivo and in vitro.