Molecular Biology and Evolution 19:619-630 (2002)
© 2002 Society for Molecular Biology and Evolution
Ancient Lineages of Non-LTR Retrotransposons in the Primitive Eukaryote, Giardia lamblia
*Department of Biology, University of Rochester;
Fred Hutchison Cancer Research Center, Seattle;
Department of Biomedical Sciences, Tufts University
Mobile elements that use reverse transcriptase to make new copies of themselves are found in all major lineages of eukaryotes. The non–long terminal repeat (non-LTR) retrotransposons have been suggested to be the oldest of these eukaryotic elements. Phylogenetic analysis of non-LTR elements suggests that they have predominantly undergone vertical transmission, as opposed to the frequent horizontal transmissions found for other mobile elements. One prediction of this vertical model of inheritance is that the oldest lineages of eukaryotes should exclusively harbor the oldest lineages of non-LTR retrotransposons. Here we characterize the non-LTR retrotransposons present in one of the most primitive eukaryotes, the diplomonad Giardia lamblia. Two families of elements were detected in the WB isolate of G. lamblia currently being used for the genome sequencing project. These elements are clearly distinct from all other previously described non-LTR lineages. Phylogenetic analysis indicates that these Genie elements (for Giardia early non-LTR insertion element) are among the oldest known lineages of non-LTR elements consistent with strict vertical descent. Genie elements encode a single open reading frame with a carboxyl terminal endonuclease domain. Genie 1 is site specific, as seven to eight copies are present in a single tandem array of a 771-bp repeat near the telomere of one chromosome. The function of this repeat is not known. One additional, highly divergent, element within the Genie 1 lineage is not located in this tandem array but is near a second telomere. Four different telomere addition sites could be identified within or near the Genie elements on each of these chromosomes. The second lineage of non-LTR elements, Genie 2, is composed of about 10 degenerate copies. Genie 2 elements do not appear to be site specific in their insertion. An unusual aspect of Genie 2 is that all copies contain inverted repeats up to 172 bp in length.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  X. Chen, T. S. Rozhdestvensky, L. J. Collins, J. Schmitz, and D. Penny Combined experimental and computational approach to identify non-protein-coding RNAs in the deep-branching eukaryote Giardia intestinalis Nucleic Acids Res., July 9, 2007; 35(14): 4619 - 4628. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. R. Heras, M. C. Lopez, J. L. Garcia-Perez, S. L. Martin, and M. C. Thomas The L1Tc C-Terminal Domain from Trypanosoma cruzi Non-Long Terminal Repeat Retrotransposon Codes for a Protein That Bears Two C2H2 Zinc Finger Motifs and Is Endowed with Nucleic Acid Chaperone Activity Mol. Cell. Biol., November 1, 2005; 25(21): 9209 - 9220. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. L. Crainey, C. F. Garvey, and C. A. Malcolm The Origin and Evolution of Mosquito APE Retroposons Mol. Biol. Evol., November 1, 2005; 22(11): 2190 - 2197. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. K. Kojima and H. Fujiwara An extraordinary retrotransposon family encoding dual endonucleases Genome Res., August 1, 2005; 15(8): 1106 - 1117. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Ullu, H. D. Lujan, and C. Tschudi Small Sense and Antisense RNAs Derived from a Telomeric Retroposon Family in Giardia intestinalis Eukaryot. Cell, June 1, 2005; 4(6): 1155 - 1157. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Upcroft, M. Abedinia, and P. Upcroft Rearranged Subtelomeric rRNA Genes in Giardia duodenalis Eukaryot. Cell, February 1, 2005; 4(2): 484 - 486. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Gorinsek, F. Gubensek, and D. Kordis Evolutionary Genomics of Chromoviruses in Eukaryotes Mol. Biol. Evol., May 1, 2004; 21(5): 781 - 798. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Fillingham, T. A. Thing, N. Vythilingum, A. Keuroghlian, D. Bruno, G. B. Golding, and R. E. Pearlman A Non-Long Terminal Repeat Retrotransposon Family Is Restricted to the Germ Line Micronucleus of the Ciliated Protozoan Tetrahymena thermophila Eukaryot. Cell, February 1, 2004; 3(1): 157 - 169. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. K. Mandal, A. Bagchi, A. Bhattacharya, and S. Bhattacharya An Entamoeba histolytica LINE/SINE Pair Inserts at Common Target Sites Cleaved by the Restriction Enzyme-Like LINE-Encoded Endonuclease Eukaryot. Cell, February 1, 2004; 3(1): 170 - 179. [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]
|
|
|
|
 |
|
 B. Wickstead, K. Ersfeld, and K. Gull Repetitive Elements in Genomes of Parasitic Protozoa Microbiol. Mol. Biol. Rev., September 1, 2003; 67(3): 360 - 375. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. D. Burke, D. Singh, and T. H. Eickbush R5 Retrotransposons Insert into a Family of Infrequently Transcribed 28S rRNA Genes of Planaria Mol. Biol. Evol., August 1, 2003; 20(8): 1260 - 1270. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Bouneau, C. Fischer, C. Ozouf-Costaz, A. Froschauer, O. Jaillon, J.-P. Coutanceau, C. Korting, J. Weissenbach, A. Bernot, and J.-N. Volff An Active Non-LTR Retrotransposon With Tandem Structure in the Compact Genome of the Pufferfish Tetraodon nigroviridis Genome Res., July 1, 2003; 13(7): 1686 - 1695. [Abstract] [Full Text] [PDF]
|
|