Eucleia Primo Betioli Contel

Characterization of Brazilian soybean cultivars using microsatellite markers

Microsatellite markers or SSR (Simple Sequence Repeats) have proved to be an excellent tool for cultivar identification, pedigree analysis and the evaluation of genetic distance among organisms. Soybean cultivars have been characterized mainly by morphological and biochemical traits. However, these traits have not been sufficient to characterize the large number of cultivars eligible to receive protection under the Brazilian Cultivar Protection Act. In order to define new soybean cultivar markers, the alleles of twelve SSR loci of 186 Brazilian soybean cultivars were studied by estimating the variation in their size range and their respective frequencies. On average, 5.3 alleles per locus were detected, with a mean genetic diversity of 0.64 ± 0.12. These loci were used to distinguish morphologically similar groups, presenting a mean similarity coefficient of 0.46; their use allowed to determine 184 profiles for the 186 cultivars. A dendrogram based on the SSR loci profiles showed good agreement with the cultivar pedigree information.

Population structure analysis of Pimelodus maculatus (Pisces, Siluriformes) from the Tietê and Paranapanema Rivers (Brazil)

Pimelodus maculatus populations from the Tiete and Paranapanema rivers were sampled and had their genetic structure analyzed by using RAPD markers, with the aim of contributing to future conservation studies. The proportion of polymorphic loci was greater than 50% in the populations of both rivers. Genetic diversity data showed that, in spite of its nine hydroelectric plants, the Tiete river population was genetically homogeneous, whereas the Paranapanema river population was structured. This might be due to the presence of high waterfalls distributed all along its course. These data may serve as indicators for future conservation studies on the Tiete and Paranapanema rivers.

Genetic control and developmental expression of malate dehydrogenase in Apis mellifera

Starch gel electrophoresis of extracts of Apis mellifera indicates that genetic variability exists for the enzyme cytoplasmatic malate dehydrogenase (E.C. 1.1.1.37). Analysis of individuals throughout development indicates that the isozyme patterns are identical for larvae and adults and suggests a dimeric structure for the molecule. The isozyme pattern observed in pupae is more complex than that of larvae and adults and may be due to an additional pupalspecific MDH gene being expressed or to an epigenetic modification of the isozymes. Forty-three colonies with artificially inseminated queens were used to study the Mendelian pattern of inheritance. The data revealed that the MDH isozymes are encoded by three alleles, Mdh-1A, Mdh-1B, and Mdh-1C. The frequency of the Mdh-1 alleles is different in two analyzed subspecies, A. m. adansonii (African bees) and A. m. ligustica (Italian bees), with Mdh-1A and Mdh-1B in the African bees being 0.768 and 0.202, respectively. For the Italian bees, these frequencies are 0.136 and 0:154, respectively.

Alcohol dehydrogenase polymorphism in Apis mellifera

A polymorphic system of ADH isozymes is described in the honeybee Apis mellifera. Three and six different electrophoretic patterns were found, respectively, in drone and worker pupae analysis. The data indicate that the ADH isozymes are controlled by three alleles, Adh-11, Adh-12, and Adh-13. The frequency of the Adh-1 alleles is different in two analyzed subspecies, Apis mellifera adansonii (African bees) and Apis mellifera ligustica (Italian bees). In the African bees, the frequencies are 0.256 and 0.697 for Adh-11 and Adh-12, respectively. In the Italian bees, these values are shown to be 0.902 and 0.098, respectively. The allele Adh-13 was not detected in the Italian bee population. The effect of NAD on the resolution of this system was investigated, and only one region of ADH activity was obtained in drone pupae analysis when NAD was used in the gels. However, two different regions of activity were observed in the same samples, in the absence of the coenzyme. ADH activity was not detected in young larvae, but it increased to a maximum in prepupal and white-eyed pupal phases. It then declined progressively to total absence in the emerging bees.

Diversidade genética da soja entre períodos e entre programas de melhoramento no Brasil

The objective of this work was to detect the effects of plant breeding over the genetic diversity of soybean germplasm grown during the last three decades by comparing six different breeding programs and releasing intervals of soybean cultivars, using microsatellite loci. Regarding the breeding programs, all loci presented significantly different allelic distributions. Some loci presented alleles restricted to unique breeding programs, while others had a same allele being the most frequent in all the six programs. The AMOVA revealed that the major proportion of the variance occurred among cultivars within breeding programs and only 5.3% (p 0.05). The results suggest that the soybean germplasm pool involved in breeding programs in Brazil has maintained a stable genetic diversity during the past 30 years, in addition to a relative heterogeneity of some breeding programs.

Structure and genetic relationships between Brazilian naturalized and exotic purebred goat domestic goat (Capra hircus) breeds based on microsatellites

The genetic relationships and structure of fourteen goat (Capra hircus) populations were estimated based on genotyping data from 14 goat populations (n = 410 goats) at 13 microsatellite loci. We used analysis of molecular variance (AMOVA), principal component analysis (PCA) and F statistics (FIS, FIT and FST) to evaluate the genetic diversity (Ho, He and ad) of the goats. Genetic distances between the 14 goat populations were calculated from allelic frequency data for the 13 microsatellite markers. Moderate differentiation was observed for the populations of the undefined breeds (including the Anglo-Nubian-M breed), the naturalized Brazilian breeds (Moxoto, Caninde), the exotic purebred breeds (Alpine, Saanen, Toggenbourg and Anglo-Nubian) and the naturalized Brazilian Grauna group. Our AMOVA showed that a major portion (88.51%) of the total genetic variation resulted from differences between individual goats within populations, while between-populations variation accounted for the remaining 11.49% of genetic variation. We used a Reynolds genetic distance matrix and PCA to produce a phenogram based on the 14 goat populations and found three clusters, or groups, consisting of the goats belonging to the undefined breed, the naturalized breeds and the exotic purebred breeds. The closer proximity of the Caninde breed from the Brazilian state of Paraiba to the Grauna breed from the same state than to the genetically conserved Caninde breed from the Brazilian state of Ceara, as well as the heterozygosity values and significant deviations from Hardy-Weinberg equilibrium suggests that there was a high number of homozygotes in the populations studied, and indicates the importance of the State for the conservation of the local breeds. Cataloguing the genetic profile of Brazilian goat populations provides essential information for conservation and genetic improvements programs.

Intrapopulational genetic differentiation in Anopheles (N.) darlingi Root, 1926 (Diptera: Culicidae) in the amazon region

Four natural Amazonian Anopheles darlingi populations were analyzed for 19 loci, 12 of which showed variation, i.e., 68.4% of polymorphic loci. The Ariquemes, Rondonia, population was the most variable, with a large number of alleles per locus (2.26 ± 0.27) and high polymorphism (P = 63.15). The highest values of observed and expected intralocus heterozygosity were observed in the Manaus, Amazonas, population (Ho = 0.432 ± 0.11; He = 0.375 ± 0.08), and the lowest in the Cachoeira Porteira, Para, population (Ho = 0.236 ± 0.09; He = 0.290 ± 0.11). Wrights F-statistic revealed disequilibrium caused by an excess of homozygotes, as shown by the Fis > Fst values (Fis = 0.083 > 0.026) reflecting intrapopulational differentiation. The four populations studied were genetically similar, as indicated by distance and similarity values. Chromosomal variation of Amazon population also did not indicate geographical differentiation, and populations in the central region of the Amazon Basin showed high polymorphism in relation to the marginal populations, which were mainly monomorphic.

Restriction fragment length polymorphism (RFLP) in exon 2 of the BoLA-DRB3 gene in South American cattle.

The Bola-DRB3 gene participates in the development of the immune response and is highly polymorphic. For these reasons, it has been a candidate gene in studies of the genetic basis of disease resistance and in population genetic analysis. South American native cattle breeds have been widely replaced by improved exotic breeds leading to a loss of genetic resources. In particular, South American native breeds have high levels of fertility and disease resistance. This work describes genetic variability in the BoLA-DRB3 gene in native (Caracu, Pantaneiro, Argentinean Creole) and exotic (Holstein, Jersey, Nelore, Gir) cattle breeds in Brazil and Argentina. PCR-RFLP alleles were identified by combining the restriction patterns for the BoLA-DRB3.2 locus obtained with RsaI, BstY, and HaeIII restriction enzymes. Allelic frequencies and deviations from the Hardy–Weinberg equilibrium were also calculated. Analysis of the 24 BoLA-DRB3 PCR-RFLP alleles identified showed differences in the allele distributions among breeds.

Genetic characterization of 12 heterologous microsatellite markers for the giant tropical tree Cariniana legalis (Lecythidaceae)

Twelve microsatellite loci previously developed in the tropical tree Cariniana estrellensis were genetically characterized in Cariniana legalis. Polymorphisms were assessed in 28 C. legalis individuals found between the Pardo and Mogi-Guaçu River basins in the state of São Paulo, Brazil. Of the 12 loci, 10 were polymorphic and exhibited Mendelian inheritance. The allelic richness at each locus ranged from 2-11, with an average of 7 alleles per locus, and the expected heterozygosity ranged from 0.07-0.88. These loci showed a high probability of paternity exclusion. The characteristics of these heterologous microsatellite markers indicate that they are suitable tools for investigating questions concerning population genetics in C. legalis.

Genetic structure of Blastocerus dichotomus populations in the Parana River basin (Brazil) based on protein variability

The population structure of 147 marsh deer (Blastocerus dichotomus) from three areas in the Paraná River basin, Brazil, was studied by observing protein polymorphism at 17 loci. Six loci were polymorphic and 11 monomorphic. The proportion of polymorphic loci (P) was 35.29% and the average heterozygosity (H) was 6.31%. Wrights FST indicated that only 4.9% of the total variation in allelic frequencies was due to genetic differences between the three groups. The high value of FIS (0.246) indicated inbreeding in the marsh deer. Genetic distance values (D = 0.014–0.051) showed little divergence between the three areas. We suggest that probable mechanisms accounting for the genetic structure are female phylopatry and polygyny and also that inbreeding has resulted from decreasing areas of wetland leading to isolation, overhunting, and diseases transmitted by cattle.