Bacterial diversity on larval and female Mansonia spp. from different localities of Porto Velho, Rondonia, Brazil.

Studies based on the bacterial diversity present in Mansonia spp. are limited; therefore, the aim of this study was to investigate the bacterial diversity in females and larvae of Mansonia spp., describe the differences between the groups identified, and compare the microbiota of larvae from different collection sites. Sequences of the 16S rRNA region from the larvae and females of Mansonia spp. were analyzed. Diversity analyzes were performed to verify the possible bacterial differences between the groups and the collection sites. The results showed Pseudomonas was the most abundant genus in both females and larvae, followed by Wolbachia in females and Rikenellaceae and Desulfovibrio in larvae. Desulfovibrio and Sulfurospirillum, sulfate- and sulfur-reducing bacteria, respectively, were abundant on the larvae. Aminomonas, an amino acid-degrading bacterium, was found only in larvae, whereas Rickettsia was identified in females. Bacterial diversity was observed between females and larvae of Mansonia and between larvae from different collection sites. In addition, the results suggest that the environment influenced bacterial diversity.

Isolation of 27 polymorphic nuclear microsatellite markers for Roupala montana var. brasiliensis (Proteaceae).

Microsatellite primers pairs were developed for the Neotropical tree Roupala montana var. brasiliensis for use in studies on genetic diversity, mating system, and gene flow. Forty-two primer pairs were developed, resulting in 27 polymorphic loci, with two to 27 alleles per locus. The primer pairs were validated against 34 R. montana var. brasiliensis adult trees from four populations. The observed (H o) and expected (H e)heterozygosities ranged among loci from 0.061 to 0.930 (mean of 0.544) and from 0.116 to 0.950 (mean of 0.700), respectively. Null alleles were observed for ten loci. No genotypic linkage disequilibrium was detected in any pair of loci. This set of loci is suitable for population genetic studies of the species.

Maintaining genetic integrity with high promiscuity: Frequent hybridization with low introgression in multiple hybrid zones of Melocactus (Cactaceae).

Hybridization and introgression between species in contact/hybrid zones provide important insight into the genetic and ecological mechanisms of speciation. Cactaceae represents the most important radiation of true succulent angiosperms in the New World. This diversification continues to date, with species experiencing few intrinsic barriers to gene flow and the frequent occurrence of natural hybridization. Here, we used RAD-Seq single-nucleotide polymorphism (SNP) data to investigate the genetic architecture of hybridization in four hybrid zones hosting Melocactus concinnus and four congeneric species (M. ernestii, M. glaucescens, M. paucispinus, and M. zehntneri). Our results revealed that M. concinnus is highly promiscuous in sympatric areas and hybridizes with various species distributed in Morro do Chapéu (Diamantina Plateau, Bahia), eastern Brazil. However, the contemporary genomic introgression among the investigated species is very low (c. 2-5%), confirming that even in the face of hybridization, Melocactus species maintain their genetic integrity. The genomic cline approach showed a large fraction of loci deviating from a model of neutral introgression, where most of the loci are consistent with selection favoring parental genotypes. Our results suggest the occurrence of weak premating but strong postmating reproductive isolation in the analyzed cactus species. Furthermore, as most of the Melocactus species are restricted in distribution, hybridization might negatively affect their integrity if hybrids replace the parental species.

Genetic structure of Lutzomyia longipalpis populations in Mato Grosso Do Sul, Brazil, based on microsatellite markers.

BACKGROUND: Lutzomyialongipalpis (Diptera: Psychodidae) is the major vector of Leishmania (Leishmania) infantum and thus plays a crucial role in the epidemiology of American visceral leishmaniasis (AVL). This vector is the best studied species of sand fly in the Neotropical region. Many studies claim that this vector is in fact a species complex; however there is still no consensus regarding the number of species that belong into this complex or the geographical distribution of sibling species. The aim of the present study was to analyze the genetic relationships within Lu. longipalpis populations in the state of Mato Grosso do Sul (MS), Brazil. METHODOLOGY/PRINCIPAL FINDINGS: We collected 30 Lu. longipalpis (15 females and 15 males) from five localities (Campo Grande, Três Lagoas, Aquidauana, Miranda and Bonito) and 30 Lu. Cruzi from Corumbá, totaling 180 sandflies from MS, and 30 Lu. longipalpis from Estrela de Alagoas, state of Alagoas (AL), Northeast Brazil. We show that eight previously described microsatellite loci were sufficient in distinguishing Lu. longipalpis from Lu. Cruzi, which is a closely related species, and in differentiating between Lu. longipalpis collected in MS versus Estrela de Alagoas. Analyses of the genotypes revealed introgression between sympatric Lu. longipalpis and Lu. Cruzi. CONCLUSIONS/SIGNIFICANCE: Our findings support the hypothesis of cryptic species within the Lu. longipalpis complex. Furthermore, our data revealed introgression between Lu. longipalpis and Lu. cruzi. This phenomenon should be further investigated to determine the level and incidence of hybridization between these two species. We also demonstrated that microsatellite markers are a powerful tool for differentiating sand fly populations and species. The present study has elucidated the population structure of Lu. longipalpis in MS and, by extension, the Neotropical Lu. longipalpis complex itself.

Microsatellite marker-based assessment of the biodiversity of native bioethanol yeast strains.

Although many Brazilian sugar mills initiate the fermentation process by inoculating selected commercial Saccharomyces cerevisiae strains, the unsterile conditions of the industrial sugar cane ethanol fermentation process permit the constant entry of native yeast strains. Certain of those native strains are better adapted and tend to predominate over the initial strain, which may cause problems during fermentation. In the industrial fermentation process, yeast cells are often exposed to stressful environmental conditions, including prolonged cell recycling, ethanol toxicity and osmotic, oxidative or temperature stress. Little is known about these S. cerevisiae strains, although recent studies have demonstrated that heterogeneous genome architecture is exhibited by some selected well-adapted Brazilian indigenous yeast strains that display high performance in bioethanol fermentation. In this study, 11 microsatellite markers were used to assess the genetic diversity and population structure of the native autochthonous S. cerevisiae strains in various Brazilian sugar mills. The resulting multilocus data were used to build a similarity-based phenetic tree and to perform a Bayesian population structure analysis. The tree revealed the presence of great genetic diversity among the strains, which were arranged according to the place of origin and the collection year. The population structure analysis revealed genotypic differences among populations; in certain populations, these genotypic differences are combined to yield notably genotypically diverse individuals. The high yeast diversity observed among native S. cerevisiae strains provides new insights on the use of autochthonous high-fitness strains with industrial characteristics as starter cultures at bioethanol plants.

Leishmania chagasi in opossums (Didelphis albiventris) in an urban area endemic for visceral leishmaniasis, Campo Grande, Mato Grosso do Sul, Brazil.

We investigated the occurrence of Leishmania infantum chagasi in Didelphis albiventris opossums at a wild animal rehabilitation center in the city of Campo Grande, Brazil. A total of 54 opossums were tested for L. i. chagasi infection in peripheral blood and bone marrow samples. The samples were analyzed by direct examination, culturing in a specific medium, and polymerase chain reaction-restriction fragment length polymorphism. Leishmania i. chagasi DNA was detected by polymerase chain reaction-restriction fragment length polymorphism in 11 (20.37%) animals. A total of 81.81% of positive opossums were captured in areas of known visceral leishmaniasis transmission. These results suggest a role for D. albiventris in the urban transmission of visceral leishmaniasis.