| Project/Area Number |
11460137
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Basic veterinary science/Basic zootechnical science
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
HAYASHI Yoshihiro Graduate School of Agriculture and Life Sciences, THE UNIVERSITY OF TOKYO, Professor, 大学院・農学生命科学研究科, 教授 (90092303)
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| Co-Investigator(Kenkyū-buntansha) |
KANO Kiyoshi Iwate University, Faculty of Agriculture, Assistant Professor, 農学部, 助手 (40312516)
KANAI Yoshiakira Graduate School of Agriculture and Life Sciences, THE UNIVERSITY OF TOKYO, Assistant Professor, 大学院・農学生命科学研究科, 助手 (30260326)
KUROHMARU Masamichi Graduate School of Agriculture and Life Sciences, THE UNIVERSITY OF TOKYO, Associate Professor, 大学院・農学生命科学研究科, 助教授 (00148636)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 2000: ¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 1999: ¥7,800,000 (Direct Cost: ¥7,800,000)
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| Keywords | testis / short photoperiod / spermatogonia / spermatocyte / mouse / hamster / Smad2 / Smad3 / Smadファミリー |
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| Research Abstract |
First, during prespermatogenesis when the testis prominently increases in size, the reproliferation and relocation of gonocytes were examined by BrdU method and electron microscopy. Gonocytes began to move from 17.5dpc and relocated on the basement membrane from 18.5dpc. BrdU-labeled gonocytes were first detected on 1.5dpp. They increased in number abruptly from 2.5dpp and then gradually increased. Secondly, histology and lectin-binding patterns in the testes of two different-body sized bats (Java fruit bat, average b.w. : 567g ; Japanese lesser horseshoe bat, average b.w. : 7g) were investigated. Both testicular morphology and lectin-bindig patterns were almost similar between these two species. Thirdly, the mouse Smad3 cDNA including the open reading frame was cloned from the mouse brain using RACE technique, and its expression pattern was analyzed by northern blot. The predicted amino acid sequences of mouse Smad3 showed a high homology with human Smad3 (99.3%) and mouse Smad2 (85.4%). Northern blot analysis revealed that Smad3 was highly expressed in brain and ovary. In situ hybridization revealed that Smad3 was detected in pyramid cells of hippocampus, granular cells of cerebral cortex, and granulosa cells of ovary. Next, the expression of Smad2 and Smad3 mRNA was examined under the influence of long and/or short photoperiod in hamsters. In situ hybridization detected both Smad2 and Smad3 mRNA in spermatogonia and spermatocytes in both photoperiods. Northern blots showed that Smad2 mRNA was detected at all stages in both photoperiods, whereas Smad3 mRNA was expressed in a short photoperiod. The photoperiodic condition would change the balance between Smad2 and Smad3 transcripts. Moreover, the localization of Smad2 and Smad3 protein was examined in both photoperiods. The Smad2 and Smad3 proteins were localized in spermatocyte cytoplasm in a long photoperiod. They accumulated in spermatocyte nucleus in a short photoperiod.
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