Related Experiment Video
Updated: Aug 10, 2026

Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing
Published on: October 16, 2018
Genetic diversity: frameshift mechanisms alter coding of a gene (Epstein-Barr virus LF3 gene) that contains multiple
Shao-An Xue1, M D Jones, Qi-Long Lu
1Viral Oncology Unit, Division of Medicine, Wright-Fleming Institute, Imperial College of Science, Technology and Medicine at St. Mary's, Norfolk Place, London W2 1PG, UK.
Abstract:
Frameshift mutations provide recognized mechanisms for changing the coding potential of an organism. Here, multiple frameshifts are identified in repetitive sequences within an Epstein-Barr virus unspliced early gene, LF3, which is associated with the viral replicative cycle and also transcriptionally expressed in many virally associated tumors. On the DNA strand encoding LF3, there are three open reading frames, only one of which contains an initiation codon. Most (>95%) of the gene consists of numerous (>20, varying with cell source) GC-rich copies of a 102-bp direct repeat (called IR 4) flanked by small unique sequences. LF3 may express a protein if its initiation and termination codons reside in the same reading frame, but this is not always the case. Frameshifting events, occurring in short runs of pyrimidines (mainly C residues) in the repeats, give rise to mutations which may provide a mechanism for escape of an LF3 function from host surveillance. Sequence studies link these frameshifts to DNA replication errors. Notably, the number of sites in LF3 at which such mutations can occur permits a very large amount of diversity in this gene. Our data also suggest a second degeneracy mechanism within the protein itself, which influences its stability and may reflect a host defense mechanism. LF3 thus provides a potentially important model for studying the quest for supremacy between a virus and its host.
More Related Videos
06:59Using Next Generation Sequencing to Identify Mutations Associated with Repair of a CAS9-induced Double Strand Break Near the CD4 Promoter
Published on: March 31, 2022
05:22Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome
Published on: September 13, 2024
Related Concept Videos
Gene Conversion
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Genome Copying Errors
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Gene Conversion
Point and Frameshift Mutations