Cell division in Malpighian tubule development in D. melanogaster is regulated by a single tip cell

Nature ◽  
1989 ◽  
Vol 342 (6249) ◽  
pp. 566-569 ◽  
Author(s):  
Helen Skaer
Development ◽  
1994 ◽  
Vol 120 (12) ◽  
pp. 3439-3450 ◽  
Author(s):  
M. Hoch ◽  
K. Broadie ◽  
H. Jackle ◽  
H. Skaer

In each Malpighian tubule of Drosophila, one cell is singled out, the tip cell, whose function during embryogenesis is to promote cell division in its neighbours. We follow the segregation of this cell, explore the genetic interactions that underlie its specification and demonstrate that tip cell allocation closely resembles neurogenesis. The tip cell arises by division of a tip mother cell, which is selected from a cluster of equivalent cells in each tubule primordium. Each cluster is marked out by the expression of proneural genes and the selection of a single cell from each group involves lateral inhibition, mediated by the neurogenic genes. We confirm the mitogenic role of the tip cell during embryogenesis by mutational analysis and show that it subsequently adopts a second fate, differentiating neural characteristics. We demonstrate that both stages in the differentiation of this cell are established by the same sequence of genetic interactions, which have not previously been shown to occur outside the neurogenic ectoderm.


Genome ◽  
2012 ◽  
Vol 55 (11) ◽  
pp. 755-763 ◽  
Author(s):  
Lydia Buntrock ◽  
František Marec ◽  
Sarah Krueger ◽  
Walther Traut

Organ growth depends on cell division and (or) cell growth. Here, we present a study on two organs whose growth depends entirely on cell growth, once they are formed in the embryo: Malpighian tubules and silk glands of the flour moth, Ephestia kuehniella . Between first and last larval instar, the volume of Malpighian tubule cells increases by a factor of ∼1800 and that of silk gland cells by a factor of ∼3100. We determined the number of endocyles required to reach these stages by Feulgen cytometry. Cells of Malpighian tubules were in the 2C stage in first instar larvae and reached 1024C after 9 endocycles in last instar larvae (1C = 0.45 pg DNA). Silk gland cells already reached a DNA content of 8C–16C in first instar larvae and attained up to 8192C in last instar larvae after a total of 12 endocycles. The nuclei were small and more or less spherical in first instar larvae, but they were huge, flat, and bizarrely branched in last instar larvae. We consider branching as a compensatory adaptation to improve molecular traffic between nucleus and cytoplasm in these excessively large and highly polyploid cells (i) by reducing the mean distance between nucleus and cytoplasm and (ii) by enlarging the surface-to-volume ratio of these nuclei.


Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 745-754 ◽  
Author(s):  
H. Skaer ◽  
A. Martinez Arias

Cell division in the Malpighian tubules of Drosophila melanogaster depends on the presence of a specialised cell at the tip of each tubule (Skaer, H. le B (1989) Nature 342, 566–569). Here we show that cell division also depends on the normal expression of the segment polarity gene, wingless. The pattern of wingless RNA and protein in developing tubules is consistent with a requirement for wingless for cell division. Analysis of the temporal requirement for wingless using a temperature- sensitive allele confirms that the normal expression of wingless is necessary during cell proliferation in the Malpighian tubules. Over-expression of the gene, induced in a stock containing the wg gene under the control of a heat-shock promoter, results in supernumerary cells in the tubules. We discuss the role of wingless in the cell interactions that govern cell division in the Malpighian tubules.


Author(s):  
L. M. Lewis

The effects of colchicine on extranuclear microtubules associated with the macronucleus of Paramecium bursaria were studied to determine the possible role that these microtubules play in controlling the shape of the macronucleus. In the course of this study, the ultrastructure of the nuclear events of binary fission in control cells was also studied.During interphase in control cells, the micronucleus contains randomly distributed clumps of condensed chromatin and microtubular fragments. Throughout mitosis the nuclear envelope remains intact. During micronuclear prophase, cup-shaped microfilamentous structures appear that are filled with condensing chromatin. Microtubules are also present and are parallel to the division axis.


Author(s):  
Krishan Awtar

Exposure of cells to low sublethal but mitosis-arresting doses of vinblastine sulfate (Velban) results in the initial arrest of cells in mitosis followed by their subsequent return to an “interphase“-like stage. A large number of these cells reform their nuclear membranes and form large multimicronucleated cells, some containing as many as 25 or more micronuclei (1). Formation of large multinucleate cells is also caused by cytochalasin, by causing the fusion of daughter cells at the end of an otherwise .normal cell division (2). By the repetition of this process through subsequent cell divisions, large cells with 6 or more nuclei are formed.


Author(s):  
Brendan Clifford

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.


Author(s):  
Ann Cleary

Microinjection of fluorescent probes into living plant cells reveals new aspects of cell structure and function. Microtubules and actin filaments are dynamic components of the cytoskeleton and are involved in cell growth, division and intracellular transport. To date, cytoskeletal probes used in microinjection studies have included rhodamine-phalloidin for labelling actin filaments and fluorescently labelled animal tubulin for incorporation into microtubules. From a recent study of Tradescantia stamen hair cells it appears that actin may have a role in defining the plane of cell division. Unlike microtubules, actin is present in the cell cortex and delimits the division site throughout mitosis. Herein, I shall describe actin, its arrangement and putative role in cell plate placement, in another material, living cells of Tradescantia leaf epidermis.The epidermis is peeled from the abaxial surface of young leaves usually without disruption to cytoplasmic streaming or cell division. The peel is stuck to the base of a well slide using 0.1% polyethylenimine and bathed in a solution of 1% mannitol +/− 1 mM probenecid.


Author(s):  
Vladimir Popenko ◽  
Natalya Cherny ◽  
Maria Yakovleva

Highly polyploid somatic nucleus (macronucleus) of ciliate Bursaria truncatella under goes severe changes in morphology during cell division. At first, macronucleus (Ma) condences, diminishes in size and turns perpendicular to longitudinal axis of the cell. After short time, Ma turns again, elongates and only afterwards the process of division itself occurs. The biological meaning of these phenomena is not clear.Localization of RNA in the cells was performed on sections of ciliates B. truncatella, embedded in “Lowicryl K4M” at various stages: (1) before cell division (Figs. 2,3); (11) at the stage of macronucleus condensation; (111) during elongation of Ma (Fig.4); (1111) in young cells (0-5min. after division). For cytochemical labelling we used RNaseAcolloidal gold complexes (RNase-Au), which are known to bind to RNA containing cell ularstructures with high specificity. The influence of different parameters on the reliability and reproducibility of labelling was studied. In addition to the factors, discussed elsewhere, we found that the balance of mono- and bivalent cations is of great significance.


2020 ◽  
Vol 64 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Ben L. Carty ◽  
Elaine M. Dunleavy

Abstract Asymmetric cell division (ACD) produces daughter cells with separate distinct cell fates and is critical for the development and regulation of multicellular organisms. Epigenetic mechanisms are key players in cell fate determination. Centromeres, epigenetically specified loci defined by the presence of the histone H3-variant, centromere protein A (CENP-A), are essential for chromosome segregation at cell division. ACDs in stem cells and in oocyte meiosis have been proposed to be reliant on centromere integrity for the regulation of the non-random segregation of chromosomes. It has recently been shown that CENP-A is asymmetrically distributed between the centromeres of sister chromatids in male and female Drosophila germline stem cells (GSCs), with more CENP-A on sister chromatids to be segregated to the GSC. This imbalance in centromere strength correlates with the temporal and asymmetric assembly of the mitotic spindle and potentially orientates the cell to allow for biased sister chromatid retention in stem cells. In this essay, we discuss the recent evidence for asymmetric sister centromeres in stem cells. Thereafter, we discuss mechanistic avenues to establish this sister centromere asymmetry and how it ultimately might influence cell fate.


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