Biology subjects

Valente, V. L. d. S.

Publications and source records attributed to Valente, V. L. d. S..

3 recordsLinked to original sources

bioRxiv2020

Evolutionary study of the 412/mdg1 lineage of the Ty3/gypsy group of LTR retrotransposons in Diptera

LTR-retrotransposons are structurally similar to retroviruses, as they possess the enzymes reverse transcriptase, Ribonuclease H, integrase, proteinase, and the gag gene and are flanked by long terminal repeats (LTRs). The 412/mdg1 lineage, belonging to the Ty3/Gypsy group, consists of the TEs 412, mdg1, stalker, pilgrim, and blood. The 412/mdg1 lineage is distinguished from the others in the gypsy group in that it has small ORFs at the beginning of the TE and is highly similar to the pol ORF among the TEs that make up the lineage. In this study, our aim was to elucidate the evolutionary history of the 412/mdg1 lineage in the 127 dipteran genomes available to date, and the characteristics of the sequences in each genome. We used the canonical TE 412 probe described in Drosophila melanogaster as the query. We found sequences homologous to the 412/mdg1 lineage restricted to the suborder Brachycera. These sequences are widely distributed in drosophilids but are also present in other groups of flies. We note the presence of the 412/mg1 lineage in tsetse flies (Glossina). Furthermore, our results showed an elaborate evolutionary history for the pol ORF in the 412/mdg1 lineage of the LTR-Retrotransposon.

evolutionary biology↗

bioRxiv2019

Evolutionary history and classification of Micropia retroelements in Drosophilidae species

Current knowledge indicates TEs have been shaping the evolution of genomes and host species, contributing to the creation of new genes and promoting rearrangements frequently associated with new regulatory networks. Support for these hypothesis frequently result from studies with model species, and Drosophila detaches as a great model organism to the study of TEs. Micropia belongs to the Ty3/Gypsy group of LTR retroelements, and comprises one of the least studied Drosophila transposable elements. In this study, we assessed the evolutionary history of Micropia within Drosophilidae, while trying to assist in the classification of this TE. At first, we analyzed its presence in the genome of several species from natural populations and then, based on searches within genomic databases, we retrieved Micropia-like sequences from distinct Drosophilidae species genomes. We expanded the knowledge of Micropia distribution within Drosophila, and detected an array of divergent sequences, which allowed subdividing this retroelement in 20 subfamilies. Even so, a patchy distribution of Micropia sequences within the Drosophilidae phylogeny could be identified combined with incongruences of the species and the Micropia phylogenies. Comparing dS values between Micropia and host nuclear sequences, we found several cases of unexpected high levels of similarity between Micropia sequences found in divergent species. All these findings propose a hypothesis to the evolution of Micropia within Drosophilidae, including several VTTs and HTTs events, associated to ancestral polymorphisms and recurrent Micropia sequences diversification.

genetics↗

bioRxiv2018

The flower flies and the unknown diversity of Drosophilidae (Diptera): a biodiversity inventory in the Brazilian fauna

Diptera is a megadiverse order, reaching its peak of diversity in Neotropics, although our knowledge of dipteran fauna of this region is grossly deficient. This applies even for the most studied families, as Drosophilidae. Despite its position of evidence, most aspects of the biology of these insects are still poorly understood, especially those linked to natural communities. Field studies on drosophilids are highly biased to fruit-breeders species. Flower-breeding drosophilids, however, are worldwide distributed, especially in tropical regions, although being mostly neglected. The present paper shows results of a biodiversity inventory of flower-breeding drosophilids carried out in several localities in Brazil, based on samples of 125 plant species, from 47 families. Drosophilids were found in flowers of 56 plant species, from 18 families. The fauna discovered showed to be highly unknown, comprising 28 species, 12 of them (>40%) still undescribed. Not taking in account opportunist species, two thirds of the diversity exclusive from flowers were undescribed. The Drosophila bromeliae species group was the most representative taxon, with eight species (six undescribed), including four polyphagous and four Solanum-specialised species. This specialisation on Solanum is reported for the first time for Drosophila. Other taxa of restrict flower-breeding drosophilids were the Drosophila lutzii species group and the genus Zygothrica. Some specimens of the genera Cladochaeta, Rhinoleucophenga and Scaptomyza were found, but their relations to flowers are unclear. Additionally, ten species of ample niche was found using flowers opportunistically. Localities and host plants are recorded for all species collected.

zoology↗