Teratorn and its relatives - a cross-point of distinct mobile elements, transposons and viruses

• Published in: Frontiers in veterinary science Vol. 10; p. 1158023
• Main Authors: Inoue, Yusuke, Takeda, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 28.04.2023
• Subjects: herpesvirus; mobile genetic element; piggyBac; teleost; transposable element; Veterinary Science; virus; recombination; herpesvirus; transposable element; mobile genetic element; teleost; piggyBac; virus
• ISSN: 2297-1769; 2297-1769
• DOI: 10.3389/fvets.2023.1158023

Mobile genetic elements (e.g., transposable elements and plasmids) and viruses display significant diversity with various life cycles, but how this diversity emerges remains obscure. We previously reported a novel and giant (180 kb long) mobile element, , originally identified in the genome of medaka, . is a composite DNA transposon created by a fusion of a -like DNA transposon ( ) and a novel herpesvirus of the family. Genomic survey revealed that -like herpesviruses are widely distributed among teleost genomes, the majority of which are also fused with suggesting that fusion with is a trigger for the life-cycle shift of authentic herpesviruses to an intragenomic parasite. Thus, -like herpesvirus provides a clear example of how novel mobile elements emerge, that is to say, the creation of diversity. In this review, we discuss the unique sequence and life-cycle characteristics of , followed by the evolutionary process of -herpesvirus fusion based on the distribution of -like herpesviruses (relatives) among teleosts. Finally, we provide other examples of evolutionary associations between different classes of elements and propose that recombination could be a driving force generating novel mobile elements.