Dmel\mdg1

General Information
Symbol	Dmel\mdg1	Species	D.melanogaster
Name	mdg1 element	FlyBase ID	FBte0000015
Feature type	natural transposable element
Recent Updates
Description	What does this section display? This section contains items that were added to this record for each release. It currently only tracks new links between this FlyBase report and other FlyBase data classes (e.g. genes, references, stocks) or controlled vocabulary terms (e.g. GO, anatomy terms). What does this section not display? This section does not currently display links that were removed or gene model changes.
Update Feed	Click the icon below to subscribe to this FlyBase record and receive updates automatically through your feed reader.
FB2013_03
FB2013_02
All updates	Click here to see a list of all updates to this record from FB2010_08 and on.
Sequences & Components
Complete element (bp)	7.3kb 7480 (Kaminker et al., 2002)
Terminal repeat (bp)	442
Reference sequence	transposon_sequence_set.embl.txt.gz
Component genes	mdg1\ORF mdg1\ORF1 (Costas et al., 2001) mdg1\ORF2 (Costas et al., 2001) mdg1\sORF2 (Costas et al., 2001)
Sequence Accessions
	DDBJ/EMBL/GenBank AL138971 K02040 K02041 M36680 M36681 S68526 V00220 V00221 X52809 X56446 X56447 X59545 Z32236 Z50274 Z71030
Sequence Ontology (SO)
Transposon type	LTR_retrotransposon (Kaminker et al., 2002, Mugnier et al., 2008, Alonso-Gonzalez et al., 2003, Lipatov et al., 2005) transposable_element (Kaminker et al., 2002, Mugnier et al., 2008)
Insertions & Copy Number
Copy number and comments	25 (Ilyin et al.) 25 in euchromatin of Release 3 genome annotation, of which 13 are full length. (Kaminker et al., 2002) TE copies retrieved from release 5.1 of the D. melanogaster genome.:42 (Lerat et al., 2011)
Search for	All insertions of this transposon Insertions in the sequenced genome Insertions in other genomes
Target Site Duplication
Size (bp)	4 (Linheiro and Bergman, 2012, )
Orthologs
Curated drosophilid orthologs	Dafs\mdg1 Dalg\mdg1 Dazt\mdg1 Dbif\mdg1 Dgua\mdg1 Dmir\mdg1 Dnar\mdg1 Dobs\mdg1 Dper\mdg1 Dpsb\mdg1 Dpse\mdg1 Dsim\mdg1 Dsub\mdg1 Dsus\mdg1 Dtol\mdg1 Dtri\mdg1
Comments
	Expression is enriched in embryonic gonads. (Shigenobu et al., 2006) Transposable elements can be used to reveal cross-over events. (Furman and Bukharina, 1998) No transposition was detected in progeny after heat shock of parents. (Arnault et al., 1997) A lower proportion of copia, mdg1 and 412 element insertion sites on the X chromosome, from various populations of D.melanogaster and D.simulans, in comparison with autosomes suggests that selection against the detrimental effects of TE insertions in the major force containing TE copies in populations. (Biemont et al., 1997) The behaviour of the retrotransposons copia, Dsim\copia and mdg1 has been analysed in hybrids between D.melanogaster and D.simulans. No somatic transposition events were detected in hybrid larvae. (Garcia-Guerreiro, 1996) Study of TE distribution (P-element, hobo, I-element, copia, mdg1, mdg3, 412, 297 and roo) along chromosome arms shows no global tendency for the TE site occupancy frequency to negatively follow the recombination rate, except for the 3L arm. The tendency for TE insertion number to increase from base to tip of some chromosome arms is simply explicable by a positive relationship with DNA content along the chromosomes. So for all TEs, except hobo, there is no relationship between distribution of TE insertion numbers weighted by DNA content and recombination rate. hobo insertion site number is positively correlated with recombination rate. (Hoogland and Biemont, 1996) Endogenous transposable elements show more instability in sublines injected with exogenous viral particles than in transgenic sublines containing a foreign viral insert, all transposable elements are not equally sensitive to such genomic stress. (Jouan-Dufournel et al., 1996) Transcriptional analysis of mdg1-Ecol\CAT fusion constructs indicates that mdg1 can be transcribed by both RNA polymerases II and III. (Arkhipova, 1995) The distribution of mdg1 elements in heterochromatin has been studied by in situ hybridisation to mitotic chromosomes. (Carmena and Gonzalez, 1995) Experiments designed to compare the insertion patterns of copia and mdg1 revealed that crossing to marker strains led to heterogeneity in insertion patterns of the copia elements, with no significant polymorphism of the mdg1 insertions. (Garcia-Guerreiro and Biemont, 1995) Spontaneous insertions and excisions of mdg1, copia, 412 and roo (excisions are outnumbered by insertions) occur during 65 generations of mass mating under laboratory conditions. Their contribution into variation for transposable element location does not seem great. (Kozhemiakina and Furman, 1995) The distribution of a number of transposable elements has been studied in 10 Harwich mutation accumulation lines. (Nuzhdin and Mackay, 1995) The distribution of transposable elements within heterochromatin indicates that they are major structural components of the heterochromatin. (Pimpinelli et al., 1995) The distribution of mdg1 elements across the chromosomes has been analysed in individuals from a natural population of D.melanogaster. (Biemont et al., 1994) Estimating the genomic numbers of transposable elements demonstrates many families of element are over-represented in heterochromatin. (Charlesworth et al., 1994) The spatial and temporal expression patterns of fifteen families of retrotransposons are analysed during embryogenesis and are found to be conserved. Results suggest that all families carry cis-acting elements that control their spatial and temporal expression patterns. (Ding and Lipshitz, 1994) The insertion patterns of mdg1 and copia are sufficiently modified to allow the unambiguous detection of an alien genome income. (Dufournel et al., 1994) 60kb repeats located in the distal heterochromatin of the X chromosome have been cloned. These regions, designated as SCLRs, are comprised of the following types of repeated elements: SteXh, copia-like elements (mdg1 elements, aurora-elements and GATE elements), LINE-elements (G-elements and R1-elements), and bb fragments. There are approximately 9 SCLR copies per haploid genome, with a twofold variation in copy number between different fly stocks. (Nurminsky et al., 1994) Element copy numbers on inversion and standard chromosomes has been determined. The copy number is significantly higher within low frequency inversions than within the corresponding standard chromosome regions. (Sniegowski and Charlesworth, 1994) Evolutionary history of mobile and nonmobile mdg1 elements in the genome is determined. (Nurminsky, 1993) Polymorphism of transposable elements in inbred lines has been examined: P-element, gypsy, jockey, I-element, mdg1, 412, mdg3 and 297 sites are largely stable, whereas roo and copia sites are polymorphic. (Aleksandrova and Alexandrov, 1992) During the course of experiments with genetically unstable MS strains gypsy elements were observed to transpose whereas mdg1 and 412 sites in the X chromosome were unchanged. (Kim et al., 1992) Numbers of mdg1, mdg3, gypsy and copia have been studied in several strains of D.melanogaster and D.simulans. Mean number of mdg1 and copia sites are drastically reduced in D.simulans. Majority of mdg1 and copia sites, and one third of mdg3 sites, are in hot spots for insertion, particularly in D.simulans. Southern blot analysis indicates that the majority of mdg1 and copia are in the euchromatin of D.melanogaster but the heterochromatin of D.simulans. (Leibovich et al., 1992) Non mobile mdg1 located in D.melanogaster heterochromatin was sequenced and compared with the transposable version of mdg1. Results suggested that the evolution of mdg1 subfamilies occurred under selective pressure on the ability to transpose. The divergence of the left and right LTRs of heterochromatic aurora-element and mdg1 elements indicates that aurora-element has been at its heterochromatic location for 0-0.15Myr and mdg1 for 0-0.7Myr. (Nurminsky and Shevelyov, 1992) One substock of inbred lines shows considerable heterogeneity of insertion sites of copia (frequency of insertions is 12% per haploid genome per generation) whereas mdg1, 412, mdg3, gypsy, 297 and HMS-Beagle were stable in all stocks examined. (Pasyukova and Nuzhdin, 1992) Sequences required for correct and precise initiation of mdg1 RNA synthesis have been determined using mdg1-Ecol\CAT regulatory fusion constructs. (Arkhipova and Ilyin, 1991) Transient expression of mdg1 deletion constructs identifies sites of 3'-end processing in the leader region of the transcribed RNA. (Cherkassova et al., 1991) The mdg1 element has been cloned and sequenced. The element contains two long partially overlapping reading frames (ORFs), ORF1 and ORF2, which encode the proteins required for reverse transcription. The mdg1 element contains unusually long leader and terminal regions. The leader region contains two short open reading frames which are separated from each other and the long ORFs by long oligo(dA) sequences. One of these short ORFs encodes a protein with a zinc-binding region. The mdg1 element shows considerable homology with the 412 element. (Avedisov et al., 1990) The mdg1 element contains transcription termination sites containing long blocks of oligo(dA) in the leader region of the element, 1kb downstream of the transcription start site. Transient expression of deletion mutants shows that a small open reading frame (ORF) in the leader region can be translated, and suggests transcription reinitiation may occur during the process of reading the main ORF of the mdg1 element. (Cherkasova and Il'in, 1990) The distribution of a number of transposable elements, including mdg1 elements, in a D.melanogaster laboratory strain with a high frequency of spontaneous mutations and its derivatives, has been studied. (Kim et al., 1990) Two regions in the mdg1 element can specifically bind nuclear proteins of D.melanogaster. The first region is 1kb downstream of the transcription start site, and the second region is localised near the 3' LTR. The two regions are recognised by different proteins and may be involved in the regulation of mdg1 transcription. Binding of proteins to the first region can be suppressed by adding 412 element DNA. (Cherkassova et al., 1989) The genomic distribution of transposable elements in somatic tissues and during development is homogeneous. (di Franco et al., 1989) A considerable proportion of mdg1 elements are located in heterochromatic chromosome regions. Many of these heterochromatic mdg1 elements are inserted into a non-mobile heterochromatic moderate repeat, named the HMR-element. HMR-elements along with the mdg1 copies inserted in them are under-replicated in polytene chromosomes. (Shevelyov et al., 1989) First described by Ilyin et al. (1978) and Georgiev et al. (1978) as being complementary to abundant poly(A)+ RNA. The sequence of the LTR shown here is the reverse complement of that published by Kulguskin et al. (1981) and the map in Lindsley, Zimm, 1992: 1103 is the reverse of that published by Ilyin et al. (1978). The direction of major transcription is left to right (Ilyin et al.). Fourteen of the eighteen bases of the putative primer binding sites of mdg1 and 412 elements are identical, as are the 27 bases adjacent to their left-hand LTRs (Will et al., 1981). Yuki et al. (1986) have identified an arginine tRNA as being the probable primer for reverse transcription of both mdg1 and 412 RNAs.
Other Information
Etymology

External Crossreferences
Sequence Crossreferences
	DDBJ/EMBL/GenBank AL138971 K02040 K02041 M36680 M36681 S68526 V00220 V00221 X52809 X56446 X56447 X59545 Z32236 Z50274 Z71030
Other Crossreferences
	TRANSFAC R03108
Synonyms & Secondary IDs ( 20 )
Reported As
Symbol Synonym	38C.28 (McGill Drosophila Genome Project, 2001.9.25, Butler, 2001, Butler et al., 2001) 38C.33 (McGill Drosophila Genome Project, 2001.9.25, Butler, 2001, Butler et al., 2001) 38D.16 (McGill Drosophila Genome Project, 2001.9.25, Butler, 2001, Butler et al., 2001) CG17485 (Butler, 2001, Butler et al., 2001, ) Dmel\mdg1 (Kalmykova et al., 2005) EG:BACR43E12.3 (Benos, 2000.2.5) mdg1 (Henikoff et al., 2009, Saito et al., 2006, Vagin et al., 2006, Shigenobu et al., 2006, Ganko et al., 2006, Linheiro and Bergman, 2012, Pane et al., 2011, Fablet et al., 2007, Gunawardane et al., 2007, Dewey et al., 2004, Lau et al., 2009, Hartig et al., 2009, Kalmykova et al., 2005, Lemos et al., 2008, Díaz-González et al., 2010, Brennecke et al., 2007, Kawamura et al., 2008, Deloger et al., 2009, Mugnier et al., 2008, Liu et al., 2011, Ghildiyal et al., 2008, Nefedova et al., 2011, Brennecke et al., 2008, Chung et al., 2008, Lipatov et al., 2005, Lerat et al., 2011, Malone et al., 2009, Anand and Kai, 2012, Zakharenko et al., 2007, Poels et al., 2004, Li et al., 2009, Maside et al., 2005, Lipardi and Paterson, 2009, Moshkovich and Lei, 2010, Handler et al., 2011, Zamparini et al., 2011, Tan et al., 2012, Sienski et al., 2012, Nayak et al., 2010, Klenov et al., 2011) MDG1 (Kapitonov and Jurka, 2003, Akhmanova and Hennig, 1998, Furman and Bukharina, 1996, Vasil'eva et al., 1995, Vasil'eva et al., 1995, Belyaeva et al., 1994, Kaidanov et al., 1994, Leibovich, 1991, Shevelyov et al., 1989, FlyBase, 1996-, Gunawardane et al., 2007, Czech et al., 2008, Zhou et al., 2009, Makunin and Yurlova, 2010, Makunin and Yurlova, 2010) mdg-1 (Carr et al., 2002, Carr et al., 2001, Yan et al., 2002, Koryakov et al., 2002, Maside et al., 2001, Maside et al., 2000, Biemont and Cizeron, 1999, Kurek et al., 1999, Pimpinelli et al., 1995, Dixon, 1993, Kimura et al., 1993, Arnault et al., 1991, Kaidanov et al., 1991, Zabanov et al., 1990, FlyBase, 1996-, Navarro et al., 2009, Klattenhoff et al., 2009, Fanti et al., 2003) Mdg1 (Furman and Bukharina, 1998, Dufournel et al., 1994, Hamilton et al., 2009, Wang and Elgin, 2011) mdg 1 (Alonso-Gonzalez et al., 2003, Alonso-Gonzalez et al., 2006) mdg1^het (Nurminsky, 1993) mdg1^tr (Nurminsky, 1993) mdg1het (Nurminsky, 1994.9.22, FlyBase, 1996-) mdg1tr (FlyBase, 1996-) Mdgl (Stapleton et al., 2001) mdgl (Madueno et al., 1995) mgd1 (Benos et al., 2001)
Name Synonym	mdg1 (Mugnier et al., 2008, Lipatov et al., 2005) mdg1 element mobile dispersed genetic element 1 (Poels et al., 2004)
Secondary FlyBase IDs
	FBgn0002697 FBgn0032866 FBtp0011447
References ( 184 )

Generate a list of	All references relating to this natural transposable element ( 184 )

List References by type	Research paper ( 161 ) Supplementary material ( 2 ) Review ( 8 ) Personal communication to FlyBase ( 2 ) Abstract ( 4 ) FlyBase analysis ( 2 ) DNA/RNA sequence record ( 2 ) Letter ( 2 ) Conference report ( 1 )
Recent research papers ( 12 )
	Anand and Kai, 2012, EMBO J. 31(4): 870--882 The tudor domain protein Kumo is required to assemble the nuage and to generate germline piRNAs in Drosophila. [FBrf0217541] Linheiro and Bergman, 2012, PLoS ONE 7(2): e30008 Whole Genome Resequencing Reveals Natural Target Site Preferences of Transposable Elements in Drosophila melanogaster. [FBrf0217478] Sienski et al., 2012, Cell 151(5): 964--980 Transcriptional silencing of transposons by piwi and maelstrom and its impact on chromatin state and gene expression. [FBrf0220033] Tan et al., 2012, Hum. Mol. Genet. 21(1): 57--65 Retrotransposon activation contributes to fragile X premutation rCGG-mediated neurodegeneration. [FBrf0216915] Handler et al., 2011, EMBO J. 30(19): 3977--3993 A systematic analysis of Drosophila TUDOR domain-containing proteins identifies Vreteno and the Tdrd12 family as essential primary piRNA pathway factors. [FBrf0216344] Klenov et al., 2011, Proc. Natl. Acad. Sci. U.S.A. 108(46): 18760--18765 Separation of stem cell maintenance and transposon silencing functions of Piwi protein. [FBrf0216776] Lerat et al., 2011, Gene 473(2): 100--109 Comparative analysis of transposable elements in the melanogaster subgroup sequenced genomes. [FBrf0212990] Liu et al., 2011, Development 138(9): 1863--1873 PAPI, a novel TUDOR-domain protein, complexes with AGO3, ME31B and TRAL in the nuage to silence transposition. [FBrf0213491] Nefedova et al., 2011, Virus Genes 42(2): 297--306 Integration specificity of LTR-retrotransposons and retroviruses in the Drosophila melanogaster genome. [FBrf0213545] Pane et al., 2011, EMBO J. 30(22): 4601--4615 The Cutoff protein regulates piRNA cluster expression and piRNA production in the Drosophila germline. [FBrf0217070] Wang and Elgin, 2011, Proc. Natl. Acad. Sci. U.S.A. 108(52): 21164--21169 Drosophila Piwi functions downstream of piRNA production mediating a chromatin-based transposon silencing mechanism in female germ line. [FBrf0217081] Zamparini et al., 2011, Development 138(18): 4039--4050 Vreteno, a gonad-specific protein, is essential for germline development and primary piRNA biogenesis in Drosophila. [FBrf0214783] Show all research papers ...
Recent reviews (0)
	All reviews listed in FlyBase were published before 2011 Show reviews ...