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The insulin-like growth factor (IGF) axis is fundamental for mammalian growth and development. However, no comprehensive reference data on gene expression across tissues and pre- and postnatal developmental stages are available for any given species. Here we provide systematic promoter- and splice variant specific information on expression of IGF system components in embryonic (Day 48), fetal (Day 153), term (Day 277, placenta) and juvenile (Day 365-396) tissues of domestic cow, a major agricultural species and biomedical model. Analysis of spatiotemporal changes in expression of IGF1, IGF2, IGF1R, IGF2R, IGFBP1-8 and IR genes, as well as lncRNAs H19 and AIRN, by qPCR, indicated an overall increase in expression from embryo to fetal stage, and decrease in expression from fetal to juvenile stage. The stronger decrease in expression of lncRNAs (average -16-fold) and ligands (average -12.1-fold) compared to receptors (average -5.7-fold) and binding proteins (average -4.3-fold) is consistent with known functions of IGF peptides and supports important roles of lncRNAs in prenatal development. Pronounced overall reduction in postnatal expression of IGF system components in lung (-12.9-fold) and kidney (-13.2-fold) are signatures of major changes in organ function while more similar hepatic expression levels (-2.2-fold) are evidence of the endocrine rather than autocrine/paracrine role of IGFs in postnatal growth regulation. Despite its rapid growth, placenta displayed a more stable expression pattern than other organs during prenatal development. Quantitative analyses of contributions of promoters P0-P4 to global IGF2 transcript in fetal tissues revealed that P4 accounted for the bulk of transcript in all tissues but skeletal muscle. Demonstration of IGF2 expression in fetal muscle and postnatal liver from a promoter orthologous to mouse and human promoter P0 provides further evidence for an evolutionary and developmental shift from placenta-specific P0-expression in rodents and suggests that some aspects of bovine IGF expression may be closer to human than mouse.

This study focused on the development and evaluation of a quantitative competitive polymerase chain reaction (QC-PCR) for detection and quantification of poultry DNA in sausage. PCR is well known to be quantitative if internal DNA standards are co-amplified together with the target DNA. A DNA competitor differing by 83 bp in length from the poultry target sequence was constructed and used for PCR together with the target DNA. Specificity of the new primers was evaluated with DNA from cattle and sheep. The results of QC-PCR showed that the percentage of contamination was in the range of 23.87–52.06%.

Aslaminejad, A.A., Nassiry, M.R., Farajollahi, H., Mahdavi, M., Abbasi, H. and Javadmanesh, A. 2010. Polymorphism in exon-3 of leptin gene in iranian native cattle breeds. J. Appl. Anim. Res., 37: 225–228. This study describes genetic variability of the leptin gene in four Iranian native cattle breeds. A 317 bp fragment of exon 3 of the leptin gene from 332 individuals in four different populations of Iranian cows including Golpayegani (N=92), Najdi (N=54), Sarabi (N=82) and Sistani (N=104) was amplified and PCR products digested with Nrul restriction enzyme. Allele C in Golpayegani, Najdi, Sarabi and Sistani breeds were 75, 78, 59 and 52 per cent, respectively. Observed heterozygosities were 0.29, 0.37, 0.68 and 0.92 for Golpayegani, Najdi, Sarabi and Sistani cattle, respectively. This study suggests that allele frequencies of leptin differed among Iranian cattle breeds.

The aim of this study was to identify the Potato Spindle Tuber Viroid (PSTVd) by Reverse Transcriptase-PCR. Among all plant diseases which are caused by viroids, PSTVd was the first viroid which is recognized by plant pathologist. Suspended potato tubers from Razavi and Northern Khorasan provinces collected and cultured. Leaves of cultured tubers were used for RNA extraction by PEG6000 Precipitation method. Subsequent RT-PCR reaction has been carried out using specific primers. A 359 bp fragment has been appeared after electrophoresis which has not appeared in healthy tuber samples. Digestion of obtained fragment with BamHI confirmed the sequence by producing two fragments of 119 and 240 bp. Sequencing has been done to certify the PSTVd. The sequencing result showed that infection in tested areas is caused by mild strain of PSTVd. In this project from 250 samples, 14 tubers were infected. This was the first report of occurrence of mild strain of PSTVd in Iran.

This study describes genetic variability in the BoLA-DRB3 gene in Iranian native cattle (Bos Indicus and Taurus) and relationships between these breeds. This is the first study of genetic polymorphism of the BoLA-DRB3 gene in Iranian native cattle. We examined exon 2 of the major histocompatibility complex (MHC) class II DRB3 gene from 203 individuals in four populations of Iranian native cattle (52 Sarabi, 52 Najdi, 49 Sistani, 50 Golpayegani cattle) using the hemi-nested PCR-RFLP method. We identified the 36 previously reported alleles and one novel pattern (*eac). Analysis of the frequencies of the various BoLA-DRB3.2 alleles in each breed indicated that DRB3.2*52 in Sarabi cattle (23%), DRB3.2 *14 and *24 alleles in Najdi cattle (13%), DRB3.2 *8 allele in Sistani cattle (22%) and DRB3.2*16 allele in Golpayegani cattle (14%), were the most frequent alleles. Allelic frequencies ranged from 1 to 23% among the 36 alleles and there were some alleles that were found only in Iranian cattle. Effective number of alleles in the four breeds was estimated to be 7.86, 11.68, 7.08 and 3.37 in Sarabi, Najdi, Sistani and Golpayegani, respectively. Observed heterozygosities were the highest in Sarabi (94%) and Najdi (94%). A population tree based on the frequency of BoLA-DRB3.2 alleles in each breed suggested that Najdi, Sarabi and Golpayegani cattle clustered together and Najdi and Sarabi were the closest breeds. Sistani cattle differed more from these three breeds. These new data suggest that allele frequencies differ between Iranian cattle breeds.

The genotypes for Beta-Lactoglobulin (BLG) and calpastatin (CAST) were determined by Polymerase Chain Reaction (PCR) and restriction enzyme digestion and genotyped for calpain (CAPN) by PCR-SSCP method in an Iranian breed sheep, Kurdi. Blood samples were collected from 100 pure bred Kurdi sheep from Kurdi breeding station located in Shirvan, Mashhad. The extraction of genomic DNA was based on Guanidin Thiocyanate-Silica gel method. After PCR reaction, amplicons were digested with restriction enzymes MspI and RsaI for beta-lactoglobulin and calpastatin genes, respectively. The beta-lactoglobulin locus had 3 genotypes with frequencies of 0.24, 0.54 and 0.22 for AA, AB and BB, respectively; calpastatin genotypes had 2 genotypes with frequencies of 0.76 and 0.24 for MM and MN genotypes, respectively. Calpain genotypes were analyzed with SSCP method, which had 2 genotypes with frequencies of 0.92 and 0.08 for AA and AB, respectively. Heterozygosity value for beta-lactoglobulin locus was 49% and for calpastatin and calpain loci was very low (24 and 8%, respectively). chi2 test confirmed the Hardy-Weinberg equilibrium for three loci in this population. These data provide evidence that Iranian's Kurdi sheep breed have a variability, which opens interesting prospects for future selection programs, especially marker-assistant selection between different genotypes of different locus and milk and cheese characteristics, gain and meat traits and also for preservation strategies.

The objective of this study was to evaluate the association of genetic differences in the bovine leptin gene and milk yield, reproduction, body condition score (BCS), and plasma glucose level in Iranian Holstein cows. In total, two hundred and thirty eight cows were used and genotyped for a restricted fragment length polymorphism at the leptin gene locus. Two genotypes, AA and AB, have been distinguished which have the frequencies of 0.89 and 0.11, respectively. The genotypes were distributed according to the Hardy - Weinberg equilibrium (Χ 2 = 0.733). During the first 12 wk of lactation, milk yield and composition, live weight, BCS and plasma glucose were measured in 50 cows. Data were analyzed based on a repeated measures ANOVA. During this period, milk yield and composition, live weight, BCS and plasma glucose level were similar among the genotypes. The first cumulative 60-d milk yield, 305-d milk yield, days to first breeding, days open and days from first breeding to conception using previous lactation records were also analyzed using Standard Least Square within mixed models. Fixed effects were year, season, parity and age at calving, and sire. For the reproductive traits the cumulative first 60-d milk yield was also added to the model. Animal was fitted as a random effect. A significant association was detected between the RFLP-AB genotype and 305-d milk yield (p

A total of 540 Japanese quail eggs were assigned to 9 treatments of 4 replicates to investigate the effect of in ovo injection of threonine (THR) on mucin2 (MUC2) mRNA expression and digestive enzyme activity. Treatments were (non-injected) eggs and those in ovo injected with saline (0.05 or 0.1 ml) with or without THR (5 mg/ml) in two sites (in or under the air sac). On hatch day, 0.05 ml in ovo injected (under the air sac: TUAS) hatchlings were divided into three groups based on NRC recommendations for THR, while all 0.1 ml in ovo injected chicks were removed due to low hatchability. The remaining treatments received the NRC recommended diet until day 10 post-hatch. Treatments had no effect on protease and amylase activities, while TUAS increased MUC2 gene expression. In conclusion, the in ovo injection of THR increased MUC2 gene expression but had no effect on enzyme activity.

Parent-of-origin-dependent (epi)genetic factors are important determinants of prenatal development that program adult phenotype. However, data on magnitude and specificity of maternal and paternal genome effects on fetal bone are lacking. We used an outbred bovine model to dissect and quantify effects of parental genomes, fetal sex, and nongenetic maternal effects on the fetal skeleton and analyzed phenotypic and molecular relationships between fetal muscle and bone. Analysis of 51 bone morphometric and weight parameters from 72 fetuses recovered at day 153 gestation (54% term) identified six principal components (PC1-6) that explained 80% of the variation in skeletal parameters. Parental genomes accounted for most of the variation in bone wet weight (PC1, 72.1%), limb ossification (PC2, 99.8%), flat bone size (PC4, 99.7%), and axial skeletal growth (PC5, 96.9%). Limb length showed lesser effects of parental genomes (PC3, 40.8%) and a significant nongenetic maternal effect (gestational weight gain, 29%). Fetal sex affected bone wet weight (PC1, p 0.0001) and limb length (PC3, p 0.05). Partitioning of variation explained by parental genomes revealed strong maternal genome effects on bone wet weight (74.1%, p 0.0001) and axial skeletal growth (93.5%, p 0.001), whereas paternal genome controlled limb ossification (95.1%, p 0.0001). Histomorphometric data revealed strong maternal genome effects on growth plate height (98.6%, p 0.0001) and trabecular thickness (85.5%, p 0.0001) in distal femur. Parental genome effects on fetal bone were mirrored by maternal genome effects on fetal serum 25-hydroxyvitamin D (96.9%, p 0.001) and paternal genome effects on alkaline phosphatase (90.0%, p 0.001) and their correlations with maternally controlled bone wet weight and paternally controlled limb ossification, respectively. Bone wet weight and flat bone size correlated positively with muscle weight (r = 0.84 and 0.77, p 0.0001) and negatively with muscle H19 expression (r = -0.34 and -0.31, p 0.01). Because imprinted maternally expressed H19 regulates growth factors by miRNA interference, this suggests muscle-bone interaction via epigenetic factors.

Identification of animal species used in commercial meat products is important with respect to economic and sanitary issues. The aim of this research was to realize ruminant species in meat products using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The universal CB7u primers pair was used for amplifying ~195 bp fragment from a variable region of cytochrome- b mitochondrial DNA gene by polymerase chain reaction. Species differentiation was realized by digestion of the amplified ~195 bp fragments with Sse9I restriction enzyme. The results indicate that 7/7 of Kebab loghmeh, 9/10 of minced meat, 4/8 of beef burger and 2/5 samples of canned stew samples, were contaminated with one of prohibited ruminant species residual. Furthermore, the results reveal that 5/30 of samples had cross-contamination with a mixture of meat originated from various species, which was against the labelled nutrition information. Our results indicate that the PCR-RFLP technique is a powerful and reproducible test for detection and separation of ruminant species residuals in commercial meat products, especially in developing countries. Keywords: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), mitochondrial DNA, ruminant species, commercial meat products, cytochrome- b gene

This study describes genetic variability in the leptin in Iranian native, Brown Swiss and Holstein cattle (Bos Indicus and Bos Taurus). This is the first study of genetic polymorphism of the leptin gene in Iranian native cattle. We examined exon 2 of the leptin gene from 587 individuals in six different populations of Iranian native cattles (86 Sarabi, 66 Taleshi, 94 Sistani, 76 Golpayegani, 104 Brown Swiss and 161 Holstein cattle) using PCR-RFLP method. Analysis of the frequencies of the various alleles ineach breed indicated that allele C in Sarabi, Taleshi, Sistani, Golpayegani, Brown Swiss and Holstein cattle with 68, 55, 69, 71, 55 and 57% value were the most frequent alleles. Observed heterozygosities were highest in Golpayegani (57.89%). These new data suggest that allele frequencies of leptin differ between the various Iranian cattle breeds.

Protein degradation in the rumen often proceeds at a rate which exceeds the ability of the microbial population to utilize the resulting breakdown products. Bacteria are the most active proteolytic organisms in the rumen, and many species of rumen bacteria are known to be proteolytic (Wallaceet al., 1985). The commonly isolated proteolytic bacteria are also able to break down peptides and amino acids, and it was assumed that they were responsible for the ruminal degradation of intact protein through to ammonia. However, studies comparing the specific activities of ammonia production between mixed ruminal bacteria and the well-known proteolytic bacteria noted that no individual bacterium had an activity which could explain the activity of the mixed ruminal culture (Russellet al., 1988). Subsequently, three gram-positive, monensin-sensitive, ammonia hyper producing (HAP) bacteria were isolated from the rumen. The present study reports the sequence of 16sr RNA for ruminal ammoniabacters of Iranian Holstein cows.

Prolactin (PRL) is a polypeptide hormones produced by cells of the anterior pituitary. The bovine PRL gene consists of 4 introns and 5 exons, located on chromosome 23. Different biological functions of PRL were subdivided into five broad categories: reproduction, osmoregulation, growth, integument, and synergism with steroids. Also, It has been shown to be important for control of mammary growth, lactogenesis and lactation (Skinkyteet al., 2005). Chung et al, (1996) showed that PRL-RsaI locus had a significant effect on milk fat percent in dairy cattle. Therefore the PRL gene was chosen as a candidate gene for milk traits in dairy cattle. The objective of this study was to evaluate the association of genetic differences in bovine PRL gene and milk fat content in Iranian Sarabi cows.

Candidate gene approaches facilitate discovering and localizing causative genes for quantitative traits and polymorphisms within selected candidate genes can be tested for association with variationin the quantitative trait (Campbell et al., 2003). Leptin is a 16-kDa protein that is synthesized and secreted predominantly by white adipocytes tissue and its expression is regulated by body fatness and energy balance. Leptin gene expressed in a variety of tissues including adipose tissue, placenta, mammary glands, skeletal muscles, gastric mucosa, brain and pituitary glands. In cattle, the leptin gene is located on chromosome 4 and consists of three exons. Several studies shown the association between polymorphism at the leptin gene and feed intake, energy balance, fertility and immune functions. It has been shown that leptin gene influences milk performance in cattle and reproduction in beef cattle(Liefers et al., 2002). Buchanan et al. (2002) described a cytosine (C) to thymine (T) substitution in exon 2 of the leptin gene of the B. taurus breeds, suggesting the existence CC, TT and CT genotypes. The aim of this study was to identify the single nucleotide polymorphism of exon 2 in Iranian Taleshi cattle.

DNA-based molecular methods have made possible genotyping of animals of any age and sex for milk and meat genes, thus providing a potentially more efficient and flexible selection tool. Among specific genes that may affect economically important traits in sheep, the Beta-lactoglobulin (BLG) locus has been extensively studied [Barillet et al., 2005]. The genotype BB of BLG seems to be associated with higher milk yield; on the other hand genotypes AA and AB seem to be superior in protein and casein content and crude yield [Garzon et al., 1992]. Another genes intensively investigated in farm animal are that of calpastatin (CAST) and calpain (CAPN). Calpastatin and calpain (CAPN) deserves special attention because of their major role in meat production. The calpain-calpastatin system (CCS) comprises a family of calcium dependent neutral proteases. The CAPNs have been shown to play the major role in post mortem tenderization in beef, lamb, and pork by degrading specific muscle structural proteins. The aim of the present study was to identify genotypes of BLG, CAST and CAPN genes in Kurdi sheep breed by PCR.

Rumen is an area with high potential for growing of diverse living organisms including anaerobic fungi. The most studies on rumen fungi focused on anaerobic fungi classified asChytridiomycetes, familyNeocallimasticaceas, while few studies have done on determination ofZygomycetesthat can be native in the rumen. The most fungi within the subkingdomZygomycotinabelong to the classZygomycetes. Fungi in this class possess some distinctive properties that contain rapid growth, nonseptate mycelium, reproduction by sporangiospores (Pittet al., 1985) and production of some hydrolytic enzymes (Vinogradovaet al.,2003). The aim of this study was microscopic examination and molecular analysis of nuclear small subunit (SSU; 18S rDNA) of ruminal fungi,Zygomycete, and its reproductive manner in sheep.