Genetic and ecological variability of Stylosanthes macrocephala determined by RAPD markers and GIS

Stylosanthes macrocephala M. B. Ferr. et S. Costa é uma leguminosa utilizada sob consorciação em pastagens, adubação e recuperação de áreas degradadas. A falta de características morfológicas e agronômicas estáveis e de informações ecogeográficas dos locais de coleta dos acessos tem dificultado o melhoramento genético da espécie. A fim de obter descritores ecológicos, moleculares e avaliar a variabilidade genética da coleção de S. macrocephala, 87 acessos foram analisados com o auxílio do Sistema de Informações Geográficas (SIG) e de marcadores moleculares RAPD. Os acessos provieram de sete Estados, cinco bacias hidrográficas, sete tipos de vegetação e sete tipos de solos. As altitudes dos locais de coleta variaram de 1 a 1.298 m e a pluviometria anual média de 550 a 2.870 mm. A variabilidade de descritores ecológicos sugeriu diversidade adaptativa na coleção. Com base em 161 marcadores RAPD, verificou-se que as distâncias genéticas entre os acessos de S. macrocephala variaram entre 0,02 e 0,42. Com base nessas distâncias, dez grupos de similaridade genética foram estabelecidos. Observou-se tendência de separação por bacias hidrográficas e elevada variabilidade genética entre os acessos coletados nos estados da Bahia e de Minas Gerais. A alta variabilidade genética da coleção de S. macrocephala evidencia a importância desses acessos para futuros trabalhos de melhoramento genético.Stylosanthes macrocephala M. B. Ferr et S. Costa is a leguminous species used as forage, cover crop and as a pioneer plant to recover degraded areas. Inexistence of stable morphological descriptors and lack of ecogeographic information about collecting sites bring difficulties to the studies of this species. The objective of this work was to use the geographic information system (GIS) and RAPD markers to obtain ecological and molecular descriptors and to study the genetic variability of 87 S. macrocephala accessions. The accessions were collected from different ecogeographical areas in seven Brazilian States, five hydrographic regions, seven vegetation types and seven soil types. Collecting sites ranged from 1 to 1,298 m above sea level with annual rainfall from 550 to 2,870 mm. Accession distribution along those diverse ecosystems indicate high adaptive diversity. Using 161 RAPD markers, genetic distances between accessions ranged from 0.02 to 0.42. These genetic distances allowed the establishment of ten genetic groups. Accessions collected in specific hydrographic region tended to be grouped in the same genetic group. Accessions collected in Bahia and Minas Gerais States showed high genetic variability. The high genetic variability observed in the accessions showed the importance of this S. macrocephala collection for breeding programs

Glândula hipofaríngeas na vespa social Polistes versicolor (Olivier): da morfologia às relações com o comportamento

As glândulas hipofaríngeas são estruturas presentes apenas na ordem Hymenoptera e apresentam-se como células epidérmicas modificadas em alguns grupos, enquanto em outros, apresentam morfologia mais elaborada, caracterizando-se como órgãos com anatomia bem definida. Muito bem estudadas em abelhas, as glândulas hipofaríngeas são glândulas exócrinas que fazem parte do sistema salivar e são responsáveis, em Apis, pela produção de substâncias que constituem a geléia real. Este produto é oferecido a todas as larvas como alimento, de maneira desigual, sendo este um fator responsável pela diferenciação das castas nas abelhas. Os objetivos do presente estudo foram analisar as glândulas hipofaríngeas de vespas, que carecem de estudos, procurando reconhecer seu papel na regulação social da colônia, bem como identificar a presença de aspectos glandulares que indicassem a ocorrência de morte celular. Utilizando Polistes versicolor, uma das espécies do gênero considerado como chave para o entendimento da evolução do comportamento social em insetos, foram realizadas análises histoquímicas, enzimológicas e ultra-estruturais das glândulas hipofaríngeas. Juntamente com estas análises foi realizado o estudo comportamental dos indivíduos analisados. Estes estudos auxiliaram no entendimento do ciclo de desenvolvimento das glândulas hipofaríngeas, bem como determinaram a constituição química da secreção glandular, representando uma contribuição inédita à identificação da morfologia e função dessas estruturas e de seu possível papel no contexto social das colônias de P. versicolor. Os resultados encontrados levam a crer que as glândulas destas vespas não estão envolvidas na produção de alimento para as larvas, como ocorre em abelhas. As características morfológicas...The hypopharyngeal glands are structures present only in the order Hymenoptera. They are constituted by modified epidermal cells in some groups, while in others, they present a more elaborated morphology and are characterized as distinct organs with a defined anatomy. These exocrine glands are part of the salivary system and have been well studied in bees. In Apis, they are the main responsible for the production of components of royal jelly. Brood is not fed equally with royal jelly resulting in cast differentiation in this genus. The aims of the present work were to analyze the hypopharyngeal glands of the wasp Polistes versicolor in order to recognize their role in the social regulation of the colony, as well as to identify the presence of glandular features that could indicate cell death. Polistes is considered a key genus for the understanding of the evolution of social behavior in insects. In the present work we used histochemical, enzymological and ultrastructural analyses. Behavioral studies were also carried out to determine the relationship between glandular development and individual activities. These studies provided important information about the development of the hypopharyngeal glands in P. versicolor and determined the histochemical characteristics of the glandular secretion. It represents an important contribution to the identification of the morphology and the roles played by these structures in the social context of P. versicolor colonies. The results suggest that these glands are not involved in food production for the brood, unlike the observed in bees. The morphological General Abstract characteristics of the secretory cells and their secretion, as well as the behavioral characteristics of these wasps suggest that the hypopharyngeal glands of P. versicolor might be involved in the production of digestive enzymes.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Histochemical characterization and secretory activity of the hypopharyngeal glands in the primitive social wasp Polistes versicolor (Hymenoptera: Vespidae)

Using histochemical techniques, the present work describes the basic histochemical characteristics of the secretion in hypopharyngeal glands of Polistes versicolor (Olivier) and estimates the secretory activity in specimens of different ages. The secretory activity was determined by glandular cell diameter and by the amount of secretion present in the glands. The results did not reveal a relationship between these parameters and the age of the wasps, not allowing us to determine the development cycle of these glands throughout the wasps' life. Also, a relationship between glandular cell diameter and amount of secretion present in the glands was not observed

The first Brazilian bovine breed: structure and genetic diversity of the Curraleiro Pé-duro

Background The production of animal-based foods from native breeds have a synergistic relationship with the regional culture, the local climate, and mainly the maintenance of alternative genetic resources for a system with a lower environmental impact. Thus the efficiency of conservation and production depends on assessing the variability of these local breeds. In the case of Curraleiro Pé-duro cattle, the most adapted individuals have undergone natural selection over five hundred years in the Brazilian savannas, mating with little or no human interference. The peculiarities of these biomes, where the regional flora is the food base and cattle is raised in extensive areas, likely influenced the genetic composition of the different groups that make up the first cattle breed of Brazil. Methods To evaluate the composition, diversity, variation, differentiation, and genetic structure of the populations studied, samples of hair follicles from 474 individuals of different animal categories (calves, yearlings, heifers, cows, and bulls) from three farms, defined as subpopulations “A”, “B”, and “C”, were collected. The animals were genotyped for 17 microsatellite markers using a DNA sequencer. After verification of monomorphic alleles, alleles outside the expected size range, and for the presence of stutter bands, the results were subjected to statistical analysis. Results The markers used were suitable for the proposed application with a mean Polymorphism Information Content (PIC) of 0.62. On average, the effective alleles were 4.25 per marker, with mean heterozygosities of 0.74 (observed and expected), which was lower in herd A (0.70) in comparison to herds B (0.77) and C (0.74). The analysis of molecular variance (AMOVA) revealed a higher rate of variation within herds (98.5%) and lower among herds (1.5%) (FSTranging from 0.00723 and 0.03198; p-values < 0.05). However no significant differences among herds where found with the Mantel test based on geographic distances. The formation of genetic clusters of all animals sampled with the software Structure resulted in minimum cluster values, with two main genetic groups (K = 2) observed among the evaluated animals. Therefore, based on PIC and heterozygosity values, a wide genetic diversity was observed, despite little differences in population structure (AMOVA, FST, and Structure results) among sampling sites

A note on the distribution of genetic diversity of Anglo-Nubian goats in central-northern farms of Piauí, Brazil

The objective of this study was to characterize the genetic variability of Anglo-Nubian goats using microsatellite markers. The study was conducted using herds from four municipalities of Central-Northern Piauí (Teresina, José de Freitas, Campo Maior, and Angical), where technical information is scarce. Seven markers suggested by FAO were used (ILSTS11, McM527, INRA23, ETH10, OarfCB304, OarfCB48, and MAF209). The samples were genotyped using a 7% polyacrylamide gel. The average number of alleles per locus was 4.0, with observed and expected heterozygosity of 0.38 and 0.55, respectively. Few deviations from the Hardy-Weinberg equilibrium were observed for each population. Only two loci deviated significantly in two localities. The coefficient of gene differentiation (GST') indicated that 11.9% of the genetic variation was distributed among populations, and according to the coefficient of inbreeding (GIS = 0.23 and FIS = 0.23), there is a deficiency of heterozygotes within populations. These findings corroborate the Bayesian analyses performed with the STRUCTURE software, which revealed three distinct and moderately structured groups. The graphic analysis showed that Teresina and José de Freitas are isolated groups, while Angical and Campo Maior share most of their alleles. Despite this, the level of diversity among herds was low. Based on this genetic structure, exchange of reproducers among municipalities is recommended for the maintenance of the breed