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.
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.
Larval copia RNA levels are variable among Drosophila species, transcripts are detected in D.melanogaster, but not in D.simulans, D.mauritiana, D.sechellia, D.yakuba, D.erecta or D.willistoni. Size variation mapping to the LTR and ULR in naturally occurring copia elements is likely generated by duplication and is of functional significance.
Phylogenetic analysis indicates that although D.melanogastercopia elements are distinct from those of D.simulans and D.mauritiana, the copia elements of these latter two species are not distinguishable from one another.
Dsim\copia elements are enriched in the heterochromatin and on the Y chromosome.
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.
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.
Larval copia RNA levels are variable among Drosophila species, transcripts are detected in D.melanogaster, but not in D.simulans, D.mauritiana, D.sechellia, D.yakuba, D.erecta or D.willistoni. Size variation mapping to the LTR and ULR in naturally occurring copia elements is likely generated by duplication and is of functional significance.
Phylogenetic analysis indicates that although D.melanogaster copia elements are distinct from those of D.simulans and D.mauritiana, the copia elements of these latter two species are not distinguishable from one another.
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.
copia elements are found in D.simulans, D.mauritiana and D.melanogaster but copia-encoded transcripts are only found in D.melanogaster. copia transcript level variation is found among natural populations of D.melanogaster : this is not due to variable copia copy number but may be due to the action of trans-acting controls.