FMRFamide-like midgut endocrine cells during the metamorphosis in Melipona quadrifasciata anthidioides (Hymenoptera, Apidae)

Abstract

The FMRFamide, gastrin and cholecystokinin (CCK) occurrence in endocrine cells of insects has been described by several authors, although their functions are still not well defined for this group of animals. In the present study, the occurrence of endocrine cells producing FMRFamide, gastrin 1 and CCK-8 in the midgut (ventriculus) of Melipona quadrifasciata anthidioides (Hymenoptera, Apidae), before, during and after the metamorphosis, were investigated by means of pre-embedding immunofluorescence techniques. FMRFamide reactivity was found in the endocrine cells as well as in the nervous fibers and neurons of the intestine of these bees. 'Open' and 'closed' types of FMRFamide-like cells were observed in last instar larvae. In the black eyed pupae the producing cells of FMRFamide seemed to be immature, and, in the workers, where the FMRFamide producing cells were more abundant, the production of this substance seemed to occur only in the open cells. Reactivity of the nervous fibers and neurons were observed, during the prepupae, white eyed pupae, and pink eyed pupae. The same did not occur with the midgut endocrine cells. There were no immunoreactivity observations for gastrin 1 and for CCK-8. The FMRFamide-like cells were present in the midgut of these insects during or close to the period that they were eating, which indicates that the FMRFamide may be involved in the control of the digestive process.

Ultrastructure of two Types of Endocrine Cells in the Midgut Epithelium of Spodoptera Exiqua Hűbner, 1808 (Insecta, Lepidoptera, Noctuidae)

“…They have microvilli, which contact the midgut lumen. In some insect species among the open endocrine cells of the posterior midgut two kinds of cells have been distinguished (NEVES et al, 2002(NEVES et al, , 2003. The cytoplasm of one type contains great numbers of electron dense granules, which are called granular cells, while the other kind has numerous vacuoles with electron lucent contents (RAES and VERBEKE, 1994;GÜL et al, 2001).…”

“…They are responsible for the regulation of enzyme synthesis and secretion (MONTUENGA et al, 1989;CHAPMAN, 1998). In some insect species only one type of endocrine cells has been found while in others several different types have been detected (MONTUENGA et al, 1989;NEVES et al, 2002NEVES et al, , 2003. They are described as oval, pyramid or bowl-shaped cells (ANDRIÉS and BEAUVILLAIN, 1988;CAVALCANTE and CRUZ-LANDIM, 1999), and originate from the regenerative cells.…”

Ultrastructure of the midgut endocrine cells in Melipona quadrifasciata anthidioides (Hymenoptera, Apidae)

“…However, ultrastructural differences among midgut endocrine cells of the same species submitted to the same technical procedure as in the present study may suggest that these cells produce different peptides. In this sense, midgut endocrine cells in M. quadrifasciata anthidioides produce FMRFamide-like, but not cholecystokinin-and gastrin-like peptides (Neves et al, 2002).…”

“…The presence of these cells was observed in Bombus sp. (Zitnan et al, 1993) and in Melipona quadrifasciata anthidioides (Neves et al, 2002). Raes & Verbeke (1994) described in details the ultrastructure, ontogeny, and distribution of two types of endocrine cells in Apis mellifera, complementing the brief observations of Jimenez & Gilliam (1990).…”

Post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers

“…The process of differentiation of intramandibular glands beginning in white-eyed pupae and completed in black-eyed pupae is still little known in stingless bees, but epidermal and non epidermal organs have complete differentiation in black-eyed pupae (Neves et al, 2002(Neves et al, , 2003Azevedo et al, 2008).…”