绿盲蝽气味结合蛋白AlucOBP33配体结合特性

本文研究了绿盲蝽气味结合蛋白AlucOBP33的配体结合特性,以期明确其在绿盲蝽化学感受过程中的生理功能。基于前期绿盲蝽触角转录组测序数据,筛选获得候选气味结合蛋白AlucOBP33。三维结构预测显示,AlucOBP33由6个α螺旋构成,包含3对保守的半胱氨酸,属于classic OBPs。室内对AlucOBP33基因进行了克隆和重组表达,采用荧光竞争结合试验研究了重组AlucOBP33蛋白与潜在的73种挥发性气味及13种味觉化合物的结合特性。结果显示,AlucOBP33重组蛋白能够分别与2种醇类、4种酮类、1种酯类、1种醛类和1种烯烃类的挥发性气味以及4种非挥发性化合物结合,推测AlucOBP33在绿盲蝽嗅觉感受和味觉识别过程中发挥双重功能。     

Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations

North America's eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programmes often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response as rate of tongue-flick (RTF). The RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating investigatory behaviours and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is potentially a low-cost alternative trap lure for the control of invasive corn snake populations.     

Role of sensory mechanisms in predatory feeding behaviorof juvenile red drum Sciaenops ocellatus

ABSTRACT:   The red drum Sciaenops ocellatus Linnaeus is an exoticaquaculture species in Taiwan. As a carnivore it preys on a varietyof food organisms, including fishes and invertebrates. Isolatingthe sensory mechanisms that govern its predatory behavior wouldhelp clarify its feeding habit. The present study focused on predationresponses influenced by vision, olfaction and lateral line in captivejuvenile red drum. Results showed that the lateral line had themost significant influence on predatory behavior of the fish. Blockingmechanoreception of the lateral line system resulted in completeloss of ability to catch prey. Ablation of olfaction, in contrast,caused a booster effect on the predation rate. Experimental fishwith scorched olfactory rosettes showed active predatory behavior. Nearor complete darkness had insignificant influence on the predationrate. When the lateral line system was blocked, the fish could notprey normally, even when vision and olfaction were left intact. Itwas concluded that mechanoreception plays the primary role and visionthe secondary role in predatory behavior of the red drum.     

昆虫味觉受体研究进展

化学感受受体在昆虫的觅食、食物选择、交配和产卵等行为中发挥着重要作用。随着果蝇、按蚊、蜜蜂、赤拟谷盗和家蚕等昆虫基因组测序的完成。各物种中完整化学感受受体（包括嗅觉受体和味觉受体）得以鉴定,并从中鉴定出与气味识别、食物选择密切相关的受体基因,如果蝇的二氧化碳受体基因DmGr21a和DmGr63a,糖受体DmGr5a,以及冈比亚按蚊识别人类气味的AgOrl等。其中,昆虫的味觉受体功能与昆虫食物选择、大量取食直接相关。本文就目前昆虫基因组中味觉受体的鉴定、进化、表达和功能等方面的研究进展进行了综述。对味觉受体功能的研究,将有助于我们认识昆虫味觉编码的分子基础和神经调控网络,也是研究昆虫与植物相互关系的热点。     

Methodology for the identification and quantitative measurement of chemical stimulants for penaeid shrimp

In a recently developed paradigm for the feeding behaviour of Crustacea, chemical stimuli are postulated to play a key role in mediating the various stages of feeding from initial excitation to sustained feeding. A hierarchical testing protocol for the screening of compounds or mixtures as chemical stimuli for Penaeus spp. was designed, utilizing: (a) a static chamber for an initial rapid assay for behavioural excitation; (b) a novel flow-through chamber for demonstrating chemotaxis; (c) a modified Y-maze choice chamber for more detailed studies on chemotaxis and feeding stimulation; and (d) aquarium feeding trials in which the most potent chemical attractants and/or feeding stimulants are incorporated into experimental feeds. In shrimp aquaculture, efficient feed utilization is of paramount importance to the economics of production and water quality. Identification and incorporation into the feed of ingredients that act as chemoattrac-tants and/or chemical feeding stimulants should lead to better food utilization, e.g. lower feed conversion ratios (FCRs), thereby producing quicker growth rates and lowering the incidence of water pollution and disease.     

不同浓度化学刺激物对多棘海盘车摄食行为及呼吸代谢的影响

实验室条件下,研究了3种贝类(太平洋牡蛎、紫贻贝、菲律宾蛤仔)不同浓度组织匀浆液及5种单一L型氨基酸(甘氨酸、谷氨酸、酪氨酸、天冬氨酸、赖氨酸)等化学刺激物对多棘海盘车(Asterias amurensis)摄食行为及呼吸代谢的影响。将多棘海盘车对刺激物的行为反应分为正趋向、负趋向和无反应3类,趋向反应由简单到复杂分为4种反应类型,通过测定耗氧率来表示呼吸代谢水平。结果显示,3种贝类组织匀浆液和5种氨基酸(浓度范围10 10~10 4mol/L,酪氨酸除外)均引起多棘海盘车的正趋向反应,且多棘海盘车产生反应的数量比例随刺激物浓度的升高而增加,反应类型也由简单逐渐趋于复杂。同种氨基酸在低浓度下引起多棘海盘车正趋向反应,但超过一定浓度(10 3~10 2mol/L)后会引起负趋向反应(实验浓度范围内谷氨酸组未出现)。不同种类刺激物对多棘海盘车摄食行为反应的影响不同,谷氨酸、甘氨酸以及菲律宾蛤仔组织匀浆液对多棘海盘车诱引效果最好。多棘海盘车的耗氧率随刺激物浓度的增加而逐渐升高。在贝类组织匀浆液中多棘海盘车的耗氧率均高于对照组;甘氨酸、谷氨酸、天冬氨酸各处理组中,只有在较高浓度下耗氧率才显著高于对照组,酪氨酸各组之间无显著差异。研究旨在为贝类底播增养殖和人工鱼礁区敌害生物的防除提供参考,同时为多棘海盘车觅食行为机制的研究提供数据支持。     

Catfish electroreceptor organ functioning during five days exposure to different calcium environments

Catfish, Ictalurus melas, were pre-adapted to artificial tap water with 1.2 mM Ca²⁺ for two weeks, and subsequently transferred to artificial tap water with 0.6, 1.2, or 2.2 mM Ca²⁺ for one week in order to investigate the effect of the environmental Ca²⁺-concentration on stimulus encoding and the frequency characteristics in ampullary electroreceptor organs. Within 30 minutes after transfer, the spontaneous activity of the primary afferents, as well as gain and phase of the stimulus induced responses changed transiently corresponding to the Ca²⁺-concentration. One day after transfer the Ca²⁺-induced changes of the spontaneous activity had disappeared as well as the differences between the sensitivities at frequencies of 2, 8, 12, 16 and 20 Hz in 0.6 and 1.2 mM Ca²⁺, whereas at 16 and 20 Hz in 2.2 mM Ca²⁺ the sensitivity was still elevated. The Ca²⁺-induced phase shift was strongly frequency dependent. At 2 Hz no Ca²⁺ effect on the phase was observed, whereas at 12, 16 and 20 Hz significant effects could be demonstrated up till three days after transfer. The latency was not affected by the transfer.The Ca²⁺-induced effects on the primary afferent spontaneous activity are probably related to a Na⁺/Ca²⁺-exchanger at the basal faces of the receptor cells. The frequency dependent effects on gain and phase are concluded to relate to properties of the apical membrane, most likely to Ca-dependent K-channels. These findings further support the concept that ampullary electroreceptor might serve as chemoreceptor organs.