فصلنامه ژنتیک نوین
سال ششم شماره 2 (پیاپی 25، تابستان 1390)

Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors comprising three different isotypes termed β/δ،α and γ. They act at the transcriptional level. PPARγ is expressed primarily in adipose tissue primarily in adipose tissue and is considered as an adipogenic factor which regulates the expression of genes associated with lipid metabolism. The ligandactivated nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) has been shown to regulate cell activation, differentiation, proliferation, and/or apoptosis. Alternative promoter regions within the PPARγ gene are responsible for the formation of three PPARγ isoforms. Occurrence of (Pro12Ala) polymorphism was found to be significantly associated with a change in lipid profile in obese carrier individuals. PPARγ is the target of the insulin sensitizing thiazplidinediones (TZDs), a class of currently used drugs in the treatment of type2 diabetes mellitus. PPARγ plays a major role in tissue differentiation. The repressive effects of PPARγ on tumor carcinoma cell lines have opened new hopes for therapeutic applications of this factor to inhibit the progress of cancer

to study the inheritance of stripe rust resistance and to estimate the genetic components of resistance in wheat, F1, F2, BC1 and BC2 generations derived from crosses between two resistant cultivars and one susceptible cultivar (Bolani) along with parental lines were evaluated in a randomized complete block design (RCBD) with three replications in greenhouse. The plant materials were inoculated with pathotype 4E0A+ of stripe rust. In all plants, resistance components including latent period and infection type were recorded after appearance of pustules on leaves. Generation mean analysis revealed that additive, dominance and epistasis play major roles in increasing and decreasing of latent period and infection type, respectively. In spite of significant additive effect, dominance effect was more important in controlling these two characteristics. Broad sense heritability and narrow sense heritability estimates for latent period was 0.33 and 0.28 and for infection type was 0.42 and 0.39 respectively

the green tiger shrimp, P. (penaeus) semisulcatus is the most important species of the Penaeidfamily in Persian Gulf. Based on morphological characters, the new subspecies P.semisulcatus persicus is recognized. In the present study, the mitochondrial 16S rRNA is used for the molecular comparison of P. semisulcatus and P.semisulcatus persicus. Ten samples of the species (five from the coast of Boushehr and five from Bandarabbas) and ten samples of the subspecies (five from the coast of Boushehr and five from Bandarabbas) were collected and utilized for this purpose. Fragments of the 16S rRNA gene were amplified and sequenced, using the 16sar and 16sbr universal primers. The sequences were aligned using ClustalW. Results showed that the amplified fragments are 561bp and A-T rich (66.4%). The sequences alignments indicated that the mitochondrial 16S rRNA of Penaeus semisulcatus collected from Boushehr and Bandarabbas are identical. Results of the present study also indicated that the mitochondrial 16S rRNA of P.semisulcatus persicus collected from Boushehr and Bandarabbas are the same. The mitochondrial 16S rRNA alignments of species and subspecies reveal that 18 nucleotide substitutions are occurred and transition to transversion ratio was 3.906. Based on Kimura 2-parameter and using MEGA 4.0.2 software, the calculated genetic distance between P. semisulcatus and its subspecies was 3.3%. The notable genetic distance between P. semisulcatus emphasizes the need for further study on this issue, employing other genetic genomic and mitochondrial markers..

Different methods for determining the effect of genotype × environment interaction, there are parametric, nonparametric and multivariate methods. Nineteen selective advanced genotypes of durum wheat from 2004-2005 advanced yield trial by cv. Saimareh with the control variety for three agronomic years (2005-2008) in five locations (i.e: Gachsaran, Gonbad, Koohdasht, Moghan and Ilam) planted by using randomized complete block design with 4 replicates. In this study, four multivariate cluster analysis methods of Lin and Butler and AMMI method for analyzing of Genotype × environment interactions were used. In methods one and three of cluster analysis genotype 14, in methods two and four of cluster analysis genotype 12 were placed in individual group and these genotypes were selected as most stable genotypes with higher yield than total mean yield. The genotypes of 2, 4 and 14 have lowest SIPC1 in AMMI method and higher average grain yield than total mean yield determined for most stable genotypes. By attention to the result, genotypes 12 and 14 with average yield of 3218 and 2970 kg/ha respectively selected as promising genotypes for introduce cultivar. Also genotypes 2, 9 and 13 can use for excel and adaptable parents in crossing block projects.

In this study, the numbers 8366, 6360, 4350, 2890 and 2430 records related to birth weight, weaning weight, 6-month weight, 9-month weight and yearling weight Zandi sheep breeding sheep station Zandi (Khojir Station), the distance between 1991 to 2007 collection was gathered, were used. Direct heritability and maternal traits with analysis using single-trait restricted maximum likelihood, and fitting six different animal models with the addition and removal maternal additive genetic effects and maternal permanent environmental, were estimated. Than the likelihood ratio test showed that the model with direct genetic effects and maternal additive genetic, regardless of birth weight for the covariance between them, the model with direct genetic effects and permanent environmental maternal for weaning weight and weight six months and models with direct genetic for nine months weight and yearling weight were appropriate. Genetic correlation, phenotypic and environmental multivariate analysis and appropriate model for each trait were estimated. Estimated breeding value genetic trend for each trait, using the best single-trait and multivariate animal model estimated. Genetic trends were estimated by regressing the mean of breeding values on year. Direct genetic trend Birth weight, weaning, 6-months, 9- months and yearling of with analysis of univariate and multivariate were estimated 2.1±0. and 3.9±1.1, 98.5±1.40 and 106.28±38.2, 89.63±21.2 and 95.47±33.4, 26.35±10.6 and 32.22 ±1. , 41.53±13.4 and 49.83± 18.20 gr per year, respectively.

Low temperature is one of the factors that limits the growth and geographical distribution of crops. Plants response to low temperature by changing cell metabolisms which in turn are resulted from changes in gene expression pattern during the acclimation process. In this study quantification of Sucrose Synthase (Su Sy) gene expression, as an important enzyme in response to abiotic stresses and cell metabolisms, along with Electrolyte Leakage Index (ELI) as a membrane damage index were examined in two cultivars of chickpea plants for different time treatments in three temperature conditions 10, 23 and -10°C. Results indicated that there were significant differences in Su Sy expression between time treatments under 10°C condition. Also data showed that there was difference between two genotypes in gene expression and ELI after acclimation for 24 hours following exposure to -10°C. Increase in Su Sy expression under acclimation which most of the times was parallel with decrease in ELI, and also decrease in expression of foregoing gene under freezing temperature indicate the importance of Su Sy as an effective gene for cold acclimation. So, it may be extrapolated that there is a negative correlation between Su Sy transcription level and ELI. This study illustrate that these two genotypes (Jam and 4322) response differently to cold stress, and acclimation period can be considered as a key factor in plant responses, as well. Also in this work more stable response and less damage of Jam genotype than that of 4322 genotype was observed under cold stress and greenhouse condition.

Acomprehensive knowledge of the amount of genetic diversity in a breeding flock would allow better management and could improve the effectiveness of breeding program. The objectives of the present study were to estimate the level of genetic similarity in a breeding flock of Afshari sheep and to compare the performance of pedigree and DNA marker based methods for estimating pairwise genetic similarities. Genetic relationships among 95 animals were estimated using both microsatellite markers and pedigree based data. A total of 102 polymorphic bands were obtained with 18 microsatellite primer pairs. Pedigree-based estimates of parent-offspring relationships and genotypic banding pattern were used to construct relatedness (a) and molecular coancestry (fM) matrices, respectively. The pedigree-based similarity (mean =0.032, range=0.00–0.75) was lower than the similarity assessed using microsatellite markers (mean= 0.36, range= 0.10–0.83). Similarity estimates were used to construct dendrograms by using the Unweighted Pair-Group Method with Arithmetic Averages (UPGMA). The degree of relationship between the similarity matrices based on marker and pedigree data was measured by the normalized Mantel test. Even though there was a large difference between the means of the two similarity measures, a low positive correlation (r=0.22, p 0.01) was detected between the two similarity matrices. The observed low correlation between molecular vs.,the pedigree based expected genetic similarities suggests that simple estimates of proportion of shared alleles using low density markers may not reflect the true proportions and it is preferable to use pedigree information whenever available.

In this research, 511 accessions of wheat collection of National Plant Gene Bank of Iran belonging to 19 different countries were investigated. Coefficient of variation indicated the usefulness of diversity in grain yield and its components, rather than phenologic traits, to be utilized in breedingprograms. The largest positive coefficient of correlation and was observed between grain yield of 5 spikes (as a trait) and number of seeds per spike and the largest negative coefficient of correlation was observed between flowering time and seed filling period. Multiple linear stepwise regression was performed by grain yield of 5 spikes as the dependent variable and six traits of number of seeds per spike, 100-grains weight, number of spikelets per spike, maturity time, number of florlet per spikelet and spike length entered the model. Results of path analysis indicated that number of seeds per spike had the largest positive effect on grain yield of 5 spikes. Five principal components comprised 81.65% of the total variation In data in principal component analysis based on origin of accessions. Accession of china and Uruguay had the lowest and of USA and former East Germany had the largest similarity based on Euclidean distance. Results of cluster analysis discriminated the origins of accessions in 4 groups. Multivariate analysis based on all quantitative confirmed the significant difference among four mentioned groups.

Genetic characterization and classification of germplasm yield important information that are quite helpful for crop breeding as well as conservation of genetic resources. The genetic relationship between the accessions and varieties of chickpea was assessed using 21 ISSR primers. Out of 361 bands, 257 showed polymorphism. Nnumber of polymorphic bands ranged from 6 to 22 per primer and the most informative loci was UBC864. Polymorphic information content (PIC value) ranged from 0.15 to 0.60 and marker index (MI) ranged from 6.43 to 60.31 per primer. A maximum genetic similarity value of 0.97 was observed between accessions 93 and 94 and a minimum similarity value of 0.54 was observed between accessions 10 and 66. Clustering analysis using UPGMA algorithm based on Jacquard's similarity coefficient, classified the chickpea accessions and cultivars into 15 major groups and the subgroups were strongly supported by high bootstrap value. Our results proved that ISSR markers to be as a reliable marker system with regards to detection of a high level of polymorphism and it can be used to guide future breeding studies and management of chickpea germplasm.

thioredoxins (Trxs) are small ubiquitous disulfide reductases that are present in all organisms from prokaryotes to higher eukaryotes and involve in the cell redox regulation. In contrast to other organisms, plants contain six different Trx types: f, m, x, y, o and h that only h type Trx has been the most extensively studied and consists of multiple forms that involved in different processes including cellular protection against oxidative stress. Cloning of a h-type thioredoxin gene was performed from grape (Vitis vinifera L. cv. Askari) berry tissue by reverse transcription polymerase chain reaction (RT-PCR) technique, and then its physico-chemical, structural and phylogenetic characteristics was analyzed. The nucleotide sequence of open reading frame, called VvTrx h4, was revealed a 345 bp long with a deduced amino acid of 114 residues, possessing a WCGPC active site. The estimated molecular mass and the predicted isoelectric point of the deduced polypeptide were 12.76 kDa and 5.22 respectively. Prediction of three-dimensional structure of VvTrx h4 using the crystal structure of AtTrx h1 from Arabidopsis was consistent with these predictions and with five β-sheets and four α helixes, contains the thioredoxin fold. The deduced protein sequence was shown a high similarity to thioredoxins h isolated from plants, e.g. Populus trichocarpa (89% similar with Pth3) and Citrus cv. Shiranuhi 86% similar with Csh). Phylogenetic studies using of thioredoxin from other plants was indicated that VvTrx h4 gene is a thioredoxin h, belonging to the subclass IA from subgroup I.