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Distribution of Mason-Pfizer virus-specific sequences in the DNA of primates
Abstract:
Iodinated Mason-Pfizer virus (MPV) 60-70S RNA has been used in molecular hybridization experiments to determine the distribution of MPV-specific proviral sequences in the DNAs of primates. Approximately 20% of the MPV genome is present as endogenous provirus in rhesus monkeys. Competitive hybridization experiments showed no homology between MPV 60-70S RNA and the 60-70S RNAs of M7, RD-114, and the simian sarcoma virus. No MPV-specific proviral sequences were detected in the DNAs of apparently normal tissues of various species of New World monkeys, apes, and humans. The part of the MPV genome that is endogenous to rhesus is also endogenous to the other species of Old World monkeys examined: baboon, African green, and patas. This was determined as a result of the following observations: (i) C(0)t(1/2) values and final extent of hybridization were the same for all four species. (ii) T(m) values of MPV 60-70S RNA and DNA of all four species were identical. (iii) The removal of MPV sequences endogenous to rhesus tissues by recycling against rhesus DNA resulted in the loss of any hybridizable MPV RNA to the DNAs of baboon, African green, and patas tissues. (iv) Mixing experiments of rhesus, African green, and baboon DNAs resulted in the same kinetics of hybridization as did rhesus DNA alone, when hybridized with MPV 60-70S RNA. These findings demonstrate that sequences that constitute an integral part of the MPV genome are conserved in the DNAs of several different species of Old World monkeys.
Insights
Mason-Pfizer virus (MPV) proviral sequences are conserved in Old World monkeys. These endogenous viral sequences are integrated into the DNA of rhesus, baboon, African green, and patas monkeys, indicating shared evolutionary history.
Area of Science:
- Virology
- Genetics
- Primate Biology
Background:
- Mason-Pfizer virus (MPV) is a retrovirus.
- Endogenous viral sequences can be integrated into host genomes.
- Understanding viral sequence distribution in primates is crucial for evolutionary studies.
Purpose of the Study:
- To investigate the presence and distribution of MPV-specific proviral sequences in primate DNAs.
- To determine if MPV sequences are conserved across different primate species, particularly Old World monkeys.
Main Methods:
- Molecular hybridization experiments using iodinated MPV 60-70S RNA.
- Competitive hybridization assays to assess sequence homology.
- Analysis of C(0)t(1/2) and T(m) values.
- DNA recycling and mixing experiments.
Main Results:
- Approximately 20% of the MPV genome exists as endogenous provirus in rhesus monkeys.
- No homology was found between MPV RNA and RNAs from M7, RD-114, or simian sarcoma virus.
- MPV-specific proviral sequences were absent in New World monkeys, apes, and humans.
- Conserved MPV sequences were detected in baboon, African green, and patas monkeys, homologous to those in rhesus monkeys.
Conclusions:
- Integral parts of the MPV genome are conserved in the DNAs of several Old World monkey species.
- These findings suggest a shared evolutionary origin and integration of MPV sequences in these primates.
- The study highlights the importance of endogenous viral elements in primate genomics.