Seasonal differences in methyl farnesoate esterase activity in tissues of the spider crabLibinia emarginata
作者:
PETER TAKAC,
JONNAS.B. AHL,
HANS LAUFER,
期刊:
Invertebrate Reproduction & Development
(Taylor Available online 1997)
卷期:
Volume 31,
issue 1-3
页码: 211-216
ISSN:0792-4259
年代: 1997
DOI:10.1080/07924259.1997.9672578
出版商: Taylor & Francis Group
关键词: Methyl farnesoate;methyl farnesoate esterase;farnesoic acid;crustaceans;Libinia emarginata
数据来源: Taylor
摘要:
Methyl farnesoate (MF), an unepoxidated form of insect JH III, is present in Crustacea. MF is synthesized by the mandibular organs and is degraded to fomesoic acid (FA) by peripheral tissues. In this study we investigated MF degradation by esterases in hepatopancreas, ovary, testes and hemolymph of the spider crabLibinia emarginatacollected at different times of the year to determine seasonal differences. The conversion of MF to FA varied among the tissues. In the summer, the hepatopancreas showed the greatest esterase activity (52.8% conversion in females and 59.16% in males), and it was twice as high (28.86%) in ovaries than in the testes (12.16%), but was low in the hemolymph of both sexes (10.84% in males, and 6.97% in females). In the fall, the conversion of MF to FA was significantly reduced in all tissues (ovary 8.55%, testes 6.21%, hepatopancreas 10.22%, hemolymph 3.96%). Eyestalk ablation of animals in the fall restored MF esterase activity to summer levels. When tissues from these animals were incubated with OTFP, a specific inhibitor of JH esterase, MF metabolism was significantly reduced. These results suggest that MF esterase activity depends on direct induction by MF, and its degradation is by a specific esterase(s).
点击下载:
PDF (423KB)
返 回