title: Widespread horizontal transfer of retrotransposons.
abstract: In higher organisms such as vertebrates, it is generally believed that lateral transfer of genetic information does not readily occur, with the exception of retroviral infection. However, horizontal transfer (HT) of protein coding repetitive elements is the simplest way to explain the patchy distribution of BovB, a long interspersed element (LINE) about 3.2 kb long, that has been found in ruminants, marsupials, squamates, monotremes, and African mammals. BovB sequences are a major component of some of these genomes. Here we show that HT of BovB is significantly more widespread than believed, and we demonstrate the existence of two plausible arthropod vectors, specifically reptile ticks. A phylogenetic tree built from BovB sequences from species in all of these groups does not conform to expected evolutionary relationships of the species, and our analysis indicates that at least nine HT events are required to explain the observed topology. Our results provide compelling evidence for HT of genetic material that has transformed vertebrate genomes.
authors.affiliation: School of Molecular and Biomedical Science,  University of Adelaide, Adelaide, SA 5005,  Australia.
authors.forename: Ali Morton
authors.initials: AM
authors.lastname: Walsh
authors.forename: R Daniel
authors.initials: RD
authors.lastname: Kortschak
authors.forename: Michael G
authors.initials: MG
authors.lastname: Gardner
authors.forename: Terry
authors.initials: T
authors.lastname: Bertozzi
authors.forename: David L
authors.initials: DL
authors.lastname: Adelson
mesh_terms: D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D020084:Long Interspersed Nucleotide Elements; D008969:Molecular Sequence Data; D010802:Phylogeny; D018626:Retroelements; D016415:Sequence Alignment; D014714:Vertebrates / Q000145:classification / Q000235:genetics
chemical_list: D018626:Retroelements