Related Experiment Videos
A leader sequence is present on mRNA A of avian infectious bronchitis virus
Abstract:
The subgenomic mRNAs of the fowl coronavirus infectious bronchitis virus (IBV) form a 3' co-terminal or 'nested' set. The RNase T1 oligonucleotide mapping data which demonstrated this form of sequence organization provided no evidence for the presence of non-contiguous (leader) sequences fused to the 5' termini of the mRNAs. However, we have been able to demonstrate, by extension of an end-labelled synthetic oligonucleotide primer, the presence of a leader sequence on IBV mRNA A. Sequencing by the chemical degradation method of the extended product has yielded the almost complete sequence of the 60 base leader and its point of fusion to the sequence of the virus genomic RNA.
Insights
Infectious bronchitis virus (IBV) subgenomic mRNAs possess a leader sequence. This finding clarifies the organization of IBV gene expression, crucial for understanding coronavirus replication.
Area of Science:
- Virology
- Molecular Biology
- Genomics
Background:
- Fowl coronavirus infectious bronchitis virus (IBV) subgenomic mRNAs are organized in a 3' co-terminal nested set.
- Previous RNase T1 mapping suggested no leader sequences at the 5' termini of these mRNAs.
Purpose of the Study:
- To investigate the presence of leader sequences on IBV mRNA A.
- To determine the sequence and fusion point of any identified leader sequence.
Main Methods:
- Extension of an end-labelled synthetic oligonucleotide primer.
- Sequencing of the extended product using the chemical degradation method.
Main Results:
- Demonstrated the presence of a leader sequence on IBV mRNA A.
- Determined the nearly complete 60-nucleotide sequence of the leader.
- Identified the fusion point of the leader sequence to the viral genomic RNA sequence.
Conclusions:
- IBV mRNA A possesses a leader sequence, contrary to previous suggestions.
- The leader sequence is fused to the viral genomic RNA, providing insights into IBV gene expression and replication mechanisms.