title: Expression of transposable elements in neural tissues during Xenopus development.
abstract: Transposable elements comprise a large proportion of animal genomes. Transposons can have detrimental effects on genome stability but also offer positive roles for genome evolution and gene expression regulation. Proper balance of the positive and deleterious effects of transposons is crucial for cell homeostasis and requires a mechanism that tightly regulates their expression. Herein we describe the expression of DNA transposons of the Tc1/mariner superfamily during Xenopus development. Sense and antisense transcripts containing complete Tc1-2_Xt were detected in Xenopus embryos. Both transcripts were found in zygotic stages and were mainly localized in Spemann's organizer and neural tissues. In addition, the Tc1-like elements Eagle, Froggy, Jumpy, Maya, Xeminos and TXr were also expressed in zygotic stages but not oocytes in X. tropicalis. Interestingly, although Tc1-2_Xt transcripts were not detected in Xenopus laevis embryos, transcripts from other two Tc1-like elements (TXr and TXz) presented a similar temporal and spatial pattern during X. laevis development. Deep sequencing analysis of Xenopus tropicalis gastrulae showed that PIWI-interacting RNAs (piRNAs) are specifically derived from several Tc1-like elements. The localized expression of Tc1-like elements in neural tissues suggests that they could play a role during the development of the Xenopus nervous system.
authors.affiliation: Center for Aging and Regeneration and Millennium Nucleus in Regenerative Biology, Pontificia Universidad Católica de Chile, Alameda, Santiago, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Faunes
authors.forename: Natalia
authors.initials: N
authors.lastname: Sanchez
authors.forename: Mauricio
authors.initials: M
authors.lastname: Moreno
authors.forename: Gonzalo H
authors.initials: GH
authors.lastname: Olivares
authors.forename: Dasfne
authors.initials: D
authors.lastname: Lee-Liu
authors.forename: Leonardo
authors.initials: L
authors.lastname: Almonacid
authors.forename: Alex W
authors.initials: AW
authors.lastname: Slater
authors.forename: Tomas
authors.initials: T
authors.lastname: Norambuena
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Taft
authors.forename: John S
authors.initials: JS
authors.lastname: Mattick
authors.forename: Francisco
authors.initials: F
authors.lastname: Melo
authors.forename: Juan
authors.initials: J
authors.lastname: Larrain
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D016678:Genome / Q000235:genetics; D009420:Nervous System / Q000196:embryology* / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D014981:Xenopus / Q000196:embryology* / Q000235:genetics*; D015053:Zygote / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D034741:RNA, Small Interfering