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. © 2013 John Wiley & Sons, Ltd.

Microsatellite loci characterized in the leaf-cutter ant Atta laevigata

Background: The leaf-cutter ant Atta laevigata (Formicidae: Attini) is an agricultural pest largely distributed in the Neotropics and a model organism for studies of evolution, speciation and population genetics. Microsatellites are a very powerful tool for these kind of studies, but such markers are not available for studies on A. laevigata. In the present report, we describe the isolation and characterization of nine microsatellite loci in A. laevigata and the testing of these markers across other species of leaf-cutter ants. Findings. Nine microsatellite loci, consisting of six dinucloeotide, one trinucleotide, one tetranucleotide, and one di/trinucleotide repeat motifs, were isolated and characterized. Primers and protocols were successfully designed to selectively amplify these markers. To test effectiveness of these markers for detailed population genetic studies, we genotyped female workers collected from 36 monogynic nests of A. laevigata and found that eight loci were within Hardy-Weinberg expectations, while the remaining locus had a deficiency of heterozygotes. Micro-Checker analysis of individuals from 55 monogynic nests indicated that loci Alae11, Alae24, Alae18 showed signs of null alleles. For the remaining six loci, the number of alleles per locus ranged between 2 and 11, with expected heterozygosity ranging between 0.07 and 0.88. All of these loci cross-amplified in other species of Atta. Conclusions: These six polymorphic microsatellite loci should prove useful for future genetic investigations of the pest species Atta laevigata, as well as studies of other species of leaf-cutter ants in the genus Atta. © 2013 Kakazu et al.; licensee BioMed Central Ltd.

Genetic Structure of Lutzomyia longipalpis Populations in Mato Grosso Do Sul, Brazil, Based on Microsatellite Markers

Background:Lutzomyia longipalpis (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. © 2013 Santos et al.

Genetic variability and efficiency of DNA microsatellite markers for paternity testing in horse breeds from the Brazilian Marajó archipelago

In this study, 15 microsatellite DNA loci used in comparative tests by the International Society for Animal Genetics were applied to the evaluation of genetic diversity and management, and the efficiency of paternity testing in Marajoara horses and Puruca ponies from the Marajó Archipelago. Based on the genotyping of 93 animals, mean allelic diversity was estimated as 9.14 and 7.00 for the Marajoara and Puruca breeds, respectively. While these values are similar to those recorded in most European breeds, mean levels of heterozygosity were much lower (Marajoara 49%, Puruca 40%), probably as a result of high levels of inbreeding in the Marajó populations. The mean informative polymorphic content of this 15-marker system was over 50% in both breeds, and was slightly higher in the Marajoara horses. The discriminative power and exclusion probabilities derived from this system were over 99% for both populations, emphasizing the efficacy of these markers for paternity testing and genetic management in the two breeds.

Identification of duplicates of cassava accessions sampled on the North Region of Brazil using microsatellite markers

Duplicatas costumam ocorrer em bancos de germoplasma e a sua identificação é necessária para facilitar o manejo dos bancos ativos de germoplasma (BAGs) e diminuir custos de manutenção. O objetivo deste trabalho foi identificar duplicatas de mandioca determinadas previamente pela caracterização morfo-agronômica, em um BAG da Amazônia Oriental. Foram selecionados 36 acessos que se agrupavam em 13 grupos de similaridade morfo-agronômica para serem genotipados com 15 locos microssatélites. Todos os locos foram polimórficos, sendo obtidos 75 alelos, com média de cinco alelos por loco e H_E = 0,66. Foram encontrados 34 pares de genótipos que apresentaram perfis multilocos idênticos e a probabilidade de identidade genética foi de 1,1x10^-12 com probabilidade de exclusão de 99,9999%. Entre essas duplicatas, estão materiais coletados em épocas e locais diferentes, e com diferentes denominações e acessos com o mesmo nome coletados em diferentes locais e anos. O estudo identificou genótipos que vem sendo cultivados em diferentes locais e que vêm sendo mantidos pelos agricultores ao longo dos anos.

Development and characterization of microsatellite loci of microglanis cottoides (siluriformes: pseudopimelodidae) and cross-species amplification

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Selfing rate estimation in sugarcane under unfavorable natural conditions of crossing by using microsatellite markers

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

Microsatellite Organization in the Grasshopper Abracris flavolineata (Orthoptera: Acrididae) Revealed by FISH Mapping: Remarkable Spreading in the A and B Chromosomes

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

Paternity identification in sugarcane polycrosses by using microsatellite markers

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

Assessing Paternity in Japanese Quails (Coturnix Japonica) Using Microsatellite Markers - Inferences for Its Mating System and Reproductive Success

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Characterization of polymorphic microsatellite markers for the Neotropical leaf-frog Phyllomedusa burmeisteri and cross-species amplification

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

Development and characterization of microsatellite markers for Brazilian four-eyed frogs (genus Pleurodema) endemic to the Caatinga biome

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

Cattle-Derived Microsatellite Markers to Study the Water Buffalo Genome

Microsatellites are well-known DNA markers used in a variety of studies such as genome mapping, genetic diversity analysis, genetic conservation and phylogenetic studies. Although microsatellites are important markers, their development and characterization demands extensive time and high cost. Thus, before new markers are developed for a particular species, it is worthwhile to test the available markers from related species. In the present study, we evaluate cattle-derived microsatellite markers for genetic studies of water buffalo. Eighty-five percents of a total of 120 microsatellite markers were optimized using buffalo DNA (Bubalus bubalis). The results showed in this paper were also deposited in the National Center for Biological Information database (NCBI) (ProbeDB and UniSTS) for use in population genetic studies of buffalo by the scientific community. The use of heterologous primers significantly reduces the cost of developing specific markers for buffalo, providing a useful short cut for the genetic population analysis and gene mapping studies.

Microsatellite analysis supports clonal propagation and reduced divergence of Trypanosoma vivax from asymptomatic to fatally infected livestock in South America compared to West Africa

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)