scholarly journals Morphology and Morphometry of the Midgut in the Stingless Bee Friesella schrottkyi (Hymenoptera: Apidae)

Insects ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 73
Author(s):  
André Oliveira ◽  
Wagner Gonçalves ◽  
Kenner Fernandes ◽  
Marcelo Barcellos ◽  
Wagner Sampaio ◽  
...  
Keyword(s):  
Endocrine Cells ◽  
Stingless Bee ◽  
Spherical Nucleus ◽  
Morphological Description ◽  
Native Forest ◽  
Apical Region ◽  
Basal Region ◽  
Posterior Midgut ◽  
Friesella Schrottkyi ◽  
Morphology And Morphometry

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and endocrine cells. The digestive cells are similar along the entire midgut length with a spherical nucleus, apex with long striated border, cytoplasmic granules in the apical region and well-developed basal labyrinth associated with mitochondria, suggesting they are multifunctional, synthesizing digestive enzymes and peritrophic matrix compounds and absorbing nutrients. Regenerative cells are located around the basal region organized in nests with some cells with a spherical nucleus. Phe-Met-Arg-Phe-NH2-amide (FMRFamide) positive endocrine cells are restricted to the posterior midgut region, suggesting a paracrine function in the midgut. This is the first morphological description of the F. schrottkyi midgut contributing to the comprehension of the digestive process of this bee.

scholarly journals Persistent directional growth capability in Arabidopsis thaliana pollen tubes after nuclear elimination from the apex

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Tube ◽  
Sperm Cell ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Apical Region ◽  
Basal Region ◽  
Specific Expression ◽  
Directional Growth

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.

scholarly journals Mites fluctuation population on peach tree (Prunus persica (L.) Batsch) and in associated plants

2011 ◽  
Vol 33 (3) ◽  
pp. 765-773 ◽  
Author(s):  
Carla Rosana Eichelberger ◽  
Liana Johann ◽  
Fernanda Majolo ◽  
Noeli Juarez Ferla
Keyword(s):  
Prunus Persica ◽  
Rio Grande ◽  
Population Diversity ◽  
Panonychus Ulmi ◽  
Apical Region ◽  
Basal Region ◽  
Rio Grande Do Sul ◽  
Phytophagous Mites ◽  
Phytoseiulus Macropilis ◽  
Tetranychus Ludeni

Despite the importance of peach (Prunus persica (L.) Batsch) in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836) and Mononychellus planki (McGregor, 1950) were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904) the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43) when compared to Eldorado (H' 0.53; EqJ 0.40). In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939), T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and January and high predator diversity was observed on associated plants and on peach plants, indicating the existence of species mobility in peach orchard.

scholarly journals Localized Ca2+ uncaging reveals polarized distribution of Ca2+-sensitive Ca2+ release sites

2002 ◽  
Vol 158 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Michael C. Ashby ◽  
Madeleine Craske ◽  
Myoung Kyu Park ◽  
Oleg V. Gerasimenko ◽  
Robert D. Burgoyne ◽  
...  
Keyword(s):  
Ryanodine Receptors ◽  
Acinar Cells ◽  
Cell Types ◽  
Pancreatic Acinar Cells ◽  
Apical Region ◽  
Basal Region ◽  
Activation Pattern ◽  
Inositol Trisphosphate Receptors ◽  
Agonist Stimulation ◽  
Major Process

Ca2+-induced Ca2+ release (CICR) plays an important role in the generation of cytosolic Ca2+ signals in many cell types. However, it is inherently difficult to distinguish experimentally between the contributions of messenger-induced Ca2+ release and CICR. We have directly tested the CICR sensitivity of different regions of intact pancreatic acinar cells using local uncaging of caged Ca2+. In the apical region, local uncaging of Ca2+ was able to trigger a CICR wave, which propagated toward the base. CICR could not be triggered in the basal region, despite the known presence of ryanodine receptors. The triggering of CICR from the apical region was inhibited by a pharmacological block of ryanodine or inositol trisphosphate receptors, indicating that global signals require coordinated Ca2+ release. Subthreshold agonist stimulation increased the probability of triggering CICR by apical uncaging, and uncaging-induced CICR could activate long-lasting Ca2+ oscillations. However, with subthreshold stimulation, CICR could still not be initiated in the basal region. CICR is the major process responsible for global Ca2+ transients, and intracellular variations in sensitivity to CICR predetermine the activation pattern of Ca2+ waves.

Root growth of lupins is more sensitive to waterlogging than wheat

2011 ◽  
Vol 38 (11) ◽  
pp. 910 ◽  
Author(s):  
Helen Bramley ◽  
Stephen D. Tyerman ◽  
David W. Turner ◽  
Neil C. Turner
Keyword(s):  
Root Growth ◽  
Oxygen Deficiency ◽  
Triticum Aestivum L ◽  
Wheat Root ◽  
Lupinus Luteus ◽  
Apical Region ◽  
Basal Region ◽  
Yellow Lupin ◽  
Wheat Roots ◽  
Root Death

In south-west Australia, winter grown crops such as wheat and lupin often experience transient waterlogging during periods of high rainfall. Wheat is believed to be more tolerant to waterlogging than lupins, but until now no direct comparisons have been made. The effects of waterlogging on root growth and anatomy were compared in wheat (Triticum aestivum L.), narrow-leafed lupin (Lupinus angustifolius L.) and yellow lupin (Lupinus luteus L.) using 1 m deep root observation chambers. Seven days of waterlogging stopped root growth in all species, except some nodal root development in wheat. Roots of both lupin species died back progressively from the tips while waterlogged. After draining the chambers, wheat root growth resumed in the apical region at a faster rate than well-drained plants, so that total root length was similar in waterlogged and well-drained plants at the end of the experiment. Root growth in yellow lupin resumed in the basal region, but was insufficient to compensate for root death during waterlogging. Narrow-leafed lupin roots did not recover; they continued to deteriorate. The survival and recovery of roots in response to waterlogging was related to anatomical features that influence internal oxygen deficiency and root hydraulic properties.

An ultrastructural study of the enigmatic "rodlet cells" in the white sucker, Catostomus commersoni (Lacépède) (Pisces: Catostomidae)

1975 ◽  
Vol 53 (11) ◽  
pp. 1483-1494 ◽  
Author(s):  
Sherwin S. Desser ◽  
Robert Lester
Keyword(s):  
Golgi Complex ◽  
Spherical Inclusion ◽  
Thick Wall ◽  
Apical Region ◽  
Basal Region ◽  
White Sucker ◽  
Catostomus Commersoni ◽  
Epithelial Surface ◽  
And Function ◽  
Rodlet Cells

The cytology of immature and mature stages of a peculiar and widespread cell, the "rodlet cell" is described from the epithelium of the operculum and gill raker of the white sucker, Catostomus commersoni. Immature stages were observed in the intermediate and basal zones of the epithelium. They were spherical to ovoid in shape and surrounded by a limiting membrane, beneath which were numerous microfilaments arranged in parallel. The cytoplasm of immature rodlet cells contained a prominent "active" Golgi complex, peripherally arranged mitochondria, numerous free ribosomes, and an extensive network of distended cisternae of granular endoplasmic reticulum. Mature rodlet cells were usually observed along the epithelial surface. These fusiform cells were surrounded by a thick wall which contained circumferentially arranged microfilaments. A nucleus, a spherical inclusion, and a Golgi complex were observed in the basal region of the cell. The cytoplasm contained many closely packed vesicles. Numerous mitochondria were aggregated in the apical region of the cell, which terminated in three or more microvillus-like processes. While the nature and function of the rodlet cells is not elucidated, it is postulated that they are not protozoan parasites.

scholarly journals Tissue-specific metabolic reprogramming during wound induced de novo organ formation in tomato hypocotyl explants

2021 ◽  
Author(s):  
Eduardo Larriba ◽  
Ana Belén Sánchez García ◽  
Cristina Martínez-Andújar ◽  
Alfonso Albacete ◽  
José Manuel Pérez-Pérez
Keyword(s):  
De Novo ◽  
Metabolic Reprogramming ◽  
Apical Region ◽  
List Type ◽  
Basal Region ◽  
Metabolic Switch ◽  
Tissue Specific ◽  
Hypocotyl Explants ◽  
Organ Formation ◽  
Organ Regeneration

SUMMARYPlants have remarkable regenerative capacity, which allows them to survive tissue damaging after biotic and abiotic stress. Some of the key transcription factors and the hormone crosstalk involved in wound-induced organ regeneration have been extensively studied in the model plant Arabidopsis thaliana. However, little is known about the role of metabolism in wound-induced organ regeneration.Here, we performed detailed transcriptome analysis and targeted metabolomics approach during de novo organ formation in tomato hypocotyl explants and found tissue-specific metabolic differences and divergent developmental pathways after wounding.Our results indicate that callus growth in the apical region of the hypocotyl depends on a specific metabolic switch involving the upregulation of the photorespiratory pathway and the differential regulation of photosynthesis-related genes and of the gluconeogenesis pathway.The endogenous pattern of ROS accumulation in the apical and basal region of the hypocotyl during the time-course were dynamically regulated, and contributed to tissue-specific wound-induced regeneration.Our findings provide a useful resource for further investigation on the molecular mechanisms involved in wound-induced organ formation in a crop species such as tomato.One-sentence SummaryMetabolic switch during wound-induced regeneration

The ultrastructual morphology of the midgut diverticulum of the calanoid copepod Calanus helgolandicus (Claus) (Crustacea)

1970 ◽  
Vol 18 (1) ◽  
pp. 9 ◽  
Author(s):  
JE Ong ◽  
PS Lake
Keyword(s):  
Amino Acids ◽  
Epithelial Cells ◽  
Myoepithelial Cell ◽  
Calanoid Copepod ◽  
Apical Region ◽  
Basal Region ◽  
Epithelial Layer ◽  
Apical Half ◽  
Mammalian Stomach ◽  
Blue Reaction

The midgut diverticulum of the marine calanoid copepod C. helgolandicus consists of a columnar epithelial layer, a myoepithelial layer, and between these a well-developed basement membrane. The apical region of the epithelial cell is thrown into tightly packed microvilli which showed an alcian blue reaction indicating the presence of acid mucopolysaccharides. The apical half of the cell contains numerous microvesicles and mitochondria as well as tiny Golgi-like bodies. The plasma membrane of the basal region of the epithelium is extremely digitated. The digitations contain numerous mitochondria and the whole structure resembles mitochondrial pumps. The epithelial cells contain a large centrally situated oval nucleus with its single nucleolus. The myoepithelial cell is squamous and contains a flattened nucleus as well as very well-developed circularly and longitudinally arranged myofibrils. It is suggested that the midgut diverticulum of Calanus is probably analogous to the mammalian stomach in that food is mechanically churned. However, it does not appear to be involved in the secretion of digestive juices but only mucopolysaccharides; it is probably involved in the absorption of amino acids which are probably actively transported, by the "mitochondrial pump" in the basal region of the epithelial cells, into the haemocoel.

An ultrastructural study on the early development of Zea mays somatic embryos

1991 ◽  
Vol 69 (4) ◽  
pp. 858-865 ◽  
Author(s):  
P. F. Fransz ◽  
J. H. N. Schel
Keyword(s):  
Zea Mays ◽  
Early Development ◽  
Embryogenic Callus ◽  
Somatic Embryos ◽  
Zea Mays L ◽  
Light And Electron Microscopy ◽  
Apical Region ◽  
Basal Region ◽  
Embryogenic Cells

Friable embryogenic callus, obtained from immature embryos of Zea mays L., was cultured on N6 medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid, 6 mM proline, and 2% sucrose. Cultured tissue fragments containing several globular embryoids were excised and examined by light and electron microscopy to follow the early development of maize embryoids. The somatic embryos consist of an apical region and a suspensor region. Cells of the apical region are small, cytoplasm rich, and mitotically active. They contain much starch and numerous bundles of microtubules. Suspensor cells are larger and more vacuolated. A high metabolic activity in both cell types is indicated by the presence of many organelles, coated vesicles, and multivesicular bodies. Transition units appear to form intermediate stages between the embryogenic callus cells and the somatic embryo. A transition unit consists of a group of embryogenic cells and shows an apical and a basal region. The unit has many intercellular spaces, and within the cells areas with organelle-free cytosol are frequently observed. Key words: somatic embryogenesis, in vitro culture, ultrastructure, Zea mays L.

scholarly journals Changes in cell surface and cortical cytoplasmic organization during early embryogenesis in the preimplantation mouse embryo

1977 ◽  
Vol 74 (1) ◽  
pp. 153-167 ◽  
Author(s):  
T Ducibella ◽  
T Ukena ◽  
M Karnovsky ◽  
E Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Surface ◽  
Early Embryogenesis ◽  
Apical Region ◽  
Basal Region ◽  
Cell Stage ◽  
Preimplantation Mouse ◽  
Cell Surface Changes ◽  
Scanning Electron

Membrane topography and organization of cortical cytoskeletal elements and organelles during early embryogenesis of the mouse have been studied by transmission and scanning electron microscopy with improved cellular preservation. At the four- and early eight-cell stages, blastomeres are round, and scanning electron microscopy shows a uniform distribution of microvilli over the cell surface. At the onset of morphogenesis, a reorganization of the blastomere surface is observed in which microvilli becomes restricted to an apical region and the basal zone of intercellular contact. As the blastomeres spread on each other during compaction, many microvilli remain in the basal region of imminent cell-cell contacts, but few are present where the cells have completed spreading on each other. Microvilli on the surface of these embryos contain linear arrays of microfilaments with lateral cross bridges. Microtubules and mitochondria become localized beneath the apposed cell membranes during compaction. Arrays of cortical microtubules are aligned parallel to regions of apposed membranes. During cytokinesis, microtubules become redistributed in the region of the mitotic spindle, and fewer microvilli are present on most of the cell surface. The cell surface and cortical changes initiated during compaction are the first manifestations of cell polarity in embryogenesis. These and previous findings are interpreted as evidence that cell surface changes associated with trophoblast development appear as early as the eight-cell stage. Our observations suggest that morphogenesis involves the activation of a developmental program which coordinately controls cortical cytoplasmic and cell surface organization.

scholarly journals Endogenous pH 6.0 β-Galactosidase Activity Is Linked to Neuronal Differentiation in the Olfactory Epithelium

Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 298
Author(s):  
José Antonio de Mera-Rodríguez ◽  
Guadalupe Álvarez-Hernán ◽  
Yolanda Gañán ◽  
Ana Santos-Almeida ◽  
Gervasio Martín-Partido ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Neuronal Differentiation ◽  
Olfactory Epithelium ◽  
Cellular Senescence ◽  
Time Windows ◽  
Lectin Histochemistry ◽  
Apical Region ◽  
Basal Region ◽  
Basal Cells ◽  
Histochemical Detection

The histochemical detection of β-galactosidase enzymatic activity at pH 6.0 (β-gal-pH6) is a widely used biomarker of cellular senescence in aging tissues. This histochemical assay also detects the presence of programmed cell senescence during specific time windows in degenerating structures of vertebrate embryos. However, it has recently been shown that this enzymatic activity is also enhanced in subpopulations of differentiating neurons in the developing central nervous system in vertebrates. The present study addressed the histochemical detection of β-gal-pH6 enzymatic activity in the developing postnatal olfactory epithelium in the mouse. This activity was detected in the intermediate layer of the olfactory epithelium. As development progressed, the band of β-gal-pH6 labeling in this layer increased in width. Immunohistochemistry and lectin histochemistry showed the β-gal-pH6 staining to be strongly correlated with the immunolabeling of the olfactory marker protein (OMP) that identifies mature olfactory sensory neurons. The cell somata of a subpopulation of differentiated olfactory neurons that were recognized with the Dolichos biflorus agglutinin (DBA) were always located inside this band of β-gal-pH6 staining. However, the β-gal-pH6 histochemical signal was always absent from the apical region where the cytokeratin-8 positive supporting cells were located. Furthermore, no β-gal-pH6 staining was found in the basal region of the olfactory epithelium where PCNA/pHisH3 immunoreactive proliferating progenitor cells, GAP43 positive immature neurons, and cytokeratin-5 positive horizontal basal cells were located. Therefore, β-gal-pH6 seems to be linked to neuronal differentiation and cannot be regarded as a biomarker of cellular senescence during olfactory epithelium development in mice.

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