The present study considers genetic diversity of 38 populations in 4 Cirsium species of the genus Cirsium Mill. (Asteraceae), occurring in different ecological regions and tries to compare degree of genetic variability among the species with wide geographical distribution versus endemic C. pyramidale showing confined geographical distribution. The results showed that the endemic species has similar value of genetic diversity parameters as the species with wider distribution. We also studied the possible admixture nature of these populations and tried to understand the relation between genetic changes, geographical distribution and polyploidy level and chromosome pairing in these species. ISSR analysis showed population difference in allele composition and frequency. Clustering and PcoA ordination produced different groupings in each species, while STRUCTURE and reticulation analyses revealed high degree of genetic admixture and gene exchange among populations as well as allelic rearrangement. No significant correlation was observed between geographical distance and genetic distance of the populations and AMOVA test revealed no significant difference among populations in each species studied. However, high amount of within population variation occurred in all 4 species indicating their cross-pollination nature and high genetic admixture. The populations also varied in chiasma frequency and chromosome pairing as well as the occurrence of heterozygote translocations all creating more variability to be used by plants for local adaptation.
Abstract:The genus Linum L. (Lineacea) has over 15 species, subspecies or ecotypes in Iran. These species show extensive geographical distribution and form many local populations throughout the country. Linum album is herbaceous medicinal plant containing important lignans such as podophyllotoxin (PTOX) and 6-methoxy podophyllotoxin (MPTOX), which have antiviral and anticancer properties. Studying the genetic and morphological diversity of different geographical populations produces detailed knowledge about population divergence and identification of the infra-species taxa if at all they are present. Moreover, the populations that differ in their genetic content and structure may also differ in their chemical and medicinal properties. The present study considers morphological and genetic diversity analyses of 20 L. album geographical populations by using nuclear ISSR markers, genome size, and cytogenetic characteristics. These populations differed significantly in many of their quantitative morphological characters and in some of their qualitative features. They also differed significantly in their molecular characteristics and genome size. Details of morphological and molecular variations are reported and discussed.
Human papillomavirus (HPV) is the most common sexually transmitted infection in the world and the main cause of cervical cancer. Nowadays, the virus-like particles (VLPs) based on L1 proteins have been considered as the best candidate for vaccine development against HPV infections. Two commercial HPV (Gardasil and Cervarix) are available. These HPV VLP vaccines induce genotype-limited protection. The major impediments such as economic barriers especially gaps in financing obstructed the optimal delivery of vaccines in developing countries. Thus, many efforts are underway to develop the next generation of vaccines against other types of high-risk HPV. In this study, we developed DNA constructs (based on L1 and L2 genes) that were potentially immunogenic and highly conserved among the high-risk HPV types. The framework of analysis include (1) B-cell epitope mapping, (2) T-cell epitope mapping (i.e., CD4+ and CD8+ T cells), (3) allergenicity assessment, (4) tap transport and proteasomal cleavage, (5) population coverage, (6) global and template-based docking, and (7) data collection, analysis, and design of the L1 and L2 DNA constructs. Our data indicated the 8-epitope candidates for helper T-cell and CTL in L1 and L2 sequences. For the L1 and L2 constructs, combination of these peptides in a single universal vaccine could involve all world population by the rate of 95.55% and 96.33%, respectively. In vitro studies showed high expression rates of multiepitope L1 (~57.86%) and L2 (~68.42%) DNA constructs in HEK-293T cells. Moreover, in vivo studies indicated that the combination of L1 and L2 DNA constructs without any adjuvant or delivery system induced effective immune responses, and protected mice against C3 tumor cells (the percentage of tumor-free mice: ~66.67%). Thus, the designed L1 and L2 DNA constructs would represent promising applications for HPV vaccine development.
Human papillomaviruses (HPVs) are a group of circular double-stranded DNA viruses, showing severe tropism to mucosal tissues. A subset of HPVs, especially HPV16 and 18, are the primary etiological cause for several epithelial cell malignancies, causing about 5.2% of all cancers worldwide. Due to the high prevalence and mortality, HPV-associated cancers have remained as a significant health problem in human society, making an urgent need to develop an effective therapeutic vaccine against them. Achieving this goal is primarily dependent on the identification of efficient tumor-associated epitopes, inducing a robust cell-mediated immune response. Previous information has shown that E5, E6, and E7 early proteins are responsible for the induction and maintenance of HPV-associated cancers. Therefore, the prediction of major histocompatibility complex (MHC) class I T cell epitopes of HPV16, 18, 31 and 45 oncoproteins was targeted in this study. For this purpose, a two-step plan was designed to identify the most probable CD8+ T cell epitopes. In the first step, MHC-I and II binding, MHC-I processing, MHC-I population coverage and MHC-I immunogenicity prediction analyses, and in the second step, MHC-I and II protein-peptide docking, epitope conservation, and cross-reactivity with host antigens’ analyses were carried out successively by different tools. Finally, we introduced five probable CD8+ T cell epitopes for each oncoprotein of the HPV genotypes (60 epitopes in total), which obtained better scores by an integrated approach. These predicted epitopes are valuable candidates for in vitro or in vivo therapeutic vaccine studies against the HPV-associated cancers. Additionally, this two-step plan that each step includes several analyses to find appropriate epitopes provides a rational basis for DNA- or peptide-based vaccine development.
Gene therapy, including small interfering RNA (siRNA) technology, is one of the leading strategies that help to improve the outcomes of the current therapeutic systems against HIV-1 infection. The successful therapeutic application of siRNAs requires their safe and efficient delivery to specific cells. Here, we introduce a superparamagnetic iron oxide nanoparticle (SPION) for delivering siRNA against HIV-1 nef (anti-nef siRNA) into two cell lines, HEK293 and macrophage RAW 264.7.SPIONs were coated with trimethyl chitosan (TMC), and thereafter, different concentrations of SPION-TMC were coated with different ratios of a carboxymethyl dextran (CMD) to modify the physicochemical properties and improve the biological properties of the nanocarriers. The nanoparticles exhibited a spherical shape with an average size of 112 nm. The obtained results showed that the designed delivery route enhanced the uptake of siRNA into both HEK293 and RAW 264.7 cells compared with control groups. Moreover, CMD-TMC-SPIONs containing anti-nef siRNA significantly reduced the expression of HIV-1 nef in HEK293 stable cells. The modified siRNA-loaded SPIONs also displayed no toxicity or apoptosis-inducing
Species identification is fundamentally important within the fields of biology, biogeography, ecology and conservation. The genus Geranium L. (Geraniaceae) comprises about 430 species distributed throughout most parts of the world. According to the most recent treatments, subg. Geranium is the largest subgenus with over 370 species classified in ten sections. The subg. Geranium is represented in Iran by 13 species. These species are grouped 3 sections. In spite vast distribution of many Geranium species that grow in Iran, there are not any available report on their genetic diversity, mode of divergence and patterns of dispersal. Therefore, we performed molecular (ISSR markers) and morphological studies of 102 accessions from 13 species of Geranium (subg. Geranium) that were collected from different habitats in Iran. The aims of present study are: 1) can ISSR markers identify Geranium species, 2) what is the genetic structure of these taxa in Iran, and 3) to investigate the species inter-relationship? The present study revealed that combination of morphological and ISSR data can identify the species.
ABSTRACT. Cotton is one of the most economically important crops in Iran; hybridization is a means to increase the genetic diversity and obtain new elite cultivars in this crop. We examined agronomic characteristics and molecular genetic diversity in the Opal cotton (Gossypium hirsutum) cultivar and in F 2 progenies. Ten homo-primers and seven hetero-primers of 26 RAPD primers produced 261 reproducible bands, with an average of 4.18 bands per primer and 22% polymorphism. The OPB12/OPH08 primer gave the highest effective number of alleles (N E ), and the largest Shannon index (I), Nei's genetic diversity (H), and polymorphism information content (PIC) values. Some RAPD bands were present in the parental genotypes but were absent in their hybrids. Ten ISSR primers produced 206 reproducible bands, with 49.4% polymorphism. The UBC807 locus gave the highest N E , I, H, and PIC values. Some ISSR bands occurred only in the parental genotype, while others were Genetic variation of intraspecific cotton hybrids only present in the hybrid genotypes. Four microsatellite loci produced 12 alleles, ranging from 181 to 236 bp, with 54% polymorphism. The TMB1421 locus, with a monomorphic allele, was digested with three restriction enzymes (CAP-microsatellite) to evaluate sequence variations among samples. Association analysis between molecular markers and agronomic data revealed a significant correlation between ISSR-UBC807-1500 and yield. The Mantel test performed among the genetic distance matrices obtained from RAPD, ISSR and SSR showed a nonsignificant regression between RAPD versus ISSR and ISSR versus SSR, while RAPD versus SSR showed a significant regression; regression for ISSR and RAPD+ISSR+SSR combined data was also significant. Cluster analysis (UPGMA) based on these three types of molecular markers differentiated cotton genotypes and their progenies. Among the molecular markers, ISSR revealed more genetic variation among the genotypes. However, using all three types of molecular markers provided a better overall view of cotton genome polymorphism.
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