title: L1 retrotransposons and somatic mosaicism in the brain.
abstract: Long interspersed element 1 (LINE-1 or L1) retrotransposons have generated one-third of the human genome, and their ongoing mobility is a source of inter- and intraindividual genetic diversity. Although retrotransposition in metazoans has long been considered a germline phenomenon, recent experiments using cultured cells, animal models, and human tissues have revealed extensive L1 mobilization in rodent and human neurons, as well as mobile element activity in the Drosophila brain. In this review, we evaluate the available evidence for L1 retrotransposition in the brain and discuss mechanisms that may regulate neuronal retrotransposition in vivo. We compare experimental strategies used to map de novo somatic retrotransposition events and present the optimal criteria to identify a somatic L1 insertion. Finally, we discuss the unresolved impact of L1-mediated somatic mosaicism upon normal neurobiology, as well as its potential to drive neurological disease.
authors.affiliation: Mater Research Institute, The University of Queensland, Translational Research Institute, Woolloongabba QLD 4102, Australia; email: faulknergj@gmail.com.
authors.forename: Sandra R
authors.initials: SR
authors.lastname: Richardson
authors.forename: Santiago
authors.initials: S
authors.lastname: Morell
authors.forename: Geoffrey J
authors.initials: GJ
authors.lastname: Faulkner
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology; D004330:Drosophila; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D009030:Mosaicism; D009474:Neurons / Q000502:physiology*; D018626:Retroelements / Q000235:genetics*; D012377:Rodentia
chemical_list: D018626:Retroelements
keywords: LINE-1; neurogenesis; neuron; retrotransposition; transposon