Fork head prevents apoptosis and promotes cell shape change during formation of the Drosophila salivary glands

Development ◽  
2000 ◽  
Vol 127 (19) ◽  
pp. 4217-4226 ◽  
Author(s):  
M.M. Myat ◽  
D.J. Andrew
Keyword(s):  
Cell Death ◽  
Salivary Glands ◽  
Cell Shape ◽  
Secretory Cell ◽  
Apoptotic Cell ◽  
Shape Change ◽  
Nuclear Migration ◽  
Secretory Cells ◽  
Apical Surface ◽  
Fork Head

The secretory tubes of the Drosophila salivary glands are formed by the regulated, sequential internalization of the primordia. Secretory cell invagination occurs by a change in cell shape that includes basal nuclear migration and apical membrane constriction. In embryos mutant for fork head (fkh), which encodes a transcription factor homologous to mammalian hepatocyte nuclear factor 3beta (HNF-3beta), the secretory primordia are not internalized and secretory tubes do not form. Here, we show that secretory cells of fkh mutant embryos undergo extensive apoptotic cell death following the elevated expression of the apoptotic activator genes, reaper and head involution defective. We rescue the secretory cell death in the fkh mutants and show that the rescued cells still do not invaginate. The rescued fkh secretory cells undergo basal nuclear migration in the same spatial and temporal pattern as in wild-type secretory cells, but do not constrict their apical surface membranes. Our findings suggest at least two roles for fkh in formation of the embryonic salivary glands: an early role in promoting survival of the secretory cells, and a later role in secretory cell invagination, specifically in the constriction of the apical surface membrane.

scholarly journals De novo variants in MPP5 cause global developmental delay and behavioral changes

2020 ◽  
Vol 29 (20) ◽  
pp. 3388-3401 ◽  
Author(s):  
Noelle Sterling ◽  
Anna R Duncan ◽  
Raehee Park ◽  
David A Koolen ◽  
Jiahai Shi ◽  
...  
Keyword(s):  
Cell Death ◽  
Developmental Delay ◽  
Cell Polarity ◽  
De Novo ◽  
Apoptotic Cell ◽  
Ventricular Zone ◽  
Behavioral Changes ◽  
Ependymal Cells ◽  
Global Developmental Delay ◽  
Apical Surface

Abstract Membrane Protein Palmitoylated 5 (MPP5) is a highly conserved apical complex protein essential for cell polarity, fate and survival. Defects in cell polarity are associated with neurologic disorders including autism and microcephaly. MPP5 is essential for neurogenesis in animal models, but human variants leading to neurologic impairment have not been described. We identified three patients with heterozygous MPP5 de novo variants (DNV) and global developmental delay (GDD) and compared their phenotypes and magnetic resonance imaging (MRI) to ascertain how MPP5 DNV leads to GDD. All three patients with MPP5 DNV experienced GDD with language delay/regression and behavioral changes. MRI ranged from normal to decreased gyral folding and microcephaly. The effects of MPP5 depletion on the developing brain were assessed by creating a heterozygous conditional knock out (het CKO) murine model with central nervous system (CNS)-specific Nestin-Cre drivers. In the het CKO model, Mpp5 depletion led to microcephaly, decreased cerebellar volume and cortical thickness. Het CKO mice had decreased ependymal cells and Mpp5 at the apical surface of cortical ventricular zone compared with wild type. Het CKO mice also failed to maintain progenitor pools essential for neurogenesis. The proportion of cortical cells undergoing apoptotic cell death increased, suggesting that cell death reduces progenitor population and neuron number. Het CKO mice also showed behavioral changes, similar to our patients. To our knowledge, this is the first report to show that variants in MPP5 are associated with GDD, behavioral abnormalities and language regression/delay. Murine modeling shows that neurogenesis is likely altered in these individuals, with cell death and skewed cellular composition playing significant roles.

Structure of the noncuticular simplex of the internal male reproductive tract of Calpodes ethlius (Hesperiidae, Lepidoptera)

1982 ◽  
Vol 60 (6) ◽  
pp. 1184-1201 ◽  
Author(s):  
J. Lai-Fook
Keyword(s):  
Cellular Structure ◽  
Secretory Cell ◽  
Reproductive Tract ◽  
Secretory Cells ◽  
Apical Region ◽  
Apical Surface ◽  
Male Reproductive Tract ◽  
Circular Layer ◽  
Secretory Products ◽  
Longitudinal Layer

The ductus ejaculatorius simplex (simplex) of the reproductive tract of the adult male of Calpodes ethlius is separated by distinct constrictions into seven segments, varying in length from 0.24 to 19.3 mm and totalling 4 cm. Two of the segments, S1 and S5, are further divisible into three and two parts, respectively, on the basis of either cellular structure or secretory products. The most distinctive region is the most anterior one which is made up of two distinctly different cells, one a merocrine secretory cell which resembles the cells of all other regions, and the other an apocrine secretory cell whose highly modified apical region is sloughed upon copulation. All segments are surrounded by two layers of muscle, a thin, inner circular layer and a more robust, outer longitudinal layer, which are supplied with tracheoles and nerves. Tracheoles also penetrate the epithelium of segment seven. The merocrine secretory cells of all segments are similar in that they all have well-developed endoplasmic reticulum, numerous Golgi and mitochondria, and a microvillate apical surface. Nonetheless, the cells of each segment are distinguished by some feature of either their structure or their secretions.

Blastokinesis in embryos of the bug, Pyrrhocoris apterus.

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 35-49
Author(s):  
Eugenie C. Enslee ◽  
Lynn M. Riddiford
Keyword(s):  
Cell Shape ◽  
Shape Change ◽  
Secretory Granules ◽  
Tube Formation ◽  
Apical Surface ◽  
Final Position ◽  
Basal Surface ◽  
Pyrrhocoris Apterus ◽  
Cell Shape Change ◽  
Dense Zone

In the bug, Pyrrhocoris apterus, blastokinesis (a reversal of the position of the embryo within the egg) is seen to involve contraction of the serosa that is attached to the embryo's head. As the serosal cells change from squamous to columnar in the course of blastokinesis, a dense zone of microfilaments appears just under the apical surface. Many apical protrusions develop above this zone. After the embryo is in its final position the zone disappears and later the cells degenerate. Laterally, the serosal cells are connected by belt desmosornes, septate junctions and gap junctions. As blastokinesis progresses, more lateral surface is recruited below them from the original basal surface. Microtubules running parallel to the plasma membrane are seen near the apical microfilaments and along other surfaces of the cell. Secretory granules are evident both within serosal cells and along the apical surface, probably providing a lubricant for movement against the chorion. Yolk cells are common basal to the serosa, possibly mobilizing nutrients for it. This study of blastokinesis in Pyrrhocoris provides a dramatic example of cell shape change that is correlated with the appearance of microfilaments. In its details blastokinesis is comparable to morphogenetic events such as amphibian neural tube formation and ascidian metamorphosis.

scholarly journals The Anatomy and Ultrastructure of the Digestive Tract and Salivary Glands of Hishimonus lamellatus (Hemiptera: Cicadellidae)

2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Lizhen Dai ◽  
Baodong Yang ◽  
Jinzhong Wang ◽  
Zhiyong Zhang ◽  
Rui Yang ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Digestive Tract ◽  
Secretory Granules ◽  
Malpighian Tubules ◽  
Midgut Epithelium ◽  
Secretory Cells ◽  
Basal Region ◽  
Apical Surface ◽  
Accessory Glands ◽  
Luminal Membrane

AbstractIn recent years, we found that Hishimonus lamellatus Cai et Kuoh is a potential vector of jujube witches’-broom phytoplasma. However, little is known about the anatomy and histology of this leafhopper. Here, we examined histology and ultrastructure of the digestive system of H. lamellatus, both by dissecting and by semi- and ultrathin sectioning techniques. We found that the H. lamellatus digestive tract consists of an esophagus, a filter chamber, a conical midgut and midgut loop, Malpighian tubules, an ileum, and a rectum. Furthermore, both the basal region of the filter chamber epithelium and the apical surface of the midgut epithelium have developed microvilli. We also identify the perimicrovillar membrane, which ensheaths the microvilli of midgut loop enterocyte, and the flame-like luminal membrane, which covers the microvilli of the conical midgut epithelium. In addition, H. lamellatus has the principal and accessory salivary glands. Our observations also showed that the endoplasmic reticulum, mitochondria, and secretory granules were all highly abundant in the secretory cells of the principal salivary glands, while the accessory glands consist of only one ovate or elbow-like acinus. We also briefly contrast the structure of the gut of H. lamellatus with those of other leafhopper species. These results intend to offer help for the future study on the histological and subcellular levels of phytopathogen–leafhopper relationships, including transmission barriers and the binding sites of pathogens and other microorganisms within their leafhopper vectors.

scholarly journals Evaluation of Dying Vocal Fold Epithelial Cells by Ultrastructural Features and TUNEL Method

2016 ◽  
Vol 202 (5-6) ◽  
pp. 355-368 ◽  
Author(s):  
Carolyn K. Novaleski ◽  
Masanobu Mizuta ◽  
Bernard Rousseau
Keyword(s):  
Cell Death ◽  
Vocal Fold ◽  
Apoptotic Cell ◽  
Standard Technique ◽  
Vocal Folds ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Apical Surface ◽  
Cell Nuclei ◽  
Vocal Fold Vibration ◽  
Immunohistochemical Marker

Cell death is a regulated mechanism of eliminating cells to maintain tissue homeostasis. This study described 2 methodological procedures for evaluating cell death in the epithelium of immobilized, approximated and vibrated vocal folds from 12 New Zealand white breeder rabbits. The gold standard technique of transmission electron microscopy evaluated high-quality ultrastructural criteria of cell death and a common immunohistochemical marker, the terminal deoxynucleotidyl transferase dUTP nick end labeling method, to confirm cell death signaling. Results revealed that ultrastructural characteristics of apoptotic cell death, specifically condensed chromatin and apoptotic bodies, were observed after vocal fold vibration and approximation. Although episodes of necrosis were rare, few enlarged cell nuclei were present after vibration and approximation. The vocal fold expresses an immunohistochemical marker for apoptosis along the apical surface of the epithelium. This study provides a solid foundation for future investigations regarding the role of cell death in vocal fold health and disease.

scholarly journals To die or not to die—a role for Fork head

2007 ◽  
Vol 176 (6) ◽  
pp. 737-739 ◽  
Author(s):  
Carl S. Thummel
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Salivary Glands ◽  
Precise Determination ◽  
Tissue Destruction ◽  
Fork Head ◽  
Massive Cell Death ◽  
Puparium Formation ◽  
Hormone Responses ◽  
And Function

The precise determination of when and where cells undergo programmed cell death is critical for normal development and tissue homeostasis. Cao et al. (2007; see p. 843 of this issue) report that the Fork head (Fkh) transcription factor, which is essential for the early development and function of the larval salivary glands in Drosophila melanogaster, also contributes to its demise. These authors show that fkh expression in the salivary glands is normally lost at puparium formation, which is ∼12 h before they undergo massive cell death triggered by the steroid hormone ecdysone, making room for their developing adult counterparts. The loss of Fkh eliminates its role in blocking cell death, allowing for subsequent ecdysone-induced reaper and head involution defective death activator expression and tissue destruction. This study provides new insights into the transcriptional regulation of programmed cell death and the mechanisms that underlie the precise spatial and temporal control of hormone responses during development.

DNA nick end labeling: a reliable marker for apoptosis?

1995 ◽  
Vol 53 ◽  
pp. 962-963
Author(s):  
Anne F. Bushnell ◽  
Sarah Webster ◽  
Lynn S. Perlmutter
Keyword(s):  
Cell Death ◽  
Cultured Cells ◽  
Apoptotic Cell ◽  
Morphological Characteristics ◽  
Detection Methods ◽  
Tissue Preparation ◽  
Preparation Methods ◽  
Dna Laddering ◽  
Disease States ◽  
Reliable Marker

Apoptosis, or programmed cell death, is an important mechanism in development and in diverse disease states. The morphological characteristics of apoptosis were first identified using the electron microscope. Since then, DNA laddering on agarose gels was found to correlate well with apoptotic cell death in cultured cells of dissimilar origins. Recently numerous DNA nick end labeling methods have been developed in an attempt to visualize, at the light microscopic level, the apoptotic cells responsible for DNA laddering.The present studies were designed to compare various tissue processing techniques and staining methods to assess the occurrence of apoptosis in post mortem tissue from Alzheimer's diseased (AD) and control human brains by DNA nick end labeling methods. Three tissue preparation methods and two commercial DNA nick end labeling kits were evaluated: the Apoptag kit from Oncor and the Biotin-21 dUTP 3' end labeling kit from Clontech. The detection methods of the two kits differed in that the Oncor kit used digoxigenin dUTP and anti-digoxigenin-peroxidase and the Clontech used biotinylated dUTP and avidinperoxidase. Both used 3-3' diaminobenzidine (DAB) for final color development.

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