polymorphism

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.

The review of published articles in the field of genomic selection shows that in the most of studies conducted in livestock and crop species, genomic evaluation and prediction of genomic breeding values ​​have been done without considering the dominance genetic effects. However, recent studies have shown that the dominance genetic effects contribute significantly to the phenotypic variation of productive traits of domestic animals. Therefore, it seems that ignoring the dominance genetic effects will affect the accuracy of the genomic evaluation. In this article, the consequences of not considering the dominance genetic effects in the genomic evaluation model on accuracy, mean square error, bias and reliability of genomic breeding values ​​were investigated.

A genome consisting of 5 chromosomes, each 1 Morgan length, containing 5000 bi-allelic single nucleotide polymorphism (SNP) was simulated at heritability level of 0.5. All quantitative trait loci (QTLs) were assigned additive genetic effects. Different distributions of QTL effects (uniform, normal and gamma) as well as three scenarios of the number of QTL as 5, 10 and 20% of the total number of SNPs (respectively 250, 500 and 1000 QTLs) were considered as simulation hypotheses. In different scenarios, dominance genetic effects were given to 0.00, 10, 25, 50 and 100% of QTLs. The genomic breeding values ​​were estimated using the genomic best linear unbiased prediction method (GBLUP) and the criteria of LR method such as prediction accuracy, mean square error of prediction, bias and reliability of the genomic breeding values ​​were used to analysis genomic breeding values ​​predicted by GBLUP.

The results showed that if the dominance genetic effects contribute to the phenotypic variation of the interested trait, but ignored from the genomic evaluation model and remain unseparated from the additive genetic effects, lead to a decrease in the accuracy of the genomic breeding values ​​by about 25%. Also, the mean square error of prediction of genomic breeding values ​​increased by 60% following increase in the percentage of QTLs with dominance effect from 0.00 to 100%. The bias of genomic breeding values ​​was also affected by ignoring dominance effects and increased by 36% following increase in the percentage of QTLs with dominance effect from 0.00 to 100%. Also, the reliability of genomic breeding values ​​was significantly reduced by about 40% with the increase in the percentage of QTLs with dominance effect from 0.00 to 100%.

In general, the results of this research showed that not separating the dominance genetic effects from additive genetic effects leads to low-accuracy, biased, and unreliable estimates of genomic breeding values, which will ultimately reduce the efficiency of genomic selection schemes. Therefore, it was suggested that in order to increase the efficiency of genomic selection, dominance genetic effects should be included in the genomic evaluation model.

Myostatin gene is an inhibitor of skeletal muscle developmentmutations in its coding regionpromotesmuscle growth in some breeds, mutation of the myostatin gene has a significant effect on the increase of the body weight and carcass traits. This study was aimed to investigate the polymorphisms in exon 3 of the myostatin gene and evaluate investigation of body weights and carcass traits measured by ultrasound in Kurdi sheep.

In this study, back fat thickness and loin muscel area traits were measured by ultrasound instrument. Blood samples were collected randomly from 139 Kurdi sheep and following DNA extraction, a 388 bp fragment from exon 3 of myostatin gene was amplified. For genotyping of myostatin gene, PCR-SSCP, PCR-RFLP, and direct sequencing techniques were used. To determine the fixed effects of gender, birth type and birth year on the studied traits, GLM procdure of SAS software was used. Least square means comparison of different fixed effects subclasses was carried out by Tukey-Kramer test at 5% probability level. To measure the relationships between tarits, pearson correlation was used.

In PCR-RFLP technique, after enzymatic digestion of all samples, only one genotype was observed and this locus was monomorphic. PCR-SSCP analysis showed two band patterns A and B, which were very similar in shape. Therefore, to determine the actual genotype, some samples with different band patterns were evaluated by direct sequencing technique. The results showed that there is no polymorphism among samples. The mean ultrasonic fat thickness and loin muscle area in this study were 0.46 cm and 7.78 cm2, respectively, with an average body weight of 43.42 kg at the time of ultrasonography. The correlation between the two ultrasound carcass traits (UBF and UMA) was positive (r=0.84, P<0.0001). The lowest correlation coefficient of carcass fat thickness and ocular muscle area with the studied traits were 0.02 and 0.3, for birth weight and weaning traits, respectively. The highest correlation coefficient of the studied traits with carcass fat thickness and loin muscle area were 0.82 and 0.87 for body weight at the time of ultrasonography and middle tail width, respectively (P=0.001).

In this study, using PCR-SSCP, PCR-RFLP and direct sequencing, only one genotype was detected in the myostatin gene. Considering that various studies have introduced the mutated allele of the myostatin gene as an effective allele on the double muscling for breeding and improving the quality and quantity of meat, the studied herd did not have the allele. Considering the relatively suitable diversity observed in the studied traits, especially the carcass traits measured by ultrasound, there will be a possiblity to improve the traits through selection.

Basic color in horses, such as black and white, brown and chestnut ASIP and MC1R gene is affected. The relationship between color horse and purity the study of gene polymorphism Aguti put special attention. The purpose of this study was to evaluate the polymorphism in exon 2 gene Aguti population of Arabic horse in Khuzestan. In this study, PCR-RFLP method for the detection of different alleles of the Aguti gene in horses used. Bleed extension of the 45 head of horses in the city of Ahvaz, Dezful and Shush were collected. Polymerase chain reaction 101 bp fragment of exon 2 gene and gene-specific primers were used Aguti. 11 bp deletion in exon 2 gene ASIP (Aguti signaling protein) occurred because of the In / del (delete and Insertion) of the gene Aguti. Finally three band pattern AA, Aa, aa abundance 0.414, 0.457, 0.127, respectively. The allele frequencies of A and a 0.644 and 0.356 respectively.The results showed that this fragment of gene polymorphism and genotype AA, Aa, aa population was established. The results showed that there is Hardy-Weinberg dis equilibrium in the studied population.

Having a fat tail is a characteristic of some Iranian native sheep breeds, whose main role is usually to store energy for using in limited food conditions. However, the amount of energy required to store fat in this tissue directly affects the efficiency of meat production and carcass quality. In Iran, the average weight of each carcass is about 15.3 kg, of which 15% is the fat tail. It requires 1.7 kg more feed per kilogram of fat tail than meat (protein), and customers pay a lower price per unit of weight for sheep with heavier fat tail. Today, researchers in the field of animal breeding have a special focus on reducing the weight of the fat tail and increasing the marketability of sheep carcasses. Bone morphogenetic protein 2 (BMP2) belongs to the β-metamorphic growth factor of the β family and plays an important role in bone and cartilage development and, therefore, seems to be the best candidate for the fat-tailed phenotype. Comparison of the results of genotype obtained from Ovine SNP50K Bead Chip in tow fat-tailed breeds with the results obtained in 13 thin tail breeds showed a missense mutation in BMP2 gene, with the frequency of different alleles in these two different groups. In this study, in order to detect the polymorphism in BMP2 gene exon 1 and investigation of its relationship with tail fat trait, blood samples from 150 same age ewes of Lori Bakhtiari breed were randomly taken which are maintained in Gahar Dorud sheep breeding center (Dorud, Lorestan). DNA extraction was performed using a special DNA extraction kit (Pars Toos, Iran) according to the manufacturer's instructions. Determination of quality and quantity of extracted DNA was performed using agarose gel electrophoresis and nanodrop spectrophotometer, respectively. BMP2 gene exon 1 was amplified successfully by a pair of specific primer. The accuracy of this process was confirmed by 1.5% agarose gel. Then, using PCR-SSCP technique, 12% polyacrylamide gel and silver nitrate staining, probable polymorphisms were tracked in this position and finally calculation of Chi-square test (χ2) for deviation from Hardy-Weinberg equilibrium (HWE) has been assessed by Popgen (Ver. 1.32) software. The relationship between genotypes and average fat tail weight (Corrected by body weight (BW)) has been analyzed with the PROC GLM procedures in Statistical Analysis System (SAS) v. 9.1 version. Based on the results, amplification of BMP2 gene exon 1 was successfully done and three different patterns of polymorphism have been detected through SSCP analysis.  Exon 1 of BMP2 gene in Lori Bakhtiari ewes containing A and B alleles with distributions of 197 and 103 and frequency of 65.7% and 34.33%, respectively, that have generated AA, AB and BB genotypes with distribution of 75, 47 and 28 and frequencies of 50%, 31.33% and 18.67%, respectively. Mean comparison of fat tail weight in each genotype using Duncan procedure showed that the effect of genotype on fat tail weight in Lori Bakhtiari breed was significant (P <0.05). AA genotype with average fat tail weight of 5.16 showed higher performance than AB genotype with average fat tail weight of 4.29 and BB genotype with average fat tail weight of 3.76. The results of statistical analysis also showed that the presence of allele A causes heavier fat tail weight and the presence of B allele causes lower fat tail weight (P <0.05). Heterozygosity and Homozygosity observed in this study are 0.3154 and 0.6846, respectively. The significance of the calculated chi-square genotypic frequency in each population at the level of 0.05 in comparison with the chi-square table shows that the studied populations are not in Hardy-Weinberg equilibrium. Which can be attributed to the pressure of selecting on reference population for genetic breeding for fat tail weight at Gahar Dorud sheep breeding center. Today, advances in genomic technologies have multiplied, and if information on loci associated with meat quality traits can be obtained and the genes that control these traits are located on chromosomal sites, they can be incorporated into breeding programs. Breeds should be used with MAS and cause genetic growth and development of these traits. Using molecular detection methods and identifying sheep carrying B alleles and selecting them as the parents of the next generation, we can move towards producing herds with lower fat tail weight and more marketability.

The myxovirus (Mx) gene play a crucial role in the antiviral responses of chicken. The Mx gene is a potential candidate as a genetic resistance marker to the avian influenza virus in chickens. This study was conducted to determine the polymorphism of myxovirus gene polymorphism using PCR-RFLP method in Khuzestan native chicken. In this research, blood samples were collected randomly from 100 Khuzestan native chicken (Malasani, Andimeshk and Shush) and DNA were extracted. Polymerase chain reaction (PCR) was used to amplify 299bp fragments of myxovirus (Mx) gene by specific primers. Then, the amplified fragment was digested with HPY8l enzyme. Allele frequency for A and G, in Shoosh 0.54 and 0.46, Mollasani 0.85 and 0.15 and Andimeshk 0.57 and 0.47 and genotype frequencies of AA, GG and AG, in Shoosh 0.40, 0.33 and 0.27, Mollasani 0.8, 0.1 and 0.1 and Andimeshk 0.45, 0.40 and 0.15 were achieved, respectively. The results showed that the frequency of allele A was higher than G. Furthermore, the observed heterozygosity and the effective number of alleles demonstrated low diversity in the population. Chi-square (X2) analysis showed that the locus allele frequencies are not in Hardy-Weinberg equilibrium. The results of this study suggested that the MX gene had polymorphism and had a high potential for use as a genetic marker for resistance to avian influenza and Newcastle disease.

turkey is important all over the world in order to improve some of food supply required for several reasons such as its weight gain and high growth rate, low feed conversion ratio, and production of more eggs and meat. The MC4R gene is one of the most important candidate genes in different species which can affect the energy homeostasis and body weight regulation. Identity the genetic aspects and major gene influence on energy balance, production, fertility, safety are the recent interests of genetic and breeding researchers. The objective of this study was undertaken to identify polymorphisms of the MC4R gene using PCR single-strand conformational polymorphism (PCR–SSCP) analysis and to evaluate association of these polymorphisms with egg performance in turkey.

For doing this research in order to investigate polymorphism of MC4R, 100 laying turkeys, randomly selected then all animals were blooded. Genomic DNA with optimal quality was extracted from blood samples using the protocol of Boom et al. PCR was done for amplifying a fragment in size of 469 bp of MC4R gene. The single strand conformation polymorphism technique (SSCP) was used to determine genotype. A statistical model was done by using GLM of SPSS software to find the association between the SSCP genotype patterns of PCR products with egg performance in turkey.

The results of PCR-SSCP by using polyacrylamide gel and silver nitrate showed that this population was polymorphic at the studied loci and four different genotypes AB, AC, BC and CC, with frequencies of 52.1%, 4.13%, 22.93% and 20.48% respectively were observed. Genotype AB and genotype AC has the highest and lowest genotypic frequencies, respectively.

The results indicated that the MC4R gene is polymorph and there was no significant difference between the genotype patterns and egg performance (egg mass, mean egg weight, and the number of eggs). Due to the importance of the MC4R gene, the study of this gene locus suggested in larger populations.

Luteinizing hormone (LH) is one of the most important reproductive hormones that is secreted by the anterior pituitary gland and plays a key role in regulating the estrous cycle, maturation of ovarian follicles, ovulation, corpus luteum formation, corpus luteum development and maintenance. The LH message is transmitted through by binding it to its extracellular receptors, so that after binding to its own receptor (LHR), LH activates the intracellular cascade chain by activating the secondary messenger cAMP, and ultimately the expression of specific proteins and enzymes. Therefore, the interaction of luteinizing hormone (LH) with its specific receptor (LHR) is one of the key steps in the path of follicular maturation and ovulation. Polymorphisms and LHR splicing are among the genetic changes that can affect LH function and consequent reproductive efficiency.The aim of this study was to compare the tertiary structure of different LHR polymorphisms and their binding affinity to LH in dairy cows.

For this purpose, LHR amino acid sequences were obtained from Gene bank. Firstly, Polymorphisms were identified by alignment analysis. Their related third structures were predicted by homology modeling technique using Modeller software. The created structures were observed and evaluated using PyMol 2.5.1 graphics software and Ramachandran plot. Also, different physico-chemical parameters of the modeled proteins such as isoelectric point, molecular weight, and number of negative and positive sequences and Grand Average of hydropathicity (GRAVY) were calculated using ProtParam tool in Expasy database. Then, the affinity of LH to each of the LHR polymorphism was evaluated using molecular docking technique based on binding energy and spatial position indices.

Based on the results, only two polymorphisms (LHR1 and LHR2) were identified among the studied sequences. The predicted models for the two polymorphisms have a good quality and there was no difference in structural and physicochemical parameters between them. Docking results showed that, despite the difference in total binding energy between the two polymorphisms, this difference could not be attributed to amino acid substitution and this difference is probably related to an orientation of the LH relative to the LHR1 and LHR2. Most of the amino acids that were involved in hydrogen bonding were similar in both the LH-LHR1 and LH-LHR2 complexes.

In general, the results of this study can be used to the relationship between LHR polymorphism and its physiological activity.

In the dairy industry, it is important to identify the genotypes resistant to mastitis while select high-yielding dairy cows. Bovine β-difensin gene polymorphism can be used as a molecular marker in the selection of mastitis-resistant dairy cows. The aim of this study was to investigate the relationship between point mutation of β4-difensin gene and the occurrence of clinical mastitis in the dairy cows using RFLP-PCR method and identification of superior genotype of dairy cows β-difensin gene for mastitis resistance.

blood sample (with EDTA anticoagulant) was taken from total 73 cows (32 with a history of mastitis and 41 with no history of mastitis) in an industrial dairy farm. After DNA extraction amplification of the region of bovine β-difensin gene (393 bp) was performed. PCR products were digested by endonuclease (NlaIII (Hin1II)) for rapid detection of polymorphism in the 2239 region of the β-difensin gene (C to T conversion). Statistical analysis was performed by Chi-square test.

Allele frequencies were 0.68 and 0.32 for C and T, respectively. Statistical analysis was performed by Chi-square test. The results of this study indicate the association between number of mastitis and polymorphism in the β-difensin gene. In other words, the incidence of mastitis was  numerically lower in cows with T allele than in cows without it (p=0.07).

It can be concluded that the bovine β-difensin gene can also be used as a molecular marker in the selection of dairy cows to reduce the incidence of mastitis.

In order to take advantage of breeding programs and productivity of poultry and other domesticated animals, it is essential to assess genetic variability and study the strategies to preserve genetic diversity. The Japanese quail is widely used as a model for animal research purposes in laboratory studies because of its small body size, short intergeneration interval, high growth rate, production of more eggs and meat. Although, Japanese quail has various benefits as a laboratory bird, but its genome sequence is not accessible now. The genome sequence of Japanese quail will deliver important genomic resources to accelerate different studies and to authenticate divergent lines of Japanese quail. Growth is a complex physiological pathway that occurs from fertilization until maturity in birds. Insulin-like growth factor I (IGF-I) gene is one of the most important candidate genes in different species which can affect the performance traits because of its function in metabolism and growth. IGF-I is a 70 amino acid polypeptide hormone with endocrine, paracrine, and autocrine effects. It has been reported that there is association of genetic polymorphisms of the IGF-I gene with growth traits in the poultry. There are relatively few reported studies about the relation between genetic markers of the IGF-I gene and body weights in quails. The objective of this study was undertaken to identify polymorphisms of the IGF-I gene using PCR single-strand conformational polymorphism (PCR–SSCP) analysis and to evaluate association of these polymorphisms with body weight in the Japanese quail.

For doing this research, body weight of the 110 quails under study (46 males and 64 females) in different ages were collected. All data were collected from the Natural Resources Research Center of East Azerbaijan. The data included the identification of the animal, year of birth, sex, body weights at 15, 30, 45 and 60 days. Genomic DNA was extracted from 10 μl of blood in presence of Pronase (Bailes et al., 2007) and stored in EDTA-coated tubes and placed immediately inside an ice box and transferred to the laboratory. The samples were stored at -20 until DNA has been extracted. The quality and quantity of extracted DNA were measured by %0/8 agarose gel electrophoresis. PCR was done for amplifying a fragment in size of 465 bp of IGF-I gene. The PCR primers for the IGF1 gene were designed based on GenBank. PCR primers of IGF-I gene was mentioned in Table 1. The PCRs were carried out in 25 μl volumes containing 1 unit Taq DNA Polymerase, reaction buffer 1X (Sina Gene, Tehran, Iran), 1/5 mM MgCl2, 0/2 μM each of dNTPs, 10 μM of each primer (Sina Gene, Tehran, Iran) and 30 ng of genomic extracted DNA as template. PCR was performed using the T-professional thermal cycler. The thermal profile consisted of 3 min at 95°C, followed by 35 cycles of 40 s at 95°C, 30 s at 58°C and 40 s at 72°C, with a final extension of 5 min at 72°C. Amplification was carried out in Mastercycler (Bailes et al.,2007). PCR products were detected by electrophoresis on %1/5 agarose gel containing ethidium bromide and were visualized in a gel documentation system with a UV transilluminator. PCR products were mixed with 20 μl of denaturing loading dye [95% deionized formamide, %0/35 xylene cyanol, %0/25 bromophenol blue and 10 mM EDTA] in a total volume of 10 μl. The mixture was denatured at 95°C for 15 min and was snap chilled on ice. The electrophoresis was performed in 0.5X TBE buffer (Tris 100 mM, boric acid 9 mM, EDTA 1 mM) at room temperature (18°C) and constant 110 V for 16 h. Polyacrylamide gels were stained with silver according to the protocol described (Benbouza et al.,2006). A statistical model included the mean of population, fixed effect of the sex, random effect of the genotype patterns and residual random term was done by using GLM of SAS software to find the association between the SSCP genotype patterns of PCR products with the body weights. Significant differences among means of different genotypes were calculated using Duncan method in the GLM program and P values of 0.05 were considered statistically significant.

The investigation of candidate genes is one of the foremost techniques to reveal whether definite genes are associated with the economic traits in animals. We successfully amplified the exon 4 of the IGF-I gene. All extracted DNAs from quail blood samples yielded a specific single band PCR product without any nonspecific band. Therefore, the PCR products were directly used for SSCP analysis. The results of SSCP showed that this population was polymorphic at the studied loci and three different genotypes with frequencies of 7.27%, 50.91% and 41.82%, respectively were observed in the examined quails (Figure 3). The results indicated that the exon-4 of IGF-1 gene is polymorph and there was a significant difference (P<0.05) between the genotype patterns and body weight on 30 days. However, for association of gender effect on body weight, there was a significant difference (P<0.05) in the age of 60 days. Also the average daily gain in females is more than males in different ages.

The goal of this study was to determine genetic polymorphism of IGF-I gene in Japanese quail. According to this research, the selected locus for investigating of IGF-I gene in quail can be considered as a locus that effects on body weight and growth rate of quails. It can be also measured as the factor that cause of difference of body weight in different periods.

In this research in order to identify the part of the gene polymorphism transforming growth factor beta-3 (TGFβ3) in broiler chickens Ross, polymerase chain reaction technique and single-strand conformation polymorphism (PCR-SSCP) were performed. For this purpose randomly selection was done between 200 chicks and selected chicks were bled, and genomic DNA was extracted. To determine the quality of the DNA extracted 1% agarose gel was used. Then, by using a pair of specific primers through polymerase chain reaction (PCR) gene fragment with the size of 294 bp from parts of fourth introns and entire fifth exons of the gene was amplified, and finally to determine the bands acrylamide gel and stained with silver nitrate were used. The analysis of band patterns lead to identify three band patterns AA, AB and BB, with 0.52, 0.42 and 0.06 frequency, respectively. Two alleles A and B, with a frequency of 0.73 and 0.27 in the study population was also identified. Shannon index and effective number of alleles for the TGFβ3 gene were 0.5833 and 1.6507, respectively. To confirm the results of PCR-SSCP some samples of each genotype were sequenced directly. Compare of least squares mean different genotypes showed that the gene polymorphism TGFβ3 has significant relation with leg weight and carcass traits.

The DMB2 gene is one of the MHC cluster genes that plays a role in the humoral immune response. This study was performed to identify the polymorphism of exon 2 of the MHC-DMB2 gene and its association with the humoral immune response in Japanese quail. For this purpose, on day 28, 0.2 mL of 5% saline suspension of sheep red blood cell (SRBC) was injected into 130 quail's breast muscle (65 males and 65 females). Seven days later, cervical vein blood sampling was performed on the 35th day. Afterward, the anti-SRBC titer antibody was determined using a micro hemagglutination technique. Also, genomic DNA was extracted from blood samples and a 333bp fragment of exon 2 was amplified using polymerase chain reaction and PCR products were digested by Hinf 1 restriction enzyme. The results showed that there were two types of C (333bp) and G (226, 107bp) alleles in this region with a frequency of 74.6% and 26.4% in the whole population, respectively. The results indicate high polymorphism and high homozygosity in the studied population. In addition, the results showed that genotype had a significant effect on antibody titers (P<0.01). The CC genotype showed the highest total antibody titer (2.13 mg/dL) and the GG genotype showed the lowest total antibody titer (0.33 mg/dL). It is suggested that the negative effects of this single nucleotide polymorphism be considered in breeding programs.

Meta-analysis is a statistical approach for combining the results from independent studies with the same assumptions, that is able to increase the statistical analysis power and the repeatability of the results in the livestock researches, comparing to single-study analysis. The polymorphism in the major genes of Diacylglycerol O-Acyltransferase 1 (DGAT1) and Leptin have drawn much attention from animal scientists during recent years, for their possible roles in the economically important traits. However, the relationships between these genes and milk production traits have been incompatible in dairy cows, it means sometimes significant and some other times no significant association has been reported. The purpose of this study was to investigate the overall effect of DGAT1 and Leptin genes on some economically important traits including milk yield, fat and protein content and percentages in dairy cows by using meta-analysis.

in this study, all researches published in the validated journals and thesis up to 2018 were used. Following to quality control, 9 and 4 studies reported for K232A and Sau3AI polymorphisms of DGAT1 and Leptin genes were used, respectively. The analysis was carried out using the Stata v. 15. Non conformance index (I 2) was significant for all parameters, so that a random risk model was used. Data were analyzed for each variable using these models for measuring the effect size, 95% confidence interval and statistical significance level of the measurements. All variables were continuously in this study. The measurement of the effect size for continuous data was carried out using the standardized mean difference (SMD) that calculated for the polymorphisms of K232A and Sau3AI loci in DGAT1 and Leptin genes on the milk yield, fat and protein content and percentage.

the results of this study showed that the polymorphism in the K223A locus of DGAT1 gene, has a significant effect on lipid content and percentage, and can play an important role in increasing of their amounts, but its relationship with milk yield and protein content and percentage is not significant. Also, the results for Sau3AI polymorphism in the Leptin revealed that this locus had no significant effect on the traits investigated in this study.

Overall, the results of this study with identifying the overall effects of the studied genotypes of DGAT1 and Leptin genes on milk production traits in dairy cows can play an important role for planning next researches in this field.

The heat shock proteins (HSPs) are a family of proteins contributing to cellular resistance against a variety of thermal stresses in different climates. In this study we aimed to characterize polymorphisms of the ovine HSP70A1A gene in Mehraban indigenous sheep breed and Romanov imported sheep breed, because they are well adapted to the cold climate. Blood samples were collected from a total of 141 sheep (100 Mehraban and 41 Romanov), and then genomic DNA was extracted according to conventional instructions. Polymerase chain reaction (PCR) was performed to amplify the 247 bp and 298 bp of the exon region of the HSP70A1A gene (Oar_v4.0; Chr 20, NC_019477.2). Also, polymorphisms of the studied fragments were explored using single strand conformational polymorphism (SSCP) technique and then the amplified DNA fragments were sequenced by Sanger sequencing method. In both Mehraban and Romanov breeds, five distinct SSCP patterns were identified that two and three electrophoretic patterns were respectively related to 247 bp segment and 298 bp segments. Furthermore, frequencies of SSCP patterns showed no differences between breeds. Five single nucleotide polymorphisms (SNPs) including g.26562252C>A, g.26562261G>C, g.26562270T>C, g.26562273C>T and g.26562279C>T were identified in 247 bp segment, and also, three SNPs including g.26561745T>C, g.26561784C>T and g.26561877G>A were identified in 298 bp segment of PCR products. Results revealed that all SNPs were in Hardy–Weinberg disequilibrium (p < 0.05), except of g.26561745T>C and g.26561877G>A. Considering the role of HSPs in resistance to the environmental stresses, it can be conclude that the identification of  these SNPs can  play an important role on understanding the mechanism of adaptation  to temperature tolerance among the Iranian indigenous sheep breeds.

In the present study, blood samples were collected from 97 Adani goat from Bushehr province in order to identify the polymorphism in the exon II region of MHC-DRB1 gene (Major Histocompatibility Complex) and also, its association with growth traits (birth weight and 3 months weight). Genomic DNA was extracted from blood samples. A 279-bp fragment was amplified using polymerase chain reaction (PCR). Eventually, the PCR products were digested by RasI enzyme. The results showed that there were 4 types of alleles A, B, C and D in this locus with the frequencies of %51, %26.8, %13.4 and %8.8, respectively. Five genotypes including AA, AB, BB, AC and AD were identified with the frequency of %14.432, %28.866, %12.371, %26.80 and %17.525, respectively. The results indicated polymorphism and high heterozygosity in the population under study. Also, the number of effective alleles, Shannon index, expected and observed heterozygosity for this site was calculated at 2.794, 1.179, 0.642 and 0.732, respectively. Moreover, the chi-square (χ2) test showed that population was not in Hardy-Weinberg equilibrium. The ANOVA results showed that the effect of different genotypes on birth weight was significant (p<0.05), but it was not significant on 3 MW (p<0.05). Furthermore, other traits such as dam age, sex, season and birth type effects were not significant on the growth traits (p<0.05). The highest birth weight was found for heterozygous AC and AD genotypes (3.05 and 3.02 Kg, respectively), and the lowest birth weight was related to pure AA genotype (1.75 Kg). It seems that selecting AC and AD genotypes can be expected to increase birth weight in Adani goat. Also, we expect that this gene can act as a candidate gene for genetic improvement of some growth traits in goat breeding programs.

In this study, the polymorphism of four microsatellite loci BMS1350, LGB, ILSTS45, and BMS1915 in chromosome 3 and their association with wool trait were investigated in Baluchi sheep. DNA extraction was performed from blood samples of 185 Baluchi sheep from Abbas Abad Breeding Station. Gene fragments of microsatellites were amplified by polymerase chain reaction with specific primers. The result shown allele E in BMS1915 locus with 0.40, Allele D in BMS1350 locus with 0.30, Allele B in LGB locus with 0.48 and Allele A in ILSTS4 locus with 0.46, had the highest frequency. The results of the Comparison of mean shown the LGB locus has the highest and ILSTS45 locus has the lowest production. Also, genotype AC in the LGB locus highest (1308 ±95.7) and genotype BC had the lowest (875 ± 54.7) of production. By comparing the coefficient of variation 4 loci founded that the greatest diversity and dispersion associated with the ILSTS45 and the lowest diversity associated with BMS1350 locus. Chi-square test (χ2) shown all of the microsatellite loci were in the Hardy-Weinberg equilibrium (P>0.05). Association analysis of polymorphism these loci shown there is no significant association between polymorphism of these loci and wool trait in Baluchi sheep (P>0.05). Statistical analysis showed there was no significant difference between loci polymorphisms and wool traits. Therefore, concluded in further research on selected studies based on molecular markers, the relationship between these loci and other traits in the Balochi sheep can be examined.

It has been shown that the occurrence of any changes in the function of DNMTs genes has a significant effect on both the embryo development and birth weight in mammals; therefore, the aim of the present study was to investigate the presence of DNA polymorphisms in the members of DNA methyl transferase superfamily and its relationship with birth weight in Sistani cattle’s. Blood sampling was done randomly from 60 Sistani cows. DNA extraction was performed using phenol chloroform method. Candidate region for the presence of functional polymorphism within the DNMTs gene including the 114-bp fragment of the exon 33 of the DNMT1 gene, the 176-bp fragment of the intron 4 of the DNMT3a gene, and the 207-bp fragment in intron 3 of the DNMT3b gene were amplified by polymerase chain reaction. PCR-SSCP followed by polyacrylamide gels silver stain analysis was done to evaluate the presence of candidate mutations in target gens. The result analysis of all analyzed region did not show any mutations in the investigated DNMTs genes. Based on the results of this study, it seems that the lack of observation of genetic diversity in the studied regions could be related to the evolutionary selection against occurrence of specific mutations in the analyzed population. In general, based on the results of this study, analysis of genetic diversity in the studied genomic region may not be effective in identifying effective markers for breeding programs in Sistani cows.

The use of artificial insemination in dairy cattle industry may improve the results of selection for production traits. This study attempts to evaluated effect of GDF9A625T and GDF9A489T candidate gene polymorphism on the sperm quality and quantity traits in Iranian bulls. A total of 108 samples of blood and semen was collected of A. I. bulls were born between 1989-2016 years. The GDF9A625T and GDF9A489T SNPs was determined by PCR- RFLP with DraI and NsiI enzymes, respectively. In A625T site, A (351 and 25 bp) and T (376 bp) alleles and in A489T site, A (184 and 24 bp) and T (208bp) alleles was obtained and also three AA, AT and TT genotypes in two marker sites were observed. The frequency results of GDF9A625T site showed that the T allele relative to the A allele was more frequent in Iranian Holstein bulls (0.6343 vs 0.3657) and 44.44, 37.98 and 17.95 percent of bulls had TT, AT and AA genotypes, respectively. In GDF9A625T site, the T allele frequency was more than A allele (0.602 vs 0.398) and 40.82, 38.78 and 20.14 percent of bulls had TT, AT and AA genotypes, respectively. Analysis of variance revealed that the effects of both loci were significant effect on sperm quality in Iranian Holstein bulls. The result of means comparison between genotypes in two marker sites showed that bulls with AT genotype significantly high value in quantitative trait and AA genotype was significantly higher in qualitative trait. Results of this research showed that these marker sites can be beneficial in genomic selection.