Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11845
Navegar
3 resultados
Resultados da Pesquisa
Item Sperm morphology of Muscidifurax uniraptor (Hymenoptera: Chalcidoidea: Pteromalidae)(Arthropod Structure & Development, 2016-05) Santos, Helen Pinto; Barcellos, Marcelo Silva; Reis, Aline Beatriz; Dolder, Heidi; Lino-Neto, JoséSperm morphology of the parasitoid Muscidifurax uniraptor was investigated under light and transmission electron microscopy. M. uniraptor sperm are filiform, spiraled, approximately 150 μm in length, with a distinctive head, hooded by an extracellular sheath and a flagellum. This extracellular layer, from which many filaments radiate, measures approximately 90 nm in thickness and covers a small acrosome and the anterior nuclear region. The acrosome is composed of an acrosomal vesicle and a perforatorium with its base inserted in the nuclear tip. The nucleus is filled with homogeneously compacted chromatin. The centriolar adjunct extends towards the anterior portion in a spiral around the nucleus for 3.5 μm in length. The two mitochondrial derivatives begin exactly at the centriole adjunct base and, in cross-section, have a circular shape with equal areas that are smaller than the axoneme diameter. It is coiled, with 9 + 9 + 2 microtubules and begins from the centriole, just below the nuclear base. The axoneme is connected to the mitochondrial derivatives by two small irregularly shaped masses. Between the derivatives and the axoneme, the ‘center-flagellar material’ is observed. Overall, these characteristics are recognized in other Chalcidoidea, especially in the eurytomids, but together they form a set of species-specific data.Item Sperm ultrastructure of the honey bee (Apis mellifera) (L) (Hymenoptera, Apidae) with emphasis on the nucleus-flagellum transition region(Tissue and Cell, 2000-05-26) Lino-Neto, J.; Báo, S.N.; Dolder, H.The flagellum of Apis mellifera (Hymenoptera, Apidae) consists of two mitochondrial derivatives, an axoneme and two accessory bodies. The mitochondrial derivatives are of unequal size and lie parallel to the axoneme. In the larger derivative four regions can be distinguished while in the smaller, only three. The region occurring only in the larger derivative consists of paracystalline material. The smaller mitochondrial derivative terminates anterior to the larger one. An extremely long centriolar adjunct is observed between the nucleus and the smaller mitochondrial derivative. This adjunct is compact, very electron dense and gradually tapers from base toward apex, finishing at the anterior extremity of the axonemal microtubules. In this flagellar region, there is only one accessory body present between the larger mitochondrial derivative and the axoneme. Anteriorly, the tips of the axonemal microtubules are inserted in a well developed mass of granular appearance. This material surrounds the nuclear base, separating it from the anterior end of the larger mitochondrial derivative. We believe that the structure identified here as a centriolar adjunct is homologous to that observed in Formicidae, Ichneumonoidea and Symphyta. Therefore, very probably, it is common to most Hymenoptera.Item Sperm structure and ultrastructure of the fire ant Solenopsis invicta (Buren) (Hymenoptera, Formicidae)(Tissue and Cell, 2002-03-22) Lino-Neto, José; Dolder, HThe spermatozoa of Solenopsis invicta are long and slender, measuring about 70 μm in length, of which the head region measures approximately 13 μm. The head consists of an acrosome formed by an acrosomal vesicle covering a perforatorium and a nucleus. This latter measures about 12 μm, has compact chromatin, and many translucent areas. The flagellum consists of an axoneme of 9+9+2 microtubules that begins just below the nuclear base. The two mitochondrial derivatives are of almost equal diameter, and there are two accessory bodies. The nucleus is attached to the flagellum by a centriolar adjunct located between the baso-lateral region of the nucleus and the anterior mitochondrial derivative extremities. Therefore, the nucleus–flagellum transition region of the spermatozoa of S. invicta is very similar to that of other ants and differs from the first description of this species [Ann. Entomol. Soc. Am. 67 (1967) 632]. In relation to other aculeates, it is possible that three characteristics (type of centriolar adjunct, presence of paracrystalline areas in each mitochondrial derivative, and the position of these areas within each derivative) may be autopomorphies for the Formicidae.