[show abstract][hide abstract] ABSTRACT: Molecular methods havesubstantially advanced our knowledge about ant systematics in the past few years. Here, we infer the molecular phylogeny of sand dune ants of the genus Mycetophylax, Emery 1913 (Formicidae: Myrmicinae: Attini) using 730 base pairs of DNA sequences of the two nuclear genes longwave rhodopsin and wingless. Our analyses indicate that Mycetophylax is monophyletic, as suggested by its morphological characters. M. morschi, previously considered a species of Cyphomyrmex due to a scrobe-like impressed area on the head, forms a well-supported cluster with the two other species of Mycetophylax, M. conformis and M. simplex. Our analysis yields the first comprehensive phylogeny of Mycetophylax based on molecular data and includes specimens from localities within a wide distributional range as well as all species belonging to the genus following the recent taxonomic revision.
Molecular Phylogenetics and Evolution 10/2013; · 4.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: The first studies on the genome size of stingless bee species showed a range from 0.27 pg (Melipona subnitida and Melipona quadrifasciata) to 1.38 pg (Melipona capixaba). Considering this variation, we quantified the DNA content of 26 species of Meliponini, in order to provide input for future comparative studies in this tribe. Haploid genome size (1C) estimates, using flow cytometry analyses (FCM), ranged from 0.26 ± 0.003 pg (Paratrigona subnuda) to 0.98 ± 0.023 pg (Melipona flavolineata), with an average of 0.54 ± 0.17 pg. FCM analyses also demonstrated a small difference in the haploid genome size between males and females of the same species, with the males generally having a smaller genome than females. Our data also evidenciated that variations in the genome size of stingless bees do not correlate with changes in chromosome number and that in some genera the DNA content is more variable than in others.
[show abstract][hide abstract] ABSTRACT: Complementary sex determination in Hymenoptera implies that heterozygosity at the sex locus leads to the development of diploid females, whereas hemizygosity results in haploid males. Diploid males can arise through inbreeding. In social species, these pose a double burden on colony fitness, from significant reduction in its worker force and through being less viable and fertile than haploid males. Apart from being “misfits”, diploid males are of interest to assess molecular correlates for possibly ploidy-related bionomic differences. Herein, we generated suppression subtractive cDNA libraries from newly emerged haploid and diploid males of the stingless bee Melipona quadrifasciata to enrich for differentially expressed genes. Gene Ontology classification revealed that in haploid males more DEGs were related to stress responsiveness, biosynthetic processes, reproductive processes and spermatogenesis, whereas in diploid ones differentially expressed genes were associated with cellular organization, nervous system development and amino acid transport were prevalent. Furthermore, both libraries contained over 40 % ESTs representing possibly novel transcripts. Quantitative RT-PCR analyses confirmed the differential expression of a representative DEG set in newly emerged males. Several muscle formation and energy metabolism-related genes were under-expressed in diploid males. On including 5-day-old males in the analysis, changes in transcript abundance during sexual maturation were revealed.
[show abstract][hide abstract] ABSTRACT: Melipona quadrifasciata is a stingless bee widely found throughout the Brazilian territory, with two recognized subspecies, M. quadrifasciata anthidioides, that exhibits interrupted metasomal stripes, and M. quadrifasciata quadrifasciata, with continuous metasomal stripes. This study aimed to estimate the genetic variability of these subspecies. For this purpose, 127 colonies from 15 Brazilian localities were analyzed, using nine species-specific microsatellite primers. At these loci, the number of alleles ranged from three to 15 (mean: 7.2), and the observed heterozygosity (Ho) ranged from 0.03-0.21, while the expected heterozygosity (He) ranged from 0.23-0.47. The genetic distances among populations ranged from 0.03-0.45. The FST multilocus value (0.23) indicated that the populations sampled were structured, and the clustering analysis showed the formation of two subgroups and two more distant populations. The first group contained the subspecies M. quadrifasciata quadrifasciata, and the other, the subspecies M. quadrifasciata anthidioides and the two M. quadrifasciata populations with continuous metasomal stripes from northern Minas Gerais. These results confirmed that the yellow metasomal stripes alone are not a good means for correctly identifying the different subspecies of M. quadrifasciata.
Genetics and Molecular Biology 03/2013; 36(1):111-7. · 0.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Melipona scutellaris is an important pollinator in natural and cultured areas from northeastern Brazil. Therefore, the goal of this work was to investigate the genetic diversity and population structure of M. scutellaris within its Bahia range, relating putative geographical influences on population dynamics. A total of 111 colonies from 13 municipalities in Bahia from sea level up to 1,011 m of altitude were sampled. Five species-specific codominant (microsatellites) and ten dominant (ISSR) primers were amplified, yielding from 2 to 13 alleles and 94 bands, respectively. The mean genetic diversity (H e) was 0.50 for microsatellites and 0.33 for ISSR markers. AMOVA revealed that most of genetic variation is found within localities (82.6 % for microsatellites and 73.6 % for ISSR), and UPGMA and Bayesian analysis revealed the formation of two genetic groups related to altitude. Therefore, conservation strategies should take altitude variation into consideration to assure the genetic integrity of M. scutellaris. conservation / ISSR / microsatellites / population genetics / stingless bee
[show abstract][hide abstract] ABSTRACT: Genome size estimates and their evolution can be useful for studying the phylogenetic relationships and taxonomy of a particular group. In the present study, the genome sizes of the three species that comprise the Mycetophylax genus were estimated by flow cytometry (FCM). There was little variation in genome size among them. The mean haploid genome size value of male and female individuals of Mycetophylax morschi was 312.96 Mbp (0.32pg) and that of Mycetophylax conformis and Mycetophylax simplex females were 312.96 Mbp (0.32pg) and 381.42 Mbp (0.39pg), respectively. At first glance, this variation could be related with the heterochromatin content. Our results, together with other previous reports, have contributed to our knowledge about Attini genome size and will be useful to improve the understanding of the evolution of this tribe. It will help select potential model species in Attini for future genomic and sequencing projects.
[show abstract][hide abstract] ABSTRACT: Males, queens and workers of stingless bees show differences in external morphology, behaviour and roles within a colony. In addition, each individual has a cuticular chemical signature responsible for mutual communication that is essential for maintaining the integrity of the colony. In this paper we characterize the cuticular hydrocarbon composition of newly emerged diploid and haploid males, workers and virgin queens of Melipona quadrifasciata by gas chromatography-mass spectrometry (GC/MS) analysis. This is the first time that the cuticular profile of diploid males in a species of stingless bee has been characterized. We found differences in the cuticular hydrocarbon composition among males, workers and virgin queens, recording both qualitative and quantitative differences among individuals of different phenotypes. However, no compound was found exclusively in diploid males. The cuticular chemical profiles of haploid and diploid males were very similar to those of workers. Moreover, the cuticular lipids of males and workers were significantly different from those of queens. Tricosane, pentacosene-2 and 7-methyl-heptacosane were the compounds responsible for this significant separation. This result correlates with the behavioural and morphological differences among these phenotypes.
[show abstract][hide abstract] ABSTRACT: Physicochemical analyses were carried out to evaluate 27 samples of honeys from three species of the Brazilian genus Melipona (M. capixaba, M. rufiventris and M. mondury) from Espírito Santo and Minas Gerais States. The parameters water activity (Aw), percentage of soluble solids (Brix %), pH, acidity (meq/Kg) and moisture (%) were evaluated. The honey characteristics obtained from these samples were very similar to the ones from other Melipona species. However, regarding the honey from Apis (honey bee), only the pH values were similar. The low pH value and the high acidity detected in Melipona honey are potential factors for increasing the honey shelf life because they do not provide favorable conditions for the microbial development. On the other hand, the high level of water activity favors the growth of microorganisms, especially yeast, which demands a more careful handled and storage. The observed differences between Melipona and Apis honey reinforce the need for specific quality settings for stingless bee honey.
Anais da Academia Brasileira de Ciências 07/2012; 84(3):605-8. · 0.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: Some studies require fresh biological material for their development. Ant colonies have been reared under laboratory conditions
for scientific purposes, and several methodologies for leafcutter ants have been reported in the literature. However, these
methods are not well adapted for rearing basal Attini. In this study, we proposed a methodology for rearing basal Attini species
in the laboratory based on the evaluation of colonies of the genus Mycetophylax. The complete system consists of two round translucent polypropylene containers inserted one inside the other, where one
serves as a chamber proper and the other as a foraging area. Both containers are sealed with their lids, protecting the environment
against desiccation. From a total of 29 colonies collected in the field, 22 colonies survived for at least 30weeks, and Mycetophylax morschi was the most adapted for rearing under laboratory conditions. The main problem with rearing basal Attini in the laboratory
is the loss of moisture. Thus, the method applied here may be adopted for rearing other basal Attini, as well as other ant
species very sensitive to moisture variation.
[show abstract][hide abstract] ABSTRACT: In Panama, species of the genus Lutzomyia are vectors of American cutaneous leishmaniasis (ACL). There is no recent ecological information that may be used to develop tools for the control of this disease. Thus, the goal of this study was to determine the composition, distribution and diversity of Lutzomyia species that serve as vectors of ACL. Sandfly sampling was conducted in forests, fragmented forests and rural environments, in locations with records of ACL. Lutzomyia gomezi, Lutzomyia panamensis and Lutzomyia trapidoi were the most widely distributed and prevalent species. Analysis of each sampling point showed that the species abundance and diversity were greatest at points located in the fragmented forest landscape. However, when the samples were grouped according to the landscape characteristics of the locations, there was a greater diversity of species in the rural environment locations. The Kruskal Wallis analysis of species abundance found that Lu. gomezi and Lu. trapidoi were associated with fragmented environments, while Lu. panamensis, Lutzomyia olmeca bicolor and Lutzomyia ylephiletor were associated with forested environments. Therefore, we suggest that human activity influences the distribution, composition and diversity of the vector species responsible for leishmaniasis in Panama.
Memórias do Instituto Oswaldo Cruz 12/2011; 106(8):1024-31. · 1.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: Lutzomyia longipalpis is the primary vector of the parasite responsible for visceral leishmaniasis in the Americas. In the present study, Lu. longipalpis was found in a domiciliary area in Limón, a district in Capira, a region in which cutaneous leishmaniasis is endemic in Panama. Previously, this species has been found in a humid forest in this same region. Finding Lu. longipalpis in domiciliary areas indicates that this species may be adapting to new habitats and that it may play a role in the transmission of leishmaniasis in Panama.
Memórias do Instituto Oswaldo Cruz 12/2011; 106(8):1049-51. · 1.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males.
Genetics and Molecular Biology 10/2011; 34(4):698-706. · 0.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Stingless bee colonies typically consist of one single-mated mother queen and her worker offspring. The stingless bee Melipona bicolor (Hymenoptera: Apidae) shows facultative polygyny, which makes this species particularly suitable for testing theoretical expectations concerning social behavior. In this study, we investigated the social structure and genetic relatedness among workers from eight natural and six manipulated colonies of M. bicolor over a period of one year. The populations of M. bicolor contained monogynous and polygynous colonies. The estimated genetic relatedness among workers from monogynous and polygynous colonies was 0.75 ± 0.12 and 0.53 ± 0.16 (mean ± SEM), respectively. Although the parental genotypes had significant effects on genetic relatedness in monogynous and polygynous colonies, polygyny markedly decreased the relatedness among nestmate workers. Our findings also demonstrate that polygyny in M. bicolor may arise from the adoption of related or unrelated queens.
Genetics and Molecular Biology 04/2011; 34(2):338-44. · 0.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pollen samples were collected in three different periods from 11 Melipona capixaba Moure & Camargo hives and analyzed with melissopalynological methodology. A total of 33 pollen types were identified, of which 23 genera and 15 families were identified. The following families showed the highest pollen richness: Fabaceae (7), Myrtaceae (3), Solanaceae (3), Arecaceae (2), Asteraceae (2), Euphorbiaceae (2), Melastomataceae/Combretaceae (2), Rubiaceae (2), and Sapindaceae (2). The most frequent pollen types (>45%) were Eucalyptus, which generated great similarities between the samples, except one in which the Tibouchina was predominant. Although the majority of the pollen types showed low percentage values, the results demonstrated that M. capixaba has taken advantage of the polliniferous sources available in the Atlantic Rainforest as well as in the "Capoeira" (brushwood, secondary forest) and "ruderal" (field) plants, probably implying its importance as a pollinator of the native flora and of the exotic species.
Psyche A Journal of Entomology 01/2011; doi: 10.1155/2011/107303(2011):ID 107303.
[show abstract][hide abstract] ABSTRACT: Partamona is a Neotropical genus of stingless bees that comprises 33 species distributed from Mexico to southern Brazil. These bees are well-adapted to anthropic environments and build their nests in several substrates. In this study, 66 colonies of Partamona helleri from five localities in the Brazilian state of Minas Gerais (São Miguel do Anta, Teixeiras, Porto Firme, Viçosa and Rio Vermelho) were analyzed using nine microsatellite loci in order to assess their genetic variability. Low levels of observed (H(o) = 0.099-0.137) and expected (H (e) = 0.128-0.145) heterozygosity were encountered and revealed discrete genetic differentiation among the populations (F (ST) = 0.025). AMOVA further showed that most of the total genetic variation (94.24%) in P. helleri was explained by the variability within local populations.
Genetics and Molecular Biology 10/2010; 33(4):781-4. · 0.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: When working at quantifying the genome size of stingless bees, it was observed that males of Lestrimelitta sp possessed the same amount of nuclear DNA as the females. Thus, we used flow cytometry (FCM) and cytogenetic analysis to confirm the ploidy of these individuals. The males analyzed proved to be diploid, since, through cytometric analysis, it was demonstrated that the mean genome size of both males and females was the same (C = 0.463 pg), and, furthermore, cytogenetic analysis demonstrated that both had 2n = 28 chromosomes.
Genetics and Molecular Biology 07/2010; 33(3):491-3. · 0.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: For a study of diversity and genetic structuring in Melipona quadrifasciata, 61 colonies were collected in eight locations in the state of Minas Gerais, Brazil. By means of PCR analysis, 119 ISSR bands were obtained, 80 (68%) being polymorphic. H(e) and H (B) were 0.20 and 0.16, respectively. Two large groups were obtained by the UPGMA method, one formed by individuals from Januária, Urucuia, Rio Vermelho and Caeté and the other by individuals from São João Del Rei, Barbacena, Ressaquinha and Cristiano Otoni. The Φst and θ(B) values were 0.65 and 0.58, respectively, thereby indicating high population structuring. UPGMA grouping did not reveal genetic structuring of M. quadrifasciata in function of the tergite stripe pattern. The significant correlation between dissimilarity values and geographic distances (r = 0.3998; p < 0.05) implies possible geographic isolation. The genetic differentiation in population grouping was probably the result of an interruption in gene flow, brought about by geographic barriers between mutually close geographical locations. Our results also demonstrate the potential of ISSR markers in the study of Melipona quadrifasciata population structuring, possibly applicable to the studies of other bee species.
Genetics and Molecular Biology 04/2010; 33(2):394-7. · 0.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers.
Genetics and Molecular Biology 04/2010; 33(2):390-3. · 0.74 Impact Factor