The Experts below are selected from a list of 6495 Experts worldwide ranked by ideXlab platform
Paolo Burighel - One of the best experts on this subject based on the ideXlab platform.
-
The highly specialised gut of Fritillariidae (Appendicularia: Tunicata)
Marine Biology, 2003Co-Authors: Carlo Brena, Francesca Cima, Paolo BurighelAbstract:The morphology and some functions of the gut of Fritillaria pellucida and Fritillaria formica (Fritillaridae) were investigated by light and electron microscopy, and also by means of histochemical and immunohistochemical techniques. Fritillarids, very important for their abundance and ecological impact in marine ecosystems, have a very simplified gut: a straight oesophagus connects the pharynx to the digestive nucleus, composed of globular stomach and rectum, connected dorsally through a very short proximal intestine. The latter is characterised by a few (two to four) extremely specialised cells, completely filled with mitochondria associated tightly with membrane infoldings showing strong ATP-ase activity, and probably involved in the osmoregulation of internal body fluids. The gut is formed of an extremely low number of cells, which, although poorly diversified, are very large in the stomach and rectum. Food transfer along the gut depends on and is regulated by well-developed cardiac and pyloric valves, and signs of general digestive and absorptive activity are recognisable all along the brush border of the main tracts. The macroscopic organisation and cytological characters of the gut in fritillarids are completely different from those of the oikopleurids. In particular, fritillarids lack specialised cells for endocytosis and Intracellular Digestion, like those described in the genus Oikopleura . The general simplification and specialisation observed in Fritillaria gut may account for their elevated growth rate and abundant diffusion in all oceans.
-
multifarious activities of gut epithelium in an appendicularian oikopleura dioica tunicata
Marine Biology, 2002Co-Authors: Francesca Cima, Carlo Brena, Paolo BurighelAbstract:The functions of the various gut regions of Oikopleuradioica (oesophagus, left and right gastric lobes, vertical intestine, mid-intestine and rectum) were investigated by means of histochemical, histoenzymatic and immunohistochemical techniques at light and electron microscopes. Ciliary food progression is evidenced by the presence of ATPases on cilia, along the entire gut, with the exception of the cardiac valve, a passive device controlling food direction. Absorptive processes (alkaline phosphatase), active transport (ATPases) and nitrogen excretion (D-amino acid oxidase) occur along the entire gut, in both ciliated microvillar and globular cells. The latter, typical of the left gastric lobe and rectum, are also involved in endocytotic processes (exogenous peroxidase as tracer) and Intracellular Digestion (α-amylase, aminopeptidase M, acid phosphatase, 5′-nucleotidase, non-specific esterase). The giant cells of the gastric band participate in extracellular Digestion; they contain secretory granules positive to various hydrolytic enzymes, the activity of which is also recognisable in faecal pellets inside the intestinal lumen. Lipid storage occurs mainly in the right gastric lobe and vertical intestine, whereas protein storage takes place in the rectal granular cells. Epithelial transport and possible osmoregulation occur along the entire gut, especially at the level of diffuse baso-lateral interdigitations, which increase the plasmalemma surface enormously, are often associated with mitochondria and possess numerous ATPase pumps. Data extend previous histological observations and hypotheses on the physiological role of the various gut regions. The remarkable and specific location of enzymatic activities and nutrient storage are in agreement with the high capacity of O. dioica to process a great quantity of food very rapidly and efficiently.
-
gut ultrastructure of the appendicularian oikopleura dioica tunicata
Invertebrate Biology, 2001Co-Authors: Paolo Burighel, Carlo Brena, Gian Bruno Martinucci, Francesca CimaAbstract:. The appendicularians, planktonic tunicates, possess a specialized, external filtering system that captures food particles <1 μm in size. In this work the alimentary canal of Oikopleura dioica has been studied by serial sections of whole animals and ultrastructure. The gut includes a dorsal esophagus, a bilobed saccular stomach, and a curved intestine, divided into vertical, mid-, and distal intestine (or rectum). No multicellular glands or cellular proliferative centers were found. Three main cell types were recognized, ciliated microvillar cells, globular cells and gastric band cells, with specializations reflecting different physiological roles in the various regions. Ciliated microvillar cells, the most diffuse, are considered to be involved in food propulsion, fecal pellet formation, absorption, and nutrient storage. Pinocytotic features and vacuoles suggest that absorption of macromolecules and Intracellular Digestion occur in the globular cells of the stomach and rectum. The large gastric band cells of the left lobe have typical features of intense protein synthesis and probably produce enzymes for extracellular Digestion. Diffuse interdigitations of many cells enormously increase the plasmalemma surface and may be involved in liquid/ion exchange. Despite the apparent structural simplicity of the gut epithelium, O. dioica efficiently processes food to fulfill the energy requirements of its exceptionally rapid life-cycle.
Tian Tian - One of the best experts on this subject based on the ideXlab platform.
-
correction to phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, Jun-yuan ChenAbstract:Proc. R. Soc. B 285 , 20180438. (Published Online 6 June 2018) ([doi:10.1098/rspb.2018.0438][1]) The order of the last two authors in the published version was incorrect. The correct author list is: Chunpeng He1, Tingyu Han1, Xin Liao2,3, Yuxin … [1]: http://dx.doi.org/10.1098/rspb.2018.0438
-
phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, J Y ChenAbstract:The digestive methods employed by amphioxus (Branchiostoma)-both Intracellular phagocytic Digestion and extracellular Digestion-have been discussed since 1937. Recent studies also show that epithelial cells lining the Branchiostoma digestive tract can express many immune genes. Here, in Branchiostoma belcheri, using a special tissue fixation method, we show that some epithelial cells, especially those lining the large diverticulum protruding from the gut tube, phagocytize food particles directly, and Branchiostoma can rely on this kind of phagocytic Intracellular Digestion to obtain energy throughout all stages of its life. Gene expression profiles suggest that diverticulum epithelial cells have functional features of both digestive cells and phagocytes. In starved Branchiostoma, these cells accumulate endogenous digestive and hydrolytic enzymes, whereas, when sated, they express many kinds of immune genes in response to stimulation by phagocytized food particles. We also found that the distal hindgut epithelium can phagocytize food particles, but not as many. These results illustrate phagocytic intercellular Digestion in Branchiostoma, explain why Branchiostoma digestive tract epithelial cells express typical immune genes and suggest that the main physiological function of the Branchiostoma diverticulum is different from that of the vertebrate liver.
-
Phagocytic Intracellular Digestion in amphioxus (Branchiostoma)
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Chunpeng He, Changwei Bi, Rui Guan, Yixin Li, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Na LuAbstract:The digestive methods employed by amphioxus (Branchiostoma)—both Intracellular phagocytic Digestion and extracellular Digestion—have been discussed since 1937. Recent studies also show that epithel...
Xiuqiang Wang - One of the best experts on this subject based on the ideXlab platform.
-
correction to phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, Jun-yuan ChenAbstract:Proc. R. Soc. B 285 , 20180438. (Published Online 6 June 2018) ([doi:10.1098/rspb.2018.0438][1]) The order of the last two authors in the published version was incorrect. The correct author list is: Chunpeng He1, Tingyu Han1, Xin Liao2,3, Yuxin … [1]: http://dx.doi.org/10.1098/rspb.2018.0438
-
phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, J Y ChenAbstract:The digestive methods employed by amphioxus (Branchiostoma)-both Intracellular phagocytic Digestion and extracellular Digestion-have been discussed since 1937. Recent studies also show that epithelial cells lining the Branchiostoma digestive tract can express many immune genes. Here, in Branchiostoma belcheri, using a special tissue fixation method, we show that some epithelial cells, especially those lining the large diverticulum protruding from the gut tube, phagocytize food particles directly, and Branchiostoma can rely on this kind of phagocytic Intracellular Digestion to obtain energy throughout all stages of its life. Gene expression profiles suggest that diverticulum epithelial cells have functional features of both digestive cells and phagocytes. In starved Branchiostoma, these cells accumulate endogenous digestive and hydrolytic enzymes, whereas, when sated, they express many kinds of immune genes in response to stimulation by phagocytized food particles. We also found that the distal hindgut epithelium can phagocytize food particles, but not as many. These results illustrate phagocytic intercellular Digestion in Branchiostoma, explain why Branchiostoma digestive tract epithelial cells express typical immune genes and suggest that the main physiological function of the Branchiostoma diverticulum is different from that of the vertebrate liver.
-
Phagocytic Intracellular Digestion in amphioxus (Branchiostoma)
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Chunpeng He, Changwei Bi, Rui Guan, Yixin Li, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Na LuAbstract:The digestive methods employed by amphioxus (Branchiostoma)—both Intracellular phagocytic Digestion and extracellular Digestion—have been discussed since 1937. Recent studies also show that epithel...
Rui Guan - One of the best experts on this subject based on the ideXlab platform.
-
correction to phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, Jun-yuan ChenAbstract:Proc. R. Soc. B 285 , 20180438. (Published Online 6 June 2018) ([doi:10.1098/rspb.2018.0438][1]) The order of the last two authors in the published version was incorrect. The correct author list is: Chunpeng He1, Tingyu Han1, Xin Liao2,3, Yuxin … [1]: http://dx.doi.org/10.1098/rspb.2018.0438
-
phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, J Y ChenAbstract:The digestive methods employed by amphioxus (Branchiostoma)-both Intracellular phagocytic Digestion and extracellular Digestion-have been discussed since 1937. Recent studies also show that epithelial cells lining the Branchiostoma digestive tract can express many immune genes. Here, in Branchiostoma belcheri, using a special tissue fixation method, we show that some epithelial cells, especially those lining the large diverticulum protruding from the gut tube, phagocytize food particles directly, and Branchiostoma can rely on this kind of phagocytic Intracellular Digestion to obtain energy throughout all stages of its life. Gene expression profiles suggest that diverticulum epithelial cells have functional features of both digestive cells and phagocytes. In starved Branchiostoma, these cells accumulate endogenous digestive and hydrolytic enzymes, whereas, when sated, they express many kinds of immune genes in response to stimulation by phagocytized food particles. We also found that the distal hindgut epithelium can phagocytize food particles, but not as many. These results illustrate phagocytic intercellular Digestion in Branchiostoma, explain why Branchiostoma digestive tract epithelial cells express typical immune genes and suggest that the main physiological function of the Branchiostoma diverticulum is different from that of the vertebrate liver.
-
Phagocytic Intracellular Digestion in amphioxus (Branchiostoma)
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Chunpeng He, Changwei Bi, Rui Guan, Yixin Li, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Na LuAbstract:The digestive methods employed by amphioxus (Branchiostoma)—both Intracellular phagocytic Digestion and extracellular Digestion—have been discussed since 1937. Recent studies also show that epithel...
Yuxin Zhou - One of the best experts on this subject based on the ideXlab platform.
-
correction to phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, Jun-yuan ChenAbstract:Proc. R. Soc. B 285 , 20180438. (Published Online 6 June 2018) ([doi:10.1098/rspb.2018.0438][1]) The order of the last two authors in the published version was incorrect. The correct author list is: Chunpeng He1, Tingyu Han1, Xin Liao2,3, Yuxin … [1]: http://dx.doi.org/10.1098/rspb.2018.0438
-
phagocytic Intracellular Digestion in amphioxus branchiostoma
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Tingyu Han, Rui Guan, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Qiang Zhou, J Y ChenAbstract:The digestive methods employed by amphioxus (Branchiostoma)-both Intracellular phagocytic Digestion and extracellular Digestion-have been discussed since 1937. Recent studies also show that epithelial cells lining the Branchiostoma digestive tract can express many immune genes. Here, in Branchiostoma belcheri, using a special tissue fixation method, we show that some epithelial cells, especially those lining the large diverticulum protruding from the gut tube, phagocytize food particles directly, and Branchiostoma can rely on this kind of phagocytic Intracellular Digestion to obtain energy throughout all stages of its life. Gene expression profiles suggest that diverticulum epithelial cells have functional features of both digestive cells and phagocytes. In starved Branchiostoma, these cells accumulate endogenous digestive and hydrolytic enzymes, whereas, when sated, they express many kinds of immune genes in response to stimulation by phagocytized food particles. We also found that the distal hindgut epithelium can phagocytize food particles, but not as many. These results illustrate phagocytic intercellular Digestion in Branchiostoma, explain why Branchiostoma digestive tract epithelial cells express typical immune genes and suggest that the main physiological function of the Branchiostoma diverticulum is different from that of the vertebrate liver.
-
Phagocytic Intracellular Digestion in amphioxus (Branchiostoma)
Proceedings of The Royal Society B: Biological Sciences, 2018Co-Authors: Chunpeng He, Changwei Bi, Rui Guan, Yixin Li, Xin Liao, Yuxin Zhou, Xiuqiang Wang, Tian Tian, Na LuAbstract:The digestive methods employed by amphioxus (Branchiostoma)—both Intracellular phagocytic Digestion and extracellular Digestion—have been discussed since 1937. Recent studies also show that epithel...
