| Project/Area Number |
11490014
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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 |
広領域
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| Research Institution | GIFU UNIVERSITY |
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Principal Investigator |
SASAKI Yoshihida Gifu University, Faculty of Agriculture, Professor, 農学部, 教授 (80144004)
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| Co-Investigator(Kenkyū-buntansha) |
KATOH Kazuo Tohoku University, Graduate School of Agriculture, Associate Professor, 農学研究科, 助教授 (60091831)
KITOH Katsuya Gifu University, Faculty of Agriculture, Assistant Professor, 農学部, 助手 (80270974)
KITAGAWA Hitoshi Gifu University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (70144003)
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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 |
¥8,000,000 (Direct Cost: ¥8,000,000)
Fiscal Year 2000: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1999: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Keywords | Japanese Black cattle / Dwarfism / Growth hormone / Insulin-like growth factor-1 / Growth hormone receptor / 黒毛の種牛 / ラロン症候群 / IGF-1 |
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| Research Abstract |
We found calves of Japanese Black cattle with growth retardation having higher serum growth hormone (GH) concentrations and lower plasma insulin-like growth factor (IGF)-1 concentration. The number of GH receptors in the liver was smaller in dwarf cattle than normal ones at the growth period, but was same after maturation. After injection of recombinant bovine GH (somatotropin) to dwarf cattle, serum IGF-1 levels increased, suggesting that the pathway from GH receptor to synthesis of IGF-1 acted normally. Sequences of the GH receptor genes exon 1, 2, and 4 were not different between the normal and dwarf cattle. Therefore, the dwarfism observed in Japanese Black cattle was not similar as Laron syndrome in humans, which had abnormal DNA sequences of GH receptor. Control factors of expression of GH receptor at the growth period have not known precisely, and researches on this field progressed. Besides, this dwarfism developed in calves from sizes in a special line. However, we could not determine what trait the disease showed. The sires associated with the dwarfism have used for copulation with Holstein cattle, but not with Japanese Black, so that occurrence of dwarfism reduced in the area.
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