Gene Variation, Population Differentiation, and Sociogenetic Structure of Nests of Partamona seridoensis (Hymenoptera: Apidae, Meliponini)

Pleistocene climate changes shaped the population structure of Partamona seridoensis (Apidae, Meliponini), an endemic stingless bee from the Neotropical dry forest

Partamona seridoensis is an endemic stingless bee from the Caatinga, a Neotropical dry forest in northeastern Brazil. Like other stingless bees, this species plays an important ecological role as a pollinator. The aim of the present study was to investigate the genetic structure and evolutionary history of P. seridoensis across its current geographic range. Workers from 84 nests from 17 localities were analyzed for COI and Cytb genic regions. The population structure tests (Bayesian phylogenetic inference, AMOVA and haplotype network) consistently characterized two haplogroups (northwestern and eastern), with little gene flow between them, generating a high differentiation between them as well as among the populations within each haplogroup. The Mantel test revealed no isolation by distance. No evidence of a potential geographic barrier in the present that could explain the diversification between the P. seridoensis haplogroups was found. However, Pleistocene climatic changes may explain this differentiation, since the initial time for the P. seridoensis lineages diversification took place during the mid-Pleistocene, specifically the interglacial period, when the biota is presumed to have been more associated with dry conditions and had more restricted, fragmented geographical distribution. This event may have driven diversification by isolating the two haplogroups. Otherwise, the climatic changes in the late Pleistocene must not have drastically affected the population dynamics of P. seridoensis, since the Bayesian Skyline Plot did not reveal any substantial fluctuation in effective population size in either haplogroup. Considering its importance and the fact that it is an endemic bee from a very threatened Neotropical dry forest, the results herein could be useful to the development of conservation strategies for P. seridoensis.

Aspectos bioecológicos e genético-comportamentais envolvidos na conservação da abelha Jandaíra, Melipona subnitida Ducke (Apidae, Meliponini), e o uso de ferramentas moleculares nos estudos de diversidade

A abelha sem ferrão Melipona subnitida atualmente está presente em quase toda a região nordeste, em função da boa adaptabilidade ao semiárido nordestino e do potencial econômico-ecológico proporcionado pela produção de mel e pela polinização de cultivos em condições de confinamento. Apesar disso, é uma espécie ameaçada devido a processos de degradação ambiental, dentre os quais estão o desmatamento, o uso indiscriminado de agrotóxicos e o extrativismo. Tais interferências tendem a isolar as populações de Jandaíra, provocando uma queda na variabilidade genética e, consequentemente, uma redução na capacidade adaptativa da espécie. Porém, técnicas de biologia molecular estão sendo implementadas, possibilitando que populações desse tipo sejam avaliadas quanto ao seu grau de variabilidade genética. Marcadores moleculares do tipo microssatélites de DNA vêm sendo bastante usados, porém, em função do alto custo exigido para seu desenvolvimento, diversos estudos vêm empregando microssatélites transferidos de táxons próximos com amplo sucesso em estudos voltados à caracterização e à diversidade genética. Dessa forma, a presente revisão objetivou avaliar os mais relevantes aspectos bioecológicos e genético-comportamentais envolvidos na conservação da abelha Jandaíra, a fim de auxiliar na avaliação do grau de diversidade genética da espécie, bem como da sua distribuição entre indivíduos e populações da abelha sem ferrão M. subnitida.

Application of microsatellite markers in conservation genetics and fisheries management: recent advances in population structure analysis and conservation strategies

Microsatellites are the most popular and versatile genetic marker with myriads of applications in population genetics, conservation biology, and evolutionary biology. These are the arrays of DNA sequences, consisting of tandemly repeating mono-, di-, tri-, and tetranucleotide units, which are distributed throughout the genomes of most eukaryotic species. Microsatellites are codominant in nature, highly polymorphic, easily typed, and Mendelian inherited, all properties which make them very suitable for the study of population structure and pedigree analysis and capable of detecting differences among closely related species. PCR for microsatellites can be automated for identifying simple sequence repeat polymorphism. Small amount of blood samples or alcohol preserved tissue is adequate for analyzing them. Most of the microsatellites are noncoding, and therefore variations are independent of natural selection. These properties make microsatellites ideal genetic markers for conservation genetics and fisheries management. This review addresses the applications of microsatellite markers in conservation genetics and recent advances in population structure analysis in the context of fisheries management.