How many species of drosophila (Diptera, Drosophilidae) remain to be described in the forests of São Paulo, Brazil?: species lists of three forest remnants

This paper describes the composition and abundance of Drosophila species found in three forest remnants in the State of São Paulo. A well-standardized sampling procedure applied on four collecting trips to the same sites on four areas resulted on 944 samples. All males collected were identified by analyses of the genitalia, this being the only data set used. One hundred and twenty five species were detected amongst the 29,289 males analyzed. From them 57,6% could be identified as described species. Thirteen of the species found were absent from the previous species list for the state of São Paulo State, thus represent an increase of 13% on the number known. We argue that the majority of the 53 unidentified species are in fact undescribed. The sites studied did not differ significantly in the proportion of identified species. On average identified species were almost seven times more abundant than unidentified ones, and this difference was significant. Rarefaction curve analysis confirmed that the proportion of unidentified species increase with sample size, and did not reach a plateau with our data set. These results illustrate the large richness of Drosophila species in forest remnants of São Paulo State. It also indicates that about half of the species in this region remain to be described. This conclusion is particularly important when one considers that this is a well studied genus of Diptera, on the best sampled region of Brazil.Este trabalho descreve a composição e a abundância de espécies de Drosophila encontradas em três remanescentes florestais do estado de São Paulo. Um procedimento de coletas bem padronizado aplicado em quatro coletas nos mesmos sítios em três áreas resultou em 944 amostras. Todos os machos coletados foram identificados pela análise da genitália, e apenas os dados destes foram analisados. Cento e vinte e cinco espécies foram detectadas entre os 29.289 machos analisados. Destas 57,6% puderam ser identificadas como espécies já descritas. Treze das espécies encontradas estavam ausentes da lista prévia de espécies do estado de São Paulo, resultado em um aumento de 13% nesta lista. A maioria das 53 espécies não identificadas são, provavelmente, não descritas. Os sítios estudados não diferem significativamente na proporção de espécies identificadas. Em média as espécies identificadas foram quase sete vezes mais abundantes do que as não identificadas, e esta diferença foi significativa. Uma análise de curvas de rarefação confirmou que a proporção de espécies não identificadas aumenta com o tamanho amostral, e não atinge um platô em nosso conjunto de dados. Estes resultados ilustram a grande riqueza de espécies de Drosophila nos remanescentes florestais do estado de São Paulo. Eles também indicam que cerca de metade das espécies desta região ainda não foram descritas. Esta conclusão mostra-se particularmente importante considerando que este é um gênero de Diptera bem estudado, na região mais bem amostrada do Brasil.011

Chromosomal localization of microsatellite loci In drosophila mediopunctata

Drosophila mediopunctata has been used as a model organism for genetics and evolutionary studies in the last three decades. A linkage map with 48 microsatellite loci recently published for this species showed five syntenic groups, which had their homology determined to Drosophila melanogaster chromosomes. Then, by inference, each of the groups was associated with one of the five major chromosomes of D. mediopunctata. Our objective was to carry out a genetic (chromosomal) analysis to increase the number of available loci with known chromosomal location. We made a simultaneous analysis of visible mutant phenotypes and microsatellite genotypes in a backcross of a standard strain and a mutant strain, which had each major autosome marked. Hence, we could establish the chromosomal location of seventeen loci; including one from each of the five major linkage groups previously published, and twelve new loci. Our results were congruent with the previous location and they open new possibilities to future work integrating microsatellites, chromosomal inversions, and genetic determinants of physiological and morphological variation3815558CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPES

Differential attraction of drosophilids to banana baits inoculated with Saccharomyces cerevisiae and Hanseniaspora uvarum within a Neotropical forest remnant

Background. Yeasts are a necessary requisite in the diet of most Drosophila species that, in turn, may vector their dispersal in natural environments. Differential attractiveness experiments and the isolation of yeasts consumed by Drosophila may be informative for characterizing this association. Hanseniaspora uvarum is among the most common yeast species isolated from Drosophila crops, with high attractiveness to drosophilids. Saccharomyces cerevisiae has been widely used to collect flies, and it allows broad sampling of almost all local Drosophila species. Pronounced differences in the field concerning Drosophila attractivity to baits seeded with these yeast species have been previously reported. However, few explicit generalizations have been set. Since late fifties, no field experiments of Drosophila attractivity were carried out in the Neotropical region, which is facing shifts in abiotic and biotic factors. Our objective is to characterize preference behavior that mediates the interaction in the wild among Neotropical Drosophila species and yeasts associated with them. We want to set a broad generalization about drosophilids attracted to these yeasts. Here we present the results of a differential attractiveness experiment we carried out in a natural Atlantic Rainforest fragment to assess the preferences of Drosophila species groups to baits inoculated with H. uvarum and S. cerevisiae. Methods. Both yeast species were cultured in GYMP broth and separately poured in autoclaved mashed banana that was left fermenting. In the field, we collected drosophilids over five arrays of three different baits: non-inoculated autoclaved banana and banana inoculated with each yeast. In the laboratory the drosophilids were sorted to five sets according to their external morphology and/or genitalia: tripunctata; guarani; willistoni; exotic; and the remaining flies pooled in others. Results and Conclusions. Uninoculated banana baits attracted virtually no flies. We found significant departures from random distribution over the other two baits (1:1 proportion) for all sets, except the pooled others. Flies of the sets willistoni and exotic preferred H. uvarum over S. cerevisiae, while the remaining sets were more attracted to S. cerevisiae. Previously, various authors reported similar patterns in attraction experiments with S. cerevisiae and H. uvarum. It is also noteworthy that both yeast species have been isolated from natural substrates and crops of Drosophila species. Taken together, these results suggest that the preferences among Drosophila species groups may be reflecting deep and stable relations with yeast species in natural environments. They can be summarized as: forest dwelling species from subgenus Drosophila (such as tripunctata and guarani groups) are attracted to banana baits seeded with S. cerevisiae; while exotic (as D. melanogaster) and subgenus Sophophora species are preferentially attracted to baits seeded with H. uvarum

Undesirable Consequences Of Neglecting Nonlinearity: Response To Comments By Liefting Et Al. (2013) On Rocha & Klaczko (2012).

In response to our previous study, Liefting et al. argue, in defense of their work on latitudinal variation of developmental-rate reaction norms (RNs), that (1) developmental rate (the reciprocal of development time: rate = time(-1) ) is a more biologically relevant variable than development time; (2) the linear RN model is a valid approximation; and (3) three experimental points suffice to estimate RN parameters. Here, we reply to their comments. First, we give evidence that the complexity of actual development challenges the appealing simplicity of developmental rate. Using the same analysis as Liefting et al. to test their hypothesis with development time, instead of rate, reveals a pattern that is the opposite of their conclusion. Second, we show that a quadratic model is consistent with the whole development-time RNs and explains this contradiction. Third, with the quadratic model, we introduce two parameters to study plasticity: the RN shape (the quadratic coefficient) and RN local plasticity (the derivative of the RN function). The first showed a statistically significant correlation with latitude; and the second showed a continuous variation pattern where all localized patterns can be found (positive, negative, or nonsignificant correlations with latitude) but certainly cannot be generalized.681548-5

The Reaction Norm For Abdominal Pigmentation And Its Curve In Drosophila Mediopunctata Depend On The Mean Phenotypic Value.

The idea of a general independence between the phenotypic plasticity and the mean value of a trait is, presently, a consensus. Here, we use the reaction norm of abdominal pigmentation (number of dark spots) of Drosophila mediopunctata in response to temperature, to test this idea. We raised eight strains, bearing two different chromosomal inversions and with varying mean phenotypic values, under 11 temperatures in a thermal gradient to test for predictions concerning mean phenotypic values, chromosomal inversions, and reaction norms. Our results revealed a strong effect of different phenotypic groups and no effect of different karyotypes on reaction norms. Moreover, we found a significant negative correlation between mean phenotypic value and the curvature of the reaction norms, revealing a high dependency of the reaction norm shape on mean phenotypic value. These results clearly reject the idea of genetic independence between mean value and phenotypic plasticity, and may indicate a pattern of correlation, which may include results from other traits and species, with an importance that has not been fully appreciated.63280-