Organization and possible functions of microtubule cytoskeleton in hymenopteran nurse cells

Abstract

The results of systematic cytochemical and EM studies on the distribution of actin filaments and microtubules in hymenopteran nurse cells are presented. We demonstrate that each nurse cell nucleus is surrounded by a thick three‐dimensional cage of microtubules that is engaged in maintaining the position of the nuclei in the cell centers during the flow of the cytoplasm from nurse cells into the oocyte. Hence, the cages represent functional counterparts of actin bundles described in the Drosophila nurse cells. Furthermore, our data suggest that a subset of the microtubules is involved in transferring nuage aggregates from the vicinity of the nucleus towards the nurse cell periphery and the nearest intercellular bridge. A conclusion is reached that despite similar polytrophic organization of the ovaries in both hymenopterans and dipterans, the physiology of their nurse cell‐oocyte syncytia appears distinctly different. Cell Motil. Cytoskeleton 43:213–220, 1999. © 1999 Wiley‐Liss, Inc.

The telotrophic ovary known from Neuropterida exists also in the myxophagan beetle Hydroscapha natans

“…This has been found in Drosophila, where the position of nurse cell nuclei is stabilized by actin filament cables oriented that way during the dumping phase (Riparbelli and Callaini 1995; Guild et al 1997). In Hymenopterans, this task is taken over by a cage of microtubules (Bilinski and Jaglarz 1999). Microtubules are common in the syncytial cytoplasm of Sialidae and even abundant in Raphidioptera (Büning 1979c(Büning , 1980.…”

Actin cytoskeleton reorganization of the apoptotic nurse cells during the late developmental stages of oogenesis inDacus oleae

“…Previous observations about the F-actin distribution in the ovarioles of various insect groups, including Lepidoptera, Coleoptera, [Gutzeit and Huebner, 1986] and Hymenoptera [Bilinski and Jaglarz, 1999], did not show the presence of F-actin cables in the nurse cells of the above species. Interestingly, Bilinski and Jaglarz demonstrated that in Hymenoptera each nurse cell nucleus is surrounded by a thick cage of microtubule network, in order to maintain the position of the nucleus in the cell center during the dumping process.…”

“…Recently, it has been shown that in Hymenopteran, each nurse cell nucleus is surrounded by a thick cage of microtubule network, in order to maintain the position of the nucleus in the cell center during the dumping process [Bilinski and Jaglarz, 1999].…”

Cytoskeletal organization of bee ovarian follicles during oogenesis

“…The RNA that passes from the nucleus into the nurse cell cytoplasm through the nuclear pore and from one nurse cell the another until reach the oocyte. As previously described, the tubulin in the passage between the nurse and oocyte chambers are involved in delivering several nurse cell products, RNA and proteins to the oocyte (Bilinsky and Jaglarz, 1999;Cooley and Theurkauf, 1994;Theurkauf and Hazelrigg, 1998).…”

“…Therefore, when the clone cells later differentiate into oocyte and nurse cells and the oocyte begins to mature, the organization of the cytoskeleton must allows the polarized transport of compounds from the nurse cells to the oocyte cell through the ring canals (Cassidy and King, 1972;Cooley and Theurkauf, 1994;Cruz-Landim, 1978;Gutzeit et al, 1993;Staurengo-da-Cunha, 1988;Theurkauf et al, 1992;Lisboa et al, 2005). Accordingly, in the bee germline cysts, the bridges interconnecting the proliferating germ cells are reinforced by microfilaments and microtubules occupy the open spaces of the bridges (Bilinsky and Jaglarz, 1999). During the differentiation of cystocytes into oocyte and germ cells, the oocyte consistently occupies a basal position in relation to the nurse cells (Patrício and Cruz-Landim, 2006).…”