Inhibition of host-seeking response and olfactory responsiveness in Anopheles gambiae following blood feeding
Inhibition of host-seeking response and olfactory responsiveness in Anopheles gambiae following blood feeding
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DOI：
10.1016/s0022-1910(00)00107-4
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发表时间：
2001-03-01
影响因子：
2.2
通讯作者：
Adam, W
中科院分区：
文献类型：
--
作者：
Takken, W;van Loon, JJA;Adam, W
在实验室使用行为生物测定法研究了一次血餐对冈比亚按蚊寻找宿主反应的影响。而在化学感觉水平上可能发生的变化则使用触角电图记录（EAG）进行监测。为避免体型可能产生的混淆效应，只选用大体型类蚊子。5岁大的雌蚊在人的手臂上吸食血液，并在3、24、40岁时在嗅觉计中暴露于人的手的散发物中。取食后48和72 h，与相应年龄的未喂蚊（对照）比较其对宿主刺激的行为和eeg反应。在卵子发育过程中，蚊子可以接触到葡萄糖和产卵盘。对宿主气味有反应的吸血蚊子的卵巢发育与未暴露于宿主气味的吸血蚊子的卵巢发育进行了比较。研究了人汗液、己酸、吲哚和香叶酮对血供蚊和对照蚊的脑电图反应。血餐后的eeg记录与行为实验中使用的相同。血餐后3和24小时无宿主寻找反应。在吸血后40小时，7%的蚊子对人的辐射有反应，48小时有27%，72小时有68%。对照组对宿主刺激的平均反应从35（在t-40小时）到67%不等。未喂食组无卵巢发育。对宿主气味有反应48 h的蚊虫中，12.5% （n=5）的卵巢处于Christophers期IV期，其余为V期；对宿主气味有反应72 h的蚊虫中，66.7% （n=94）的卵巢处于V期，31.2% （n=44）的蚊虫刚刚产卵。在Christophers I-III期，血供蚊和对照蚊的最大eeg振幅相似。而在IV期，血液喂养组记录的脑电图幅度明显低于相应的对照组，这是对培养的汗液顶空和吲哚的反应。结果表明，黄芪对黄芪寻找寄主有较强的抑制作用。在冈比亚，在吃完血后，至少需要40个小时。宿主寻找在进食72小时后恢复到血餐前水平，并与卵子成熟有关。寻找寄主行为的抑制伴随着对孵育汗液和吲哚顶空的嗅觉敏感性的抑制，就在寻找寄主反应恢复之前。讨论了这些发现对利用宿主气味进行蚊虫监测的意义。2001爱思唯尔科学有限公司版权所有。
The effect of a single blood meal on the host-seeking response of Anopheles gambiae was investigated in the laboratory using a behavioural bioassay. whereas possible changes at the chemosensory level were monitored using electroantennogram recording (EAG). To avoid the possible confounding effect of body size, mosquitoes of a large size class only were used. Five-day old female mosquitoes were given a blood meal on a human arm and exposed to the emanations of a human hand in an olfactometer at 3, 24, 40. 48 and 72 h following the meal and their behaviour and EAG response to host stimuli were compared with that of unfed mosquitoes (controls) of corresponding age. During egg development, mosquitoes had access to glucose and an oviposition tray. The ovarian development of blood-fed mosquitoes that responded to host odours was compared with that of blood-fed mosquitoes that had not been exposed to host odours. The EAG response of blood-fed and control mosquitoes to host odour was examined upon stimulation with air led over incubated human sweat, hexanoic acid, indole and geranyl acetone. EAGs were recorded at times after a blood meal corresponding with those used in the behavioural experiment. There was no host-seeking response at 3 and 24 h post blood meal (pbm). Seven percent of the mosquitoes responded to human emanations 40-h pbm, 27% at 48 h and 68% at 72 h following a blood meal. The average response of controls to host stimuli varied from 35 (at t-40 h) to 67%. There was no ovarian development in the unfed group of mosquitoes. Of the mosquitoes that responded to host odour 48 h pbm, 12.5% (n=5) had ovaries in Christophers stage IV and the remainder in stage V. Of the mosquitoes that responded 72 h pbm, 66.7% (n=94) had ovaries in stage V and 31.2% (n=44) had recently oviposited. Maximum EAG amplitudes recorded from blood-fed and control mosquitoes were similar for mosquitoes in Christophers stages I-III. whereas in stage IV EAG amplitudes recorded from the blood-fed group were significantly lower than those of the corresponding control group in response to headspace of incubated human sweat and to indole. The results show that there was a strong inhibition of host seeking in An. gambiae for a period of at least 40 h following a blood meal. Host-seeking returned to pre-blood meal levels 72-h post feeding and was associated with egg maturation. The inhibition of host-seeking behaviour was accompanied by an inhibition of olfactory sensitivity to headspace of incubated sweat and indole just before the resumption of the host-seeking response. The implications of these findings for mosquito surveillance with host odours are discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.