Dmel\hobo
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| Symbol | Dmel\hobo | Species | D.melanogaster |
| Name | hobo element | FlyBase ID | FBte0000154 |
| Feature type | natural transposable element | ||
Recent Updates
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| Description |
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| 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
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| Complete element (bp) |
2959
3016
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| Terminal repeat (bp) |
12
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| Reference sequence | transposon_sequence_set.embl.txt.gz | ||
| Component genes | |||
Sequence Accessions
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Sequence Ontology (SO)
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| Transposon type | |||
Insertions & Copy Number
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| Copy number and comments |
0-50 (McGinnis and Beckendorf, 1983; Streck et al., 1986).
24 in euchromatin of Release 3 genome annotation, of which 1 is full length.
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| Target Site Duplication | |||
| Size (bp) | |||
Orthologs
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| Curated drosophilid orthologs |
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Comments
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Sequences flanking a donor hobo do not influence subsequent integration site preference, whereas sequences contained within 31bp flanking an integration
hot spot have a significant effect on the frequency of integration into that site. The lack of a common sequence motif in
the DNA flanking several hot spots suggests that higher order DNA structural characteristics of the DNA and/or chromatin may
influence integration site selection by the hobo.
GD sterility, hobo mobilisation and male recombination have been investigated for 13 strains of D.melanogaster.
Molecular and GD sterility tests are not sufficient to classify strains in the hobo system. All the components of the dysgenic syndrome must be taken into account.
Several Drosophilid and tephritid species are permissive for hobo motility, tephritid species harbour hobo-related elements. hobo excision occurred in the absence, as well as the presence, of hobo\T in both insect families. This suggests that cross-mobilisation systems exist in a broad range of insects.
The function of hobo transposon in tephritid species is tested in transient embryonic excision assays. Wild-type and mutant strains of A.suspensa, B.dorsalis, B.cucurbitae, C.capitata and T.curvicauda all support hobo excision or deletion both in the presence and absence of co-injected hobo transposase source. This indicates a permissive state for hobo motility and the existance of endogenous systems capable of mobilising hobo.
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.
The distribution of hobos in heterochromatin has been studied by in situ hybridisation to mitotic chromosomes.
Inversion present in the Uc-1 X chromosome are produced by ectopic recombination between a pair of hobos in opposite orientation.
Mobility of the hobo transposon has been assayed using an in vivo transient assay in several Drosophila species. In D.melanogaster devoid of hobos, excision occurs only after co-injection of a helper plasmid. In species confirmed not to contain hobo, excision occurred at significant rates both in the presence and absence of co-injected helper plasmid. hobo is capable of functioning in the soma during embryogenesis, and its mobility is unrestricted in drosophilids. Drosophilids
not containing hobo are able to mobilize hobo, presumably by a hobo-related cross-mobilizing system. The cross-mobilizing system in D.virilis is not functionally identical to hobo with respect to excision sequence specificity.
The distribution of a number of transposable elements has been studied in 10 Harwich mutation accumulation lines.
The distribution of transposable elements within heterochromatin indicates that they are major structural components of the
heterochromatin.
A modified hobo introduced into embryos of the housefly, M.domestica, and the Queensland fruitfly, B.tryoni, is capable of transposition and transposition products have all the landmarks of hobo transposition products recovered from D.melanogaster.
The transposition behaviour of hobos has been analysed in two laboratory strains.
The distribution and copy number of P-elements and hobos has been studied in long-term D.melanogaster cage populations kept under different culture conditions.
hobo excision is similar to Ac and Tam3 element excision in plants, the empty donor sites are very similar. hobos can be mobilised in M.domestica in the absence of hobo-encoded transposase as M.domestica has hobo-transposase-like factors.
Interactions between hobos are responsible for the instability of the Uc unstable X chromosome. Interactions between widely separated elements produce
gross rearrangements and interactions between nearby elements cause regional instabilities, which may arise when a copy of
hobo transposes a short distance, creating a pair of hobos that can interact to produce small rearrangements.
Stability of 11 transposable element families compared by Southern blotting among individuals of lines that had been subjected
to 30 generations of sister sib matings. 412, roo, blood, 297, 1731 and G-element all appear stable, whereas copia, hobo, I-element, gypsy and jockey elements show instability.
hobos occupy both cytological breakpoints of 3 out of 4 endemic inversions sampled from natural populations of D.melanogaster in the Hawaiian islands. The fourth has a hobo at one breakpoint. This is direct evidence that transposable elements are responsible for causing specific rearrangements
found in nature, and that chromosome rearrangements can arise in nature in a manner predicted by the results of hybrid dysgenic
crosses in the laboratory.
The pattern of occurrence of hobos in D.melanogaster and D.simulans is polymorphic. Most tested strains in both species have both complete (3.0kb) and smaller hobos, although in both species some strains completely lack such canonical hobos.
46 strains derived from American and French natural populations have been tested for the presence of hobos by Southern blotting and a gonadal dysgenesis assay. The oldest available strains show weak hybridisation to the hobo probe and have neither hobo-activity potential or hobo-repression potential. In contrast all recently collected strains have hobo sequences and have a strong hobo-repression potential but no strong hobo-activity potential.
Southern blot analysis of 134 species of the genus Drosophila shows that hobo sequences are limited to the melanogaster and montium subgroups of the melanogaster-species group. Of the hobo-bearing species, only D.melanogaster, D.simulans and D.mauritiana contain potentially complete hobos, while D.sechellia contains sequences that probably represent internally deleted hobos.
Deleted versions of the hobo found in natural populations fall into three classes by restriction mapping: Oh (1,870bp), Th1 (1,510bp) and Th2 (1,490bp).
The hobo family of transposable elements can promote high rates of chromosomal instability.
First described by McGinnis and Beckendorf (1983) as being associated with the Sgs4 allele in the strain Stromsvreten 8. The
sequence and map in Lindsley, Zimm, 1992: 1102 are of hobo100 (Streck et al., 1986). This element contains a single long open
reading frame that reads from left to right. Blackman et al. (1989) have identified a fully functional hobo element and have
used it to introduce a marked element into the genome. Some strains appear to lack hobo elements, whereas others have 10-50
copies. These are called 'E' and 'H' strains, respectively (Streck et al., 1986). The frequency of hobo activity is elevated
in some strains and in some cases is increased in the progeny of crosses between E and H strains (Yannopoulos et al., 1987;
Blackman et al.). Lim (1988) has evidence that recurring chromosome aberrations that he has found on an unstable X chromosome
are due to recombination between hobo elements that lie at the breakpoints. The majority of strains derived from natural populations
before the mid-1950's harbor few hobo homologous sequences. In contrast almost all present-day populations carry numerous
hobo elements and two specific deletion-derivative elements called Th1 and Th2 (Periquet, Hamelin, Bigot and Lepissier, 1989).
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Other Information
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Etymology
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External Crossreferences
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| Sequence Crossreferences | |||
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Synonyms & Secondary IDs
( 9 )
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| Reported As | |||
| Symbol Synonym |
HDC12224
H-element
HFL1
Hobo
hobo
(Kovalenko et al., 2006, Zakharenko et al., 2006, Linheiro and Bergman, 2012, Souames et al., 2003, Aulard et al., 2004, Pane et al., 2011, Petrov et al., 2011, Boussy and Itoh, 2004, Brennecke et al., 2007, Kim et al., 2011, Brennecke et al., 2008, Kawamura et al., 2008, Malone et al., 2009, Alonso-Gonzalez et al., 2006, Torres et al., 2006, de Freitas Ortiz and Loreto, 2009, Kikuno et al., 2006, Zakharenko et al., 2007, Li et al., 2009, Bazin et al., 2004, Ortiz and Silva Loreto, 2008, O'Brochta et al., 2009, Zakharenko and Perepelkina, 2009, Ruiz and Carareto, 2003, Tan et al., 2012, Sienski et al., 2012)
HOBO
Hobo transposon
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| Name Synonym |
hobo element
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| Secondary FlyBase IDs | |||
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References
( 212 )
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Recent research papers ( 6 )
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Recent reviews (0)
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| All reviews listed in FlyBase were published before 2011 | |||
Recent Updates
