Spermatogenesis of Zaprionus indianus and Zaprionus sepsoides (Diptera, Drosophilidae): Cytochemical, structural and ultrastructural characterization

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Espermatogênese de Zaprionus indianus e Zaprionus sepsoides (Diptera: Drosophilidae): caracterização citoquímica, estrutural e ultraestrutural

Pós-graduação em Genética - IBILCE

Fitness components of a recently-established population of Zaprionus indianus (Diptera, Drosophilidae) in Brazil

This study aimed to evaluate fitness components of Zaprionus indianus Gupta, 1970, a species recently introduced in Brazil and currently in process of colonization. Longevity, productivity, developmental speed and viability of flies sampled from a population from Mirassol (state of São Paulo, Brazil) were evaluated. Longevity was higher than that of some Indian populations and productivity was similar or higher than in other Drosophilidae. Time of development, one of the main fitness components for competition, was very similar to the values scored in Drosophila sturtevanti Duda, 1927, a species that occurs in high frequencies in the same area as Z. indianus. These data might contribute further for understanding the colonization success of this newcomer species in South America.

Ecology of colonizing populations of the figfly Zaprionus indianus (Diptera, Drosophilidae) in Porto Alegre, Southern Brazil

Ecological parameters such as trophic niche overlap and niche breadth were computed from the frequency of all drosophilid species collected in 2001 and 2002, in the urban area of Porto Alegre city, Brazil. Independently of place, drosophilids community composition and components breeding or feeding sites, the highest frequencies of Zaprionus indianus (Gupta, 1970) were obtained during seasons with higher average temperatures, especially during summer. From a total of the 19,146 individuals of Z. indianus sampled, 80% were found in this season. The data of trophic niche breadth suggest a higher opportunism of adult flies in feeding substrate use, but the females are still selective in oviposition substrate choice. For the values of niche overlap, only for some species, did we find any correlation between these and species richness and/or number of resources, and the most of the correlation values considering breeding and feeding sites were positive. The colonization of Z. indianus in Porto Alegre could be leading to adjustments in the survival strategies of the resident species, but it is possible that many species have conditions for coexisting with the invader.

Ocorrência de Zaprionus indianus gupta (Diptera: Drosophilidae) em frutos de juazeiro Ziziphus joazeiro mart. (rhamnaceae) no estado do Rio Grande do Norte

Este trabalho relata, pela primeira vez, a ocorrência de Zaprionus indianus Gupta, 1970 (Diptera: Drosophilidae) em frutos de juazeiro Ziziphus joazeiro Mart., em Mossoró, Estado do Rio Grande do Norte. Foram amostrados frutos, coletados na árvore e no solo, de plantas de juazeiro presentes no Câmpus da Universidade Federal Rural do Semi-árido (UFERSA). Os frutos coletados foram levados ao Laboratório de Entomologia Aplicada da UFERSA, pesados, acondicionados em recipientes plásticos contendo vermiculita e cobertos com tecido voile, para obtenção dos pupários. Das amostras de frutos, foram obtidos 932 pupários, dos quais emergiram 188 exemplares de Z. indianus.

Copia Retrotransposon in the Zaprionus Genus: Another Case of Transposable Element Sharing with the Drosophila melanogaster Subgroup

Copia is a retrotransposon that appears to be distributed widely among the Drosophilidae subfamily. Evolutionary analyses of regulatory regions have indicated that the Copia retrotransposon evolved through both positive and purifying selection, and that horizontal transfer (HT) could also explain its patchy distribution of the among the subfamilies of the melanogaster subgroup. Additionally, Copia elements could also have transferred between melanogaster subgroup and other species of Drosophilidae-D. willistoni and Z. tuberculatus. In this study, we surveyed seven species of the Zaprionus genus by sequencing the LTR-ULR and reverse transcriptase regions, and by using RT-PCR in order to understand the distribution and evolutionary history of Copia in the Zaprionus genus. The Copia element was detected, and was transcriptionally active, in all species investigated. Structural and selection analysis revealed Zaprionus elements to be closely related to the most ancient subfamily of the melanogaster subgroup, and they seem to be evolving mainly under relaxed purifying selection. Taken together, these results allowed us to classify the Zaprionus sequences as a new subfamily-ZapCopia, a member of the Copia retrotransposon family of the melanogaster subgroup. These findings indicate that the Copia retrotransposon is an ancient component of the genomes of the Zaprionus species and broaden our understanding of the diversity of retrotransposons in the Zaprionus genus.

On the Relationship between Zaprionus spinipilus Chassagnard & McEvey and Z. vittiger Coquillett, the Type Species of the Genus Zaprionus (Diptera: Drosophilidae)

Zaprionus vittiger Coquillett is the type species of the genus Zaprionus Coquillett. However, the species is only known from five old museum specimens collected from South Africa and Malawi. It has often been confused with many other Zaprionus species, especially with Z. spinipilus Chassagnard & McEvey, a widespread species in Africa known from Madagascar, Malawi, Ethiopia and Cameroon. We have recently collected flies from the type localities of both species (South Africa and Madagascar, respectively). This has prompted us to test the taxonomic boundaries of these two nominal species using molecular (the mitochondrial COII and the nuclear Amyrel genes), chromosomal, morphological (internal and external genitalia), and reproductive isolation analyses. The results suggest Z. spinipilus to be a junior synonym to Z. vittiger.

Evolução do retroelemento gypsy em espécies de Drosophila e Zaprionus indianus : uma abordagem filogenética

Resumo não disponível.

Scenario of the spread of the invasive species Zaprionus indianus Gupta, 1970 (Diptera, Drosophilidae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Polyphyly of the Zaprionus genus group (Diptera: Drosophilidae)

The Zapnionus genus group comprises three drosophilid genera (Zaprionus, Phorticella and Samoaia) that are thought to be related to the Drosophila immigrans species group. We revised the phylogenetic relationships among the three genera and their placement within the subfamily Drosophilinae using one mitochondrial (COII) and one nuclear (Amyrel) gene. The Bayesian tree inferred from concatenated amino acid sequences of the two genes strongly suggests the polyphyly of the Zaprionus genus group and of each of the genera Zaprionus and Phorticella. Paraphyly of the D. immigrans species group was also shown here; the quadrilineata subgroup formed the sister clade to the genus Samoaia. These results suggest the necessity of taxonomic revisions for some relevant genera and species groups included within the genus Drosophila. (C) 2009 Elsevier B.V. All rights reserved.

Copia Retrotransposon in the Zaprionus Genus: Another Case of Transposable Element Sharing with the Drosophila melanogaster Subgroup

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DNA barcode discovers two cryptic species and two geographical radiations in the invasive drosophilid Zaprionus indianus

Comparing introduced to ancestral populations within a phylogeographical context is crucial in any study aiming to understand the ecological genetics of an invasive species. Zaprionus indianus is a cosmopolitan drosophilid that has recently succeeded to expand its geographical range upon three continents (Africa, Asia and the Americas). We studied the distribution of mitochondrial DNA (mtDNA) haplotypes for two genes (CO-I and CO-II) among 23 geographical populations. mtDNA revealed the presence of two well-supported phylogenetic lineages (phylads), with bootstrap value of 100%. Phylad I included three African populations, reinforcing the African-origin hypothesis of the species. Within phylad II, a distinct phylogeographical pattern was discovered: Atlantic populations (from the Americas and Madeira) were closer to the ancestral African populations than to Eastern ones (from Madagascar, Middle East and India). This means that during its passage from endemism to cosmopolitanism, Z. indianus exhibited two independent radiations, the older (the Eastern) to the East, and the younger (the Atlantic) to the West. Discriminant function analysis using 13 morphometrical characters was also able to discriminate between the two molecular phylads (93.34 +/- 1.67%), although detailed morphological analysis of male genitalia using scanning electron microscopy showed no significant differences. Finally, crossing experiments revealed the presence of reproductive barrier between populations from the two phylads, and further between populations within phylad I. Hence, a bona species status was assigned to two new, cryptic species: Zaprionus africanus and Zaprionus gabonicus, and both were encompassed along with Z. indianus and Zaprionus megalorchis into the indianus complex. The ecology of these two species reveals that they are forest dwellers, which explains their restricted endemic distribution, in contrast to their relative cosmopolitan Z. indianus, known to be a human-commensal. Our results reconfirm the great utility of mtDNA at both inter- and intraspecific analyses within the frame of an integrated taxonomical project.

Multiple invasions of Gypsy and Micropia retroelements in genus Zaprionus and melanogaster subgroup of the genus Drosophila

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