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Cocoon silk chemistry of non-cyclostome Braconidae, with remarks on phylogenetic relationships within the Microgastrinae (Hymenoptera: Braconidae)

2004; Taylor & Francis; Volume: 38; Issue: 17 Linguagem: Inglês

10.1080/00222930310001617760

1464-5262

Donаld L. J. Quicke, Mark Shaw, Masayoshi Takahashi, Bonnie Yanechin,

Silkworms and Sericulture Research

AbstractBulk amino acid composition was determined for cocoon silks for 54 species of non-cyclostome braconid wasps collectively representing 14 subfamilies. Little intraspecific variation was encountered either between conspecific individuals of differing origin or between physically different silk layers within a single cocoon. Variation within subfamilies was small except in the Microgastrinae. Most taxa, excluding most microgastrines, had silk of a fairly typical fibroin type with high relative abundances of alanine, serine or glycine (of which either alanine or serine was the most abundant) and usually with moderately low molar concentrations of presumed acidic residues (aspartate/asparagine (As(x)) and glutamate/glutamine (Gl(x))) which ranged from approximately 2% up to nearly 30% (in Helconinae and Blacinae). In the Microgastrinae, members of the genus Microplitis (four species) were similar to the other non-cyclostome subfamilies in having 14.3–26.1 molar % As(x), but the other 10 microgastrine genera investigated produced silks with As(x) the most abundant detected residue comprising 32.4–50.5 molar % while glycine represented less than 10% of residues, indicating an α-helical silk. These data are discussed in the light of some recent independent phylogenetic studies on the Microgastrinae that also suggest a basal position for Microplitis within the subfamily, despite its apparently highly specialized biology.Keywords: Cocoonssilk compositionBraconidaephylogenyMicrogastrinaeMicroplitis AcknowledgementsThis work was funded by a Royal Society small project grant to D.L.J.Q. and by the NERC Initiative in Taxonomy.Notes1Present address: UNIFESP-Escola Paulista de Medicina, Departmento de Bioquìmica, INFAR -5 andar, Rua Trís de Maio, 100 Vila Clementino, CEP 04044-020, Sao Paulo, Brazil.Additional informationNotes on contributorsMasayoshi Takahashi1Present address: UNIFESP-Escola Paulista de Medicina, Departmento de Bioquìmica, INFAR -5 andar, Rua Trís de Maio, 100 Vila Clementino, CEP 04044-020, Sao Paulo, Brazil.