Analysis of bovine growth hormone gene polymorphism of local and Holstein cattle breeds in Kerman province of Iran using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP)

Bovine growth hormone (bGH) gene is a part of the multiple gene family that contains prolactin and placental lactogens. Also, variations in introns have potential usefulness as genetic markers and could help in the genetic improvement of populations. Genomic DNA was isolated from blood samples of two local herds (53 animals) and two Holstein herds (50 animals). Genomic DNA samples were genotyped for the GHI-AluI polymorphism by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). A 211 bp (bGH) gene exon 5 segment was amplified by PCR using bovine specific primers. RFLPs in this segment were studied using AluI restriction enzyme. The frequencies of V and L alleles in the local and Holstein herds were 0.2 and 0.65, respectively. For both herds, significant difference from the Hardy-Weinberg equilibrium was observed.Key words: Growth hormone, polymorphism, polymerase chain reaction restriction fragment length polymorphism, local herds, Holstein herds

Genetic variation of Mehraban sheep using two intersimple sequence repeat (ISSR) markers

Genetic diversity within Mehraban sheep populations, as one of the main breeds of Iranian sheep, was studied using (AG)9C and (GA)9C as two inter-simple sequence repeat (ISSR) markers. Blood samples were collected from 210 animals in 6 flocks, 35 heads each, in different parts of Hamedan province. In the polymerase chain reaction (PCR) products, (AG)9C and (GA)9C primers amplified 28 and 36 fragments, respectively, which ranged from 100 to more than 3100 bp. Percentages of polymorphic bands in the different populations ranged from 69 to 77%. In the pooled population, all inter-simple sequence repeat (ISSR) fragments were polymorphic. Shannon and Nei gene diversity indices were 0.2256 and 0.1258, respectively, which indicated low genetic diversity of Mehraban sheep. The population studied was at Hardy-Weinberg equilibrium for most of the ISSR-loci. Analysis of molecular variance (AMOVA) partitioned the ISSR variation into inter and intra population components, where inter-populations and intra-populations accounted for 9 and 91% of the total variation, respectively. The results of this study showed that the Mehraban sheep is a pure native breed that has a low genetic diversity between subpopulations and could be noticed for its potentials in response to selection or crossing with other breeds.Key words: Inter-simple sequence repeat (ISSR) markers, Mehraban sheep, genetic diversity

Clostridium perfringens isolate typing by multiplex PCR

Clostridium perfringens is an important pathogen that provokes numerous different diseases. This bacterium is classified into five different types, each of which capable of causing a different disease. There are various methods for the bacterial identification, many are labor-intensive, time-consuming, expensive and also present low sensitivity and specificity. The aim of this research was to identify the different types of C. perfringens using PCR molecular method. In this study, 130 sheep-dung samples were randomly collected from areas around the city of Kerman, southeastern Iran. After processing and culturing of samples, the produced colonies were morphologically studied, gram stain test was also carried out and the genera of these bacteria were identified through biochemical tests. DNA extracted from isolated bacteria for genotyping was tested by multiplex PCR with specific primers. Based on length of synthesized fragments by PCR, toxin types and bacterial strains were detected. C. perfringens isolated types were divided as follows: 17.39% type A, 21.74% type B, 34.78% type C and 26.09% type D. It should be emphasized that, up to the present moment, C. perfringens type A has not been reported in Iran