Yeast communities as descriptors of habitat use by the Drosophila fasciola subgroup (repleta group) in Atlantic rain forests

Abstract

Yeast communities associated with four species of the Drosophila fasciola subgroup (repleta group) in tropical rain forests were surveyed in an abandoned orchard, and rain forest sites of Rio de Janeiro and Ilha Grande, State of Rio de Janeiro, Brazil. Adult flies of Drosophila carolinae, Drosophila coroica, Drosophila fascioloides and Drosophila onca frequently carried Candida colliculosa, Geotrichum sp, Kloeckera apiculata and a Pichia membranaefaciens-like species. The most frequent yeasts in the crop of flies included Candida collicullosa, C. krusei, Pichia kluyveri and a P. membranaefaciens-like species. The physiological abilities and species composition of these yeast communities differed from those of other forest-inhabiting Drosophila. The narrow feeding niches of the fasciola subgroup suggested the use of only part of the substrates available to the flies as food in the forest environment, as noted previously for cactophilic Drosophila serido (mulleri subgroup of the repleta group) in a sand dune ecosystem. The cactophilic yeasts that were isolated have not been previously found in forests. The fasciola subgroup probably used epiphytic cactus substrates as breeding and feeding sites in the forest. The physiological profile of yeasts associated with the fasciola flies was broader than that of yeasts associated with the cactophilic Drosophila serido, suggesting that the fasciola subgroup represents an older lineage from which the South American repleta species evolved.

Chromosomal phylogeny of the Drosophila fasciola species subgroup revisited (Diptera, Drosophilidae)

“…pothesis was required for the subgroup fasciola to be considered ancestral of the repleta group with a forest origin, as proposed by Throckmorton (1975Throckmorton ( , 1982 and "supported" by morphological and ecological data (Pipkin, 1965;Pipkin et al, 1966;Sene et al, 1977;Pereira et al, 1983;Morais et al, 1995). This new phylogenetic hypothesis, based on chromosomal inversions, offers a better perspective to understanding the relationships within the subgroup to be inferred from other markers as in Costa and Sene (2002).…”

“…In forest environments, besides these substrates, these flies use epiphytic cacti (Rhypsalis sp.) as breeding sites (Sene et al, 1977, Morais et al, 1995.…”

“…At the present time, and on anatomical grounds especially, the major separation within the repleta group is between the hydei subgroup on the one hand and the remaining subgroups on the other, with the fasciola subgroup being the most primitive among the latter forms". Supporting this idea, Morais et al (1995) proposed the possibility of the repleta group ancestor having inhabited the forests, and, based in composition studies of yeasts, associated to these flies, suggesting that the fasciola subgroup represents the oldest lineage from which the South American species of the repleta group may have evolved. This statement is in agreement to the ecological data mentioned above.…”

Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces

“…Another set of adult flies was surfacesterilized in the field by immersion in 70 % ethanol for 1 min and transported to the laboratory within 2 h in tubes containing sterile water on ice. These flies were directly streaked on to YM agar (Morais et al, 1995). Plates were incubated at room temperature (25±3 u C).…”

Phylogenetic relationships in the Drosophila fasciola species subgroup (Diptera, Drosophilidae) inferred from partial sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene

“…One hypothesis suggests that the ancestral populations of the fasciola subgroup were forest inhabitants that colonized the dry areas and led to the development of the species of the other repleta group subgroups (Throckmorton, 1975(Throckmorton, , 1982Morais et al, 1995;Tatarenkov and Ayala, 2001), while the other hypothesis considers that the fasciola subgroup is derived from species adapted to dry areas which later invaded forests (Wasserman, 1962(Wasserman, , 1992 but this hypothesis was based on the sharing of the 3c inversion among species in the fasciola subgroup and the mulleri complex.…”