LINE-1 transposable elements may be able to spread by horizontal gene transfer, according to a new study.
Researchers from the University of Adelaide analyzed more than 750 plant, fungal, and animal genomes to trace the path of LINE-1 (L1) and Bovine-B (BovB) transposable elements. L1 transposable elements have been tied to cancer in humans, the Telegraph notes.
"L1 elements were thought to be inherited only from parent to offspring," first author Atma Ivancevic, a postdoc at Adelaide, says in a statement. "Most studies have only looked at a handful of species and found no evidence of transfer. We looked at as many species as we could."
As they report in Genome Biology, Ivancevic and her colleagues found that L1 elements jumped to the therian mammal lineage — the group that includes marsupial and placental mammals — about 150 million years ago. This event coincides with the split of theria and monotremes, suggesting that it could have been fueled in part by the effect of L1 retrotransposons on genomic structure, the researchers say.
L1 transposable elements didn't originate in mammals, the Telegraph notes, as they are absent in monotremes. In their paper, the researchers hypothesize that L1 transposable elements are ancient and note that BovB transposable elements are much younger.