Genetic characterization of a new Apis mellifera esteraseM.C.C. Ruvolo-Takasusukia, M.A. Del Lamaa and A.E.E. Soaresb
a Departamento de Genética e Evolução, Universidade Federal de São Carlos, Rodovia Washington Luiz, km 235, Caixa Postal 676-13565.905 - São Carlos, SP
b Departamento de Genética, Faculdade de Medicina de Ribeirão Preto (USP), Av Bandeirantes s/n - 14049.900 - Ribeirão Preto, SP, Brazil
Abstract - A new esterase, denoted esterase-1a (Est-1a), was first identified by starch gel electrophoresis of abdomen extracts from adult drones of Apis mellifera. This enzyme was developed only with 4-methylumbelliferyl esters and its inhibition properties suggest that it is an arylesterase. It does not contain reactive sulfhydryl groups and has a monomeric structure. A genetic variant (Est-1a92) was detected at an average frequency of 4.2% in drones collected from five apiaries. Genetic linkage studies showed no close linkage between the Est-1a locus and the genetic markers Est-6, Mdh-1 and Hk-1. Esterase-1 a activity was observed in the reproductive and digestive tracts of sexually mature drones, queens and egg-laying workers, suggesting its association with sexual maturation. In view of its presence in the egg and its restricted localization in the middle portion of the digestive tract (midgut), this enzyme may play a proteolytic role in early embryonic development.
Key words: esterases / Africanized honeybees / genetic characterization / tissue expression / development expression