1994 Fiscal Year Final Research Report Summary
Cytochemical study on the transitional regions between endoplasmic reticulum and Golgi apparatus
| Project/Area Number |
05670009
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NODA Toru Kyoto University, Department of Anatomy, Instructor, 医学部, 助手 (50156204)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Golgi apparatus / Endoplasmic reticulum / cytochemistry / small intestine |
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| Research Abstract |
Morphological and cytochemical characteristics of the transitional regions between endoplasmic reticulum (ER) and Golgi apparatus (GA) was investigated in duodenal epithelial cells. Recently machinary of protein transport between ER and GA has been well studied and most of all the hypotheses are based on vesicle transport. However, we found several morphological evidences which suggest other ways of substancial transport than vesicular carrier. The first evidence is cisternal transition from rough ER to Golgi cisternae, frequently observed in immature absorptive cells. In this type of transition, the cisternae of rough ER positioned on the trans face of GA approach and stack onto the trans-most cisterna losing their ribosomes on the way of stacking. Cytochemical labeling of the comparative cisternae by inosine diphosphatase (IDPase) which differentially labels ER and trans Golgi cisternae with light and heavy reaction products, respectivery, show different staining pattern in the same
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cisterna as being ER-type labeling away of Golgi stack and Golgi-type within the Golgi stack. The second type of morphological transition of ER and GA is observed in more matured absorptive cells which start appearing lipid particles in Golgi. In this stage, the cis-most cisterna of GA becomes very characteristic mesh structure, which should be expressed as the "net" knitted with tubules rather than lamellar cisterna. Observation of the thick sections stained with zink-iodide-osmium technique reveals large expansion of the net and the peripheries of this net is found to be demarcated by thicker tube which contains small lipid-like particles. The same type of particles are also recognized in the special tubes which connect to the cis-most net. Therefore, these particles are thought to be delivered from apical cytoplasm through the special tube to the cis side of GA.From the several cytochemical results suggest that this tubes appear to possess both ER and Golgi characteristics. These are the main new findings obtained in this project. These results contain very deep implications which would give new insights not only to protein transport from ER to GA,but also to biogenesis of GA. Less
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