محمد زندی

If spermatogonial stem cells (SSCs) are transplanted into the testicles of lambs that do not have this type of cell, they begin to produce sperm in the testis of the recipient rams. The aim of this study was to prepare recipient lambs. For this purpose, heat treatments of 35, 45, 55 and 65 °C or water-ice treatment for 20, 40 and 60 minutes were used for three replicates with two days interval. The results showed that the condition of the testicles was normal at 45 °C, but the treatment at 55 °C caused infection in the seminiferous tubules and at 65 °C, the testicles were completely destroyed. The use of water-ice treatments did not change the appearance of the testes. Colony formation after extraction and culture of SSCs at 45 °C treatment and water-ice treatments were significantly reduced compared to the control (P <0.05). Also, the expression of c-myc, plzfand gfrl genes as specific SSC markers was significantly reduced in 45 °C and cold treatments compared with the control (P <0.05). Accordingly, for reducing the number of SSCs in lambs’ testicles, water ice or 45 °C treatments for 20 minutes can be used three times at intervals of two days.

Accurate estimation of genetic variance components is essential for the correct prediction of breeding values. The discovery of SNP markers and advances in molecular genetics and the discovery of new methods for sequencing the entire genome of living organisms and the development of bioinformatics methods and computer science, etc. have provided a great deal of molecular data and created a branch of genetics called genomics. This study aimed to estimate the genomic variance components of Border sheep using SNP data.

For this study, the SNP panel, which was genotyped with a 50k marker chip from Illumina, was used. Data were collected at Falkiner Farm in Australia. The studied traits were birth and weaning weights, diameter, and length of wool yarn. To study the relationship between allelic frequency and the amount of justified genetic variance justified, SNPs were classified into five different groups of rare allelic frequency (MAF), with approximately equal numbers in each group. The analyses were performed with the approach of limited genomic maximum likelihood and the method of analysis of complex genome traits with GCTA software.

Genomic heritability estimated by SNPs with a rare allelic frequency of more than one percent for birth weights, weaning, diameter, and length of wool were 0.58, 0.47, 0.59, and 0.2, respectively. The contribution of different groups of SNPs with rare allelic frequencies in justifying genetic variance for different traits was different and in general a significant part of genetic variance was justified by SNPs with

Although the number of SNPs was different in different groups, the amount of genetic variance justified by different MAF groups was different. According to the results, a very large, ideal sample size and better coverage of low-frequency variants are needed to obtain a stronger and more reliable inference.

Prolactin is secreted from the anterior pituitary gland and plays an important role in the mammary gland development, differentiation and lactation. The aim of current study was to evaluate prolactin receptor gene polymorphisms in the Shal breed and Shal×Romanov crossbreeds. For this purpose, after blood sampling of animals and extraction of DNA using phenol chloroform method, two fragments of 176 and 215 base pairs from intron 1 of prolactin receptor gene were amplified using PCR reaction. Then PCR products were analysed by acrylamide gel electrophoresis and silver staining. Results showed that AB and AC genotypes were identified in 176 base pairs fragment of prolactin receptor gene (PRLP1) in Shal breed. The frequencies of these genotypes were 0.92 and 0.08, respectively; and the frequencies of A, B and C alleles were 0.5, 0.46 and 0.04, respectively. Also, in the position of PRLR1 of this gene in Shal×Romanov crossbreeds, the frequencies of AB and AC genotypes were 0.94 and 0.06, respectively; and the frequencies of A, B and C alleles were 0.50, 0.46 and 0.04, respectively. A polymorphism study in the 215 bp fragment of the prolactin receptor gene (PRLR2) in the Shal and Shal×Romanov crossbreeds showed only AA genotype. Results of this study showed that PRLP1 position in Shal breed and Shal×Romanov crossbreeds was polymorphic, however the PRLP2 position in the studied samples was monomorphic.

The goal of this paper was to study the effect of ginger extracts and vitamin E on the performance of ovine Spermatogonial Stem Cells (SSCs). For this purpose, different concentrations of hydro and hydroethanolic extracts of ginger and vitamin E on viability, colony formation and expression of inhibiting (bcl2ll and bcl2)and inducing (bax) apoptosisgenes were studied. Spermatogonial Stem Cells (SSCs) were extracted from lamb testes with slaughterhouse origin using two steps enzymatic digestion method and enrichment by differential plating method. The characterization of SSCs was carried by alkaline phosphatase staining and expression of c-kit and oct-4 genes. Results have shown that the viability of SSCs was decreased significantly by using more than 800 µg/mL of hydroethanolic extract of ginger, in comparision with control group (P

Aim and Successful in vitro embryo production extremely depends on the components of culture media during in vitro maturation. With ingredients like Anitol, Fennel has properties similar to estrogen. The aim of this study was to investigate the effect of Fennel essence on nuclear maturation of bovine oocyte.
In order to in vitro maturation off oocytes, Cumulus-oocyte complexes (No. 772) from follicles 2–8 mm in diameter were aspirated and cultured in M199 maturation media containing 10% FBS, 10% bovine follicular fluid, 5 µg/ml FSH, 1 µg/ml oestradiol- 17β, 0.81mM sodium pyruvate and 50 µg/ml gentamicin sulfate. Maturation culture media supplemented with 0, 5, 10, 20, 30 and 50 mg/ml of Fennel essence and were cultured in a CO2 incubator containing 5% CO2 and 95% humidity in air at 38.5ºC for 24 h.
Results showed that the amount of maturation of oocytes under 5, 10, 20 and 30 mg/ml of Fennel essence were not significantly different based on expansion of cumulus cells and polar body extrusion in compared with control (P>0.05). However, 50 mg/ml of Fennel essence significantly decreased expansion of cumulus cells and polar body extrusion in compared to other groups (P From the results of current study we can conclude that, Fennel essence, based on cumulus expansion and polar body extrusion, unable to improve nuclear maturation of bovine oocytes. In order to investigate the effect of Fennel essence on nucleus and cytoplasmic maturation of bovine oocytes, it is suggested to use in vitro fertilization.

Introduction A simple and efficient method for producing multi-transgenic animals is required for medical and veterinary applications. The principal technique for the production of transgenic animals is pronuclear microinjection, which has a low efficiency for the generation of transgenic farm animals expressing a single transgene. Recently, nuclear transfer has been used to clone large animals, and could allow multiple genetic manipulations to be undertaken in vitro, prior to a single nuclear transfer, rather than complex and time consuming breeding programs. However, at present the frequency of success in cloning large animals is very low and is very expensive. The production of transgenic livestock by sperm mediated gene transfer (SMGT) has a number of advantages compared to other transgenic techniques such as nuclear transfer and microinjection. Both nuclear transfer and microinjection techniques are technically demanding and labor intensive. In contrast, SMGT requires no sophisticated equipment or technical expertise. Furthermore, bovine genetics are distributed through sperm in the dairy industry consequently making it easy to distribute genetically modified sperm. SMGT is based on the ability of sperm to bind to exogenous DNA molecules and transfer it to the oocyte during fertilization. The major benefits of the SMGT technique were found to be its high efficiency, low cost and ease of use compared to other methods. SMGT was first described in a small animal model, with high efficiency reported in the mouse. Recently the technique has been successfully adapted and optimized for use in large animals. Studies have shown that spermatozoa from numerous species, including bovine, can bind and take up foreign DNA and transfer it to the embryo. In bovine studies, the efficiency of SMGT can vary widely depending on both the transgene and the gene transfer method. Liposomes have been shown to be particularly effective in transferring DNA into bovine sperm. However, not all embryos derived from transfected sperm contain the transgene, suggesting that mechanisms exist, which impede SMGT. The aim of this study was to investigate the possibility of gene transfer to bull spermatozoa by using lipofection.
Materials and Methods Ram testes collected from Meysam abattoir slaughterhouse immediately after slaughter and were brought to the laboratory in an ice chest. In the laboratory, the testes were rinsed twice with normal saline and were then trimmed to remove the extra testicular tissue and washed properly with saline containing 0.1% streptomycin sulphate. Connective tissue covering the cauda epididymis was removed by careful dissection, with care to avoid rupturing blood vessels or the epididymal duct. For detection of transfected spermatozoa, they stained with Rodamine. In order to transfection of sperm, 2 μg of Rodamine labeld DNA and 0.5 μl of TurboFect were diluted in 25 μl of transfection medium separately, and incubated for 5 min at room temperature. Then, the diluted DNA was added to diluted TurboFect (total volume=50 μl) and incubated for 20 min at room temperature. 1×106 sperm were added to 50 μl of DNA- TurboFect complexes and mixed gently by rocking the plate back and forth. To evaluation of transfected spermatozoa motility, acridine orange staining was used. Each experiment was replicated at least three times, and for each replicate, at least 50 ES cell colonies were used. Data were analysed with a statistical software program (SPSS 16). Comparisons between two treatments and multiple numeric datasets were performed using t-test and one-way ANOVA followed by Duncan multiple-range test, respectively. Results are expressed as mean±SEM and statistical significance was accepted at P0.05). The comparison of transfected and normal spermatozoa reveal that, motility of transfected spermatozoa at 60 minutes after transfection was significantly lower than normal ones (p

In order to investigate the effect of linseed on reproduction performance of fresh dairy Holstein cows, 99 primiparous and 100 multiparous cows were used under the control and linseed treatments till 28th day after parturition, and after that the same diet were used. For statistical analysis, the LOGESTIC procedure of SAS statistical software were used. Results showed that, reproductive performance of dairy cows such as mean number of artificial insemination, conception rate and endometritis were not affected by linseed treatment. The incidence of cystic ovary was similar for multiparous and primiparous cows fed linseed. However, it was higher for multiparous cows, when fed the control treatment. Do to the lower incidence of cystic ovary in multiparous cows, it is suggested to feed dairy cows with linseed especially in those farms that have management problems.

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of blastocyst and differentiate into all three embryonic germ layers: ectoderm، endoderm، and mesoderm. There is less information available about the factors that are affecting buffalo ES cells in culture. In this study، expression profiles of the Leukemia Inhibitory Factor (LIF) and basic Fibroblast Growth Factor (FGF-2) signaling pathways were investigated to better understand the relationships of the signaling pathways for self-renewal in buffalo ES cells. Buffalo ES cells were derived from in vitro fertilized (iESC)، parthenogenetic (pESC) and handmade cloned (cESC) embryos. Alkaline phosphatase and immune-fluorescence staining were used to characterize buffalo ES cells. Feeder layer was used for ESCs culture، and culture medium consisting of Knockout- Dulbecco’s Modified Eagle’s Medium (Ko-DMEM) supplemented with Knockout Serum Replacement (KSR)، leukemia inhibitory factor (LIF)، basic fibroblast growth factor-2 (FGF-2)، L-glutamine، nonessential amino acids and gentamicin. Gene expression was analysed by RT-PCR for signaling pathways. Results showed that، the expression of FGF-2 was higher than LIF in buffalo ESCs. LIF، FGF، their receptors and intermediate signaling pathways was expressed at almost same level in three sources of buffalo ESCs.

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of blastocyst and differentiate into all three embryonic germ layers: ectoderm، endoderm، and mesoderm. In this study، ESCs are derived from Hand Made Cloning (HMG) blastocysts and their efficiencies compared to ESCs derived from In Vitro Fertilization (IVF) embryos. Feeder layer was used for ESCs culture، and culture medium consisting of Knockout- Dulbecco’s Modified Eagle’s Medium (Ko-DMEM) supplemented with Knockout Serum Replacement (KSR)، Leukemia Inhibitory Factor (LIF)، Basic Fibroblast Growth Factor-2 (FGF-2)، L-glutamine، nonessential amino acids and gentamicin. The cell surface antigens used for characterization were the SSEA-1، SSEA-4، TRA-1-60 and TRA-1-81 and the pluripotency markers were NANOG، OCT3/4 and SOX2. Results showed that، the growth rate of ESCs colonies in ESCs from IVF embryos was significantly higher than ESCs from HMG embryos (120% compared with 65%، respectively). Not only real-time PCR results revealed the same expression level of SOX2، OCT3/4 and cMYC between them، but also ESCs from HMG embryos resulted to higher expression of NANOG. Both of ESCs groups maintain in pluripotency state for more than two years and differentiated to the different types of cells like neuron، epithelial، lipid and muscle cells.

Multiple choice exams are one of the most common objective exams used in medical education. So, it is important to find ways to improve the quality of these exams, especially in residency programs. Thus the aim of this study was to investigate the effect of education on quality improvement of Multiple Choice Questions (MSQ) designed in Annual Residency Exams of Dental Faculty. In this experimental study, the structure and taxonomy in all MCQs designed by dental faculty for annual residency exams in 2008 were analyzed through valid and reliable checklist. Checklist items were based on Millman’s principles and several other resources. The same process was repeated for MCQs after running a workshop for question designers. The pre- and post- workshop data were compared using Z test. From 1239 questions, 63.1% and 76.3% of the questions developed in 2008 and 2009 had no structural flaw, which revealed a significant difference between the two years (P<0.001). Regarding high taxonomy questions, a significant increase was observed in the year 2009 (P=0.039). Considering the results of this study, designing and running training workshop for question designers improved quality of MCQs and these workshops can lead to improvement of MCQ exams in other universities.