Numerous Mitochondria (numerous + mitochondria)

Distribution by Scientific Domains

Selected Abstracts

Histology and Mucin Histochemistry of The Digestive Tract of Yellow Catfish, Pelteobagrus fulvidraco

X. J. Cao
Summary The histology and characteristics of mucins secreted by epithelial mucous cells of the digestive tract in yellow catfish, Pelteobagrus fulvidraco were investigated using light microscope and transmission electron microscope. The digestive tract was divided into a pharynx, oesophagus, U-shaped stomach (with a cardiac, fundic and pyloric part) and intestine, composed of anterior intestine, middle intestine and posterior intestine, which consisted of a mucosa (epithelial layer), lamina propria-submucosa, muscularis and serosa. A large number of isolated longitudinal striated muscular bundles were present in the lamina propria-submucosa of pharynx. Goblet cells were observed throughout the digestive tract, except in the stomach. In the cardiac and fundic stomach, a plenty of gastric glands were observed, whereas they were absent in the pyloric part. Numerous mitochondria and endoplasmic reticulum were observed in the columnar epithelial cells of the intestine, especially of the anterior part. The epithelial mucous cells contained neutral or other two mixtures of acid and neutral mucins, the first being the most common. The neutral mucin was the only type of mucins in the stomach, anterior intestine and middle intestine. The results of this study will be helpful for understanding the digestive physiology and diagnosing some gastrointestinal diseases in yellow catfish. [source]

A novel exocrine structure of the bicellular unit type in the thorax of termites

ACTA ZOOLOGICA, Issue 2 2010
Teresa Telles Gonçalves
Abstract Gonçalves, T. T., DeSouza, O. and Billen, J. 2010. A novel exocrine structure of the bicellular unit type in the thorax of termites , Acta Zoologica (Stockholm) 91: 193,198 Studying the thorax of some Termitidae species, we found two pairs of hitherto unknown lateral glands in the mesothorax and metathorax of both workers and soldiers. The glands consist of distinct clusters of class 3 secretory cells accompanied by their duct cells, located in the upper lateral portion of the thoracic wall. Ultrastructural observations reveal numerous mitochondria, a well-developed Golgi apparatus and vesicular smooth endoplasmic reticulum, indicating a cytoplasm with intensive metabolic activity. The gland is reported to occur in Microcerotermes strunckii, Cornitermes cumulans and Nasutitermes minor, three species comprising an interesting morpho-behavioural gradient, respectively, from only mechanical, through mechanical,chemical, to only chemical defence systems. The extent of such a gradient allows speculations that this gland would be related to the general needs of termites, rather than to some specificities of a single group. We warn, however, that complementary studies are needed, before any conclusions can be drawn. [source]

Functional respiratory anatomy of a deep-sea orbiniid polychaete from the Brine Pool NR-1 in the Gulf of Mexico

Stéphane Hourdez
Abstract. An undescribed species of Orbiniidae (Annelida; Polychaeta) is found in large numbers associated with communities of the mussel, Bathymodiolus childressi at hydrocarbon seeps on the Louisiana slope (Gulf of Mexico). Their microhabitat is often hypoxic and sulfidic, which poses serious respiratory challenges for an aerobic metazoan. They display several anatomical features that are quite unusual for this family, which likely allow them to live in their food-rich, but oxygen-limited, habitat. The anterior gills are hypertrophied whereas the posterior gills are not. These anterior gills provide the worms with a large gill surface area (,9.9 cm2/g wet weight), which represents 90,95% of the total gill surface area. The gills contain two blood vessels: a central blood vessel, delimited by a coelomic epithelium, and an intra-epidermal vessel. The diffusion distance between this latter and the environment is only 3 ,-m in the anterior gills, which facilitates gas diffusion. Only the anterior gills are ciliated, which may also facilitate gas exchange across this respiratory surface. The gill cells also contain numerous mitochondria and other electron-dense organelles that might be involved in sulfide detoxification. [source]

Ultrastructure of the Male Reproductive System of Cotesia vestalis (Hymenoptera: Braconidae) with Preliminary Characterization of the Secretions

Fang Huang
Abstract The morphology and ultrastructure of testes and accessory glands along with the characterization of their secretions were investigated for a braconid species Cotesia vestalis (Hymenoptera: Braconidae) using light and electron microscopes. The male internal reproductive system of this species is distinguished by a pair of testes, one vas deferens, and a pair of male accessory glands. The testes are separate, and the accessory glands are oval and not fused. It was observed that the secretory cells of testes have characteristic smooth and rough endoplasmic reticulum, and that the cytoplasm is filled with an array of granule droplets usually of two to three types. The secretory cells in the case of accessory glands are typified by the presence of microvilli on their apical cell surfaces and numerous mitochondria in their cytoplasm. SDS-PAGE profile when performed depicted a similarity in most bands of the secretions from both testes and accessory glands, except for four proteins of which two were present only in testes, while the other two only appeared in accessory glands. Their molecular weights were 117 and 55 kDa for testes and 196 and 30 kDa for accessory glands, respectively. This study gives new insights into the intriguing features of male internal reproductive system and it especially constitutes the first report of its kind about the secretion properties of these organs in C. vestalis. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source]