GE54CH23_Feschotte ARjats.cls September 12, 2020 7:34 Annual Review of Genetics A Field Guide to Eukaryotic Transposable Elements Jonathan N. Wells and Cédric Feschotte Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850; email:
[email protected],
[email protected] Annu. Rev. Genet. 2020. 54:23.1–23.23 Keywords The Annual Review of Genetics is online at transposons, retrotransposons, transposition mechanisms, transposable genet.annualreviews.org element origins, genome evolution https://doi.org/10.1146/annurev-genet-040620- 022145 Abstract Annu. Rev. Genet. 2020.54. Downloaded from www.annualreviews.org Access provided by Cornell University on 09/26/20. For personal use only. Copyright © 2020 by Annual Reviews. Transposable elements (TEs) are mobile DNA sequences that propagate All rights reserved within genomes. Through diverse invasion strategies, TEs have come to oc- cupy a substantial fraction of nearly all eukaryotic genomes, and they rep- resent a major source of genetic variation and novelty. Here we review the defining features of each major group of eukaryotic TEs and explore their evolutionary origins and relationships. We discuss how the unique biology of different TEs influences their propagation and distribution within and across genomes. Environmental and genetic factors acting at the level of the host species further modulate the activity, diversification, and fate of TEs, producing the dramatic variation in TE content observed across eukaryotes. We argue that cataloging TE diversity and dissecting the idiosyncratic be- havior of individual elements are crucial to expanding our comprehension of their impact on the biology of genomes and the evolution of species. 23.1 Review in Advance first posted on , September 21, 2020.