Cotesia kariyai larvae need an anchor to emerge from the host Pseudaletia separata
Cotesia kariyai larvae need an anchor to emerge from the host Pseudaletia separata
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DOI：
10.1002/arch.20189
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发表时间：
2007-09-01
影响因子：
2.2
通讯作者：
Harvey, J. A.
中科院分区：
文献类型：
--
作者：
Nakamatsu, Y.;Tanaka, T.;Harvey, J. A.
在25 I ℃的长日照光照条件下，群居性寄生蜂柯氏盘绒茧蜂的成熟幼虫在寄生后约10天结茧化蛹，并从其宿主Pseudoletio sepoIroto中羽化。寄生蜂幼虫在羽化前在寄主血锥中形成包囊。这些胶囊的功能是“锚”，使它们能够从宿主内部压在宿主的外皮上。根据以往的研究表明，该锚蛋白由糖蛋白组成，并且寄生蜂幼虫的丝腺从第2期开始发育，推测该锚蛋白可能是由寄生蜂幼虫分泌的丝蛋白组成。C.经SH-PAGE分析，kariyoi幼虫主要由分子量为300.6和46.7kDa的两种蛋白质组成。在拟寄生蜂出现之前，从锚蛋白中检测到一定分子量的纤维瘤样蛋白。这些结果表明，锚组装与纤维蛋白样蛋白，并形成前parositoid出现，而在宿主体腔。注射牛胰蛋白酶可抑制寄生蜂幼虫从宿主体内的出现，这是因为胰蛋白酶分解了寄生蜂的锚。胰蛋白酶活性在寄生寄主血淋巴增加后，寄生蜂出现。
Mature larvae of the gregarious encloparositoid Cotesia koriyoi construct cocoons for pupation approximately 10 days after parasitization and emerge from their host Pseudoletio sepoIroto under a long day photo-regime (16181)) at 25 I degrees C. The parositoid larvae make capsules in the host hemoconel just prior to their emergence. These capsules function as "anchors," which enable them to press against the host integument from inside the host. It was predicted that this anchor might be composed of silk proteins secreted from the parositoid larvae, because a previous study showed that the anchor was made up of a glycopiotein and that the silk gland of parasitoid larvae developed from 2nd larval stage. Fibroin-like proteins in C. kariyoi larva mainly consist of two proteins with molecular mosses of the 300.6 and 46.7 kDa estimated by SH-PAGE. The fibrom-like proteins with the some molecular mass were detected from the anchor proteins just prior to parositoid emergemce. These results indicate that the anchor was assembled with fibrion-like proteins and was formed just before parositoid emergence while in the host body cavity. Injection of bovine pancreatic trypsin inhibited the emergence of parositoid larvae from the host because the anchor was decomposed by ttypsin. Trypsin activity in the parasitized host hemolymph increased only after parasitoid emergence.