Molecular domestication of transposable elements: From detrimental parasites to useful host genes

Abstract

Transposable elements (TEs) are commonly viewed as molecular parasites producing mainly neutral or deleterious effects in host genomes through their ability to move. However, during the past two decades, major interest has been focusing on the positive contribution of these elements in the evolution of gene regulation and in the creation of diverse structural host genes. Indeed, DNA transposons carry an attractive and elaborate enzymatic machinery as well as DNA components that have been co-opted in several cases by the host genome via an evolutionary process referred to as molecular domestication. A large number of transposon-derived genes known to date have been recruited by the host to function as transcriptional regulators; however, the biological role of the majority of them remains undetermined. Our knowledge on the structure, distribution, evolution and mechanism of transposons will continue to provide important contributions to our understanding of host genome functions.

Selfish genetic elements, genetic conflict, and evolutionary innovation

“…Classic examples include the utilization of TART and HetA TEs for telomeres in drosophilid flies and the likely origin of V[D]J recombination (used in vertebrates to generate immunoglobin diversity) from mariner-TC1 family TEs. New and exciting discoveries further indicate that domestication of TEs is important in the evolution of genomes, such as the evolution of new protein-coding genes (including regulatory DNA binding factors), cis-regulatory sequences, and regulatory small RNAs from TEs (28,37,38). Both the DNA binding and catalytic domains from the transposase genes of DNA TEs have been involved in domestication events in animals, plants, and fungi.…”

“…Both the DNA binding and catalytic domains from the transposase genes of DNA TEs have been involved in domestication events in animals, plants, and fungi. The SETMAR gene in primates is a chimera derived from fusion of a mariner-like element with the SET domain from a histone methyltransferase gene 40-58 million years ago (37,38). Its function is unknown but possibly involved in DNA repair.…”

“…Its function is unknown but possibly involved in DNA repair. Widely distributed TEs have been involved in independent domestication events in diverse taxa, such as Pogo elements in both mammals and fission yeast (37). Intriguingly, a number of regulatory DNA binding proteins appear to have evolved from the DNA binding domains of TEs, such as PAX6 (sensory development in metazoans), CENP-B (centromere function in vertebrates), and Bric-aBrac (tissue development in insects).…”

Construction and Characterization of a Repetitive DNA Library in Parodontidae (Actinopterygii: Characiformes): A Genomic and Evolutionary Approach to the Degeneration of the W Sex Chromosome

“…4C). A. hasemani contains terminal sites on pairs 2, Z, 5,8,12,13,18,20,24,26,27 and at the terminal region on the short arm of the W chromosome (Fig. 4D).…”

Domesticated transposable element gene products in human cancer

“…Over 10,000 TE-derived genomic regions have been subject to strong purifying selection 6 and ~50 protein-coding genes have arisen via this mechanism. 1,7 The majority of domesticated genes are functionally uncharacterized; those that have been studied have been found to be involved in a variety of cellular processes, including transcriptional regulation, proliferation, cell cycle progression, and apoptosis.…”