Turkey astrovirus
Higher order taxa
Virus; ssRNA positive-strand viruses, no DNA stage; Astroviridae; Avastrovirus
Species
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NCBI: Taxonomy |
Genus species
Description and significance
Astrovirus originated from ‘astron’, a Greek word for star because of the five-pointed or six-pointed side projection which can be detected by negative stained electron microscopy (EM). They were first described by Madeley & Cosgrove in 1975 as the causal for gastroenteritis in infants. Astrovirus disease is known as the causal for gastroenteritis, it is usually mild but more serious cases have been discovered in poultry. Astrovirus is most commonly found in turkeys and can lead to mortality. In 1980, turkey astrovirus was first described and was linked with turkey poults in the UK that were suffering from diarrhea and increased mortality. They were discovered in the U.S. the same year. Although replication is only routinely detected in the intestines, experimentally infected poults show thymus and bursal atrophy and the virus can be isolated in other tissues.
Genome structure
Genomically, astrovirus have positive-sense, single stranded, RNA genome which are about 6.8 to 7.9 kb in length. Their genomes have three open reading frames (ORFs) which are organized from 5’ to 3'. ORF1a encodes a serine protease, ORF1b encodes the RNA dependent polymerase and ORF 2 encodes the structural proteins. The space between the ORF1b (open reading frame) stop codon and the ORF2 is 18 nucleotides. There is also a translation machinery for ORF1b, although its sequence do not give a clear picture to the overall translation strategy. The frameshift structure allows for the translation of ORF1a and ORF1b to occur in order for polyprotein to cleave into functional subunits.
Cell structure and metabolism
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Ecology
Habitat; symbiosis; contributions to the environment.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Current Research
Enter summarries of the most rescent research here--at least three required
References
Edited by student of Emily Lilly at University of Massachusetts Dartmouth.
