Characterization of a Limb Autotomy Factor, LAFpro, That Suspends Molting in Crustaceans

螃蟹和龙虾通过周期性地脱落坚硬的外骨骼生长，这一过程被称为蜕皮。脱毛和肢体再生是由眼柄和身体内分泌器官分泌的激素调控的。然而，先前的研究表明，对换羽的控制更为复杂。如果在动物蜕皮之前将再生的行走腿（肢体芽）切除（自动），则蜕皮将延迟2-3周，这使得丢失的组织有时间再生。Mykles博士及其同事已经证明，肢体芽产生一种称为肢体自切因子-前解（LAFpro）的脱皮抑制蛋白。这个项目的总体目标是了解这个因素是如何延缓换羽过程的。该方案包括三个具体目标：(1)从肢体芽中分离出LAFpro；(2)确定LAFpro对靶器官的作用机制；(3)确定神经系统在介导组织再生反应中的作用。本研究对了解节肢动物的整体生长控制具有广泛的应用价值。通过组织再生而中止换羽的现象并非甲壳类动物所独有。再生还会延迟多种昆虫的蜕皮。这暗示了一个共同的机制。如果是这样，他应该能够开发出控制害虫的全新策略。

Crabs and lobsters grow by periodically shedding the hard exoskeleton through a process called molting. Molting and limb regeneration is regulated by hormones produced by endocrine organs located in the eyestalks and body. Previous studies, however, indicate that control of molting is more complex. If a regenerating walking leg (limb bud) is removed (autotomized) before the animal molts, molting is delayed 2-3 weeks, which allows time for the lost tissue to be regenerated. Dr. Mykles and associates have shown that limb buds produce a molt-inhibiting protein, termed limb autotomy factor - proecdysis (LAFpro). The overall goal of this project is to understand how this factor suspends molting processes. The proposal consists of three specific aims: (1) to isolate LAFpro from limb buds; (2) to determine the mechanism of LAFpro action on target organs; and (3) to determine the role of the nervous system in mediating the response to tissue regeneration.This research has broad application to understanding the control of growth in arthropods as a whole. Suspension of molting by tissue regeneration is not unique to crustaceans. Regeneration also delays molting in a variety of insects. This suggests a common mechanism. If so, he should be able develop entirely new strategies for controlling insect pests.