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Yang G, Fattash I, Lee CN, Liu K, Cavinder B. Birth of three stowaway-like MITE families via microhomology-mediated miniaturization of a Tc1/Mariner element in the yellow fever mosquito. Genome Biol Evol 2014; 5:1937-48. [PMID: 24068652 PMCID: PMC3814204 DOI: 10.1093/gbe/evt146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Eukaryotic genomes contain numerous DNA transposons that move by a cut-and-paste mechanism. The majority of these elements are self-insufficient and dependent on their autonomous relatives to transpose. Miniature inverted repeat transposable elements (MITEs) are often the most numerous nonautonomous DNA elements in a higher eukaryotic genome. Little is known about the origin of these MITE families as few of them are accompanied by their direct ancestral elements in a genome. Analyses of MITEs in the yellow fever mosquito identified its youngest MITE family, designated as Gnome, that contains at least 116 identical copies. Genome-wide search for direct ancestral autonomous elements of Gnome revealed an elusive single copy Tc1/Mariner-like element, named as Ozma, that encodes a transposase with a DD37E triad motif. Strikingly, Ozma also gave rise to two additional MITE families, designated as Elf and Goblin. These three MITE families were derived at different times during evolution and bear internal sequences originated from different regions of Ozma. Upon close inspection of the sequence junctions, the internal deletions during the formation of these three MITE families always occurred between two microhomologous sites (6–8 bp). These results suggest that multiple MITE families may originate from a single ancestral autonomous element, and formation of MITEs can be mediated by sequence microhomology. Ozma and its related MITEs are exceptional candidates for the long sought-after endogenous active transposon tool in genetic control of mosquitoes.
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Affiliation(s)
- Guojun Yang
- Department of Biology, University of Toronto Mississauga, Ontario, Canada
- *Corresponding author: E-mail:
| | - Isam Fattash
- Department of Biology, University of Toronto Mississauga, Ontario, Canada
| | - Chia-Ni Lee
- Department of Biology, University of Toronto Mississauga, Ontario, Canada
| | - Kun Liu
- Department of Botany and Plant Sciences, University of California Riverside
| | - Brad Cavinder
- Department of Plant Pathology and Microbiology, University of California Riverside
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Fernández-Medina RD, Ribeiro JMC, Carareto CMA, Velasque L, Struchiner CJ. Losing identity: structural diversity of transposable elements belonging to different classes in the genome of Anopheles gambiae. BMC Genomics 2012; 13:272. [PMID: 22726298 PMCID: PMC3442997 DOI: 10.1186/1471-2164-13-272] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 06/08/2012] [Indexed: 01/10/2023] Open
Abstract
Background Transposable elements (TEs), both DNA transposons and retrotransposons, are genetic elements with the main characteristic of being able to mobilize and amplify their own representation within genomes, utilizing different mechanisms of transposition. An almost universal feature of TEs in eukaryotic genomes is their inability to transpose by themselves, mainly as the result of sequence degeneration (by either mutations or deletions). Most of the elements are thus either inactive or non-autonomous. Considering that the bulk of some eukaryotic genomes derive from TEs, they have been conceived as “TE graveyards.” It has been shown that once an element has been inactivated, it progressively accumulates mutations and deletions at neutral rates until completely losing its identity or being lost from the host genome; however, it has also been shown that these “neutral sequences” might serve as raw material for domestication by host genomes. Results We have analyzed the sequence structural variations, nucleotide divergence, and pattern of insertions and deletions of several superfamilies of TEs belonging to both class I (long terminal repeats [LTRs] and non-LTRs [NLTRs]) and II in the genome of Anopheles gambiae, aiming at describing the landscape of deterioration of these elements in this particular genome. Our results describe a great diversity in patterns of deterioration, indicating lineage-specific differences including the presence of Solo-LTRs in the LTR lineage, 5′-deleted NLTRs, and several non-autonomous and MITEs in the class II families. Interestingly, we found fragments of NLTRs corresponding to the RT domain, which preserves high identity among them, suggesting a possible remaining genomic role for these domains. Conclusions We show here that the TEs in the An. gambiae genome deteriorate in different ways according to the class to which they belong. This diversity certainly has implications not only at the host genomic level but also at the amplification dynamic and evolution of the TE families themselves.
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Affiliation(s)
- Rita D Fernández-Medina
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
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Han MJ, Shen YH, Gao YH, Chen LY, Xiang ZH, Zhang Z. Burst expansion, distribution and diversification of MITEs in the silkworm genome. BMC Genomics 2010; 11:520. [PMID: 20875122 PMCID: PMC2997013 DOI: 10.1186/1471-2164-11-520] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 09/27/2010] [Indexed: 01/31/2023] Open
Abstract
Background Miniature inverted-repeat transposable elements (MITEs) are widespread in plants and animals. Although silkworm (Bombyx mori) has a large amount of and a variety of transposable elements, the genome-wide information of the silkworm MITEs is unknown. Results We used structure-based and homology approaches to search for MITEs in the silkworm genome. We identified 17 MITE families with a total of 5785 members, accounting for ~0.4% of the genome. 7 of 17 MITE families are completely novel based on the nucleotide composition of target site duplication (TSD) and/or terminal inverted repeats (TIR). Silkworm MITEs were widely and nonrandom distributed in the genome. One family named BmMITE-2 might experience a recent burst expansion. Network and diversity analyses for each family revealed different diversification patterns of the silkworm MITEs, reflecting the signatures of genome-shocks that silkworm experienced. Most silkworm MITEs preferentially inserted into or near genes and BmMITE-11 that encodes a germline-restricted small RNA might silence its the closest genes in silkworm ovary through a small RNA pathway. Conclusions Silkworm harbors 17 MITE families. The silkworm MITEs preferred to reside in or near genes and one MITE might be involved in gene silence. Our results emphasize the exceptional role of MITEs in transcriptional regulation of genes and have general implications to understand interaction between MITEs and their host genome.
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Affiliation(s)
- Min-Jin Han
- The Key Sericultural Laboratory of Agricultural Ministry, Southwest University, Chongqing 400715, China.
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4
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Characterization of new hAT transposable elements in 12 Drosophila genomes. Genetica 2008; 135:67-75. [DOI: 10.1007/s10709-008-9259-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Accepted: 02/28/2008] [Indexed: 12/19/2022]
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Eiglmeier K, Wincker P, Cattolico L, Anthouard V, Holm I, Eckenberg R, Quesneville H, Jaillon O, Collins FH, Weissenbach J, Brey PT, Roth CW. Comparative analysis of BAC and whole genome shotgun sequences from an Anopheles gambiae region related to Plasmodium encapsulation. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 35:799-814. [PMID: 15944077 DOI: 10.1016/j.ibmb.2005.02.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 02/10/2005] [Accepted: 02/15/2005] [Indexed: 05/02/2023]
Abstract
The only natural mechanism of malaria transmission in sub-Saharan Africa is the mosquito, generally Anopheles gambiae. Blocking malaria parasite transmission by stopping the development of Plasmodium in the insect vector would provide a useful alternative to the current methods of malaria control. Toward this end, it is important to understand the molecular basis of the malaria parasite refractory phenotype in An. gambiae mosquito strains. We have selected and sequenced six bacterial artificial chromosome (BAC) clones from the Pen-1 region that is the major quantitative trait locus involved in Plasmodium encapsulation. The sequence and the annotation of five overlapping BAC clones plus one adjacent, but not contiguous clone, totaling 585kb of genomic sequence from the centromeric end of the Pen-1 region of the PEST strain were compared to that of the genome sequence of the same strain produced by the whole genome shotgun technique. This project identified 23 putative mosquito genes plus putative copies of the retrotransposable elements BEL12 and TRANSIBN1_AG in the six BAC clones. Nineteen of the predicted genes are most similar to their Drosophila melanogaster homologs while one is more closely related to vertebrate genes. Comparison of these new BAC sequences plus previously published BAC sequences to the cognate region of the assembled genome sequence identified three retrotransposons present in one sequence version but not the other. One of these elements, Indy, has not been previously described. These observations provide evidence for the recent active transposition of these elements and demonstrate the plasticity of the Anopheles genome. The BAC sequences strongly support the public whole genome shotgun assembly and automatic annotation while also demonstrating the benefit of complementary genome sequences and of human curation. Importantly, the data demonstrate the differences in the genome sequence of an individual mosquito compared to that of a hypothetical, average genome sequence generated by whole genome shotgun assembly.
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Affiliation(s)
- Karin Eiglmeier
- Biochimie et Biologie Moléculaire des Insectes, CNRS-FRE 2849, Institut Pasteur, 25, rue du Dr. Roux, F-75724 Paris Cedex 15, France
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6
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Boulesteix M, Biémont C. Transposable elements in mosquitoes. Cytogenet Genome Res 2005; 110:500-9. [PMID: 16093703 DOI: 10.1159/000084983] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Accepted: 01/27/2004] [Indexed: 11/19/2022] Open
Abstract
We describe the current state of knowledge about transposable elements (TEs) in different mosquito species. DNA-based elements (class II elements), non-LTR retrotransposons (class I elements), and MITEs (Miniature Inverted Repeat Transposable Elements) are found in the three genera, Anopheles, Aedes and Culex, whereas LTR retrotransposons (class I elements) are found only in Anopheles and Aedes. Mosquitoes were the first insects in which MITEs were reported; they have several LTR retrotransposons belonging to the Pao family, which is distinct from the Gypsy-Ty3 and Copia-Ty1 families. The number of TE copies shows huge variations between classes of TEs within a given species (from 1 to 1000), in sharp contrast to Drosophila, which shows only relatively minor differences in copy number between elements (from 1 to 100). The genomes of these insects therefore display major differences in the amount of TEs and therefore in their structure and global composition. We emphasize the need for more population genetic data about the activity of TEs, their distribution over chromosomes and their frequencies in natural populations of mosquitoes, to further the current attempts to develop a transgenic mosquito unable to transmit malaria that is intended to replace the natural populations.
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Affiliation(s)
- M Boulesteix
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Lyon 1, Villeurbanne, France
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Saito M, Yonemaru J, Ishikawa G, Nakamura T. A candidate autonomous version of the wheat MITE Hikkoshi is present in the rice genome. Mol Genet Genomics 2005; 273:404-14. [PMID: 15883824 DOI: 10.1007/s00438-005-1144-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2004] [Accepted: 03/09/2005] [Indexed: 11/30/2022]
Abstract
A miniature inverted-repeat transposable element (MITE), designated as Hikkoshi, was previously identified in the null Wx-A1 allele of Turkish bread wheat lines. This MITE is 165 bp in size and has 12-bp terminal inverted repeats (TIRs) flanked by 8-bp target site duplications (TSDs). Southern and PCR analyses demonstrated the presence of multiple copies of Hikkoshi in the wheat genome. Database searches indicated that Hikkoshi MITEs are also present in barley, rice and maize. A 3.4-kb element that has Hikkoshi-like TIRs flanked by 8-bp TSDs has now been identified in the rice genome. This element shows high similarity to the 5' subterminal region of the wheat Hikkoshi MITE and contains a transposase (TPase) coding region. The TPase has two conserved domains, ZnF_TTF and hATC, and its amino acid sequence shows a high degree of homology to TPases encoded by Tip100 transposable elements belonging to the hAT superfamily. We designated the 3.4-kb element as OsHikkoshi. Several wheat clones deposited in EST databases showed sequence similarity to the TPase ORF of OsHikkoshi. The sequence information from the TPase of OsHikkoshi will thus be useful in isolating the autonomous element of the Hikkoshi system from wheat.
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Affiliation(s)
- M Saito
- Department of Crop Breeding, Tohoku National Agriculture Research Center, 4 Akahira, Shimo-Kuriyagawa, Morioka, Iwate, 020-0198, Japan
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Tu Z, Coates C. Mosquito transposable elements. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2004; 34:631-644. [PMID: 15242704 DOI: 10.1016/j.ibmb.2004.03.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Accepted: 03/18/2004] [Indexed: 05/24/2023]
Abstract
The completion of the genome assembly for the African malaria mosquito, Anopheles gambiae, and continuing genomic efforts for the yellow fever mosquito, Aedes aegypti, have allowed the use of bioinformatics tools to identify and characterize a diverse array of transposable elements (TEs) in these and other mosquito genomes. An overview of the types and number of both RNA-mediated and DNA-mediated TEs that are found in mosquito genomes is presented. A number of novel and interesting TEs from these species are discussed in more detail. These findings have significant implications for our understanding of mosquito genome evolution and for future modifications of natural mosquito populations through the use of TE-mediated genetic transformation.
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Affiliation(s)
- Zhijian Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA.
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Biedler J, Qi Y, Holligan D, della Torre A, Wessler S, Tu Z. Transposable element (TE) display and rapid detection of TE insertion polymorphism in the Anopheles gambiae species complex. INSECT MOLECULAR BIOLOGY 2003; 12:211-216. [PMID: 12752653 DOI: 10.1046/j.1365-2583.2003.00403.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Transposable element (TE) display was shown to be a highly specific and reproducible method of detecting the insertion sites of TEs in individuals of the African malaria mosquito, Anopheles gambiae, and its sibling species, A. arabiensis. Relatively high levels of insertion polymorphism were observed during the TE display of several families of miniature inverted-repeat TEs (MITEs) that have variable copy numbers. The genomic locations of selected insertion sites were identified by matching the sequences of their corresponding bands in a TE display gel to specific regions of the draft A. gambiae genome assembly. We discuss different scenarios in which TE display will provide powerful dominant and co-dominant genetic markers to study the behaviour of TEs in A. gambiae populations and to illustrate the complex population genetics of this intriguing disease vector. We suggest that TE display can also provide tools for a phylogenetic analysis of the A. gambiae complex.
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Affiliation(s)
- J Biedler
- Department of Biochemistry, Virginia Polytechnic Institute and State University, USA
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10
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de Almeida RW, Tovar FJ, Ferreira II, Leoncini O. Chymotrypsin genes in the malaria mosquitoes Anopheles aquasalis and Anopheles darlingi. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2003; 33:307-315. [PMID: 12609516 DOI: 10.1016/s0965-1748(02)00245-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Four closely related chymotrypsin genes were identified in Anopheles aquasalis and Anopheles darlingi (Anachy1, Anachy2, Andchy1 and Andchy2). The deduced amino-acid sequences were compared to other chymotrypsin sequences. These sequences were used to infer phylogenetic relationships among the different species. Genomic cloning revealed that, in contrast to An. aquasalis and A. gambiae, the chymotrypsin genomic locus in An. darlingi had a short intergenic region that accompanied the inverted position of the genes, suggesting inversion mechanisms in this species related to transposable elements. Alignments of the sequences upstream of the transcription start sites of Anachy1, Anachy2, Andchy1 and Andchy2 revealed areas with high similarity containing palindromic sequences. Northern analysis from An. aquasalis indicated that the transcription of chy 1 and 2 are induced by blood feeding.
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Affiliation(s)
- R W de Almeida
- Instituto de Biologia, Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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11
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Abstract
Members of the Tourist family of miniature inverted-repeat transposable elements (MITEs) are very abundant among a wide variety of plants, are frequently found associated with normal plant genes, and thus are thought to be important players in the organization and evolution of plant genomes. In Arabidopsis, the recent discovery of a Tourist member harboring a putative transposase has shed new light on the mobility and evolution of MITEs. Here, we analyze a family of Tourist transposons endogenous to the genome of the nematode Caenorhabditis elegans (Bristol N2). One member of this large family is 7568 bp in length, harbors an ORF similar to the putative Tourist transposase from Arabidopsis, and is related to the IS5 family of bacterial insertion sequences (IS). Using database searches, we found expressed sequence tags (ESTs) similar to the putative Tourist transposases in plants, insects, and vertebrates. Taken together, our data suggest that Tourist-like and IS5-like transposons form a superfamily of potentially active elements ubiquitous to prokaryotic and eukaryotic genomes.
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Affiliation(s)
- Q H Le
- Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada
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Kubo Y, Okazaki S, Anzai T, Fujiwara H. Structural and phylogenetic analysis of TRAS, telomeric repeat-specific non-LTR retrotransposon families in Lepidopteran insects. Mol Biol Evol 2001; 18:848-57. [PMID: 11319268 DOI: 10.1093/oxfordjournals.molbev.a003866] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
TRAS1 is a non-LTR retrotransposon inserted specifically into the telomeric repeat (TTAGG)(n) in the silkworm, Bombyx mori. To characterize the evolutionary origin of TRAS-like elements, we identified seven TRAS families (TRAS3, TRAS4, TRAS5, TRAS6, TRASY, TRASZ, and TRASW) from B. mori and four elements from two Lepidoptera, Dictyoploca japonica (TRASDJ) and Samia cynthia ricini (TRASSC3, TRASSC4, and TRASSC9). More than 2,000 copies of various Bombyx TRAS elements accumulated within (TTAGG)(n) sequences as unusual but orderly tandem repeats. The 5' and 3' regions were highly conserved within each class of Bombyx TRAS elements without truncation. This suggests that distinct classes of TRAS have been maintained independently by retrotransposition into (TTAGG)(n). The phylogenetic tree of site-specific retroelements showed that nine TRAS families in Lepidoptera constitute a single phylogenetic group that is closely related to the R1 family that inserts specifically into arthropod 28S rDNA. The higher amino acid sequence identity from endonuclease (EN) to reverse transcriptase (RT) domains between TRAS groups (about 37%-70%) than among TRAS elements and R1Bm (about 25%-30%), may reflect the presence of some DNA structure responsible for their target specificity. Sequence comparison from EN to RT domains among non-LTR elements revealed several regions conserved only within TRAS elements. We found a highly conserved region that resembles the Myb-like DNA-binding structure, between the EN and RT domains. These regions may be involved in site-specific integration of TRAS elements into the (TTAGG)(n) telomeric repeats.
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Affiliation(s)
- Y Kubo
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
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13
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Tu Z. Eight novel families of miniature inverted repeat transposable elements in the African malaria mosquito, Anopheles gambiae. Proc Natl Acad Sci U S A 2001; 98:1699-704. [PMID: 11172014 PMCID: PMC29320 DOI: 10.1073/pnas.98.4.1699] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eight novel families of miniature inverted repeat transposable elements (MITEs) were discovered in the African malaria mosquito, Anopheles gambiae, by using new software designed to rapidly identify MITE-like sequences based on their structural characteristics. Divergent subfamilies have been found in two families. Past mobility was demonstrated by evidence of MITE insertions that resulted in the duplication of specific TA, TAA, or 8-bp targets. Some of these MITEs share the same target duplications and similar terminal sequences with MITEs and other DNA transposons in human and other organisms. MITEs in A. gambiae range from 40 to 1340 copies per genome, much less abundant than MITEs in the yellow fever mosquito, Aedes aegypti. Statistical analyses suggest that most A. gambiae MITEs are in highly AT-rich regions, many of which are closely associated with each other. The analyses of these novel MITEs underscored interesting questions regarding their diversity, origin, evolution, and relationships to the host genomes. The discovery of diverse families of MITEs in A. gambiae has important practical implications in light of current efforts to control malaria by replacing vector mosquitoes with genetically modified refractory mosquitoes. Finally, the systematic approach to rapidly identify novel MITEs should have broad applications for the analysis of the ever-growing sequence databases of a wide range of organisms.
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Affiliation(s)
- Z Tu
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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Eight novel families of miniature inverted repeat transposable elements in the African malaria mosquito, Anopheles gambiae. Proc Natl Acad Sci U S A 2001. [PMID: 11172014 PMCID: PMC29320 DOI: 10.1073/pnas.041593198] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Eight novel families of miniature inverted repeat transposable elements (MITEs) were discovered in the African malaria mosquito, Anopheles gambiae, by using new software designed to rapidly identify MITE-like sequences based on their structural characteristics. Divergent subfamilies have been found in two families. Past mobility was demonstrated by evidence of MITE insertions that resulted in the duplication of specific TA, TAA, or 8-bp targets. Some of these MITEs share the same target duplications and similar terminal sequences with MITEs and other DNA transposons in human and other organisms. MITEs in A. gambiae range from 40 to 1340 copies per genome, much less abundant than MITEs in the yellow fever mosquito, Aedes aegypti. Statistical analyses suggest that most A. gambiae MITEs are in highly AT-rich regions, many of which are closely associated with each other. The analyses of these novel MITEs underscored interesting questions regarding their diversity, origin, evolution, and relationships to the host genomes. The discovery of diverse families of MITEs in A. gambiae has important practical implications in light of current efforts to control malaria by replacing vector mosquitoes with genetically modified refractory mosquitoes. Finally, the systematic approach to rapidly identify novel MITEs should have broad applications for the analysis of the ever-growing sequence databases of a wide range of organisms.
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Severson DW, Brown SE, Knudson DL. Genetic and physical mapping in mosquitoes: molecular approaches. ANNUAL REVIEW OF ENTOMOLOGY 2001; 46:183-219. [PMID: 11112168 DOI: 10.1146/annurev.ento.46.1.183] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The genetic background of individual mosquito species and populations within those species influences the transmission of mosquito-borne pathogens to humans. Technical advances in contemporary genomics are contributing significantly to the detailed genetic analysis of this mosquito-pathogen interaction as well as all other aspects of mosquito biology, ecology, and evolution. A variety of DNA-based marker types are being used to develop genetic maps for a number of mosquito species. Complex phenotypic traits such as vector competence are being dissected into their discrete genetic components, with the intention of eventually using this information to develop new methods to prevent disease transmission. Both genetic- and physical-mapping techniques are being used to define and compare genome architecture among and within mosquito species. The integration of genetic- and physical-map information is providing a sound framework for map-based positional cloning of target genes of interest. This review focuses on advances in genome-based analysis and their specific applications to mosquitoes.
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Affiliation(s)
- D W Severson
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA.
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16
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Caccone A, García BA, Mathiopoulos KD, Min GS, Moriyama EN, Powell JR. Characterization of the soluble guanylyl cyclase beta-subunit gene in the mosquito Anopheles gambiae. INSECT MOLECULAR BIOLOGY 1999; 8:23-30. [PMID: 9927171 DOI: 10.1046/j.1365-2583.1999.810023.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Genomic DNA corresponding to the soluble guanylyl cyclase beta-subunit (GCSbeta) gene was cloned and sequenced from Anopheles gambiae. The sequence was 8103 bp long and presumably included the entire coding region. The deduced amino acid sequence was 71% and 62% similar to previously known Drosophila and vertebrate GCSbeta, while the C-terminus of A. gambiae GCSbeta was shorter. Because of the conserved characteristics in each functional domain, the high G+C% in the third codon positions compared to the introns, the lack of internal stop codons, and the fact that we identified the gene from a cDNA, we conclude that this A. gambiae gene is functional. This is the first detailed description of a guanylyl cyclase gene structure (e.g. intron-exon boundaries). Interestingly, within the fifth intron we found high similarity to the flanking regions of the Pegasus-27 transposable element and other noncoding regions of the A. gambiae genome.
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Affiliation(s)
- A Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut 06520-8106, USA.
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Mathiopoulos KD, della Torre A, Predazzi V, Petrarca V, Coluzzi M. Cloning of inversion breakpoints in the Anopheles gambiae complex traces a transposable element at the inversion junction. Proc Natl Acad Sci U S A 1998; 95:12444-9. [PMID: 9770505 PMCID: PMC22850 DOI: 10.1073/pnas.95.21.12444] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Anopheles arabiensis, one of the two most potent malaria vectors of the gambiae complex, is characterized by the presence of chromosomal paracentric inversions. Elucidation of the nature and the dynamics of these inversions is of paramount importance for the understanding of the population genetics and evolutionary biology of this mosquito and of the impact on malaria epidemiology. We report here the cloning of the breakpoints of the naturally occurring polymorphic inversion 2Rd' of A. arabiensis. A cDNA clone that cytologically mapped on the proximal breakpoint was the starting material for the isolation of a cosmid clone that spanned the breakpoint. Analysis of the surrounding sequences demonstrated that adjacent to the distal breakpoint lies a repetitive element that exhibits distinct distribution in different A. arabiensis strains. Sequencing analysis of that area revealed elements characteristic of transposable element terminal repeats. We called this presumed transposable element Odysseus. The presence of Odysseus at the junction of the naturally occuring inversion 2Rd' suggests that the inversion may be the result of the transposable element's activity. Characteristics of Odysseus' terminal region as well as its cytological distribution in different strains may indicate a relatively recent activity of Odysseus.
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Affiliation(s)
- K D Mathiopoulos
- Istituto di Parassitologia, Fondazione Pasteur-Cenci Bolognetti, Università di Roma "La Sapienza," Rome 00185, Italy.
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Dotson EM, Cornel AJ, Willis JH, Collins FH. A family of pupal-specific cuticular protein genes in the mosquito Anopheles gambiae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 1998; 28:459-472. [PMID: 9718679 DOI: 10.1016/s0965-1748(98)00016-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have cloned and sequenced members of a cuticular protein multi-gene family from the mosquito Anopheles gambiae. Three genes (agcp2a-c), each approximately 1 kb in length, were found in a 17.4 kb genomic phage clone. Analysis of ten cDNAs revealed that at least four related genes are present. The open reading frame of the genes and cDNAs showed 95% sequence identity. Divergence was observed in the sequence of the 3' ends and the number of copies of two repeated coding sequences. In situ hybridizations with a probe prepared from one of these circular protein genes physically mapped to two loci, 26B on chromosome 2L and 37A on 3R. Transcription of these An. gambiae cuticular protein genes appears to be limited to pharate pupae and the expressed protein(s) is found in early pupae. The deduced amino acid sequence of these proteins contains a hydrophilic region with significant similarity to other cuticular proteins including the pupal-specific cuticular protein, EDG84, of Drosophila melanogaster (Apple and Fristrom).
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Affiliation(s)
- E M Dotson
- Divison of Parasitic Diseases, Centers of Disease Control and Prevention, Chamblee, GA 30341, USA
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Tu Z. Three novel families of miniature inverted-repeat transposable elements are associated with genes of the yellow fever mosquito, Aedes aegypti. Proc Natl Acad Sci U S A 1997; 94:7475-80. [PMID: 9207116 PMCID: PMC23846 DOI: 10.1073/pnas.94.14.7475] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/1997] [Accepted: 05/12/1997] [Indexed: 02/04/2023] Open
Abstract
Three novel families of transposable elements, Wukong, Wujin, and Wuneng, are described in the yellow fever mosquito, Aedes aegypti. Their copy numbers range from 2,100 to 3,000 per haploid genome. There are high degrees of sequence similarity within each family, and many structural but not sequence similarities between families. The common structural characteristics include small size, no coding potential, terminal inverted repeats, potential to form a stable secondary structure, A+T richness, and putative 2- to 4-bp A+T-biased specific target sites. Evidence of previous mobility is presented for the Wukong elements. Elements of these three families are associated with 7 of 16 fully or partially sequenced Ae. aegypti genes. Characteristics of these mosquito elements indicate strong similarities to the miniature inverted-repeat transposable elements (MITEs) recently found to be associated with plant genes. MITE-like elements have also been reported in two species of Xenopus and in Homo sapiens. This characterization of multiple families of highly repetitive MITE-like elements in an invertebrate extends the range of these elements in eukaryotic genomes. A hypothesis is presented relating genome size and organization to the presence of highly reiterated MITE families. The association of MITE-like elements with Ae. aegypti genes shows the same bias toward noncoding regions as in plants. This association has potentially important implications for the evolution of gene regulation.
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Affiliation(s)
- Z Tu
- Department of Entomology and Center for Insect Science, University of Arizona, Tucson, AZ 85721, USA.
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Mukabayire O, Besansky NJ. Distribution of T1, Q, Pegasus and mariner transposable elements on the polytene chromosomes of PEST, a standard strain of Anopheles gambiae. Chromosoma 1996; 104:585-95. [PMID: 8662251 DOI: 10.1007/bf00352298] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The chromosomal locations of four families of transposable elements, T1, Q, Pegasus and mariner, have been determined by in situ hybridization to polytene chromosomes of ovarian nurse cells of the mosquito Anopheles gambiae. As part of this effort, we have developed a vigorous pink-eyed laboratory strain of A. gambiae (PEST), rendered homozygous standard for chromosomal inversions on all autosomes. Ten different individuals of this strain were studied with each transposable element probe. The average number of hybridization sites per genome was 83.9 for T1, 63.4 for Q, 31.5 for Pegasus and 64.7 for mariner, excluding pericentric and centromeric regions. However, some degree of polymorphism was observed within each family such that, considering all ten individuals, 94 different sites were detected for T1, 82 sites for Q, 45 sites for Pegasus and 71 sites for mariner. The mean occupancy per site varied from 0.70 (Pegasus) to 0.91 (mariner), which, while significantly higher than that seen for transposable elements in natural populations of Drosophila melanogaster, is comparable to that seen in established laboratory stocks. In addition, these element families were not randomly distributed. All but Pegasus were concentrated in centromeric heterochromatin and centromere-proximal euchromatin, most showed a deficit of hybridization sites in the distal section of chromosomes, and a significant proportion of sites were coincident between families. These results provide the first detailed examination of the cytogenetic location of transposable elements in a nondrosophilid insect, and, through comparison with the behavior of transposable elements in Drosophila, may provide insight into the interaction between elements and host. The mapped elements are also expected to serve as landmarks useful in integrating the developing physical map of the PEST strain with the chromosomal banding pattern.
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Affiliation(s)
- O Mukabayire
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
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