فهرست مطالب reza tohidi

Sheep are used as a genetic model to study the relationship between genetic diversity and ovulation rate. Previous studies have shown that ovulation rate and litter size can be controlled by a set of genes called fecundity genes . Three fertility genes have been identified in sheep called BMPR1B or FecB, GDF9 or FecG and BMP15 or FecX. Tetra-ARMS-PCR is a suitable alternative method in the context of expensive methods such as sequencing and PCR-RFLP to identify SNPs whose sequences are known. The entry of the Booroola allele into the Afshari breed increased the frequency of litter size. The aim of this study was to investigate the polymorphism of two fertility genes including FecB and FecG in Mughani, Afshari and Baluchi sheep in Khorasan Razavi province.Blood samples were taken from 95 Afshari, Baluchi and Mughani sheep. Two pairs of control (outer) and specific (inner) primers were used to amplify FecB and FecG gene fragments by the Tetra-ARMS PCR method. Temperature cycling of PCR amplification for FecB started at 94°C for 4 minutes, followed by 35 cycles consisting of 94°C for 25 seconds, annealing temperature at 54°C for 35 seconds, extension at 72°C for 20 seconds and a final extension at 72°C for 5 minutes. For amplification of the G1 point mutation on the FecG gene, the annealing temperature was 54°C for 35 s, extension was 70°C for 40 s, and final extension was 70°C for 5 minutes. The PCR products were electrophoresed on a 2% agarose gel.Three genotypes have been observed for the FecB gene in Afshari sheep; wild homozygous (++), heterozygous (B+) and homozygous mutant (BB). All Mughani and Baluchi sheep were homozygous for this gene. A 108 bp band was detected for mutant homozygotes. A band of 213 bp was observed in wild homozygotes. The frequency of wild homozygotes was high in the three breeds,. The frequency of the wild allele in this breed was 0.39 and that of the mutant allele 0.61, the overall frequencies for the three breeds being 0.8 and 0.2, respectively. The result of Tetra-ARMS-PCR for the G1 point mutation of the GDF9 gene showed polymorphism in all three breeds, however, the frequency of wild homozygotes was high. In the Balochi breed, only two animals (4%) were heterozygous and 96% of the animals showed the wild homozygous genotype. In the Mughani breed, 16% were heterozygous and only one animal was homozygous mutant. In addition, only one heterozygote was observed in the Afshari breed. Several studies have shown the association of the FecB, FecG and FecX genes with litter size in sheep. Due to the high frequency of wild homozygotes and the fact that Mughani and Baluchi ewes mostly gave birth to single lambs, the role of FecB mutation in litter size of Afshari ewes was observed. The ram used in this herd was heterozygous for FecB. In general, it can be concluded that the mutant FecB allele has a correlation with litter size in Iranian sheep. However, the statistical confirmation of this issue requires a dedicated study with a detailed record of reproductive traits.The results of this study demonstrated the presence of a Booroola mutation in the Afshari ewes that were offspring of heterozygous rams. In addition, all of these ewes had litter size in at least one of the two pregnancies. Hence, the Booroola mutation may potentially increase the litter size of ewes. However, a more comprehensive study measuring biological indicators such as sex hormone levels, ovulation rate and follicle size is needed to demonstrate the effect of these types of mutations on increasing fertility.

Rangeland plants provide most of the nutritional requirements of small ruminants in Iran. Data about the nutritional value of some range plants are scarce. Hence, we investigated the nutritional characteristics of four range plants (Pulicaria gnaphalodes, Amaranthus blitoides, Heliotropium europaeum, and Solanum nigrum) through different laboratory analyses. In 2021, twenty samples of each plant species were randomly collected in the flowering stage from mountain pastures of Torbat-e Jam, Iran. We observed different ranges of dry matter (15.98–45.23 %), crude protein (8.59–23.31 %), ether extract (1.88–4.5 %), neutral detergent fiber (31.52–64.71 %), acid detergent fiber (26.97–47.05 %), ash (6.09–16.06 %), and non-fiber carbohydrates contents (13.99–31.55 %) among the range plants species. The mineral compounds including calcium (33.28 g/kg DM), phosphorus (2.28 g/kg DM), magnesium (13.61 g/kg DM), potassium (25.83 g/kg DM), iron (501.89 mg/kg DM), and manganese (35.70 mg/kg DM) were the highest in H. europaeum, P. gnaphalodes, H. europaeum, S. nigrum, H. europaeum, and S. nigrum, respectively. Solanum nigrum exhibited the lowest potential gas production (23.50 ml/200 mg DM). P. gnaphalodes and A. blitoides had the highest values of mtabolizable energy (6.89 and 6.77 MJ/kg DM, respectively). It is concluded that the studied plants can easily supply the maintenance requirements of small ruminants. Based on the present results, it seems that the nutritional value of P. gnaphalodes and A. blitoides was superior to H. europaeum and S. nigrum. Excessive consumption of H. europaeum due to its toxic effects should be done with more caution.

Nanotechnology brings new solution for improving ruminal fermentation. Meta-analysis study of the effect of nanoparticles on ruminal fermentation can help to better understand how to manipulate ruminal fermentation. After searching and selecting appropriate articles, data related to ruminal fermentation parameters were extracted. Meta-analyses were carried out using the Comprehensive Meta-Analysis package, version 3. The effect sizes of across studies were calculated with fixed and random effect models. Possible publication bias was evaluated with funnel plot and statistical tests. The results of meta-analysis showed that the administration of nanoparticles in the diet, has a positive effect on gas production, total VFAs concentration and apparent dry matter digestibility. Addition of nanoparticles in the diet decrease N-NH3 concentration. The values of I2 for GP and TVFAs indicated moderate and values of I2 for N-NH3 concentration and apparent dry matter digestibility effect size indicated high heterogeneity, respectively. Administration of nanoparticles can improve ruminal fermentation process due to its positive effects on microbial growth, fiber degradation, DM digestibility, TVFAs concentration, and reduce the ratio of acetate to propionate and methane production.

In order to investigate the rates of inbreeding trend and also the effect of inbreeding on milk, fat and protein yields, the pedigree data of 2,394,517 Iranian Holstein cattle from 1986 to 2019 which collected was used. CFC software was utilized to calculate the inbreeding coefficients, and WOMBAT program was applied to estimate the inbreeding depression by determining regression coefficient of production traits on inbreeding coefficient. The average of inbreeding coefficients in the whole population and inbred animals were estimated as 0.777 and 1.681 percent, respectively. In general, the rate of inbreeding trend was positive and for recent years it was 0.17 percent per year. However, this rate was estimated as -0.29 percent per year for inbred animals, the number of inbred animals was increasing. Examination of the effect of inbreeding on production traits showed that per 1 percent increase in inbreeding coefficient resulted in 11.87, 0.39 and 0.29 kg decrease in milk, fat and protein yields, respectively. The use of domestic sperms and cows has limited the population and increased relative mating. However, close relative mating has been controlled. The existence of negative effect of inbreeding on production traits and on the other hand, increasing the number of inbred animals indicates that breeding and mating strategies of animals need to be continuously reviewed, and if it is necessary close relative mating can be limited using imported sperms.

Heat stress is one of the main environmental factors causing economic losses to the poultry industry, as it reduces growth and production performance of chickens. The heat shock proteins (HSPs) involved in the key cellular defense mechanisms during exposure in hot environmental conditions. Elevated level of expression of HSPs helps to overcome the stress caused by high temperatures. The aim of this study was to evaluate the expression level of HSPA2 and HSPB1 transcripts in the liver of Khorasan native chickens under acute heat stress. Sixteen 42days old chickens were divided into two groups of control (25 C and 50% humidity) and heat treated (40 and 42 C, 50% humidity for 24h), and then the liver was sampled after killing. The transcription level of HSPA2 and HSPB1 was evaluated using RT-qPCR method. The HSPA2 expression was significantly induced (P0.05). However, the expression of HSPB1 did not show any change. The analysis of protein-protein interaction revealed that HSPA2 and HSPB1 had no interaction, however, four pathways in gene ontology including Protein processing in endoplasmic reticulum, Progesterone-mediated oocyte maturation, MAPK signaling pathway and VEGF signaling pathway had the highest significancy. The results indicated that Khorasan native chickens have suitable genetic reaction to acute heat stress and HSPA2 has the ability to express under high ambient temperature to protect the structure of cellular proteins.

The genetic divergence could define as a mechanism which two or more breeds within the same species with a common ancestor could differently evolutionary separated in genome structure. Molecular genetics may provide proper tools for estimation of the level of diversity and mutational events on this breed over time. Accordingly, the main objective of the present report was to evaluate and compare the candidate gene polymorphisms for two meat and dairy type of goat breeds using candidate gene polymorphism approach. For this purpose, in overall, 30 goat individuals for two meat and dairy goat breed were chosen for genotyping of six candidate genes (Calpastatin, Myostatin, Insulin growth like hormone, Leptin, Pituitary-specific transcription factor and SCD genes using PCR-RFLP techniques. Molecular descriptive Statistics such as genotype and allele frequencies observed and expected heterozygosity, Minor allele frequency ,and Hardy-Weinberg Equilibrium was calculated and compared using POPGENE software between populations. The Chi-square test was used for significant differences between the two populations for screened genes. The observed results interesting showed significant genotype and allele frequency pattern between the two studied breeds. Obtained outputs may insight to the understanding of Genetic divergence between well-known breeds due to domestication and artificial selection as well as geographical

Control of diseases is one of the concerns in poultry industry worldwide. Despite the use of proper vaccines, antibiotics and sanitation in poultry farms, still disease outbreaks make irreparable economical loss. Another effective way of increasing the resistance of poultry to diseases is the genetic improvement of the immune system, which can reduce the current cost of taking vaccine and medicine. Considering the importance of IL-2 in the immune system, the present study was conducted to investigate the structure of IL-2 gene in Khorasan native chickens. To conduct this research, 20 DNA samples from Khorasan native chickens were used to amplify and sequence of 875-base pairs from the IL-2 gene. Comparison of the sequences obtained from the Khorasan native chickens with the sequence deposited in the NCBI showed mutations in the IL-2 gene, so that these mutations in the exon 1 region altered the amino acids. Exon mutations at 733, 738, 744 and 794 base pairs made to replace adenine bases instead of cytosine, thymine instead of adenine, adenine instead of cytosine, and thymine instead of cytosine. Identifying these mutations can allow them to be used as a genetic marker. To confirm this, we need to investigate the frequency of mutations and also examine their effect on IL-2 performance through proteomics experiments.