MosquI, a novel family of mosquito retrotransposons distantly related to the Drosophila I factors, may consist of elements of more than one origin

被引:20
作者
Tu, Z [1 ]
Hill, JJ
机构
[1] Virginia Polytech Inst & State Univ, Dept Biochem, Blacksburg, VA 24061 USA
[2] Univ Arizona, Dept Entomol, Tucson, AZ 85721 USA
[3] Univ Arizona, Ctr Insect Sci, Tucson, AZ 85721 USA
关键词
non-LTR; retrotransposon; Aedes aegypti; Drosophila; I factor; evolution;
D O I
10.1093/oxfordjournals.molbev.a026081
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A novel family of non-long-terminal-repeat (non-LTR) retrotransposons, named MosquI, was discovered in the yellow fever mosquito, Aedes aegypti. There were approximately 14 copies of MosquI in the A. aegypti genome. Four of the five analyzed MosquI elements were truncated at the 5' ends while one of them, MosquI-Aa2, was full-length. All five MosquI elements ended with 4-10 TAA tandem repeats, as the Drosophila I factors do. Interestingly, MosquI elements were often found near genes and other repetitive elements. The 6,623-bp MosquI-Aa2 contained two open reading frames (ORFs) flanked by a 404-bp 5' untranslated region and a 326-bp 3' untranslated region. The two ORFs code for nucleocapsids, endonuclease, reverse transcriptase, and RNase H domains. Although overall structural and sequence comparisons suggest that MosquI is highly similar to the Drosophila I factors, phylogenetic analysis based on the reverse transcriptase domains of 40 non-LTR retrotransposons indicate that MosquI and I factors are likely paralogous elements which may have been separated before the split between the ancestors of mollusca and arthropoda. Pairwise comparisons between the four truncated MosquI elements showed 96.7%-99.5% identity at the nucleotide level, while comparisons between the full-length MosquI-Aa2 and the truncated copies showed only 80.2%-81.8% identity. These comparisons and preliminary phylogenetic analyses suggest that the full-length and truncated MosquI elements may belong to two subfamilies originating from two source genes that diverged a long time ago. In contrast to the defective I factors in Drosophila melanogaster, which are likely very old components of the genome, the truncated MosquI elements seem to have been recently active. Finally, the genomic distribution and evolution of MosquI elements are analyzed in the context of other non-LTR retrotransposons in A. aegypti.
引用
收藏
页码:1675 / 1686
页数:12
相关论文
共 49 条
[21]  
FINNEGAN DJ, 1989, MOBILE DNA, P503
[22]   Cytoplasmic ribonucleoprotein complexes containing human LINE-1 protein and RNA [J].
Hohjoh, H ;
Singer, MF .
EMBO JOURNAL, 1996, 15 (03) :630-639
[23]  
HUGHES MA, 1996, P 20 INT C ENT FLOR, P276
[24]   Taming of transposable elements by homology-dependent gene silencing [J].
Jensen, S ;
Gassama, MP ;
Heidmann, T .
NATURE GENETICS, 1999, 21 (02) :209-212
[25]   Transposable elements as sources of variation in animals and plants [J].
Kidwell, MG ;
Lisch, D .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1997, 94 (15) :7704-7711
[26]   IDENTIFICATION OF A REPETITIVE ELEMENT IN THE SNAIL BIOMPHALARIA-GLABRATA - RELATIONSHIP TO THE REVERSE TRANSCRIPTASE-ENCODING SEQUENCE IN LINE-1 TRANSPOSONS [J].
KNIGHT, M ;
MILLER, A ;
RAGHAVAN, N ;
RICHARDS, C ;
LEWIS, F .
GENE, 1992, 118 (02) :181-187
[27]   It's prime time for reverse transcriptase [J].
Levin, HL .
CELL, 1997, 88 (01) :5-8
[28]   REVERSE TRANSCRIPTION OF R2BM RNA IS PRIMED BY A NICK AT THE CHROMOSOMAL TARGET SITE - A MECHANISM FOR NON-LTR RETROTRANSPOSITION [J].
LUAN, DD ;
KORMAN, MH ;
JAKUBCZAK, JL ;
EICKBUSH, TH .
CELL, 1993, 72 (04) :595-605
[29]   The age and evolution of non-LTR retrotransposable elements [J].
Malik, HS ;
Burke, WD ;
Eickbush, TH .
MOLECULAR BIOLOGY AND EVOLUTION, 1999, 16 (06) :793-805
[30]   THE 5' UNTRANSLATED REGION OF THE I FACTOR, A LONG INTERSPERSED NUCLEAR ELEMENT-LIKE RETROTRANSPOSON OF DROSOPHILA-MELANOGASTER, CONTAINS AN INTERNAL PROMOTER AND SEQUENCES THAT REGULATE EXPRESSION [J].
MCLEAN, C ;
BUCHETON, A ;
FINNEGAN, DJ .
MOLECULAR AND CELLULAR BIOLOGY, 1993, 13 (02) :1042-1050