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Researcher Kaur, Anupriya
Source KrishiKosh-Indian National Agricultural Research System
Content type Text
Educational Degree Master of Science (M.Sc.)
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Life sciences; biology ♦ Microorganisms, fungi & algae
Subject Keyword Biotechnology ♦ Gliadin Genes
Abstract Celiac Disease (CD) is an inflammatory disorder of the small intestine that damages the lining of the small intestine and prevents it from absorbing components of food that are important for staying healthy. The allergic reaction to the gluten proteins which are present in wheat and other cereals such as barley and rye leads to an autoimmune response in the celiac disease patients which cause damage to the jejunal mucosa (subtotal villous atrophy). In India the prevalence of Celiac Disease has been found to be 1.04 percent in Northern India. Based on the community studies 5-8 million people are expected to have Celiac disease in India. The α-gliadins have been shown to be the most active proteins in triggering CD owing to their containing several peptides or epitopes that constitute the main toxic components in CD. The α-gliadins are encoded by Gli-2 loci on short arm of group 6 chromosomes (gli-A2, -B2 and -D2). For the analysis of CD causing epitopes (glia-α9, glia-α2, glia-α20, glia-α) 48 wheat varieties/landraces were selected which were released from 1905 to 2011. DNA isolation was carried out followed by PCR amplification, elution, cloning and sequencing. Out of the 390 positive clones sequenced and from their deduced amino acid sequences, 67 complete ORFs, 158 incomplete ORFs and 165 pseudogenes (containing one or more internal stop codons) were obtained. A total of 212 sequences clustered with A genome, 47 with the B genome and 93 with the D genome on phylogenetic analysis. Sequence comparison demonstrated that all the sequenced genes possessed typical structural features of the previously characterized α-gliadin genes i.e. no introns. The obtained amino acid sequences were screened for the variations in epitopic regions and total of 12 variants were observed for the Glia-α9, 17 for Glia-α2, 8 for Glia-α20 and 4 for Glia-α. The prevalence of intact epitopes was observed more in the varieties released after 1965 while the varieties released before 1965 has variants of these epitopes which are expected non-immunogenic for the celiac disease. On comparison among all the varieties for the celiac disease causing epitopes, varieties PBW54, NP770 and NP824 were found to have all the four epitopes in variant form with changes reported to cause disruption of T-cell stimulatory response, hence can be good candidates for consumption by CD patients after further testing and trials. Keywords: α-Gliadin, Amino Acids, Celiac disease, Cloning, Epitopes, Immune Response, Modern wheat cultivars, Old wheat varieties, Phylogenetic Analysis, Sequencing, Wheat cultivars
Educational Use Research
Education Level UG and PG
Learning Resource Type Thesis
Size (in Bytes) 2.62 MB