Related Experiment Videos
Progressive multifocal leucoencephalopathy: analysis of JC virus DNA from brain and kidney tissue
Abstract:
JC virus-specific DNA from both brain and kidney of the PML case G.S. was analysed by restriction mapping and Southern blot analysis. The genome of JCV DNA from brain (JCV GS-B) was full length, whereas JCV DNA GS from kidney (JCV GS-K) was 120 bp smaller. Restriction maps, constructed from JCV GS-B using various enzymes showed that most cleavage sites were consistent with standard map sites. Comparison of virus DNA from brain and kidney revealed that JCV GS-specific cleavage sites were identical, and that the DNAs were therefore of the same subtype. The deletion in kidney DNA was situated in the area of the origin of replication which is known to be hypervariable in the JCV genome. Restriction maps revealed that the DNA from each organ was homogeneous in length but a proportion of the DNA molecules were heterogeneous in restriction sites. It is concluded from these data that initial infection with one JCV subtype was followed by the development of heterogeneous DNA molecules.
Insights
JC virus (JCV) DNA analysis revealed identical subtypes in brain and kidney but with a deletion in kidney DNA. This suggests initial infection by one JCV subtype evolved into heterogeneous DNA molecules.
Area of Science:
- Virology
- Molecular Biology
- Genetics
Background:
- Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system.
- JC virus (JCV) is the causative agent of PML.
- Understanding JCV genome variations is crucial for comprehending disease pathogenesis.
Purpose of the Study:
- To analyze and compare JC virus-specific DNA from the brain and kidney of a PML patient.
- To investigate potential genomic variations and their implications for JCV infection.
Main Methods:
- Restriction mapping of JCV DNA.
- Southern blot analysis of JCV DNA from brain and kidney samples.
- Comparative analysis of restriction sites and genome length.
Main Results:
- JCV DNA from the brain (JCV GS-B) was full-length, while JCV DNA from the kidney (JCV GS-K) had a 120 bp deletion.
- Identical JCV GS-specific cleavage sites were observed between brain and kidney DNA, indicating the same subtype.
- The deletion in kidney DNA was located in the origin of replication region, a known hypervariable area.
- While DNA length was homogeneous within each organ, restriction sites showed heterogeneity, suggesting molecular evolution.
Conclusions:
- Initial infection with a single JCV subtype likely occurred.
- Subsequent evolution led to the development of heterogeneous DNA molecules within the same subtype.
- Genomic variations, particularly deletions in the origin of replication, may play a role in JCV pathogenesis and tissue tropism.