GENETICS IN THE 3RD MILLENNIUM
Year:2011 | Volume:9 | Issue:1|Papers Count:11

Shigellosis is one of the major causes of morbidity and mortality worldwide and the disease causes around millions deaths per year. Due to the increasing number of infected persons in some areas of the world, in addition to the emergence of strains resistant to multiple antibiotics, WHO has put emphasis on the need for an effective vaccine. Shigella bacteria attach to M- cells in epithelial cells through invasion factors and then cause mucosal ulceration, inflammation and bleeding. IpaD has an important role in pathogenicity of Shigella. The N-terminal region is the most significant functional fragment of IpaD. In this study, the induction of the immunity response against the N-terminal region of IpaD has been investigated. Ni-NTA column chromatography was used for purification of the N-terminal region of IpaD. Afterwards, the recombinant protein was injected to Guinea pigs for producing polyclonal antibodies. Produced antibody titers were measured by ELISA. This antibody was purified with a column of protein G and then examined by Western blot test.The result of Western blot confirmed the expression of the purified protein. High ELISA titers of antibody were observed in the serum of animals immunized with the protein. The polyclonal antibody purified with protein G column chromatography was confirmed by immunobloting test.

Peroxisomes are regarded as one of the organelles in eukaryotic cells with various functions. One of the matrix proteins for peroxisome is termed peroxisomal protein (PEP) which was formerly cloned in mice in 2002. PEP consists of 209 amino acid residues and seems to have a possible role in tissue differentiation of mouse embryo. Studies have shown that PEP expression is increased during myogenesis and neurogenesis. To study the further role of PEP in neurogenesis, it was required to construct an expression vector of this gene to be regulated using Doxycycline or tetracycline in different stages of neurogenesis. Thus, appropriated primers were designed introducing restriction enzymes at the head and tail of the fragment. Moreover, Kozak sequences were considered for high expression of PEP protein. PEP cDNA was amplified and ligated into pTRE2pur vector of Tet off expression system. Tet off expression system contains two vectors, a vector called Tet off which produces a protein element which controls the gene expression in the second vector called pTRE2pur off via tetracycline or Doxycycline induction. Tet off vectors can be transferred into cells. In addition to generating TRE2pur/PEP, we inserted EGFP cDNA into the vector TRE2pur and made TRE2pur/EGFP structure to assess the functionality of this system in the cells.

In this study, several designed Creb1-specific shRNAs cloned into lentiviral transfer vectors were screened in293T by transient transfection assays. Relative Creb1 expression was determined by relative qRT-PCR. All of the designed shRNAs gave some level of knockdown. One shRNA was more effective for knocking down the specific gene among others. The predicted siRNAs activities as determined by Reynolds et al were compared to the actual potencies. Our results showed a general correlation between the predicted and actual siRNA activities.

LTP gene encodes lipid transfer protein in plants. LTP gene is rich for GC bases. Thus, designated primers may form secondary structures in the annealing step of PCR and cannot bind to the template appropriately. This may results in undesired product. Substances such as Betaine, Dimethyl Sulfoxide (DMSO) and Ammonium Sulfate (AMS) can solve this problem. In this study, different gradients of each material were used in the PCR reaction. Ultimately, the optimum concentration was obtained for these materials. Among them, 4.5 ml betaine (5M), 2.25 ml DMSO (10%) and 2.25 ml AMS in 25 ml of PCR mixture were reported to be optimal concentrations.

Genetic diseases affect children physically and psychologically and create psychological and economic problems for their families. Parents who are in need to seek help on issues related to the disease need to be aware of the status of their children as much as possible. In order to assess parental knowledge and information on genetic diseases, we used a questionnaire to evaluate the information and opinions of 100 parents (37 fathers and 63 mothers).The study showed that there were significant correlations between knowledge scores, educational level of the parents, parental cohabitation (not being separated) and parental age. With increase in awareness, acquiring information regarding the disease and its treatment is enhanced through different sources. Families that were previously trained needed more verbal information. Improvement of the social and economic status of the families with genetically affected children will result in better care and improve quality of life of the patients. In conclusion, it is prudent to devise plans to familiarize families with genetically affected children with counseling centers.

Antioxidant enzymes are one of the most important defensive strategies of plants in Reactive Oxygen Species (ROS) detoxification. In this work, two temperatures, 4oC and 10oC were investigated in order to find the appropriate temperature cold acclimation of desi chickpea. Results showed that plants responded to 10oC better than the other one. Then, the activity and relative gene expression of catalase and peroxidase enzymes, along with some physiological and biochemical indices, were measured in both desi and kabuli genotypes of chickpea. More membrane stability, no significant increase of H2O2, more antioxidants enzyme activity and more stable and further accumulation of transcript levels of these genes in Jam cv. plants showed that this genotype could withstand the effects of cold stress better. The increase of the expression level of APX suggested that APX could work at cold stress and compensate for the loss of CAT activities. It seems that early response to cold acclimation and cold stress may start shortly after exposure to the stress condition and that this short time can make some chickpea plants ready to encounter lower temperatures.

Apoptosis, the genetically programmed suicide, plays a critical role in a number of physiological and pathological cell conditions. Several molecules and signaling pathways involved in apoptosis have been recently identified and many of them are well characterized. However, the role of cytosolic organelles and their interactions during apoptosis is unknown and requires further investigation. In some reports, cytosolic organelles including the mitochondria, endoplasmic reticulum, Golgi apparatus, peroxisome, lysosome and nucleus are recognized as the members of a “third pathway” of apoptosis. This pathway is considered completely different from the intrinsic and extrinsic pathways of apoptosis. The present paper will review the function of several cytosolic organelles separately, and discuss the importance of the third pathway of apoptosis.

Systemic Sclerosis (SSc) is a connective tissue disease that affects various organs including the skin, lungs, kidneys, and heart. The etiology is poorly understood; however, a causative agent may initiate the disease in a patient with a genetic predisposition for SSc. There are three features responsible for the clinical and pathologic manifestations of the disease: vascular lesions of small arteries, excessive deposition of collagen in skin and internal organs, and alterations of humoral and cellular immunity. Type I collagen, the major component of extracellular matrix in skin and other tissues, is a heterotrimer of two a1 and one a2 collagen polypeptides. The synthesis of both of the chain types is highly regulated by several cis-acting regulatory elements and trans-acting protein factors, which are involved in basal gene expression. Also, several cytokines have been identified that positively and negatively influence dermal fibroblast proliferation and collagen synthesis, including: TGF-b, CTGF and IFN-Y. TGF-b and CTGF are profibrotic cytokines, whereas IFN-Y is antifibrotic cytokine. Imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinases might also contribute to the excess accumulation of collagen in the dermis. Because of high mortality and morbidity in SSc which directly related to the extent of the fibrotic, a precise understanding of the molecular mechanism of fibrosis will help to find effective therapeutic agents for this incurable disease in the future. This review focuses on collagen genes and proteins and then factors involved in synthesis and degradation of collagen in connection with systemic sclerosis will be explained briefly.

In this review, we have focused on current knowledge about the influence of genetic polymorphisms in certain genes on the lipoprotein response to dietary fat and cholesterol. The DNA polymorphisms on the genes encoding apo A-IV, apo C-III, apo E, have been found to be associated with the plasma lipoprotein response to dietary intervention.The plasma lipid response to changes in dietary fat and cholesterol can vary between individuals. An Adenine to Guanine (A®G) mutation in the promoter of the apolipoprotein A1 gene (apoA-1) has been suggested to affect plasma high-density lipoprotein cholesterol. Some studies have reported that subjects with the A allele have higher concentrations of HDL cholesterol than do subjects who are homozygous for the most common G allele. The results of other studies indicate that the presence of the 360His allele of apoA-IV is responsible, at least partially, for the inter-individual variability in HDL-C response to dietary fats, with subjects who have this allele presenting a greater increase in HDL-C levels after consuming fat-rich diets.Many studies have shown that the effect of cholesterol feeding on total HDL cholesterol produces no change in E3/E2 subjects, a small increase in E3/E3 subjects, and the largest increase in E4/E3 subjectsAn improved understanding of the influence of specific genes on lipoprotein responsiveness to dietary fat may allow us to counsel individuals to meet their own dietary fat requirements so that they may reduce their risk of developing hyperlipidemia and coronary artery disease.