Format

Send to

Choose Destination
J Vis Exp. 2016 Mar 22;(109). doi: 10.3791/53840.

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites.

Author information

1
Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute.
2
Chromatin Structure and Mobile DNA, The Francis Crick Institute.
3
Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute; alan_engelman@dfci.harvard.edu.

Abstract

Retroviruses exhibit signature integration preferences on both the local and global scales. Here, we present a detailed protocol for (1) generation of diverse libraries of retroviral integration sites using ligation-mediated PCR (LM-PCR) amplification and next-generation sequencing (NGS), (2) mapping the genomic location of each virus-host junction using BEDTools, and (3) analyzing the data for statistical relevance. Genomic DNA extracted from infected cells is fragmented by digestion with restriction enzymes or by sonication. After suitable DNA end-repair, double-stranded linkers are ligated onto the DNA ends, and semi-nested PCR is conducted using primers complementary to both the long terminal repeat (LTR) end of the virus and the ligated linker DNA. The PCR primers carry sequences required for DNA clustering during NGS, negating the requirement for separate adapter ligation. Quality control (QC) is conducted to assess DNA fragment size distribution and adapter DNA incorporation prior to NGS. Sequence output files are filtered for LTR-containing reads, and the sequences defining the LTR and the linker are cropped away. Trimmed host cell sequences are mapped to a reference genome using BLAT and are filtered for minimally 97% identity to a unique point in the reference genome. Unique integration sites are scrutinized for adjacent nucleotide (nt) sequence and distribution relative to various genomic features. Using this protocol, integration site libraries of high complexity can be constructed from genomic DNA in three days. The entire protocol that encompasses exogenous viral infection of susceptible tissue culture cells to integration site analysis can therefore be conducted in approximately one to two weeks. Recent applications of this technology pertain to longitudinal analysis of integration sites from HIV-infected patients.

PMID:
27023428
PMCID:
PMC4829050
DOI:
10.3791/53840
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for MyJove Corporation Icon for PubMed Central
Loading ...
Support Center