فصلنامه ژنتیک نوین
سال پانزدهم شماره 1 (پیاپی 60، بهار 1399)

The availability of nutrients such as phosphorus in plant, in addition to plant yield increment, could increase growth rate and thus reduce plant growth period. Therefore, identification and overexpression of genes involved in nutrient uptake are the important steps to increase of yield and tolerance to environmental stresses particularly the end seasons stresses. Purple acid phosphatases, one of the most important phosphatase family, play a key role in increasing phosphorus availability in plants. In this study, the effect of knock-out and overexpression of AtPAP17 and AtPAP26 genes (two important members of Arabidopsis thaliana purple acid phosphatase family) on some physiological and phonological traits of Arabidopsis thaliana was investigated under Pi-sufficient (1.25 mM KH2PO4) and Pi-deficient (0 mM KH2PO4) conditions. For this purpose, single and double mutant plants of AtPAP17 and AtPAP26 genes were studied in this research. To confirm the function of mentioned genes in mutant plants, transformed Arabidopsis plants containing the CaMV-35S:AtPAP17 and CaMV-35S:AtPAP26 constructs were studied as overexpressed plants of AtPAP17 and AtPAP26 genes, respectively. The result showed that biomass and phosphorus content of plants increased in single mutant plants as compared to double mutant plants under Pi-sufficient condition. Superiority of single mutant plants as compared to double mutant plants indicated a remarkable contribution of AtPAP17 and AtPAP26 genes in phosphatase compensation network. Our results showed at least one of these genes (AtPAP17 and AtPAP26) activity is essential for increasing phosphorus availability and fast growth in Arabidopsis thaliana. Also, overexpressed plants displayed a significant increase in phosphorus content, flowering percentage, and biomass as compared to WT plants (Col-0). The results of this study showed that AtPAP17 and AtPAP26 genes could be important candidates for developing the plants with high ability of nutrient uptake, especially phosphorus, thereby reducing plant growth period.

Mastitis is the most costly disease in dairy cattle and usually occurs in response to intramammary bacterial infections. The identification of genes that their expression are altered in response to bacterial infections and to classify them into biologically functional groups help to understanding of the host response to a specific pathogen. Therefore, the aims of this study were to investigate the expression of IL-2 gene in the mammary gland of healthy Holstein heifers at three stages of early, mid and late lactation and E.coli mastitis heifers. For this purpose, total RNA extracted from milk somatic cell of 18 healthy Holstein heifers (6 animals for each stage of lactation) and 4 clinical E.coli mastitis heifers in first lactation. To study of gene expression, the expression of IL-2 gene was compared with GADPH gene as a reference gene. For gene expression analysis, the REST, V2.0.13 2009 software was used. Our results showed significant increase of IL-2 expression in E.coli mastitis in comparison of different lactation stages. Maximum and minimum differences were found with early and late stages of lactation, respectively. Our study indicates that it was possible to verify changes in the expression of IL-2 gene in normal and E.coli mastitis heifers and the IL-2 gene may play important role in fighting intramammary infection caused by E.coli.

In this study, the effect of TiO2 nanoparticles (concentrations of 0, 5, 50, 100, 150 and 200 mg/l) on cytogenetic indices of cell devision and physiological responses of chickpea genotype (Sel96Th11439) was investigated. There was no chromosomal abnormalities in the control samples, and the mitotic index was 25%. By increasing the concentration of nanoparticles, the amount of mitosis index decreased (except for 25 mg/l TiO2, which showed the most increase). The lowest amount of mitosis index (14%) was found at 200 mg/l TiO2, which showed significant different compared to control samples. The effect of TiO2 nanoparticles on the mitotic index, chromosomal deviation index and anaphase index was significant whereas the metaphase and telophase indices did not show significant difference. There were no metaphase, anaphase, and telophase abnormality in control samples as well as at concentrations up to 50 mg/l, while at the concentration of 100, 150 and 200 mg/l, telophase, anaphase, metaphase and telophase abnormalities were observed, respectively. At lower concentrations of TiO2 (5 mg/l), there was not significant differences in cytogenetic and physiological indices compared to the control plants. Due to sever damages the mitosis index decreased at 100 mg/l of TiO2. It seems that at high concentrations of TiO2, ROS accumulation undermined organelles and DNA, led to chromosomal abnormalities and a decrease in mitosis index.

The tumor cell process occurs in most cases by environmental and sometimes occasional factors, but in some cases, hereditary factors play an important role. Colorectal cancer (CRC) is the second most common cancer in developed countries. More than 10% of CRC cases are of HNPCC (Hereditary non-polyp sis colorectal cancer) and FAP (Familial adenomatous polyposis) type. HNPCC is the most common type of hereditary colorectal cancer accounting for approximately 1-10% of all colorectal cancers. Germ line mutations in MMR (Mismatch repair) genes, in particular MSH2, MLH1 and MSH6 genes, are the causes of some colorectal cancers. Mutations in MSH2 gene, located on chromosome 2 (2p21), account for 25% of HNPCC cases, with 17-50% involving deletions.A total of 50 tissue samples from patients with CRC were subjected to genomic DNA extraction. Genomic DNA was then subjected to AAT mutation analysis by HRMA (high resolution melting analyze) technique, and confirmed by DNA sequencing technique. In the research with HRMA technique, all samples were found to be of wild type with respect to AAT deletion in MSH2 gene.The results showed that HRMA can be used as a new and highly effective tool for molecular detection and prevention of diseases.

Heat shock proteins in Closteroviruses play many roles, especially moving from cell to cell to create systemic contamination. In the present study, the genetic differences of the heat shock protein gene of Iranian isolates of Cucurbit chlorotic yellows virus. Also, the selection pressure imposed on selected isolates was estimated and the. For this purpose, 195 samples with symptoms such as yellowing, stunting and leaf deformations were collected. From the cucurbits field of Sistan and Baluchestan province and for 15 samples a 462 bp fragment using specific primers for the heat shock protein genetic region of the CCYV was amplified by RT-PCR and 7 isolates were phylogenetically analyzed. The results showed that 7% of the samples were infected with Cucurbit chlorotic yellows virus in surveyed areas. Phylogenetic analysis of nucleotide and amino acid sequences showed that CCYV isolates were divided into two Iranian groups and East Asia, and isolates of Sistan and Baluchestan were divided into two separate branches. The putative amino acid sequence of heat shock protein alignment and Selection pressure studies on 7 isolates in the study with 3 Iranian isolates and isolates from other countries of this virus showed: the HSP70h gene in Iranian isolates and other isolates of this virus is under positive selection pressure at codon 82 leading to change of nucleic acid sequences (CTC to TTC) for isolates from the central regions of the province and isolates from Zabol, Hirmand and Nimroz at position 244, respectively, And the leucine amino acid has changed to phenylalanine in the heat shock protein. The results indicate that there are various CCYV isolates in the country, and the difference in nucleotide and amino acid sequences may reflect the differences in the host origin. Therefore, selection pressure has been implicated in the genetic diversity of the isolates.

Drought stress is one of the main obstacles in the of crops  production. A factorial experiment in a completely randomized design with four replications, first factor cultivars include Roshan and Kaver (Drought tolerate), Qods and Mahdavi (drought sensitive), Shole and Tabasi (medium resistance to drought) and the second factor was the osmotic stress applied with polyethylene glycol 8000 at three levels of 0,- 5 and -10 bar, Seeds of germinated cultivars were cultured under hogland conditions for 15 days under osmotic stress. In this study, the importance of the expression of P5CS and P5CR genes in relation to proline and MDA accumulation and their physiological role under osmotic stress conditions in six wheat cultivars was investigated. The effect of cultivars on proline accumulation was significant at 5% level .Proline contents of leaf and root of drought tolerant cultivars was -10 times more resistant than drought sensitive cultivars. In order to compare the mean interactions of osmotic stress × cultivars, the highest mean in the cultivars bright (drought tolerant) at osmotic stress level of -10 bars was showed. No significant accumulation of proline was observed in Roshan and Kaver cultivars, which are known as more resistant cultivars. Increasing osmotic stress and increasing MDA concentration were higher in Shole and Tabasi cultivars than other cultivars. By increasing the level of osmotic stress in the cultivars, the relative expression of genes P5CS and P5CR transcription increased. The genes showed at the level of osmotic stress -10 bar in Qods cultivar (sensitive), the gave highest expression in relative transcripts. While The highest relative expression was observed in the osmotic stress level of -5 bar in the Roshan cultivar (drought resistant).

Dams can potentially affect the size of populations and their connectivity, reduce genetic variation and increase genetic differences among isolated riverine fish populations. Therefore, in this research, the effect of Shahid Rajaee dam on the genetic variation of Capoeta capoeta gracilis in the Tajan River was investigated using sequences of cytochrome b gene. The Capoeta capoeta gracilis samples were collected from upstream and downstream of the dam. Sequence and analysis of this gene showed 11 haplotypes in the samples. Nucleotide diversity and haplotype diversity were 0.00062, 0.00939, 0.37778 and 0.70526 for upstream and downstream populations, respectively. Analysis of molecular variance (AMOVA) showed that 88.45% of genetic variation contained within population and 6.21% of genetic variation among groups. The analysis of the FST showed that there is a significant genetic difference between the studied populations. In total, it can be concluded that there was a significant genetic differentiation between the upstream and downstream populations of the Capoeta capoeta gracilis in the Tajan River (P = 0.05). However, this conclusion should be cautious, because only one gene was used in this research. For better results, it is recommended to use other genes as well as other genetic indexes such as microsatellite and in addition, similar studies need to be performed in other rivers.

Genetic variation was investigated for the number of 15 Agropyron cristatum accessions using the number of 15 ISSR primers. The number of 12 primers can be scored. The ISSR primers produced the number of 71 bands. The polymorphism has been observed for the number of 66 bands. The primers of IS1 and UBC857 presented the highest number of bands, i. e. eight bands; while the IS7 and UBC869 showed the lowest number which is only three bands. The primer of UBC844 were showed the lowest polymorphism percentage (83.33%) and IS2, IS6, IS7, UBC848, UBC865, UBC868 and UBC869 had the highest polymorphism percentage (100%). The polymorphism percentage average was 94.15%. The average of bands was 5.92 in each primer for 15 genotypes and the average of polymorphic bands was 5.50. IS6, UBC865 and UBC869 can determinate genetic distance of genotypes better than other primers. The genotypes of G4 with G2 had the most similarity and G1 with G8 had the lowest similarity. The results of UPGMA cluster analysis based on Jacard's similarity coefficient were fallen the genotypes in three groups, which confirmed by principal coordinate analysis and molecular variance analysis. The genetic diversity of the populations was matched based on the studied marker with their geographic distribution, and the populations of Gorgan and Isfahan were similar, which, on the other hand, showed greater distance with Karaj populations.