Background The hypopharyngeal gland of worker bees contributes to the production of the royal jelly fed to queens and larvae. into rosette-like products of three cells. Two of these will become the secretory cell and the duct cell of the adult secretory units; the third cell contributes only temporarily to the development of the secretory units and is eliminated by apoptosis in the second half of pupal life. (3) The three-cell units of flask-shaped cells Geldanamycin undergo complex changes in cell morphology. Thus, by mid-pupal stage, the gland is structurally similar to the adult hypopharyngeal gland. (4) Concomitantly, the prospective secretory cell attains its characteristic subcellular organization by the invagination of a small patch of apical membrane domain, its extension to a tube of about 100?m in length (termed a canaliculus), and the expansion of the tube to a diameter of about 3?m. (6) Finally, the canaliculus-associated F-actin system becomes reorganized into rings of bundled actin filaments that are positioned at regular distances along the membrane tube. Conclusions The morphogenesis of the secretory units in the hypopharyngeal gland of the worker bee seems to be based on a developmental program that is conserved, with slight modification, among insects for the production of dermal glands. Elaboration of the secretory cell as a unicellular seamless epithelial tube occurs by invagination of the apical membrane, its extension likely by targeted exocytosis and its expansion, and finally the reorganisation of the membrane-associated F-actin system. Our function is fundamental for long term research of environmental results about hypopharyngeal gland advancement and morphology. Electronic extra materials The online edition of this content (doi:10.1186/s12983-017-0207-z) contains supplementary materials, which is certainly obtainable to certified users. range in the inset) through a hypopharyngeal gland at stage G1 tagged with DAPI and fluorophore-tagged phalloidin (F-actin). a and … Extra document 1: Computer animation of an picture collection through a hypopharyngeal gland primordium, impure with phalloidin (green) Rabbit Polyclonal to IFIT5 and DAPI (blue). Whole-mount example of beauty; inter-plane range, 0.34?m; intent zoom lens, Zeiss C-Apochromat 40x/1.2?W. Discover Fig.?3a-f for information. (AVI 10486?kb)(10M, avi) Cellular morphology of developing hypopharyngeal glands In hypopharyngeal gland primordia at stage G1, the bounding epithelium was pseudostratified and about 40?m heavy (Fig.?4a, age and we). In addition to mitotic cells in the apical area, the epithelium comprised of flask-like interphase cells with their nuclei placed at different amounts in the middle and basal area of the epithelium. Interphase nuclei had been measured and oval about 5?m simply by 3?m, with the Geldanamycin lengthy axis oriented in an apicobasal path in the epithelial coating. A mobile procedure that was 1C2?m heavy and 10C20?m very long extended from the cell body to the luminal surface area. Intense staining with phalloidin of the apicolateral sides of these processes indicated that F-actin occurred at adherens junctions (Fig.?4a inset). In addition, weaker staining over the entire apical surface of the cell processes suggested the presence of microvilli-like structures. Fig. 4 Differentiation of hypopharyngeal gland during the first half of pupal life. Glands were isolated, fixed, labeled with phalloidin (in a-d, in a-d), and imaged by confocal serial sectioning. a and a A package … Differentiation of the canaliculus Since the timing and manner of formation of the canaliculus of the secretory cells are unknown, we wished to analyze this morphogenetic process by the use of probes specific for this membrane domain name. We have shown previously that anti-phosphorylated ERM (anti-pERM) and anti-phosphotyrosine selectively stain the canalicular system of adult secretory cells. Whereas anti-pERM outlines membrane segments between adjacent actin rings, anti-phosphotyrosine identifies dot-like structures that are associated with the canaliculus and that may represent microvillar tips . Unfortunately, however, neither anti-pERM nor anti-phosphotyrosine stained any structures in prospective secretory cells of the pupal hypopharyngeal glands, suggesting that either these Geldanamycin cells lack a canaliculus throughout pupal development, or that the expression of these proteins and/or their localization.