Strains isolated from Central Brazil (the centre of D.willistoni distribution) show a high degree of Dwil\P-element polymorphism, while strains closer to the origin have large numbers of deleted elements. The number of element copies is much lower than in D.melanogaster. The presence of complete elements in all studied populations suggests that elements in old laboratory populations cannot undergo transposition, but elements from wild strains are still capable.
Examination of the P-element phylogeny in light of the species phylogeny suggests that additional horizontal transfers may have occurred at various times in the past and may explain the overall structure of the P-element phylogeny in Sophophora.
Dwil\P-element homologous sequences are detected in South American populations. In laboratory populations, nearly devoid of natural inversions, hybridisations sites are confined to the chromocenter. In wild populations, hybridisation sites coincide with several inversions break points and other sites are located very close to these points.
P-element sequences from nine Dipteran species, including D.willistoni, have been compared. The P-element phylogeny contradicts the phylogeny of the species, suggesting that horizontal transfer of P-elements may have occurred.
An extensive survey of the occurrence of P-element homologous sequences in the genus Drosophila has been carried out by Southern blot analysis. The strongest hybridisation of P-element probes occurs in species from the closely related willistoni and saltans groups. Dwil\P-element has been cloned, and differs from the D.melanogaster sequence by one base pair substitution.
Strains isolated from Central Brazil (the centre of D.willistoni distribution) show a high degree of Dwil\P-element polymorphism, while strains closer to the origin have large numbers of deleted elements. The number of element copies is much lower than in D.melanogaster. The presence of complete elements in all studied populations suggests that elements in old laboratory populations cannot undergo transposition, but elements from wild strains are still capable.
Examination of the P-element phylogeny in light of the species phylogeny suggests that additional horizontal transfers may have occurred at various times in the past and may explain the overall structure of the P-element phylogeny in Sophophora.
Dwil\P-element homologous sequences are detected in South American populations. In laboratory populations, nearly devoid of natural inversions, hybridisations sites are confined to the chromocenter. In wild populations, hybridisation sites coincide with several inversions break points and other sites are located very close to these points.
A phylogenetic survey has identified four major P-element subfamilies in the saltans and willistoni species groups of Drosophila.
P-element sequences from nine Dipteran species, including D.willistoni, have been compared. The P-element phylogeny contradicts the phylogeny of the species, suggesting that horizontal transfer of P-elements may have occurred.
An extensive survey of the occurrence of P-element homologous sequences in the genus Drosophila has been carried out by Southern blot analysis. The strongest hybridisation of P-element probes occurs in species from the closely related willistoni and saltans groups. Dwil\P-element has been cloned, and differs from the D.melanogaster sequence by one base pair substitution.