RESUMO
The Meliponini, also known as stingless bees, are distributed in tropical and subtropical areas of the world and plays an essential role in pollinating many wild plants and crops These bees can build nests in cavities of trees or walls, underground or in associations with ants or termites; interestingly, these nests are sometimes found in aggregations. In order to assess the genetic diversity and structure in aggregates of Nannotrigona testaceicornis (Lepeletier), samples of this species were collected from six aggregations and genetically analyzed for eight specific microsatellite loci. We observed in this analysis that the mean genetic diversity value among aggregations was 0.354, and the mean expected and observed heterozygosity values was 0.414 and 0.283, respectively. The statistically significant Fis value indicated an observed heterozygosity lower than the expected heterozygosity in all loci studied resulting in high homozygosis level in these populations. In addition, the low number of private alleles observed reinforces the absence of structuring that is seen in the aggregates. These results can provide relevant information about genetic diversity in aggregations of N. testaceicornis and contribute to the management and conservation of these bees' species that are critical for the pollination process.
Assuntos
Abelhas/genética , Variação Genética , Animais , Brasil , Heterozigoto , Repetições de MicrossatélitesRESUMO
Here, we explore the mating pattern and genetic structure of a tropical tree species, Cariniana estrellensis, in a small population in which progeny arrays (n=399), all adults (n=28) and all seedlings (n=39) were genotyped at nine highly informative microsatellite loci. From progeny arrays we were able to identify the source tree for at least 78% of pollination events. The gene immigration rates, mainly attributable to pollen, were high, varying from 23.5 to 53%. Although gene dispersal over long distance was observed, the effective gene dispersal distances within the small population were relatively short, with mean pollination distances varying from 69.9 to 146.9 m, and seed dispersal distances occurring up to a mean of 119.6 m. Mating system analyses showed that C. estrellensis is an allogamous species (tm=0.999), with both biparental inbreeding (tm-ts=-0.016) and selfing rates (s=0.001) that are not significantly different from zero. Even though the population is small, the presence of private alleles in both seedlings and progeny arrays and the elevated rates of gene immigration indicate that the C. estrellensis population is not genetically isolated. However, genetic diversity expressed by allelic richness was significantly lower in postfragmentation life stages. Although there was a loss of genetic diversity, indicating susceptibility of C. estrellensis to habitat fragmentation, no evidence of inbreeding or spatial genetic structure was observed across generations. Overall, C. estrellensis showed some resilience to negative genetic effects of habitat fragmentation, but conservation strategies are needed to preserve the remaining genetic diversity of this population.
Assuntos
Ecossistema , Variação Genética , Genética Populacional , Lecythidaceae/genética , Árvores/genética , Brasil , Conservação dos Recursos Naturais , DNA de Plantas/genética , Genótipo , Endogamia , Repetições de Microssatélites , Polinização/genética , Reprodução/genética , Análise de Sequência de DNARESUMO
Descreveram-se os marcadores isoenzimáticos e estimou-se a variabilidade genética de 20 subpopulações brasileiras de escargots (Helix aspersa). O estudo dos oito locos foi feito por eletroforese em gel de amido, em amostras com 30 indivíduos cada, obtidas em criatórios dos estados de Santa Catarina, São Paulo e Rio de Janeiro (uma, duas e 17 amostras, respectivamente). Observou-se polimorfismo nos locos das enzimas LAP, 6-PGD, PEP 2, PEP 1 e MDH, com três alelos nos três primeiros locos e dois nos demais. Os locos da ME, da SOD e da PGI apresentaram-se monomórficos. As freqüências gênicas de sete amostras ajustaram-se ao modelo de Hardy-Weinberg (P<0,05), e as de outras seis amostras ajustaram-se ao modelo de Wright (P<0,05), indicando que elas estão submetidas a diferentes regimes reprodutivos. Os desvios da panmixia para toda a população (F IT ) e dentro das subpopulações (F IS) não foram significativos (P³0,05). O desvio entre as subpopulações (F ST=0,0485) foi significativo (P<0,05) e apontou pequena diferenciação entre elas. As estimativas de diversidade total (Ht), entre subpopulações (Dst) e dentro das subpopulações (Hs), indicaram que a diversidade genética é reduzida e sua maior parte encontra-se dentro das subpopulações, sugerindo uma base genética estreita para essa população. As distâncias genéticas também foram pequenas, não permitindo a construção de um dendrograma.
Assuntos
Eletroforese em Gel de Amido/métodos , Variação Genética , Caracois Helix , Isoenzimas/análiseRESUMO
Descreveram-se os marcadores isoenzimáticos e estimou-se a variabilidade genética de 20 subpopulações brasileiras de escargots (Helix aspersa). O estudo dos oito locos foi feito por eletroforese em gel de amido, em amostras com 30 indivíduos cada, obtidas em criatórios dos estados de Santa Catarina, São Paulo e Rio de Janeiro (uma, duas e 17 amostras, respectivamente). Observou-se polimorfismo nos locos das enzimas LAP, 6-PGD, PEP 2, PEP 1 e MDH, com três alelos nos três primeiros locos e dois nos demais. Os locos da ME, da SOD e da PGI apresentaram-se monomórficos. As freqüências gênicas de sete amostras ajustaram-se ao modelo de Hardy-Weinberg (P<0,05), e as de outras seis amostras ajustaram-se ao modelo de Wright (P<0,05), indicando que elas estão submetidas a diferentes regimes reprodutivos. Os desvios da panmixia para toda a população (F IT ) e dentro das subpopulações (F IS) não foram significativos (P³0,05). O desvio entre as subpopulações (F ST=0,0485) foi significativo (P<0,05) e apontou pequena diferenciação entre elas. As estimativas de diversidade total (Ht), entre subpopulações (Dst) e dentro das subpopulações (Hs), indicaram que a diversidade genética é reduzida e sua maior parte encontra-se dentro das subpopulações, sugerindo uma base genética estreita para essa população. As distâncias genéticas também foram pequenas, não permitindo a construção de um dendrograma.(AU)
In order to assess genetic variability in subpopulations of Helix aspersa, eight isoenzyme loci in 30 individuals in each of 20 subpopulations, obtained from breeders in Santa Catarina (1), São Paulo(2) and Rio de Janeiro (17) states of Brazil, were examined. Polymorphic loci included LAP, 6-PGD, PEP 2, PEP 1 and MDH, with three alelles at each of the first three loci and two at each of the others. The ME, SOD and PGI loci were monomorphic. Gene frequencies in 7 of 20 subpopulations were consistent with the Hardy-Wienberg equilibrium (P<0.05), and 6 were consistent with Wright model, indicating that these subpopulations did not meet requirements for genotypic equilibrium to be achieved. Despite the fact that some F values were high, FIS and FIT were not significantly different from zero (P³0.05). Although small, the FST value (0.0485) was significant, suggesting small differences among populations. Most of the low genetic variation at isoenzyme loci was observed within subpopulations rather than among subpopulations, suggesting a small genetic basis for these samples. Estimated genetic distances among pairs of subpopulations also were low.(AU)
Assuntos
Variação Genética , Eletroforese em Gel de Amido/métodos , Isoenzimas/análise , Caracois HelixRESUMO
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%. Wright's 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 F(IS) (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.
Assuntos
Proteínas Sanguíneas/genética , Cervos/genética , Variação Genética , Genética Populacional , Animais , Brasil , Feminino , Frequência do Gene , Heterozigoto , Masculino , Polimorfismo GenéticoRESUMO
The giant anteater (Myrmecophaga tridactyla) is found from Belize and Guatemala to Paraguay and Argentina. Its conservation status is considered vulnerable by IUCN. Here we report the isolation and characterization of six microsatellite loci. Positive loci for (GT)(n) were isolated using a magnetic bead hybridization selection protocol. The number of alleles per locus as well as the heterozygosity and PCR conditions are described. These loci will be useful for studying population structure, genetic diversity, and paternity in M. tridactyla wild populations.
Assuntos
Repetições de Microssatélites/genética , Xenarthra/genética , Animais , Sequência de Bases , Primers do DNA , Heterozigoto , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
African-derived mitochondrial DNA (mtDNA) have been described in South American and Caribbean native cattle populations, which could have been introduced into America from Iberia or by direct importation from Africa. However, the similarity among described haplotypes is not known. We examined mtDNA variation in Guadeloupe Creole and Spanish cattle in an attempt to identify African-derived mtDNA haplotypes and compare them with those previously described. Eleven haplotypes clustered into the European taurine haplogroup (T3), two haplotypes into the African taurine (T1) haplogroup, and three haplotypes into the African-derived American haplogroup (AA). The AA1 and Eucons haplotypes were the most frequently observed. The presence of the AA haplogroup in Spanish cattle confirms historical records and genetic evidence of Iberian cattle as the main source of American native cattle origin. The possible origin of African-derived mitochondrial haplotypes in Iberian and Creole cattle is discussed, and the accumulated evidence does not support a founder effect from African ancestral cattle by direct importations. The presence of taurine AA and T3 haplotypes in Brazilian Nellore may indicate introgression by local European-derived cattle. Data presented in this work will contribute to the understanding of the origin of Guadeloupe Creole cattle.
Assuntos
Cruzamento , Bovinos/genética , DNA Mitocondrial/genética , Variação Genética , Filogenia , África , Animais , Sequência de Bases , Brasil , Região do Caribe , Primers do DNA , Haplótipos/genética , Dados de Sequência Molecular , Dinâmica Populacional , Análise de Sequência de DNA , Espanha , Especificidade da EspécieRESUMO
This article reports the nucleotide diversity within the control region of 42 mitochondrial chromosomes belonging to five South American native cattle breeds (Bos taurus). Analysis of these data in conjunction with B. taurus and B. indicus sequences from Africa, Europe, the Near East, India, and Japan allowed the recognition of eight new mitochondrial haplotypes and their relative positions in a phylogenetic network. The structure of genetic variation among different hypothetical groupings was tested through the molecular variance decomposition, which was best explained by haplotype group components. Haplotypes surveyed were classified as European-related and African-related. Unexpectedly, two haplotypes within the African cluster were more divergent from the African consensus than the latter from the European consensus. A neighbor-joining tree shows the position of two haplotypes compared to European/African mitochondrial lineage splitting. This different and putatively ancestral mitochondrial lineage (AA) is supported by the calibration of sequence divergence based on the Bos-Bison separation. The European/African mitochondria divergence might be subsequent (67,100 years before present) to that between AA and Africans (84,700 years before present), also preceding domestication times. These genetic data could reflect the haplotype distribution of Iberian cattle five centuries ago.
Assuntos
Bovinos/genética , Variação Genética , Mitocôndrias/genética , África , Análise de Variância , Animais , Evolução Biológica , Cruzamento , Frequência do Gene , Haplótipos , FilogeniaRESUMO
African beetles Onthophagus gazella from both sexes were analyzed by electrophoresis for an investigation of esterase isozymes using alpha-naphthyl propionate and methylumbelliferyl propionate as substrates. Only one of the esterases (Est. 6) reacted with one of the substrates (alpha-naphthyl propionate). Six areas of activity were found, two of them being polymorphic (Est. 3 and Est. 4). For presence of Est. 3, 337 individuals were analyzed, including descendants of 32 controlled crossings: two alleles were identified, whose frequencies are Est. 3A = 0.447 and Est. 3B = 0.553. The population is in equilibrium for this locus (qui-square = 4.18; 0.2 > P > 0.1). For Est. 4, 338 individuals, descendants of 32 controlled crossings, were analysed. In this case, three alleles were identified whose frequencies are: Est. 4A = 0.277; Est. 4B = 0.661; and Est. 4C = 0.062. The population is not in equilibrium for this locus (qui-square = 40.259; p < 0.001). Two esterases were detected only in the pupal stage and another one in larvae. Of the 23 loci analyzed in these insects up to now, 3 are polymorphic (13 percent), which indicates very low variability in the population here studied
Assuntos
Animais , Masculino , Feminino , Besouros , Esterases , Besouros , Esterases , Frequência do Gene , Variação Genética , Isoenzimas , Polimorfismo GenéticoRESUMO
The electrophoretic pattern of the intracellular esterase of the dermatophyte Trichophyton rubrum was altered when this fungus was grown in the presence of subinhibitory concentrations of the antimycotics tioconazole or griseofulvin. All strains (original isolate and antimycotic resistant mutants) presented five clearly visible bands when cultivated on medium containing below-minimum inhibitory concentrations (sub-MICs) of tioconazole or griseofulvin, and only two clearly visible bands when cultivated in medium without antimycotics. No extra bands were detected in the electrophoretic patterns of the extracellular esterase of these fungi (mutants or the original isolate) when cultivated with or without tioconazole or griseofulvin (sub-MIC values). These results suggest that additional forms of esterase are produced inside the cell and may be a nonspecific response to cellular stress, or may participate in cellular detoxification processes in the presence of these antimycotics.
Assuntos
Antifúngicos/farmacologia , Hidrolases de Éster Carboxílico/metabolismo , Griseofulvina/farmacologia , Imidazóis/farmacologia , Trichophyton/efeitos dos fármacos , Trichophyton/enzimologia , Carboxilesterase , Resistência Microbiana a Medicamentos , Testes de Sensibilidade Microbiana , Mutação , Trichophyton/genética , Trichophyton/crescimento & desenvolvimentoRESUMO
African beetles Onthophagus gazella from both sexes were analyzed by electrophoresis for an investigation of esterase isozymes using alpha-naphthyl propionate and methylumbelliferyl propionate as substrates. Only one of the esterases (Est. 6) reacted with one of the substrates (alpha-naphthyl propionate). Six areas of activity were found, two of them being polymorphic (Est. 3 and Est. 4). For presence of Est. 3, 337 individuals were analyzed, including descendants of 32 controlled crossings: two alleles were identified, whose frequencies are Est. 3A = 0.447 and Est. 3B = 0.553. The population is in equilibrium for this locus (qui-square = 4.18; 0.2 > P > 0.1). For Est. 4, 338 individuals, descendants of 32 controlled crossings, were analysed. In this case, three alleles were identified whose frequencies are: Est. 4A = 0.277; Est. 4B = 0.661; and Est. 4C = 0.062. The population is not in equilibrium for this locus (qui-square = 40.259; p < 0.001). Two esterases were detected only in the pupal stage and another one in larvae. Of the 23 loci analyzed in these insects up to now, 3 are polymorphic (13%), which indicates very low variability in the population here studied.
Assuntos
Besouros/enzimologia , Esterases/genética , Animais , Besouros/genética , Esterases/metabolismo , Feminino , Frequência do Gene , Variação Genética , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Polimorfismo GenéticoRESUMO
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.
Assuntos
Bovinos/genética , Bovinos/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Polimorfismo de Fragmento de Restrição , Alelos , Animais , Argentina , Brasil , DNA/genética , DNA/isolamento & purificação , Éxons , Frequência do Gene , Especificidade da EspécieRESUMO
Fourteen goat populations were studied regarding their genetic relationship and structure. Parameters of genetic diversity (HT, HS and GST) and F statistic (FIS, FIT and FST) were estimated. Undefined breed populations presented high homogeneity, as did imported breed populations. Naturalized breed populations showed high differentiation. The genetic distances separating these 14 goat populations were calculated from gene frequency data for eight blood genetic markers (esterase D, phosphoglucomutase 1, carbonic anhydrase II, peptidase B, amylase, haemoglobin, transferrin, and protein X). Working with the genetic distance matrix of Nei corrected for small samples (DA), we constructed a dendrogram using the unweighted pair group method with arithmetic mean. DA values ranged from 0.0027 to 0.1518. The dendrogram divided the populations into two groups, one consisting of three populations of naturalized breeds, and another including the other populations (imported breeds, undefined breeds and some other naturalized breeds).
Assuntos
Genética Populacional , Cabras/genética , Animais , BrasilRESUMO
Yellowfever mosquitoes, Aedes aegypti (L), were collected from 3 towns located within 70 km of each other in the State of Sao Paulo to evaluate the protein variability of natural populations. Electrophoretic analysis permitted the identification of 6 loci responsible for the production of leucine aminopeptidase, 3 for esterases and malic enzyme, 2 for malate dehydrogenase, isocitrate dehydrogenase and alpha-glycerophosphate dehydrogenase, and 1 for phosphoglucomutase. For the 3 populations, the range for alleles per locus (1.63-2.03), the proportion of polymorphic loci (37.5-50.0%), and the expected mean heterozygosity (0.48-0.53) were greater than reported for other populations of A. aegypti. Although the 3 populations were similar genetically, the 1.8% differentiation was significant.
Assuntos
Aedes/enzimologia , Enzimas/genética , AnimaisRESUMO
The esterases, leucine aminopeptidase and alpha-glycerophosphate dehydrogenase revealed modifications in gene expressions during the development of Anopheles darlingi. The esterases showed five activity bands, 1 and 2 being more deeply stained during the larval stages than in pupae or adults, esterases 3 and 4 more deeply stained in pupae and adults whereas esterase 5 was present throughout development. Leucine aminopeptidase showed five activity bands: LAP2 and LAP5 were characteristic of larvae, LAP3 was specific for pupae and adults, LAP4 was detected only in pupae, and LAP1 and LAP6 were detected in all stages. alpha-Glycerophosphate dehydrogenase presented one activity band on starch gel whose intensity increased with development. Two activity bands were detected on polyacrylamide gel (alpha-GPDH1 and alpha-GPDH2) in 4th-instar larvae (old pigmented larvae) and this activity increased with development.
Assuntos
Anopheles/genética , Esterases/genética , Glicerolfosfato Desidrogenase/genética , Leucil Aminopeptidase/genética , Animais , Anopheles/enzimologia , Anopheles/crescimento & desenvolvimento , Esterases/metabolismo , Expressão Gênica , Glicerolfosfato Desidrogenase/metabolismo , Leucil Aminopeptidase/metabolismoRESUMO
To detect genetic markers, electrophoretic analyses were carried out on Tetragonisca angustula, a stingless bee well adapted to its wide area of occurrence, which is becoming economically important because of the quality of its honey. Polymorphism of the enzyme hexokinase was detected and it was demonstrated that, although it presents two bands in meliponines, this enzyme is under the control of a single locus whose product probably undergoes postranslational modification. The more common allele occurs in the two Tetragonisca subspecies studied here, but the other seems to be characteristic of only one subspecies. Four variants involving the two glycerol-3-phosphate dehydrogenase loci are also described. These two enzymes share the property of presenting two electrophoretic bands, one of which is characteristic of actively flying adult thoraces.
Assuntos
Abelhas/enzimologia , Glicerolfosfato Desidrogenase/química , Hexoquinase/química , Isoenzimas/química , Animais , Comportamento Animal , Feminino , Isocitrato Desidrogenase/química , Malato Desidrogenase/química , Masculino , Fosfoglucomutase/química , Polimorfismo Genético , Processamento de Proteína Pós-TraducionalRESUMO
Hexokinase enzyme was studied by means of starch-agarose gel electrophoresis in Plebeia droryana. Three anodal bands with enzyme activity were observed during the development: hexokinase-1 (HK-1), the intensity of which increases from larvae to adult, probably related with energy supply to thoracic flight muscles and, therefore, with flight activity; hexokinase-2 (HK-2), that reaches maximum intensity in clear brown eyed pupae and hexokinase-3 (HK-3), the intensity of which reaches maximum peak in winged pupae and is not observed in the adult phase. This isozyme should have important functions in the bee metamorphosis.
Assuntos
Abelhas/enzimologia , Voo Animal/fisiologia , Hexoquinase/análise , Isoenzimas/análise , Animais , Abelhas/crescimento & desenvolvimento , Eletroforese em Gel de Amido , Larva/enzimologiaRESUMO
Glycerol-3-phosphate dehydrogenase (G-3-PDH) isozymes were investigated in several bee and wasp species to verify if variations detected in G-3-PDH-2 isozymes are closely related to the age and activity of adult workers in the nest or hive of social species. In the solitary, the semisocial, and one social bee species, no phenotypic variations were detected for G-3-PDH-2 isozymes, and this was also the case for all wasp species investigated which were characterized as social. These results allow us to suggest that the variation detected in G-3-PDH-2 isozymes is a phenomenon closely related not only to adult age and activity in the hive, but also to a gradual acquisition of the ability to fly, which is not present in newly emerged worker meliponids in particular.
Assuntos
Abelhas/enzimologia , Glicerolfosfato Desidrogenase/genética , Isoenzimas/genética , Vespas/enzimologia , Fatores Etários , Animais , Abelhas/genética , Voo Animal/fisiologia , Variação Genética , Glicerolfosfato Desidrogenase/fisiologia , Isoenzimas/fisiologia , Fenótipo , Comportamento Social , Especificidade da Espécie , Vespas/genéticaRESUMO
In only 1 bee species (Tetragona clavipes) of 24 sampled in 145 colonies (0.69%) did we detect the presence of more than one allele for glycerol-3-phosphate dehydrogenase (EC 1.1.1.8), an enzyme that is involved in flight. In 34 colonies containing 9 wasp species, 5 colonies of only 2 species (Polybia paulista and P. sericea) showed variation in larval G-3-PDH (14.7%). The small amount of variation observed for the G-3-PDH-1 locus in the bee and wasp species analyzed in the present study agrees with that reported for the G-3-PDH system in other insects.