Molecular Biology and Evolution 18:2213-2224 (2001)
© 2001 Society for Molecular Biology and Evolution
Evolutionary Dynamics in a Novel L2 Clade of Non-LTR Retrotransposons in Deuterostomia
in
ek
an Kordi
Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Slovenia;
Department of Biochemistry and Molecular Biology, Jo
ef Stefan Institute, Ljubljana, Slovenia
The evolution of the novel L2 clade of non-long terminal repeat (LTR) retrotransposons and their evolutionary dynamics in Deuterostomia has been examined. The short-term evolution of long interspersed nuclear element 2s (LINE2s) has been studied in 18 reptilian species by analysis of a PCR amplified 0.7-kb fragment encoding the palm/fingers subdomain of reverse transcriptase (RT). Most of the reptilian LINE2s examined are inactive since they contain multiple stop codons, indels, or frameshift mutations that disrupt the RT. Analysis of reptilian LINE2s has shown a high degree of sequence divergence and an unexpectedly large number of deletions. The evolutionary dynamics of LINE2s in reptiles has been found to be complex. LINE2s are shown to form a novel clade of non-LTR retrotransposons that is well separated from the CR1 clade. This novel L2 clade is more widely distributed than previously thought, and new representatives have been discovered in echinoderms, insects, teleost fishes, Xenopus, Squamata, and marsupials. There is an apparent absence of LINE2s from different vertebrate classes, such as cartilaginous fishes, Archosauria (birds and crocodiles), and turtles. Whereas the LINE2s are present in echinoderms and teleost fishes in a conserved form, in most tetrapods only highly degenerated pseudogenes can be found. The predominance of inactive LINE2s in Tetrapoda indicates that, in the host genomes, only inactive copies are still present. The present data indicate that the vertical inactivation of LINE2s might have begun at the time of Tetrapoda origin, 400 MYA. The evolutionary dynamics of the L2 clade in Deuterostomia can be described as a gradual vertical inactivation in Tetrapoda, stochastic loss in Archosauria and turtles, and strict vertical transmission in echinoderms and teleost fishes.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
K. Ichiyanagi and N. Okada Mobility Pathways for Vertebrate L1, L2, CR1, and RTE Clade Retrotransposons Mol. Biol. Evol., June 1, 2008; 25(6): 1148 - 1157. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Shedlock, C. W. Botka, S. Zhao, J. Shetty, T. Zhang, J. S. Liu, P. J. Deschavanne, and S. V. Edwards Phylogenomics of nonavian reptiles and the structure of the ancestral amniote genome PNAS, February 20, 2007; 104(8): 2767 - 2772. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. K. Kojima and H. Fujiwara Long-Term Inheritance of the 28S rDNA-Specific Retrotransposon R2 Mol. Biol. Evol., November 1, 2005; 22(11): 2157 - 2165. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Hood, M. Katawczik, and T. Giraud Repeat-Induced Point Mutation and the Population Structure of Transposable Elements in Microbotryum violaceum Genetics, July 1, 2005; 170(3): 1081 - 1089. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Kajikawa, K. Ichiyanagi, N. Tanaka, and N. Okada Isolation and Characterization of Active LINE and SINEs from the Eel Mol. Biol. Evol., March 1, 2005; 22(3): 673 - 682. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-N. Volff, H. Lehrach, R. Reinhardt, and D. Chourrout Retroelement Dynamics and a Novel Type of Chordate Retrovirus-like Element in the Miniature Genome of the Tunicate Oikopleura dioica Mol. Biol. Evol., November 1, 2004; 21(11): 2022 - 2033. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. K. Kojima and H. Fujiwara Cross-Genome Screening of Novel Sequence-Specific Non-LTR Retrotransposons: Various Multicopy RNA Genes and Microsatellites Are Selected as Targets Mol. Biol. Evol., February 1, 2004; 21(2): 207 - 217. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Biedler and Z. Tu Non-LTR Retrotransposons in the African Malaria Mosquito, Anopheles gambiae: Unprecedented Diversity and Evidence of Recent Activity Mol. Biol. Evol., November 1, 2003; 20(11): 1811 - 1825. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. V. Kapitonov and J. Jurka The Esterase and PHD Domains in CR1-Like Non-LTR Retrotransposons Mol. Biol. Evol., January 1, 2003; 20(1): 38 - 46. [Abstract] [Full Text] [PDF] |
||||


