REPRODUCTIVE COSTS ASSOCIATED WITH RESISTANCE IN A MOSQUITO-FILARIAL WORM SYSTEM
REPRODUCTIVE COSTS ASSOCIATED WITH RESISTANCE IN A MOSQUITO-FILARIAL WORM SYSTEM
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DOI：
10.4269/ajtmh.1993.49.756
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发表时间：
1993-12-01
影响因子：
3.3
通讯作者：
CHRISTENSEN, BM
中科院分区：
文献类型：
--
作者：
FERDIG, MT;BEERNTSEN, BT;CHRISTENSEN, BM
蚊虫在摄食后36小时内可包裹并杀死80%的马来丝虫微丝虫(MF)。构成这种黑色素包裹反应的一系列生化事件在其他蚊子生物事件中也很重要，包括卵绒毛膜晒黑。某些生化实体，包括酪氨酸前体，被认为在这些生物活性中是共有的。由于这种所谓的酪氨酸联系，而且因为血粉既启动卵子发育又是MF的来源，我们评估了当抵抗宿主对从受感染的血粉中获得的MF做出反应时，产生生殖成本的可能性。对寄生虫有反应的蚊子的平均产卵时间显著长于对照组(77.7小时对66.5小时)。感染蚊子的卵巢中的酪氨酸水平在24小时和48小时时不到对照组的一半，在喂血后72小时仍显著降低。通过测量和总蛋白质含量评估的卵巢发育，在实验组也显著延迟，卵巢宽度和蛋白质含量从未达到对照组蚊子的水平。血餐后24小时的卵巢切片显示，卵子发育的正常过程，包括卵黄的积累，也发生了巨大的变化。我们考虑了这些结果的生物学意义。
The mosquito Armigeres subalbatus can encapsulate and kill > 80% of Brugia malayi microfilariae (mf) within 36 hr following ingestion. The cascade of biochemical events constituting this melanotic encapsulation response is also important in other mosquito biological events, including egg-chorion tanning. Certain biochemical entities, including a tyrosine precursor, are thought to be shared among these biological activities. Because of this purported tyrosine link, and because the blood meal both initiates egg development and is the source of mf, we evaluated the possibility that reproductive cost is incurred by the resistant host when undergoing a response to mf acquired in an infected blood meal. Mean time to oviposition was significantly longer for mosquitoes responding to parasites than for controls (77.7 versus 66.5 hr). Tyrosine levels in ovaries from infected mosquitoes were less than half those of controls at 24 and 48 hr, and were still significantly reduced at 72 hr following bloodfeeding. Ovary development, assessed via measurements and total protein content, also was delayed significantly in the experimental group, with ovary width and protein content never attaining levels found in control mosquitoes. Sections from 24-hr post-blood meal ovaries demonstrated that the normal processes of egg development, including vitelline accumulation, was drastically altered as well. The biological implications of these results are considered.