one hundred and fifty blood samples were prepared from cattle of a region in isfahan. the extracted dna from blood cells were analyzed by a. centrale (amori strain) specific nested-pcr using primers derived from 16s rrna gene. all blood smears were negative for a. centrale like structures. the results showed that 2 of total 150 blood samples (1.33%) were a. centrale (amori strain) positive by s...

Studies on earthworms using molecular markers are rare in Africa except a handful from South Africa. Reports on Libyodrilus violaceous,an earthworm found in West Africaare available including their metal tolerance and bioaccumulation capacity but their molecular characterization and ecotoxicology studies are scarce. In this study, triplicate L. violaceous specimens were collec...

Ribosomal RNA (rRNA) genes, whose activity results in nucleolus formation, constitute an extremely important part of genome. Despite the extensive exploration into avian genomes, no complete description of avian rRNA gene primary structure has been offered so far. We publish a complete chicken rRNA gene cluster sequence here, including 5'ETS (1836 bp), 18S rRNA gene (1823 bp), ITS1 (2530 bp), 5...

mycoplasma agalactiae (m. agalactiae) is one of the main causes of contagious agalactia, an infectious syndrome of sheep and goats in khuzestan province –southwest of iran that is characterized by mastitis and subsequent failure of milk production, arthritis, abortion and keratoconjunctivitis. this study was carried out to isolation and identification of m. agalactiae with culture and polymeras...

contagious agalactia (c.a) is an infectious syndrome of sheep that is characterized by mastitis and subsequent failure of milk production, arthritis, abortion and keratoconjunctivitis. mycoplasma agalactiae (m. agalactiae) is the main cause of the disease in sheep. the aim of this study was isolation and identification of m. agalactiae with culture and polymerase chain reaction (pcr) assay f...

The silencing of one parental set of rRNA genes in a genetic hybrid is an epigenetic phenomenon known as nucleolar dominance. We showed previously that silencing is restricted to the nucleolus organizer regions (NORs), the loci where rRNA genes are tandemly arrayed, and does not spread to or from neighboring protein-coding genes. One hypothesis is that nucleolar dominance is the net result of h...

Pasteurella multocida is known as an important heterogenic bacterial agent causes some severe diseases such as fowl cholera in poultry and haemorrhagic septicaemia in cattle and buffalo. A polymerase chain reaction (PCR) assay was developed using primers derived from conserved part of 16S-23S rRNA gene. The PCR amplified a fragment size of 0.7 kb using DNA from nine avian P. multocida  isolates...

The gene encoding the 5S rRNA for Leptospira interrogans serovar canicola strain Moulton was isolated and sequenced. The 5S rRNA gene occurs as a single copy within the genome and encodes a 117-nucleotide-long RNA molecule. The 5S rRNA gene is flanked at both the 5' and 3' ends by regions of A + T-rich sequences, and the 5'-flanking region contains a promoter sequence. L. interrogans has a uniq...

Analysis of 16S rRNA gene sequences has become the primary method for determining prokaryotic phylogeny. Phylogeny is currently the basis for prokaryotic systematics. Therefore, the validity of 16S rRNA gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics. Discrepancies between 16S rRNA gene analyses and DNA-DNA hybridization and phenotypic analyses have bee...