...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Marine biology >Digestive enzymes in the ontogenetic stages of the southern king crab, Lithodes santolla
【24h】

Digestive enzymes in the ontogenetic stages of the southern king crab, Lithodes santolla

机译：南部帝王蟹Lithodes santolla的个体发育阶段的消化酶

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The early ontogenetic stages of the sub-Antarctic king crab Lithodes santolla were analyzed for the presence and activities of a set of important digestive enzymes. The eggs and non-feeding larvae (zoea Ⅰ-Ⅲ, megalopa) showed high activities of esterases, phos-phatases, and exopeptidases indicating the enzymatic ability to utilize endogeneous yolk reserves. SDS-PAGE showed a continuous decrease of proteins or proteids in the range of 59-81 kDa during ontogenetic development from the eggs through the zoeal stages to the first juvenile crab stage, CI. This reduction reflects the degradation of storage compounds during lecithotrophic larval development. Activities of the endopeptidases, trypsin and chymotrypsin, were low in eggs and larvae but increased significantly in the first juvenile crab stage. These enzymes typically facilitate the first steps of proteolysis in the extra-cellular spaces of the midgut gland and in the stomach. Their scarcity indicates that the larvae of L. santolla are physiologically not prepared to digest external food. This ability seems to appear first in the CI stage. Extracts of juvenile midgut glands and the gastric fluids of adults snowed high activities of a variety of digestive enzymes including phosphatases, carbohyd-rases, as well as endo- and exopeptidases. High activities of digestive enzymes in adults may compensate for scarce food supply and rate-limiting low temperatures in the predominantly sub-Antarctic habitats of L. santolla.
机译：分析了南极亚帝王蟹Lithodes santolla的早期成因阶段，发现了一组重要的消化酶的存在和活性。卵和不喂食的幼虫（Ⅰ-Ⅲ类，甲加洛巴）具有很高的酯酶，磷酸酶和外肽酶活性，表明其具有利用内源卵黄储备的酶促能力。 SDS-PAGE显示在从卵到幼虫阶段到第一个幼蟹阶段CI的自体发育过程中，蛋白质或蛋白质在59-81 kDa范围内持续减少。这种减少反映了营养化幼虫发育过程中储存化合物的降解。卵和幼虫中的内肽酶，胰蛋白酶和胰凝乳蛋白酶的活性较低，但在幼蟹的第一个阶段显着增加。这些酶通常在中肠腺的细胞外空间和胃中促进蛋白水解的第一步。它们的稀缺性表明，Santolla的幼虫在生理上未准备好消化外部食物。此功能似乎首先出现在CI阶段。幼体中肠腺和成年人胃液的提取物具有多种消化酶的高活性，包括磷酸酶，碳糖酶以及内肽酶和外肽酶。在成年人中，消化酶的高活性可能补偿了稀有的食物供应和限速的低温，主要是在南极洲的L. santolla栖息地。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号