Leucine aminopeptidase, HlLAP, from the ixodid tick Haemaphysalis longicornis, plays vital roles in the development of oocytes
Leucine aminopeptidase, HlLAP, from the ixodid tick Haemaphysalis longicornis, plays vital roles in the development of oocytes
复制标题
DOI：
10.1016/j.parint.2010.03.001
复制
发表时间：
2010-06-01
影响因子：
1.9
通讯作者：
Fujisaki, Kozo
中科院分区：
文献类型：
--
作者：
Hata, Takeshi;Tsuji, Naotoshi;Fujisaki, Kozo
雌性硬蜱是一种神奇的无脊椎动物，它们能有效地将大量来自于它们摄入的血液中的营养物质转化为卵。虽然卵母细胞的发育（卵黄发生）在蜱是由血餐触发，并被认为是由来自卵巢细胞连接卵母细胞的营养支持，很少有人知道卵巢分子处理营养物质的卵黄发生。在这项研究中，我们提出了一个假定的功能，亮氨酸氨基肽酶（HlR）在孤雌生殖的成年硬蜱Haemaphysalis longicornis卵巢中的负输出的生殖后，HlR基因的RNA干扰破坏。内源性卵泡激素定位于卵巢细胞，包括卵巢上皮细胞和花梗细胞，这些细胞被认为为发育中的卵母细胞提供营养。组织学研究表明，大多数未成熟的卵母细胞在HlxB基因敲除蜱转化为异常的形态组织学卵母细胞与空泡化的细胞质和/或浓缩的核。两者合计，在HlxB基因敲除蜱中产卵数量的减少可能是由于在剥夺营养物（例如不仅由中肠HlxB而且由卵巢HlxB提供的氨基酸）后未成熟卵母细胞的退化。调节蜱分子参与生殖的营养代谢，包括血液消化和卵黄发生，将有助于控制蜱种群和蜱传病原体。(c)2010爱思唯尔爱尔兰有限公司版权所有。
Female ixodid ticks are amazing invertebrate animals which efficiently convert a large amount of nutrients derived from their ingested blood meals into eggs. Although oocyte development (vitellogenesis) in ticks is triggered by a blood meal and is assumed to be supported by nutrition derived from ovarian cells connecting oocytes, little is known about the ovarian molecules processing nutrient materials for the vitellogenesis. In this study, we have suggested a putative function of leucine aminopeptidase (HlLAP) in the ovary of parthenogenetic adult ixodid tick Haemaphysalis longicornis regarding a negative output of reproduction following disruption of HlLAP gene by RNA interference. Endogenous HlLAP was shown to be localized in the ovarian cells, including ovarian epithelial and pedicel cells which were assumed to provide nutrients for the developing oocytes. Histological studies demonstrated that a majority of immature oocytes in HlLAP gene knockdown ticks were transformed into abnormal morpho-histological oocytes with vacuolated cytoplasm and/or condensed nucleus. Taken together, a reduction of the numbers of laid eggs in the HlLAP gene knockdown ticks may be due to the degeneration of immature oocytes following deprivation of nutrients such as amino acids supplied not only by midgut HlLAP but also by the ovarian HlLAP. Regulation of the tick molecules involved in nutrient metabolism for the reproduction, including blood digestion and vitellogenesis, would help in controlling the tick population and tick-borne pathogens. (c) 2010 Elsevier Ireland Ltd. All rights reserved.