1997 Fiscal Year Final Research Report Summary
Apoptotic regulation of number of eggs in blood-fed female mosquitoes
| Project/Area Number |
08670289
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
寄生虫学(含医用動物学)
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| Research Institution | Juntendo University School of Medicine |
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Principal Investigator |
UCHIDA Keikichi Juntendo University, Dept.of Biology, Lecturer, 医学部, 講師 (40053368)
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| Co-Investigator(Kenkyū-buntansha) |
ESHITA Yuki Kurume University, Dept.of Parasitol., Lecturer, 医学部, 講師 (10082223)
OHMORI Daijiro Juntendo University, Dept.of Chemistry, Assoc.Prof., 医学部, 助教授 (00124967)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Culex pipiens pallens / Ovarian development / Regulation of the number of mature eggs / Cathepsins / Apoptosis |
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| Research Abstract |
1.In Culex pipiens pallens ovaries, activities of cathepsins B and L increase as the folliclar growth proceeds after a bloodmeal, with the optimal pH of 4.5. Cystein proteinase inhibitor E 64 completely inhibited the activities of these cathepsin-like proteinases.
2.Yolk granules collected from degenrating follicles showed stronger fluorescence than those from normally-developing follicles when incubated with synthesized fluorescent substrate for cathepsins B and L.
3.Degenerating follicles also showed stronger fluorescence when incubated with acridine orange, which suggested acidic environment inside the cells of the follicles.
4.Takara Apoptosis Detection Kit indicated that apoptosis occured in those degenerating follicles.
<Summary>Mosquitoes seems to have developed an apoptotic system to regulate the number of maturing follicles after a bloodmeal, in which some part of once-activated follicles degenerate by means of apoptosis. Apoptotic degeneration is necessary to keep the balance between the number of mature follicles and available raw materials supplied from the midgut for yolk protein synthesis. The degeneration occurs when internal environment of the follicles becomes acidified by some factor, which in turn activates cathepsin B and L-like intercellular proteinases.These proteinases first help digest yolk proteins in the oocyte, and then lead to the degeneration of the entire follice.Although Gelatin SDS PAGE indicated that these proteinase have molecular weights of about 28000-30000, the analytical method needs to be modified for further accuracy.
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