However, even with a reverse
transcriptase gene in the genome, the RNA may not replicate, but instead could simply help organize the centrosome or hold it together, he cautions.
Their discovery of NIRVs
in mammalian
genomes corroborates a study
in the 7 January issue of Nature
in which John Coffin of Tufts University School of Medicine
in Boston and colleagues reported that another group of RNA viruses that lack reverse
transcriptase, bornavirus, can integrate their
genes into mammals.