Genetic variations of 21 STR markers on chromosomes 13, 18, 21, X, and Y in the south Iranian population.

Quantitative fluorescent polymerase chain reaction (QF-PCR), in recent years, has been accepted as a rapid, high throughput, and sensitive method for prenatal diagnosis of common chromosomal aneuploidies. Since short tandem repeats (STRs) are the cornerstone of QF-PCR technique, selection of the most polymorphic STR markers is an essential step for a successful QF-PCR assay. The genetic variation parameters of each STR marker differ among different populations. In this study, we investigated the size, frequency, heterozygosity, polymorphism information content, power of discrimination, and other genetic polymorphism data for 21 STR markers on chromosomes 13, 18, 21, X, and Y in 1000 amniotic fluid samples obtained from south Iranian women. Our results showed that all the 21 STR markers are highly polymorphic and informative in our population. The heterozygosity, polymorphism information content, and power of discrimination of the markers were 62-91.1%, 0.61-0.91, and 0.830-0.976, respectively. The locus D18S386 was the most polymorphic STR, while the locus DXYS218 was the least polymorphic STR among all the studied STRs. The present study has provided extensive data regarding the efficiency of the 21 STR markers for diagnosis of chromosomes 13, 18, 21, X, and Y aneuploidies in the south Iranian population.

Construction of bacterial ghosts for transfer and expression of a chimeric hepatitis C virus gene in macrophages.

The bacterial ghost (BG) production is a field of biotechnology for applications in vaccine and drug delivery. We assessed the capacity of BG for delivery of a recombinant gene encoded for both cell mediated and antibody dependent epitopes of hepatitis C virus (HCV) into murine macrophages. Escherichia coli (E. coli) cells were transformed with the lysis plasmid (pHH43). To produce chimeric gene, NS3 (non-structural protein 3) and core regions of HCV genome were fused together by splicing by overlap extension (SOEing) PCR and were cloned into plasmid pEGFP-C1. Bacterial ghosts were loaded with recombinant pEGFP-C1 and then were transferred to murine macrophages (RAW 264.7). To investigate plasmid transfection and chimeric mRNA transcription, fluorescent microscopy and RT-PCR were used. In vitro studies indicated that bacterial ghosts loaded with pEGFP-C1 plasmid were efficiently taken up by murine macrophages and indicated a high transfection rate (62%), as shown by fluorescent microscopy. RT-PCR from extracted intracellular mRNAs for chimeric Core-NS3 gene showed a specific 607 bp fragment of the gene. The sequence analysis of purified PCR products demonstrated the expected unique mRNA sequence. We constructed a chimeric HCV gene containing both cell mediated and antibody dependent epitopes with a significant expression in murine macrophages delivered by bacterial ghost.