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General Information
D. melanogaster
Feature type
FlyBase ID
Sequences and Components
Complete element (bp)
Terminal repeat (bp)
Component genes
Sequence Accessions
GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
Sequence Ontology (SO)
Insertions and Copy Number
Copy number and comments


17 in euchromatin of Release 3 genome annotation, of which 13 are full length.

Target Site Duplication
Size (bp)
Curated drosophilid orthologs

Southern blot hybridisation analysis indicates that "Kermit" and flea cross-hybridise at high stringency, suggesting either that their sequences are identical or that they are very closely related.

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.

The flea element is a retrotransposon-like element that is found at approximately 20 copies per genome in D.melanogaster. flea encodes a polyprotein containing the sequence motifs for a nucleic acid binding CCHC protein, a proteinase, a reverse transcriptase and an integrase, as is typically found in retroviruses.

Only one copy of blastopia has been described; it was found within the 87E1-6 region in Canton S but not Oregon R DNA. It has been mapped by Bender (map in Lindsley, Zimm, 1992: 1103). There are no sites for the enzymes BamHI, HindIII, or SalI and there may be additional sites for EcoRI at the ends of the element. flea first described associated with four different fa mutations. The map shown in Lindsley, Zimm, 1992: 1100 is the reverse of that published by Kidd and Young (1986). There are no sites for the enzyme BglII. These are copia-like elements and Kidd and Young have reported sequences from the ends of the LTRs. The elements in the N locus have inserted in target sites within the consensus ATG/GTAT.

Other Information

Etymology: "blastopia" is named owing to its early expression in the blastoderm embryo, and its close relationship to micropia.

External Crossreferences and Linkouts ( 6 )
GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
Synonyms and Secondary IDs (15)
Reported As
Secondary FlyBase IDs
  • FBgn0045760
  • FBgn0001302
  • FBgn0000665
  • FBtp0011413
  • FBgn0014947
  • FBtp0011427
References (67)