Related Experiment Video

Updated: Aug 17, 2026

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
09:31

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

Published on: March 22, 2016

Infectious viral DNA of murine leukemia virus

D Smotkin, A M Gianni, S Rozenblatt

    Proceedings of the National Academy of Sciences of the United States of America
    |December 1, 1975
    PubMed

    Insights

    Infectious Moloney leukemia virus DNA was identified in mouse cells early after infection. This viral DNA, both supercoiled and nonsupercoiled, carries essential genetic information for viral replication.

    Area of Science:

    • Virology
    • Molecular Biology
    • Genetics

    Background:

    • Moloney leukemia virus (MLV) infection involves viral DNA integration into host cells.
    • Early stages of MLV infection produce unintegrated viral DNA fractions.

    Purpose of the Study:

    • To determine the infectivity of unintegrated viral DNA from MLV-infected mouse cells.
    • To characterize the molecular properties of infectious unintegrated viral DNA.

    Main Methods:

    • XC plaque assay to detect viral infectivity.
    • Calcium phosphate co-precipitation for DNA exposure.
    • Analysis of DNA concentration-dependent plaque formation.

    Main Results:

    • A fraction of early unintegrated viral DNA is infectious.
    • Infectivity is demonstrated via XC plaque assay.
    • Supercoiled viral DNA (approx. 5.5 x 10^6 daltons) is infectious and its plaque formation is dose-dependent.
    • Nonsupercoiled viral DNA (approx. 5-6 x 10^6 daltons) is also infectious and appears double-stranded.

    Conclusions:

    • Single molecules of supercoiled viral DNA contain all necessary information for MLV replication.
    • Both supercoiled and nonsupercoiled forms of unintegrated viral DNA are infectious and contribute to the viral life cycle.

    More Related Videos

    Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions10:10

    Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions

    Published on: May 28, 2017

    A Murine Model of Dengue Virus-induced Acute Viral Encephalitis-like Disease04:23

    A Murine Model of Dengue Virus-induced Acute Viral Encephalitis-like Disease

    Published on: April 28, 2019

    Related Concept Videos

    Mechanisms of Retrovirus-induced Cancers01:51

    Mechanisms of Retrovirus-induced Cancers

    Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
    Rous Sarcoma Virus (RSV) and Cancer01:03

    Rous Sarcoma Virus (RSV) and Cancer

    Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans.
    RSV is a retrovirus that contains two copies of a plus-strand  RNA genome. Its genome consists of four main open...
    Rabies01:28

    Rabies

    Rabies is a lethal zoonotic disease caused by a single-stranded, negative-sense RNA virus of the Lyssavirus genus, within the family Rhabdoviridae. Its primary mode of transmission to humans is through bites or saliva-contaminated scratches from infected mammals such as dogs, bats, raccoons, or foxes. Transmission can also occur if infectious saliva contacts abraded skin or intact mucous membranes, including the conjunctiva.Viral Entry and Early ReplicationOnce introduced at the bite or scratch...
    Cytomegalovirus Disease01:27

    Cytomegalovirus Disease

    Cytomegalovirus (CMV) disease is caused by human cytomegalovirus, a double-stranded DNA virus of the Herpesviridae family. While primary CMV infection is often asymptomatic in immunocompetent individuals, the virus can cause severe disease in neonates and immunocompromised patients. CMV is the most common cause of congenital viral infection in the United States, and a major pathogen in solid organ and hematopoietic stem cell transplant recipients.CMV is transmitted via bodily fluids, sexual...