ABSTRACT
In recent years, acute severe outbreaks of infectious bursal disease (IBD) are frequently observed in commercial chicken populations of the North East Region (NER) of India, resulting in huge economic loses to poultry farmers. Field outbreaks of IBD in 30 different poultry farms in the NER were confirmed by clinicopathologic examination and reverse transcriptase PCR. A total of 10 isolates of IBD virus (IBDV) from these outbreaks were characterized by the genetic analysis of VP1 and the hypervariable region of the VP2 gene. Nucleotide sequences, deduced amino acid sequences, and phylogenetic analysis of both VP2 and VP1 genes revealed two genetically diverse strains of very virulent IBDV (vvIBDV) and one intermediate strain circulating in the NER. These isolates differ at nucleotide and amino acid levels from vvIBDV isolates of mainland India and are clustered in distinctly separate groups in the phylogenetic tree. Six of the isolates revealed a unique combination of vvIBDV amino acid signatures in the VP2 gene (A222, I256, I294), while bearing the non-vvIBDV amino acid signatures of the VP1 gene (146E, 147G, 242D), but they are clearly classified as vvIBDV in a phylogenetic analysis of both genes. Interestingly, one of the isolates showed 99% sequence homology with attenuated vaccine strains in the VP2 gene and clustered together. This study demonstrates the diversity of IBDVs in India and document for the first time the possible involvement of attenuated vaccine strains in the epidemiology of IBD in India.
Subject(s)
Birnaviridae Infections/veterinary , Genetic Variation , Infectious bursal disease virus/genetics , Poultry Diseases/virology , Amino Acid Sequence , Animals , Base Sequence , Birnaviridae Infections/epidemiology , Birnaviridae Infections/virology , Capsid Proteins/chemistry , Capsid Proteins/genetics , Chickens , Disease Outbreaks/veterinary , India/epidemiology , Infectious bursal disease virus/classification , Infectious bursal disease virus/isolation & purification , Phylogeny , Poultry Diseases/epidemiology , Sequence AlignmentABSTRACT
The complete mitochondrial genome of Junonia iphita was determined to be 15,433 bp in length, including 37 typical mitochondrial genes and an AT-rich region. All the protein coding genes (PCGs) are initiated by typical ATN codons, except cox1 gene that is by CGA codon. Eight genes use complete termination codon (TAA), whereas the cox1, cox2 and nad5 genes end with single T; nad4 and nad1 ends with stop codon TA. All the tRNA show secondary cloverleaf structures except trnS1 (AGN). The A + T rich region is 546 bp in length containing ATAGA motif followed by a 18 bp poly-T stretch, two microsatellite-like (TA)9 elements and 8 bp poly-A stretch immediately upstream of trnM gene.
Subject(s)
Genome, Mitochondrial , Lepidoptera/classification , Lepidoptera/genetics , Animals , Base Composition , Genes, Mitochondrial , Genome Size , Open Reading Frames , Phylogeny , Regulatory Sequences, Nucleic Acid , Sequence Analysis, DNA , Whole Genome SequencingABSTRACT
In the present study, the near complete mitochondrial genome (mitogenome) of Junonia iphita (Lepidoptera: Nymphalidae: Nymphalinae) was determined to be 14,892 bp. The gene order and orientation are identical to those in other butterfly species. The phylogenetic tree constructed from the whole mitogenomes using the 13 protein coding genes (PCGs) defines the genetic relatedness of the two J. iphita species collected from two different regions. All the Junonia species clustered together, and were further subdivided into clade one consisting of J. almana and J. orithya and clade two comprising of the two J. iphita which were collected from Indo and Indochinese subregions separated by river barrier. Comparison between the two J. iphita sequences revealed minor variations and Single Nucleotide Polymorphisms were identified at 51 sites amounting to 0.4% of the entire mitochondrial genome.
