昆虫病原线虫感染期幼虫恢复发育的研究进展

昆虫病原线虫的感染期幼虫（infective juvenile，IJ）是其一生中唯一具有侵染能力和可自由生活于寄主体外的虫态，一般滞育不取食，体外包裹着已经蜕去的第2龄幼虫的表皮，对外界不良环境的耐受能力强，又称为耐受态幼虫(dauer juvenile，DJ)，类似于秀丽隐杆线虫Caenorhabditis elegans的耐受态幼虫。在食物信息的诱导下，感染期幼虫脱鞘，释放出共生细菌，恢复取食并继续发育，这个过程称为感染期幼虫的恢复（IJ recovery）。这个过程是发生在寄生性线虫入侵寄主时的发育过程，对于成功寄生是必要的，在线虫的产业化培养中发挥着重要作用，感染期线虫的恢复率及其发育的同步性直接影响了线虫的产量。本文概述了感染期线虫的恢复发育过程，并对诱导感染期线虫恢复发育的食物信号（food signals）、恢复的影响因素及其检测手段进行了综述，同时讨论了未来的研究方向。

Research advances in infective juvenile recovery in entomopathogenic nematodes

The infective juvenile(IJ)of entomopathogenic Steinernema and Heterorhabditis nematodes is the only stage,which is free-living and can infect host insect.It is non-feeding and non-reproductive.The IJ,retaining the cuticle of the second stage(L2)as a sheath,has the capability to withstand the harsh environment outside the host and is also called "dauer juvenile"(DJ).It is similar to the Caenorhabditis elegans dauer juvenile.Food signals stimulate the IJs to undergo a process called IJ recovery:they exsheath(the L2 cuticle),release their symbiotic bacteria,and resume feeding and development.The developmental process that occurs in parasitic nematodes upon host invasion is necessary for successful parasitism and plays an important role in their mass production.The IJ recovery rate and developmental synchronicity influence the yield of entomopathogenic nematodes directly.In this article,the process of IJ recovery in entomopathogenic nematodes is described,and the research advances in food signals,their effect factors and detection methods of IJ recovery are reviewed.The future prospects of the IJ recovery research are outlined.