Repeated horizontal transfer of P transposons between Scaptomyza pallida and Drosophila bifasciata.
Two distinct P element subfamilies, designated M-type and O-type, reside in the genome of D. bifasciata. PCR-screening of 65 Drosophila species revealed that only D. bifasciata and its closest relative D. imaii possess O-type elements. Outside the genus, O-type elements were detected in Scaptomyza pallida. Restriction analyses show that the general structure of the O-type elements from S. pallida and D. bifasciata is the same. Sequence divergence turned out to be extremely low (0.43%). These results suggest that the O-type subfamily of D. bifasciata has been received by horizontal transfer from an external source, most probably from the genus Scaptomyza, as has been previously suspected for the M-type family. Since the sequence divergence between M-type elements from S. pallida and D. bifasciata is eighteen-fold higher than that between O-type elements, two independent intergeneric transfer events have to be postulated. In order to re-examine the taxonomic status of S. pallida, a partial sequence (489 bp) of the Adh gene was analysed. The data clearly prove that S. pallida has to be placed far outside the D. obscura group.
Hagemann
S
S
Institut für Allgemeine Biologie, AG Genetik, Medizinische Fakultät, Universität Wien, Austria.
Haring
E
E
Pinsker
W
W
D000426:Alcohol Dehydrogenase / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics*; D004330:Drosophila / Q000235:genetics*; D018428:Drosophilidae / Q000235:genetics*; D017344:Genes, Insect; D014644:Genetic Variation / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D004251:DNA Transposable Elements; D000426:Alcohol Dehydrogenase