Helena and BS: two travellers between the genera Drosophila and Zaprionus

Abstract

The frequency of horizontal transfers of transposable elements (HTTs) varies among the types of elements according to the transposition mode and the geographical and temporal overlap of the species involved in the transfer. The drosophilid species of the genus Zaprionus and those of the melanogaster, obscura, repleta, and virilis groups of the genus Drosophila investigated in this study shared space and time at some point in their evolutionary history. This is particularly true of the subgenus Zaprionus and the melanogaster subgroup, which overlapped both geographically and temporally in Tropical Africa during their period of origin and diversification. Here, we tested the hypothesis that this overlap may have facilitated the transfer of retrotransposons without long terminal repeats (non-LTRs) between these species. We estimated the HTT frequency of the non-LTRs BS and Helena at the genome-wide scale by using a phylogenetic framework and a vertical and horizontal inheritance consistence analysis (VHICA). An excessively low synonymous divergence among distantly related species and incongruities between the transposable element and species phylogenies allowed us to propose at least four relatively recent HTT events of Helena and BS involving ancestors of the subgroup melanogaster and ancestors of the subgenus Zaprionus during their concomitant diversification in Tropical Africa, along with older possible events between species of the subgenera Drosophila and Sophophora. This study provides the first evidence for HTT of non-LTRs retrotransposons between Drosophila and Zaprionus, including an in-depth reconstruction of the time frame and geography of these events.

High frequency of horizontal transfer in Jockey families (LINE order) of drosophilids

“…Our research group has been dedicated to the study of HTT between Zaprionus and the species of the subgroup melanogaster of Drosophila for a decade. The results reported in this study for the Jockey families agree with the hypothesis of recent transfer of retrotransposons with LTR (Gypsy, Micropia and Copia) [42, 43] and the non-LTR retrotransposons Helena and BS [9] between genomes of species of the subgenus Zaprionus and the subgroup melanogaster . Thus, the evidence we add here provides a consolidated picture of the extensive exchange of TEs between the species of these two groups in central Africa during the late Miocene.…”

“…Studies have also shown that HTT occurs more frequently between closely related species than between more distantly related ones [45–47]. Regarding the ecology and biology of the species involved in HTT, it has been shown that species with overlapping habitats share more TEs by HTT than species that are distributed in different environments [9, 42], as well as share more viruses that can be vectors of TEs [48]. Although susceptibility to viruses shows a strong phylogenetic correlation, susceptible hosts can occasionally be grouped into phylogenetically distant groups, allowing parasites to jump great phylogenetic distances [49].…”

“…The sequences of these genes were aligned using MAFFT [59] and later concatenated to reconstruct a phylogenetic tree of the host species. Additionally, the tree was inferred by maximum likelihood (ML), as described in Simão et al [9].…”

“…Of the 243 cases reported, 126 (51.9%) are of DNA transposons, 103 (42.4%) are of LTR (long terminal repeat) retrotransposons, and only 14 (5.8%) involve non-LTR retrotransposons. For non-LTR retrotransposons in particular, only six families of the LINE order are involved, such as Jockey ( D. melanogaster / D. funebris ), F ( D. melanogaster / D. yakuba ), Doc ( D. melanogaster / D. yakuba ), I ( D. simulans / D. melanogaster ) (reviewed in [1, 2, 8]; HTT-DB platform), and Helena and BS ( melanogaster complex/subgenus Zaprionus ) [9]. The same marked difference in the HTT rate of different types of TEs was also recently detected by Reiss et al [10], in a study of 460 species covering 19 orders of arthropods that focused on one LTR retrotransposon (Copia), one non-LTR retrotransposon (Jockey) and one DNA transposon (Mariner).…”

Diversity of fruit fly species in agricultural area Chott Zahrez Chergui (Djel-fa): First record of Trupanea amoena (Diptera: Tephritidae) in Algeria

“…Among which, Drosophila melanogaster and Zaprionus indianus are the dominant species in the investigated orchard. These two Drosophilidae species that damage small fruit have invaded the Neotropics in recent decades (Valadão et al, 2019). The predominance of fruit flies in agroecosystems has been highlighted in African continent from their introduction into certain countries in and since that they had rapidly spread and established successfully across the continent (Mutamiswa et al, 2021).…”