the pb2 protein of influenza a viruses has been shown as host range determinant. in this study pb2gene of five h9n2 isolates from tehran province during the period of 1998-2001 were partially amplifiedand sequenced to do phylogenetic study. iranian isolates could be classified in eurasian lineage according totheir pb2 gene sequences. the pb2 genes of these isolates are different from those of m...

the earliest evidences on circulation of avian influenza (ai) virus on the iranian poultry farms date back to 1998. great economic losses through dramatic drop in egg production and high mortality rates are characteristically attributed to h9n2 ai virus. in the present work non-structural (ns) genes of 10 iranian h9n2 chicken ai viruses collected during 1998-2007 were fully sequenced and subjec...

tropical theileriosis is a tick-transmitted disease which caused by obligative intracellular protozoan theileria annulata. diagnosis is usually based on identification of parasite in giemsa stained smears of peripheral blood, spleen or lymph nodes. today, the molecular methods with high sensitivity and specificity are used for diagnosis of infected and carrier animals, epidemiological and phylo...

Phylogenetic analysis is the study of evolutionary relationships among molecules, phenotypes, and organisms. In the context of protein sequence data, phylogenetic analysis is one of the cornerstones of comparative sequence analysis and has many applications in the study of protein evolution and function. This unit provides a brief review of the principles of phylogenetic analysis and describes ...

We present a preliminary overview of our molecular phylogenetics research on the superfamily Scarabaeoidea. The molecular data consists of 28S ribosomal DNA sequences (mainly D2 and D3 expansion regions) for over 600 taxa and 18S ribosomal DNA sequences (mainly E17 to E35 expansion regions) for over 150 representative taxa within the lineages sampled. Based on our preliminary molecular phylogen...

Phylogenetic diversity--patterns of phylogenetic relatedness among organisms in ecological communities--provides important insights into the mechanisms underlying community assembly. Studies that measure phylogenetic diversity in microbial communities have primarily been limited to a single marker gene approach, using the small subunit of the rRNA gene (SSU-rRNA) to quantify phylogenetic relati...

With 3,480 E. coli strains isolated from the Yeongsan River basin, South Korea, correlations between phylogenetic groups and horizontal fluorophore enhanced rep-PCR (HFERP) genotypes were examined, and environmental factors affecting E. coli phylogenetic groups in the river water were determined. Interestingly, multidimentional scaling (MDS) analyses based on HFERP DNA fingerprint data indicate...