2023  1,500
2022  1,200
2021  1,540
2020  1,374
2019  1,023
2018  0,932
2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 58(2024) N 1 p. 43-61; DOI 10.1134/S0026893324010114 Full Text

M.V. Puzakov1*, L.V. Puzakova1

Structure and Evolution of DNA Transposons of the L31 Superfamily in Bivalves

1Kovalevsky Institute of Biology of the Southern Seas, Russian Academy of Sciences, Sevastopol, 299011 Russia

Received - 2023-04-07; Revised - 2023-06-09; Accepted - 2023-06-09

The mobile genetic elements IS630/Tc 1/mariner (ITm) are widespread DNA transposons that make a significant contribution to the evolution of eukaryotic genomes. With the start of large-scale application of next-generation sequencing (NGS) technologies and the emergence of many new whole genome sequences of organisms in nucleotide sequence collections, the ITm elements have been identified in most taxa of the eukaryotic tree of life. Although ITm diversity has been studied in detail, new elements are still found, thus expanding the respective DNA transposon group and calling for review of its classification. Bivalve L31 elements were for the first time analyzed in detail to describe their structures, diversity, distribution, and phylogenetic position among the ITm elements. The L31 transposons were found to form an independent superfamily of an ancient origin within the ITm group. Rather high diversity was observed within the L31 clade; i.e., five phylogenetic clusters were identified. In mollusks, the L31 transposons have been detected only in the subclass Autobranchia and predominate in diversity and number in the infraclass Pteriomorphia. A protein encoded by open reading frame 2 (ORF2) was shown to be an integral structural component of almost all full-length L31 elements. The results provide for a better understanding of the evolution of particular ITm transposons. Further study of the L31 transposons in other taxa (cnidarians) and functional investigation of the ORF2 protein product will help to better understand the evolution of DNa transposons, the mechanisms of their horizontal transfer, and their contribution to eukaryotic biodiversity.

DNA transposons, L31 transposons, bivalves, genome evolution, biodiversity