Drosophila transposable elements

O Hare K, Baibin GM (1983) Structures of P transposable elements and their sites of insertion and excision in the Drosophila melanogaster genome. Cell 34 25-35... 

Once a new element is isolated, it is possible to find homologous DNA sequences in closely related species by DNA hybridization. It is unlikely, however, that this method would detect homologous DNA in Drosophila species which diverged more than 10-20 million years ago, because transposable elements have a more rapid rate of evolutionary change. An exception to this rapid divergence rate is seen in the copia and P elements, which are transmitted horizontally, and therefore cross-hybridization is the method of choice for isolating these elements in new species. 

Rubin, G. M. and A. C. Spradling. (1982) "Genetic transformation of Drosophila with transposable element vectors." Science 218 348-353. 

Transposable elements have been demonstrated in many eukaryotes, including maize. Drosophila, yeast, and bacteria. Gene transposition in eukaryotic systems presents some strong similarities to and some distinct differences from transposition in bacteria. The first major distinction is that integration and excision are distinct processes in eukaryotes. Thus, the transposable element can be isolated in free form, often as a double-strand circular DNA. Second, replication of that DNA often involves the synthesis of an RNA intermediate. Both of these properties are seen in the retroviruses of vertebrates, perhaps the most widely studied class of eukaryotic transposable elements. 

Transposable elements in eukaryotic cells show striking resemblances to retroviruses in sequence organization. The term retrotransposon is used to denote this class of elements. These similarities are illustrated in Figure 25.39 for two retroviruses Ty, a transposon of yeast copia and 412, transposable elements in Drosophila, and LAP, a transposon found in the mouse genome. 

Toh, H., Kikuno, R., Hayashida, H., Miyata, T., Kugimiya, W., et al (1985) Close structural resemblance between putative polymerase ol a Drosophila transposable genetic element 17.6 and pol gene produci of Moloney murine leukaemia virus. EMBO J. 4 1267-1272. 

DDT-R in Drosophila is a useful model system for a number of reasons. DDT was one of the earliest and most widespread pesticides ever used. In addition, individual flies can be readily genotyped for the presence of the resistance-associated mutation using a simple Polymerase Chain Reaction (PCR) based diagnostic that exploits the insertion of the Accord transposable element. This allows us to identify all three genotypes DDT-S/DDT-S (DDT sensitive), DDT-R/ DDT-S and DDT-R/DDT-R (or SS, RS and RR) in individual flies. Recently, in an outstanding example of parallel evolution, insertion of a different transposable element in the 5 end of the Cyp6gl homolog in D. simulans was also shown to be associated with insecticide resistance [8]. DDT-R is therefore a widespread, representative and current mechanism of insecticide resistance. 

Pardue ML, DeBaryshe PG. Drosophila telomeres two transposable elements with important roles in chromosomes. Genetica. 1999 107 189-96. 

Charlesworth, B and C.H. Langley 1990 The Population Genetics of Transposable Elements in Drosophila. In, Evolution at the molecular level, edited by R.K. Selander, A.G. Clark and T.S. Whittam, Sinaur Associates, Inc., Sunderland MA. 

Loukeris TG, Area B, Livadaras I, Dialektaki G, Savakis C (1995) Introduction of the transposable element Minos into the germ line of Drosophila melanogaster. Proc Natl Acad Sci USA 92 9485-9489. 

Chew, Y.C., West, J.T., Kratzer, S.J., Ilvarsonn, A.M., Eissenberg, J.C., Dave, B.J., Klinkebiel, D., Christman, J.K., and Zempleni, J., 2008. Biotinylation of histones represses transposable elements in human and mouse cells and cell lines, and in Drosophila melanogaster. Journal of Nutrition. 138 2316-2322. 

Figure 2 A gene in Drosophila (a) has had a transposable element Docl420 inserted into the second exon (b), generating a new gene that confers organophosphate resistance, is evolving rapidly, and has increased in abundance in the past few decades (Reproduced with permission from reference 10. Copyright 2005 AAAS.)...

PimpineUi S., Berloco M., Fanti L., Dimitri R, Bonaccorsi S., Marchetti E., Caizzi R., Caggese C., and Gatti M. 1995. Transposable elements are stable structural components of Drosophila melanogaster heterochromatin. Proc. Natl. Acad. Sci. 92 3804—3808. 

Spradling A.C., Stern D., Kiss I., Roote J., Laverty T., and Rubin G.M. 1995. Gene disruptions using P transposable elements An integral component of the Drosophila genome project. Proc. Natl. Acad. Sci. 92 10824-10830. 

One of the best known eukaryotic transposons is the P element of Drosophila, which transposes only within the germ line cells of developing embryos, somatic cells being unaffected.265 625 626 It belongs to... 

P-elements have been used as gene vectors in the closely related species D. simulans (12). In addition, the P-elements were found to undergo transposition in the more distantly related species D. hawaiiensis, although the capacity to act as a gene vector could not be demonstrated in this species (13). However, the transposable functionality of P-elements has not been demonstrated for insects outside the genus Drosophila. 

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