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A morphological and ultrastructural study of the spermatheca of some species of Orthoptera Tettigoniidae was carried out to understand the role of this female organ in the reproductive biology because no literature exists about it in this insect group. In all the examined species, the spermatheca is of ectodermal origin and is composed of a seminal receptacle, mainly involved in the collection and storage of the spermatozoa, and of a spermathecal duct. In both these organs, the epithelium of the wall is made up of two different cell types: cuticle-forming cells, underlying the cuticular intima, and gland cells. Both of these cell types have secretory features that differ among the species and also within the same species, in relation to the tracts examined. In particular, the ultrastructure of the distal tract of the spermathecal duct indicates a more marked secretory activity than in the other tracts of the duct. This activity is often accompanied by ultrastructural aspects, suggesting a lysis activity in both the epithelium and the upper cuticle. Based on these findings, it is hypothesized that the seminal receptacle and the spermathecal duct have different functional roles, despite having a similar general structural organization.

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In Tettigoniidae (Orthoptera), male reproductive accessory glands are involved in the construction of a two-part spermatophore; one part, the spermatophylax, is devoid of sperm and considered a nuptial gift. The morphology, ultrastructure, and secretion protein content of the male reproductive accessory glands from Bolivarius siculus were investigated. Two main groups of gland tubules open into the ejaculatory duct: the "first-order" glands, a number of large anterior tubules, and the "second-order" glands, smaller and more numerous tubules positioned posteriorly. Along with a further subdivision of the gland tubules, we here describe for the first time an additional gland group, the intermediate tubules, which open between first and second-order glands. The mesoderm-derived epithelium of all glands is a single layer of microvillated cells, which can be either flattened or cylindric in the proximal or distal region of the same gland. Epithelial cells, very rich in RER and Golgi systems, produce secretions of both electron-dense granules and globules or electron-transparent material, discharged into the gland lumen by apocrine or merocrine mechanisms, respectively. With one exception, a unique electrophoresis protein profile was displayed by each of the gland types, paralleling their unique morphologies. To assess the contribution of different types of accessory glands to the construction of the spermatophore, the protein patterns of the gland secretions were compared with those of the extracts from the two parts of the spermatophore. All samples showed bands distributed in a wide range of molecular weight, including proteins of very low molecular mass. However, one major high molecular weight protein band (>180 kDa) is seen exclusively in extracts from the first-order glands, and corresponds to an important protein component of the spermatophylax.

Tel. + 39 (95) 31 2355; Far +39 (95) 327990 SummaryWe studied the sperm changes occumng during storage in the female genital tract of Eyprepocnemis plorans (Orthoptera: Acrididae). In this species the spermatheca consists of a long duct with two terminal diverticula: a preapical one with a U-bend and a straight apical one. After copulation the spermatozoa reach the diverticula where they undergo a peculiar uncoating process which leads to the complete re moval of the glycocalyx. This prepares the spermatozoa to interact with the female gametes. A different role is performed by the two diverticula in sperm storage. In the preapical one most sperm are stored until fertilization of the egg; in the apical diverticulum a limited number of spermatozoa are stored but most are progressively dismantled. These modifications may reduce any excess of spermatozoa or operate a mechanism of selection, aiming to favour sperm from the last mating.