التحري تجريبياً عن الجينات المرمزة لبروتينات PSA الغشائية في جينوم سلالة من اللشمانيا الكبرى Leishmania major المعزولة محلياً

PSA (promastigote surface antigen) is a Leishmania family of membranebound or secreted proteins, whose main signature consists in a specific LRR sequence. As for the other membrane proteins, PSAs are encoded by multicopy genes. Before the complete sequencing of L. major genome, the number of copies was largely unknown. Recently, a bioinformatics study has been predicted the presence of 32 genes dispersed on chromosomes 5, 9, 12, 21 and 31. That study was based on a BLAST search analysis performed against the complete genome sequences using as a query sequence some of the PSA protein sequences reported in the literature. In our study, we have first isolated, cultivated, typed and strain of L. major. Then we have investigated experimentally the complete list of PSA genes coding for membrane proteins in its genome, using PCR approach based on specific primers. In conclusion, we have detected the physical presence of 22 different genes coding for membrane proteins in the genome of Syrian strain of L. major