Fine structure of sensilla on the ovipositor of the tephritid fly Urophora affinis

1986 ◽  
Vol 64 (4) ◽  
pp. 973-984 ◽  
Author(s):  
R. Y. Zacharuk ◽  
R. M. K. W. Lee ◽  
D. E. Berube
Keyword(s):  
Fine Structure ◽  
Epidermal Cell ◽  
Fruit Flies ◽  
Sheath Cell ◽  
Outer Sheath ◽  
Dendritic Segment ◽  
Tubular Body ◽  
Tubular Bodies ◽  
Sheath Cells

There are four types of sensilla on the ovipositor blade of Urophora affinis Frauenfeld, one more than was observed on three other species of fruit flies studied by other authors. Three of the types, uniporous gustatory pegs, campaniform organs, and tactile short hairs are common to the four species and generally are in similar positions on the blade. The fourth, uniporous gustatory plates, were noted in U. affinis only. The chemosensilla are innervated by three chemosensory dendrites that terminate below the pore and a mechanosensory dendrite with a tubular body that is attached to a basal cuticular apodeme of the covering cuticle. The dendritic tubular bodies of the campaniform organs and tactile hairs terminate parallel to the surface in a right-angular bend, where they are attached to basal apodemes of the covering cuticle. The chemosensilla and tactile hairs have individual outer and inner sheath cells, but the campaniform organs have individual inner sheath cells only. The part of the ciliary dendritic segment that is encased by the dendritic sheath passes through an epidermal cell, often with several sensilla sharing the same epidermal cell in place of an outer sheath cell. The role of these sensilla during oviposition is discussed.

Ultrastructure of the uniporous sensilla on the galea of larval Mamestra configurata (Walker) (Lepidoptera: Noctuidae)

1994 ◽  
Vol 72 (11) ◽  
pp. 2016-2031 ◽  
Author(s):  
Vonnie D. C. Shields
Keyword(s):  
Sheath Cell ◽  
Bright Field ◽  
Mamestra Configurata ◽  
Outer Sheath ◽  
Transmission Electron ◽  
Campaniform Sensillum ◽  
Tubular Body ◽  
Styloconic Sensillum ◽  
Lepidoptera Noctuidae ◽  
Sheath Cells

The structure and innervation of sensilla on the galea of fifth-instar Bertha armyworms, Mamestra configurata, were examined using bright-field light, scanning electron, and transmission electron microscopy. Four sensillar types were identified. The galea bears two uniporous styloconic sensilla, one aporous spire-shaped basiconic sensillum, two aporous basiconic sensilla, and one campaniform sensillum. The uniporous styloconic sensillum consists of a small socketed peg inserted into a large cone or style. Each styloconic sensillum is innervated by five bipolar neurons and associated with three sheath cells. Four distal dendrites end in the peg at various levels beneath the pore and the fifth ends in a tubular body at the base of the peg. The intermediate and outer sheath cells enclose a very large liquor-filled sensillar sinus. The inner sheath cell forms a nonlapped cylindrical sleeve around the neurons. These sensilla exhibit features of contact chemosensilla.

Ultrastructure of the aporous sensilla on the galea of larval Mamestra configurata (Walker) (Lepidoptera: Noctuidae)

1994 ◽  
Vol 72 (11) ◽  
pp. 2032-2054 ◽  
Author(s):  
Vonnie D. C. Shields
Keyword(s):  
Distal Portion ◽  
Sheath Cell ◽  
Mamestra Configurata ◽  
Bipolar Neuron ◽  
Campaniform Sensillum ◽  
Tubular Body ◽  
Lepidoptera Noctuidae ◽  
Sheath Cells

The galea of fifth-instar Bertha armyworms, Mamestra configurata, has three types of aporous sensilla: one spire-shaped basiconic peg, two short basiconic pegs, and one campaniform sensillum. The spire-shaped peg is set in an inflexible socket, innervated by three bipolar neurons, and enveloped by three sheath cells. One microtubule-laden dendrite completely fills the distal portion of the dendritic sheath and ends within the peg. It is joined by a lamellate and a scolopidium-like dendrite that end near and below the base of the peg, respectively. The ciliary sinus is large and the membrane of the enveloping inner sheath cell is highly elaborate. This sensillum exhibits features characteristic of thermo-hygrosensilla. The short basiconic pegs and campaniform sensillum are each innervated by a single bipolar neuron and each is associated with three sheath cells. In both sensilla, the dendrite ends in a tubular body, typical of mechanosensilla.

Ultrastructure of the larval antenna of Tenebrio molitor L. (Coleoptera: Tenebrionidae): structure of the trichoid and uniporous peg sensilla

1982 ◽  
Vol 60 (7) ◽  
pp. 1528-1544 ◽  
Author(s):  
J. W. Bloom ◽  
R. Y. Zacharuk ◽  
A. E. Holodniuk
Keyword(s):  
Tenebrio Molitor ◽  
Instar Larva ◽  
Terminal Segment ◽  
Sheath Cell ◽  
Dendrite Bundles ◽  
Tubular Body ◽  
Coleoptera Tenebrionidae ◽  
Sheath Cells

The antenna of the final instar larva of Tenebrio molitor has three segments. The reduced third (terminal) segment bears a large trichoid sensillum, four uniporous peg sensilla, one blunt tipped peg sensillum, and one papillate sensillum. The second segment bears a very large multiporous placoid sensillum, three uniporous peg sensilla, one blunt-tipped peg sensillum, and one papillate sensillum. The numbers and arrangement of these sensilla are usually stereotyped, but variations occur.The trichoid sensillum is a long, thin, unsocketed, aporous hair. It is innervated by two (sometimes one) bipolar neurones and has five sheath cells. The three sheath cells which distally delimit the large sensillar sinus have extremely elaborate microvillate inner borders. The uniporous peg sensillum is a short, stout, socketed peg with a single terminal pore. It is innervated by two to six (usually six) bipolar neurones. The dendrite from one of these always ends as a tubular body in the base, while the dendrites from the others extend to the tip of the peg. This sensillum has a small sensillar sinus and only four sheath cells. The inner sheath cell of both types of sensilla forms a cylindrical, nonlapped sleeve around the dendrite bundles.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

Role of actin in epidermal cell indirect adhesion.

1991 ◽  
Vol 53 (1) ◽  
pp. 3-6
Author(s):  
SHIN'ICHI INOHARA
Keyword(s):  
Epidermal Cell

Pieces of Mind

2018 ◽  
Author(s):  
Carrie Figdor
Keyword(s):  
Mathematical Models ◽  
Moral Status ◽  
Entire Range ◽  
Fruit Flies ◽  
Literal Interpretation ◽  
Psychological Capacities

Many people accept that chimpanzees, dolphins, and some other animals can think and feel. But these cases are just the tip of a growing iceberg. If biologists are right, fruit flies and plants make decisions, worms and honeybees can be trained, bacteria communicate linguistically, and neurons have preferences. Just how far does cognition go? This book is the first to critically consider this question from the perspective of the entire range of new ascriptions of psychological capacities throughout biology. It is also the first to consider the role of mathematical models and other quantitative forms of evidence in prompting and supporting the new ascriptions. It defends a default literal interpretation of psychological terms across biological domains. It also considers the implications of the literal view for efforts to explain the mind’s place in nature and for traditional ways of distinguishing the superior moral status of humans relative to other living beings.

scholarly journals Four Mutant Alleles Elucidate the Role of the G2 Protein in the Development of C4 and C3 Photosynthesizing Maize Tissues

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 787-797
Author(s):  
Lizzie Cribb ◽  
Lisa N Hall ◽  
Jane A Langdale
Keyword(s):  
Cell Types ◽  
Bundle Sheath ◽  
Primary Role ◽  
Ribulose Bisphosphate Carboxylase ◽  
Sheath Cell ◽  
Mesophyll Cells ◽  
Phenotypic Data ◽  
Bisphosphate Carboxylase ◽  
Bundle Sheath Cell

Abstract Maize leaf blades differentiate dimorphic photosynthetic cell types, the bundle sheath and mesophyll, between which the reactions of C4 photosynthesis are partitioned. Leaf-like organs of maize such as husk leaves, however, develop a C3 pattern of differentiation whereby ribulose bisphosphate carboxylase (RuBPCase) accumulates in all photosynthetic cell types. The Golden2 (G2) gene has previously been shown to play a role in bundle sheath cell differentiation in C4 leaf blades and to play a less well-defined role in C3 maize tissues. To further analyze G2 gene function in maize, four g2 mutations have been characterized. Three of these mutations were induced by the transposable element Spm. In g2-bsd1-m1 and g2-bsd1-s1, the element is inserted in the second intron and in g2-pg14 the element is inserted in the promoter. In the fourth case, g2-R, four amino acid changes and premature polyadenylation of the G2 transcript are observed. The phenotypes conditioned by these four mutations demonstrate that the primary role of G2 in C4 leaf blades is to promote bundle sheath cell chloroplast development. C4 photosynthetic enzymes can accumulate in both bundle sheath and mesophyll cells in the absence of G2. In C3 tissue, however, G2 influences both chloroplast differentiation and photosynthetic enzyme accumulation patterns. On the basis of the phenotypic data obtained, a model that postulates how G2 acts to facilitate C4 and C3 patterns of tissue development is proposed.

scholarly journals Gab1 and SHP-2 promote Ras/MAPK regulation of epidermal growth and differentiation

2002 ◽  
Vol 159 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Ti Cai ◽  
Keigo Nishida ◽  
Toshio Hirano ◽  
Paul A. Khavari
Keyword(s):  
Epidermal Cell ◽  
Mapk Signaling ◽  
Dominant Negative ◽  
Mapk Activity ◽  
Ras Activation ◽  
Proliferation And Differentiation ◽  
Epidermal Proliferation ◽  
Epidermal Growth ◽  
Docking Protein

În epidermis, Ras can influence proliferation and differentiation; however, regulators of epidermal Ras function are not fully characterized, and Ras effects on growth and differentiation are controversial. EGF induced Ras activation in epidermal cells along with phosphorylation of the multisubstrate docking protein Gab1 and its binding to SHP-2. Expression of mutant Gab1Y627F deficient in SHP-2 binding or dominant-negative SHP-2C459S reduced basal levels of active Ras and downstream MAPK proteins and initiated differentiation. Differentiation triggered by both Gab1Y627F and SHP-2C459S could be blocked by coexpression of active Ras, consistent with Gab1 and SHP-2 action upstream of Ras in this process. To study the role of Gab1 and SHP-2 in tissue, we generated human epidermis overexpressing active Gab1 and SHP-2. Both proteins stimulated proliferation. In contrast, Gab1Y627F and SHP-2C459S inhibited epidermal proliferation and enhanced differentiation. Consistent with a role for Gab1 and SHP-2 in sustaining epidermal Ras/MAPK activity, Gab1−/− murine epidermis displayed lower levels of active Ras and MAPK with postnatal Gab1−/− epidermis, demonstrating the hypoplasia and enhanced differentiation seen previously with transgenic epidermal Ras blockade. These data provide support for a Ras role in promoting epidermal proliferation and opposing differentiation and indicate that Gab1 and SHP-2 promote the undifferentiated epidermal cell state by facilitating Ras/MAPK signaling.

Insight into the exciton fine structure, the role of phonons and depolarization effects in halide perovskite nanocrystals

2021 ◽  
Author(s):  
jacky even ◽  
philippe tamarat ◽  
philipe bourges ◽  
guido roma ◽  
claudine katan ◽  
...  
Keyword(s):  
Fine Structure ◽  
Perovskite Nanocrystals ◽  
Halide Perovskite ◽  
Insight Into

Fine Structure of Swarmers of Cladophora and Chaetomorpha

1971 ◽  
Vol 9 (3) ◽  
pp. 581-601
Author(s):  
D. G. ROBINSON ◽  
R. D. PRESTON
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Spatial Arrangement ◽  
Cell Wall Synthesis ◽  
Fibrous Layer ◽  
Etching Technique ◽  
Freeze Etching

Naked swarmers of both Cladophora rupestris and Chaetomorpha melagonium have been examined by the freeze-etching technique. The swarmers of Cladophora, collected just after settling, reveal several layers of granules external to the plasmalemma and internal to the so-called ‘fibrous-layer’. Chaetomorpha swarmers collected just before settling show extrusion of vesicles through the plasmalemma. The structures associated with the membranes are discussed in relation to known features of these swarmers already observed by sectioning. The role of granules in the synthesis of cell wall microfibrils is strengthened though the spatial arrangement of the granules seen in this investigation does not completely fulfil the ‘ordered granule’ hypothesis. Description of, and comments on, features related to cell wall synthesis, particularly the Golgi and vacuolar systems, are given.

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