Related Experiment Video

Updated: Aug 20, 2026

Production of Replication-Defective Retrovirus by Transient Transfection of 293T cells
09:40

Production of Replication-Defective Retrovirus by Transient Transfection of 293T cells

Published on: December 4, 2007

Incomplete viral synthesis in Friend leukemia virus-induced reticulum cell sarcomas

D R Black, A H Fieldsteel

    International Journal of Cancer
    |February 15, 1976
    PubMed

    Insights

    Friend leukemia virus (FV) induced sarcomas in mice do not produce infectious virus. However, FV can be retrieved when these cells are cultured with other viruses, suggesting a late-stage block in FV assembly.

    Area of Science:

    • Virology
    • Oncology
    • Molecular Biology

    Background:

    • Friend leukemia virus (FV) causes reticulum cell sarcomas in BALB/c mice.
    • Tissue-culture-passaged FVTCT-BALB cells, derived from these sarcomas, do not produce infectious FV.
    • Infectious FV can be rescued from FVTCT-BALB cells via co-cultivation with murine leukemia virus (MLV)-producing cell lines.

    Observation:

    • FVTCT-BALB cells were analyzed to understand FV rescue mechanisms.
    • 3H-uridine labeling and reverse transcriptase assays confirmed no C-type virus particle release from FVTCT-BALB cells.
    • Nucleic acid hybridization revealed viral RNA synthesis levels in FVTCT-BALB cells were comparable to MLV-infected cells.

    Findings:

    • FVTCT-BALB cells are FV non-producer cells.
    • Viral RNA is synthesized in FVTCT-BALB cells.
    • FV replication is blocked at a late stage of virus assembly in FVTCT-BALB cells.

    Implications:

    • This study elucidates a late-stage block in FV assembly within non-producer cells.
    • Understanding this block could inform strategies for controlling FV replication.
    • The findings contribute to the broader understanding of retroviral assembly and host-virus interactions.

    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

    Murine Model of Leukemia Relapse to Induction Chemotherapy for Acute Lymphoblastic Leukemia08:31

    Murine Model of Leukemia Relapse to Induction Chemotherapy for Acute Lymphoblastic Leukemia

    Published on: October 17, 2025

    Related Concept Videos

    Retrovirus Life Cycles01:10

    Retrovirus Life Cycles

    Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...
    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...
    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...
    Respiratory Syncytial Virus Disease01:29

    Respiratory Syncytial Virus Disease

    Human respiratory syncytial virus (RSV) is a widespread pathogen that primarily targets infants and young children but also poses a serious health risk to elderly and immunocompromised individuals. Belonging to the Pneumoviridae family, RSV is a negative-sense, single-stranded RNA virus within the Pneumovirus genus. Its global health burden is significant, with millions of cases annually resulting in hospitalizations and mortality, particularly in resource-limited settings. Although most...