ABSTRACT
This work carried out to evaluates the polymorhism in the silkworm of different lineages using the isoenzymes electrophoresis to detect biochemical markers and to investigate the genetics of populations for those lineages. They were used as samples individual extracts of silk glands of second day old larvas of the fifth instar, originating from seven Japanese lineages and eight pure Chinese lineages maintained by the Cocamar- Cooperativa Agroindustrial de Maringá. The isozymes acid phosphatase (ACP), alkaline phosphatase (AKP) and carbonic anhydrase (CA) they were submitted to the electrophoresis in starch gels 14%. The esterases (EST) were analyzed in polyacrylamide gels to 10% and stained with α and ß-naphtyl acetate. The total of 21 loci was detected, and 04 (19.05%) they are polymorphic, Est-11, Acp, Akp, Ca. The fixation index (Fis) for the analyzed isozymes it was 0.0751, indicating excess of homozygotes. The value of Fst (0.6128) it shows that the lineages are well differentiated. The dendrogram obtained with the values of genetic distance didn't separate the Chinese and Japanese lineages analyzed totally. That preliminary evaluation of the lineages of B. mori shows that they present genetic material that it can be used in breeding programs that have the purpose of producing hybrid for silk production.
Este trabalho teve como objetivo avaliar o polimorfismo em lagartas do bicho-da-seda de diferentes linhagens utilizando a eletroforese de isoenzimas para detectar marcadores bioquímicos e investigar a genética de populações para essas linhagens. Foram utilizados como amostras extratos individuais de glândulas sericígenas de lagartas do segundo dia da quinta idade, de sete linhagens japonesas e oito linhagens chinesas puras mantidas pela Cocamar-Cooperativa Agroindustrial de Maringá. As isozimas fosfatase ácida (ACP), fosfatase alcalina (AKP) e anidrase carbônica (CA) foram avaliadas por meio de eletroforese em géis de amido de milho a 14%. As esterases (EST) foram analisadas por meio de eletroforese vertical em géis de poliacrilamida a 10% e coloração com α e ß- naftil acetato. Foram observados 21 locos, dentre os quais quatro (19.05%) são polimórficos, Est-11, Acp, Akp, Ca. O índice de fixação (Fis) para as isozimas analisadas foi 0.0751, indicando excesso de homozigotos. O valor de Fst (0.6128) permite sugerir que as linhagens estão bem diferenciadas. O dendograma obtido a partir dos valores de distância genética não separou totalmente as linhagens chinesas e japonesas analisadas. Essa avaliação preliminar das linhagens de B. mori mostra que elas apresentam material genético que pode ser utilizado em programas de cruzamentos que tenham a finalidade de produzir híbridos para produção de seda.
Subject(s)
Bombyx , Isoenzymes , Polymorphism, GeneticABSTRACT
Esterases form a large, diverse group of enzymes with wide, overlapping substrate specificities and patternsof inhibition. These enzymes occur in a large variety of isoforms encoded by distinct gene loci with ahigh genetic variability and temporal differences in expression that make them appropriate for studyingpopulation structure. In this work, we investigated the substrate specificity and pattern of esterase expressionin body parts of the stingless bees Tetragonisca angustula and Tetragona clavipes. Fourteen hives of T.angustula were collected in Cianorte and T. clavipes were collected from three colonies in Maringá, twocities in the southern Brazilian state of Paraná. The esterase electrophoretic patterns were determinedusing polyacrylamide gels. Seven bands of esterase activity were detected in T. clavipes (EST-1 to EST-7)and two bands in T. angustula (EST-1 and EST-2). There was variation in the tissue esterase activity of T.clavipes, with EST-6 occurring in the abdomen of workers and EST-7 occurring in cephalic/thoracic extracts.The differences in the number of esterase bands and substrate specificity were attributed to the number ofesterase loci involved in each species, and/or variation in substrates specificities. The variation seen hereshould be useful for determining the role of esterases in intermediate metabolism in the Trigonini, as wellas to use esterases as a genetic marker for this stingless bee.