IEGEBA   24053
INSTITUTO DE ECOLOGIA, GENETICA Y EVOLUCION DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
Cytogenetic characterization of Diachasmimorpha longicaudata (Hymenoptera: Braconidae), a parasitoid wasp used as a biological control agent
Autor/es:
CARABAJAL PALADINO, L. Z.; PAPESCHI, A. G.; LANZAVECCHIA, S.; CLADERA, J. L.; BRESSA, M. J.
Revista:
EUROPEAN JOURNAL OF ENTOMOLOGY (CESKE BUDEJOVICE)
Editorial:
CZECH ACAD SCI
Referencias:
Lugar: Ceske Budejovice; Año: 2013 vol. 110 p. 401 - 409
ISSN:
1210-5759
Resumen:
Diachasmimorpha longicaudata (Hymenoptera: Braconidae) is a parasitoid wasp widely used in the biological control of
fruit flies. In this paper, we present a detailed analysis of the karyotype of this species based on the results of classical and molecular
cytogenetic techniques. The cytogenetic analysis confirmed the male and female chromosome numbers previously reported (n =
20, 2n = 40). The entire short arm of most chromosomes is made up of a large constitutive heterochromatic segment. The high heterochromatin
content differentiates D. longicaudata from other braconid species. Fluorescence in situ hybridization (FISH) using
autologous 18S rDNA probes revealed six clusters of rDNA, i.e. six nucleolar organizer regions (NORs), in the heterochromatic
short arms of different chromosomes in the haploid male karyotype. This number is exceptionally high for Hymenoptera, which usually
have two NORs in the diploid complement. It is noteworthy that these rDNA-FISH experiments represent the first use of this
technique on a braconid species using autologous probes. Since Ag-NOR-bands were coincident with C-positive bands on metaphase
chromosomes, it was not possible to identify active nucleoli. The physical characteristics of the D. longicaudata karyotype, especially
the content and distribution of heterochromatin and the number and location of rDNA clusters, contribute to a better understanding
of the structure and organization of braconid chromosomes and provide a basis for genomic and evolutionary studies.