Transposable elements in South American populations of Drosophila simulans

Mobilization of a Hobo-related Sequence in the Genome of Drosophila simulans

“…One of these substrains is almost devoid of complete hobo elements, having only a faint band corresponding to a complete element (dpp-like mutant strain), although other sub-strains show a strong band corresponding to a complete hobo element (Loreto, Zaha and Valente, 1998). As stated above, these conditions point to the possible activity of the hobo element in this strain.…”

“…All other strains, originated from North America, Australia, Europe and South Africa, showed a very strong hybridization signal corresponding to the complete hobo element, as well as a 0.7 kb band corresponding to an internally deleted element of 1.1 kb. Loreto, Zaha and Valente (1998) increased the number of South American populations analyzed and found two other populations with faint signals corresponding to the complete hobo element and, interestingly, all populations analyzed were devoid of the 1.1 kb deleted element, always present in the samples from other parts of the world, as showed by Boussy and Daniels (1991). Engels (1989) has suggested that deleted elements do accumulate in the genome as a function of time after invasion.…”

“…The hypothesis that canonical hobo is maintained active in some D. simulans populations, including the hypermutable strain that gave origin to the white mutant (Dswhm), was invigorated from the observation in Loreto, Zaha and Valente (1998) that South American D. simulans populations were possibly the last ones to suffer the invasion of their genomes by the canonical hobo. This proposition is substantiated by findings described by Boussy and Daniels (1991) in an analysis by Southern Blot of 27 strains collected in different places of the world.…”

Transposable elements P and gypsy in natural populations of Drosophila willistoni

“…The strong pattern similarity between gypsy strains found by Bayev et al (1984) using Southern blotting suggests that this element invaded the D. melanogaster genome early in the evolutionary history of this species, the same appearing to be true for Drosophila simulans (Loreto et al, 1998b). However, little information is available about how gypsy element sequences evolved in the genomes of different Drosophila populations around the world.…”

“…The gypsy element is a long 7.3 kb retrotransposon containing 0.5 kb of well-conserved long terminal repeats (LTRs) and is widely distributed in Drosophila and the subgenus Sophophora (Stacey et al, 1986;Loreto et al, 1998b), the retroviral properties of gypsy probably explaining this wide distribution (Bayev et al, 1984;Terzian et al, 2000;Vázquez-Manrique et al, 2000;Mejlumian et al, 2002;Pélisson et al, 2002;Heredia et al, 2004). The strong pattern similarity between gypsy strains found by Bayev et al (1984) using Southern blotting suggests that this element invaded the D. melanogaster genome early in the evolutionary history of this species, the same appearing to be true for Drosophila simulans (Loreto et al, 1998b).…”