The Indeterminate Phase of Chagas' Disease: Ultrastructural Characterization of Cardiac Changes in the Canine Model

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

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Ultrastructural Characterization of Malpighian Tubules of Rhodnius prolixus During the Insect's Feeding Cycle and Under Hyperosmotic Shock

Entomological News ◽

10.3157/021.129.0208 ◽

2020 ◽

Vol 129 (2) ◽

pp. 189

Author(s):

Jacenir Reis dos Santos-Mallet ◽

Simone Patrícia Carneiro Freitas ◽

Maria Luiza Ribeiro de Oliveira ◽

Alice Helena Ricardo-Silva ◽

Aníbal Gil Lopes ◽

...

Keyword(s):

Rhodnius Prolixus ◽

Malpighian Tubules ◽

Hyperosmotic Shock ◽

Ultrastructural Characterization ◽

Feeding Cycle

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Morphological and Ultrastructural Characterization of Hemocytes in an Insect Model, the Hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae)

Insects ◽

10.3390/insects12070640 ◽

2021 ◽

Vol 12 (7) ◽

pp. 640

Author(s):

Natalia R. Moyetta ◽

Fabián O. Ramos ◽

Jimena Leyria ◽

Lilián E. Canavoso ◽

Leonardo L. Fruttero

Keyword(s):

Cell Biology ◽

Cell Types ◽

Transmission Electron ◽

Ultrastructural Characterization ◽

Current Classification ◽

Contrast Microscopy ◽

First Time ◽

Controversial Aspect

Hemocytes, the cells present in the hemolymph of insects and other invertebrates, perform several physiological functions, including innate immunity. The current classification of hemocyte types is based mostly on morphological features; however, divergences have emerged among specialists in triatomines, the insect vectors of Chagas’ disease (Hemiptera: Reduviidae). Here, we have combined technical approaches in order to characterize the hemocytes from fifth instar nymphs of the triatomine Dipetalogaster maxima. Moreover, in this work we describe, for the first time, the ultrastructural features of D. maxima hemocytes. Using phase contrast microscopy of fresh preparations, five hemocyte populations were identified and further characterized by immunofluorescence, flow cytometry and transmission electron microscopy. The plasmatocytes and the granulocytes were the most abundant cell types, although prohemocytes, adipohemocytes and oenocytes were also found. This work sheds light on a controversial aspect of triatomine cell biology and physiology setting the basis for future in-depth studies directed to address hemocyte classification using non-microscopy-based markers.

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Infestin, a thrombin inhibitor presents in Triatoma infestans midgut, a Chagas’ disease vector: gene cloning, expression and characterization of the inhibitor

Insect Biochemistry and Molecular Biology ◽

10.1016/s0965-1748(02)00035-8 ◽

2002 ◽

Vol 32 (9) ◽

pp. 991-997 ◽

Cited By ~ 60

Author(s):

I.T.N. Campos ◽

R. Amino ◽

C.A.M. Sampaio ◽

E.A. Auerswald ◽

T. Friedrich ◽

...

Keyword(s):

Gene Cloning ◽

Chagas Disease ◽

Triatoma Infestans ◽

Thrombin Inhibitor ◽

Disease Vector

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Ultrastructural characterization of a pigment mutant of the red alga Palmaria palmata

Canadian Journal of Botany ◽

10.1139/b84-153 ◽

1984 ◽

Vol 62 (6) ◽

pp. 1101-1107 ◽

Cited By ~ 11

Author(s):

C. M. Pueschel ◽

J. P. van der Meer

Keyword(s):

Red Alga ◽

Palmaria Palmata ◽

Wild Type ◽

Ultrastructural Examination ◽

Dark Treatment ◽

Prolamellar Bodies ◽

Ultrastructural Characterization ◽

Wild Type Control

Ultrastructural examination of a green-pigmented mutant of the red alga Palmaria palmata (L.) O. Kuntze revealed unusual features of the chloroplasts. Encircling peripheral thylakoids, characteristic of the wild-type plastids and florideophyte plastids generally, were lacking. Parallel evenly spaced thylakoids occurred in groups, leaving large volumes of thylakoid-free stroma. Irregularly shaped, electron-dense inclusions with an amorphous substructure and diameters up to 3 μm occurred in some plastids. Cells of the sporeling holdfasts contained structures resembling prolamellar bodies. Attempts to induce formation of prolamellar bodies in blades by dark treatment for 5 weeks were unsuccessful. However, some plastids did develop highly corrugated thylakoids with the crests of one thylakoid apposed to the troughs of the adjacent thylakoid. Thylakoid morphology of the wild-type control was not altered by the absence of light.

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