Western Honeybee Drones and Workers (Apis mellifera ligustica) Have Different Olfactory Mechanisms than Eastern Honeybees (Apis cerana cerana)

The honeybees Apis mellifera ligustica (Aml) and Apis cerana cerana (Acc) are two different western and eastern bee species that evolved in distinct ecologies and developed specific antennal olfactory systems for their survival. Knowledge of how their antennal olfactory systems function in regards to the success of each respective bee species is scarce. We compared the antennal morphology and proteome between respective sexually mature drones and foraging workers of both species using a scanning electron microscope, two-dimensional electrophoresis, mass spectrometry, bioinformatics, and quantitative real-time polymerase chain reaction. Despite the general similarities in antennal morphology of the drone and worker bees between the two species, a total of 106 and 100 proteins altered their expression in the drones' and the workers' antennae, respectively. This suggests that the differences in the olfactory function of each respective bee are supported by the change of their proteome. Of the 106 proteins that altered their expression in the drones, 72 (68%) and 34 (32%) were overexpressed in the drones of Aml and Acc, respectively. The antennae of the Aml drones were built up by the highly expressed proteins that were involved in carbohydrate metabolism and energy production, molecular transporters, antioxidation, and fatty acid metabolism in contrast to the Acc drones. This is believed to enhance the antennal olfactory functions of the Aml drones as compared to the Acc drones during their mating flight. Likewise, of the 100 proteins with expression changes between the worker bees of the two species, 67% were expressed in higher levels in the antennae of Aml worker contrasting to 33% in the Acc worker. The overall higher expressions of proteins related to carbohydrate metabolism and energy production, molecular transporters, and antioxidation in the Aml workers compared with the Acc workers indicate the Aml workers require more antennal proteins for their olfactory mechanisms to perform efficient foraging activities than do the Acc worker bees. These data decipher the mechanisms of the western and eastern drone and worker bees acting in response to their different olfactory system in their distinct ecosystem.     

Antennal malformations in light ocelli drones of Apis mellifera (Hymenoptera, Apidae)

Malformed antennae of Apis mellifera light ocelli drones were drawn, dissected and mounted permanently on slides containing Canada balsam, in order to count the olfactory discs present in each segment, in comparison with the number of those structures in normal antennae of their brothers. Some drones presented morphological abnormalities in a single segment of the right or left antenna, but others had two or more malformed segments in a same antenna. Drones with malformations in both antennae were also observed. The 4th and 5th flagellum segments were the most frequently affected. In a low number of cases the frequency of olfactory discs in malformed segments did not differ from that one recorded for normal segments. However, in most cases studied, the antennal malformations brought about a significant reduction in the number of olfactory discs from malformed segments.     

中华蜜蜂气味受体AcerOR57的表达及定位分析

为研究中华蜜蜂气味受体AcerOR57的表达及定位,利用实时荧光定量PCR和Western blot技术检测气味受体AcerOR57 mRNA及蛋白在1日龄工蜂和雄蜂、采集蜂及性成熟雄蜂各部位(触角、头、胸、腹和足)的相对表达量;通过免疫组织化学技术检测该基因受体蛋白在中华蜜蜂触角中的表达定位。结果表明:AcerOR57转录本在1日龄工蜂和采集蜂,1日龄雄蜂和性成熟雄蜂各部位均有表达,但表达程度不一:在1日龄工蜂、采集蜂的触角和1日龄雄蜂、性成熟雄蜂的头部中高丰度表达,均极显著高于其它部位(P0.01);Western blot结果显示,AcerOR57受体蛋白在1日龄工蜂和采集蜂触角中的表达量高于其它部位,这与荧光定量PCR结果相一致;但该蛋白在1日龄雄蜂和性成熟雄蜂的触角和头部表达均不明显,与mRNA水平表达结果相反;免疫组化结果显示,AcerOR57在工蜂和雄蜂触角的毛形感器、板形感器和锥形感器中表达。在1日龄工蜂和性成熟雄蜂中,毛形感器所占的比例大于板形感器,说明其主要在毛形感器中表达;在1日龄雄蜂和采集蜂中,板形感器的表达量比毛形感器表达量多,说明其主要在板形感器中表达;除采集蜂外,其它样本中均发现少量锥形感器的表达。推测AcerOR57可能在探测外界气味分子中发挥一定的作用,这为进一步研究气味受体的功能提供了理论依据。     

Olfactory subsystems in the honeybee: sensory supply and sex specificity

The antennae of honeybee (Apis mellifera) workers and drones differ in various aspects. One striking difference is the presence of Sensilla basiconica in (female) workers and their absence in (male) drones. We investigate the axonal projection patterns of olfactory receptor neurons (ORNs) housed in S. basiconica in honeybee workers by using selective anterograde labeling with fluorescent tracers and confocal-microscopy analysis of axonal projections in antennal lobe glomeruli. Axons of S. basiconica-associated ORNs preferentially projected into a specific glomerular cluster in the antennal lobe, namely the sensory input-tract three (T3) cluster. T3-associated glomeruli had previously been shown to be innervated by uniglomerular projection (output) neurons of the medial antennal lobe tract (mALT). As the number of T3 glomeruli is reduced in drones, we wished to determine whether this was associated with the reduction of glomeruli innervated by medial-tract projection neurons. We retrogradely traced mALT projection neurons in drones and counted the innervated glomeruli. The number of mALT-associated glomeruli was strongly reduced in drones compared with workers. The preferential projections of S. basiconica-associated ORNs in T3 glomeruli together with the reduction of mALT-associated glomeruli support the presence of a female (worker)-specific olfactory subsystem that is partly innervated by ORNs from S. basiconica and is associated with the T3 cluster of glomeruli and mALT projection neurons. We propose that this olfactory subsystem supports parallel olfactory processing related to worker-specific olfactory tasks such as the coding of colony odors, colony pheromones and/or odorants associated with foraging on floral resources.     

Pattern formation and determination in the antenna of the homoeotic mutant Antennapedia of Drosophila melanogaster

The development of the antenna in the antennal-leg homoeotic mutant Antennapedia (Antp^R) was investigated using somatic crossing-over to mark clones of cells in Antp^R antennal appendages. Antp^R antennae ranged from a nearly normal antenna to a nearly normal leg. The arrangement of clones of marked bristles and cuticle in the more antennalike antennae was similar to the wild type antenna, and that of the leglike antennae was similar to the wild-type leg. The contiguity of clones argued against extensive individual cell migration. The regions occupied by homoeotic leg varied considerably between different Antp^R antennae. Observation of Antp^R antennae in these phenotypic mosaics showed that specific leg parts replaced specific antennal parts. Even small groups of leg sensilla appeared only at precise locations in the antenna. These results suggest that homoeotic leg cells and antennal cells can both respond to the same positional information or prepattern. An analysis of clone size provided estimates for cell number in the Antp^R antenna. It was found that cell numbers in the wild-type and Antp^R antennae are about the same until the third instar, when the Antp^R cells start dividing more rapidly than wild type. Previous work had shown that clonal inheritance of a commitment for homoeotic leg also did not occur prior to the early third instar. It is suggested that determination for homoeotic leg occurs in the early third instar, and that thereafter this commitment is inherited by the progeny of the determined cells. The increase in growth rate is probably due to a faster growth rate in cells with a leg commitment than in cells with an antennal commitment. The results suggest that, once initiated, determination may be of two types—a clonally inherited determination (for example, to be homoeotic leg) and an environmental determination (for example, to be a specific part of a homoeotic leg). Clonal inheritance of determination in normal embryonic development and in sex determination in intersexes is discussed.     

Tactile localisation: the function of active antennal movements in the crayfishCherax destructor

Video recordings and single frame analysis were used to study the function of the second antennae of crayfish (Cherax destructor) as a sensory system in freely behaving animals. Walking crayfish move their antennae back and forth through horizontal angles of 100 degrees and more, relative to the body long axis. At rest, animals tend to hold their antennae at angular positions between 20 and 50 degrees. Movements of the two antennae are largely independent of each other. Before and during a turn of the body the ipsilateral antenna is moved into the direction of the turn. Solid objects are explored by repeatedly moving the antennae towards and across them. Both seeing and blinded crayfish can locate stationary objects following antennal contact. On antennal contact with a small novel object, a moving animal withdraws its antenna and attacks the object. When the antenna of a blinded crayfish is lightly touched with a brush the animal turns and attacks the point of stimulation. The direction taken and the distance covered during an attack can be correlated with: the angle at which the antenna is held at the moment of contact and the distance along the antennal flagellum at which the stimulus is applied. From behavioural evidence we conclude that crayfish use information about the angular position of their antennae and about the position of stimulated mechanoreceptors along the antennal flagellum to locate objects in their environment. We suggest ways in which an active tactile system-like the crayfish's antennae--could supply animals with information about the three-dimensional layout of their environment.     

东北大黑鳃金龟嗅感器超微结构

利用扫描电镜和透射电镜对东北大黑鳃金龟Holotrichia diomphalia成虫触角嗅感器进行超微结构研究。结果表明： 其嗅感器集中于触角鳃片上,着生在表皮内陷形成的凹腔里。嗅感器包括锥形感器和板形感器两种,锥形感器根据锥体形状的差异可分为4种类型,板形感器根据盘体形状的不同可分为5种类型。嗅感器表皮为单壁,壁上具有微孔和孔道微管。嗅感器内神经元的数目并不一致,1～3个不等。雄性触角鳃片的长度长于雌性触角鳃片,并且雄性触角嗅感器的总数远远多于雌性,其中雄性板形感器的数目与雌性差异不大,但雄性锥形感器的数目却远远的多于雌性,几乎是雌性的9倍。由此推测锥形感器是感受性信息素的感器,而板形感器用于感受植物气味。     

Ultrastructure and development of single-walled sensilla placodea and basiconica on the antennae of the Sphecoidea (Hymenoptera : aculeata)

While the pore plates of some species of the Sphecoidea (Hymenoptera) rise above the antennal surface, those of other species are flush with it. Not all species possess pore plates. On the antennae of those species, which lack pore plates, small sensilla basiconica are found. The pore plates of Psenulus concolor were studied in detail. The cuticular apparatus rises above the antennal surface. Cuticular features are the encircling ledge and delicate cuticular ledges reinforcing the perforated plate, as well as a joint-like membrane that anchors the plate into the antennal cuticle. Each pore plate is associated with 9–23 sense cells and 4 envelope cells, the second of which is doubled. In very early developmental stages, however, supernumerary envelope cells are observed; they degenerate before the cuticulin layer is secreted. Envelope cell 1 secretes a temporary dendrite sheath, while the envelope cells 2–4 are responsible for the secretion of the cuticular apparatus.The morphology and the development of the small sensilla basiconica are described in Trypoxylon attenuatum. The curved sensillum pointing to the tip of the antenna is anchored by a joint-like membrane. About 15 sense cells innervate the sensillum. The number and the arrangement of the envelope cells resemble that of the sensilla placodea. During very early developmental stages, supernumerary envelope cells are also observed. They degenerate before the cuticle of the cone is secreted by the surviving envelope cells 2–4.     

Queen pheromone transfer within honeybee colonies

ABSTRACT. The observations provided strong circumstantial evidence that workers in a queen's court obtain queen pheromone on their antennae, and that queen pheromone is distributed through the colony during antennal contact between workers. Workers that had just left the court of a mated or virgin queen had an increased tendency to make reciprocated antennal contacts with other workers. This tendency was reinforced when the workers concerned licked the queen in addition to palpating her with their antennae, probably because they spent longer in the court. The first workers contacted by those leaving the court also had an increased tendency to make reciprocated antennal contacts. Antennal contacts were more likely to be initiated by bees other than those from the queen's court. Workers from the court and those they first contacted, participated in food transfer more than did workers selected at random. Workers that licked a virgin queen subsequently participated in food transfer more than those that palpated her with their antennae only. Within about 5 min of leaving the court, a worker's participation in reciprocated antennal contacts and in food transfer diminished to the level of non-court workers. Workers chosen at random made more transient and non-reciprocated antennal contacts when in a colony with a mated queen than when in a colony with a virgin queen.     

Structure and localization of sensilla on antennae of caddisflies (Insecta: Trichoptera)

Structure of antenna segments and ultrastructure of antennal sensillae in representatives of 28 caddisfly families from both modern suborders were studied by electron and light microscopy methods. On Trichoptera antennae, 16 types of sensillae were found, some of them being described for the first time. Morphological peculiarities of cuticular ultrastructures on the antennal surface demonstrate essential differences in structure both at the family level and at the lower taxonomic levels. Specialized sensory fields structurally different from the remaining antennal surface were revealed on antennal flagellae in representatives of the Phryganeina suborder. A new classification of sensillae based on the structure of their cuticular section is proposed.     

Gross and fine structure of the antennal circulatory organ in cockroaches (Blattodea,Insecta)

The antennal circulatory organ of Periplaneta americana and Blaberus craniifer was investigated by light and electron microscopy. This organ consists of two pulsatile ampullae located near the antennal base which are interconnected by a large transverse muscle and associated blood vessels which run into the antennae. Diastole is caused simultaneously in both ampullae by the transverse muscle. Systole is produced passively by the elasticity of the wall of the ampullae and minute accessory tendons. Both elastic structures contain fine unbanded extracellular filaments. The antennal vessels possess two distinct regions: a proximal convoluted region lying within the hemocoel of the head and a narrower distal region running through the antenna and opening near the antennal apex. The length of the proximal portion increases markedly during ontogeny in correlation with the growing antenna. Its wall consists of a high-prismatic epithelium ensheathed by a thick layer of collagen fibrils. The structure of the wall cells is comparable to that found in some salt transporting epithelia: it shows a polar organization with basal infoldings, a large number of mitochondria, and typical arrangement of the junctions or mitochondrial-scalariform junctional complexes. The possible physiological function of this epithelium in ionic or osmoregulation of the hemolymph entering the antenna is discussed. The wall of the distal vessel region consists of a flat single-layered epithelium and seems to be specialized only for delivery of hemolymph to antennae. The structure and function of the antennal heart in cockroaches is compared to that found in other insects.     

伪鞘榕小蜂雌雄成虫触角感器的超微形态、分布及适生意义

伪鞘榕小蜂Sycoscapter trifemmensis是一种寄生于鸡嗉子榕间花期榕果的专性寄生蜂,雌雄两性繁殖策略分化明显,为更好理解和诠释雌蜂寄主定位和雄蜂配偶识别机制,有必要对两性的触角感器进行观察。运用环境扫描电镜观察,对比和探讨了伪鞘榕小蜂雌雄成虫的触角和触角感器类型、分布、数量及其生态适应性。结果表明:雌蜂触角鞭节由11鞭小节组成,总长817.82±33.23μm,分布有毛形感器、刺形感器(类型1)、锥形感器(类型1)、多孔板形感器(类型1)、栓锥形乳突状感器5类5种;雄蜂触角鞭节仅由6鞭小节组成,全长为雌蜂的1/3,且各节有明显的缩短和增粗特征,着生感器包括毛形感器、刺形感器(类型2和类型3)、锥形感器(类型1和类型2)、多孔板形感器(类型2)、腔锥形感器5类7种。雌蜂触角感器的数量与分布显著高于雄蜂,且同类型感器在雌蜂上具有明显的延伸、增粗、分支的特征,以板形感器和锥形感器最为突出。伪鞘榕小蜂雌雄成虫的触角及其感器有明显的性二型,特别是与化学信息识别相关的感器,反映了雌雄蜂在不同生态环境和繁殖压力下的形态分化、行为策略和生态适应。     

Dimorphic antennal systems in gynandromorphic honey bees,Apis Mellifera l. (Hymenoptera: Apidae)

Gynandromorphic honey bees, Apis mellifera (Hymenoptera: Apidae), were examined to determine characteristic morphological and anatomical features of the antennal system. The antennae of gynandromorphic individuals are predominantly worker or drone-like. Hybrid antennae, composed of female and male tissues, occur only rarely (7 out of 188 examined antennae). Depending on the mosaic pattern of the head, both antennae can be drone-like or worker-like, or one can be drone-like and the other worker-like. Examination of the antennal lobes of six characteristic specimens revealed that antennal lobes, which are innervated by drone-like antennae, always have drone-specific enlarged tracts and macroglomerular complexes, whereas antennal lobes innervated by worker-like antennae always are composed of normally sized glomeruli. Thus, there is a strict correlation between the sexual morphology of the antennae and the sexual organization of the antennal lobe neuropil. In one antennal lobe, innervated by a hybrid antenna, we found a hypertrophied glomerulus, certainly homologous to one of the macroglomerular complexes in drone-like antennal lobes.jy 1999 Elsevier Science Ltd. All rights reserved.     

Social facilitation of insect reproduction with motor-driven tactile stimuli

Tactile stimuli provide animals with important information about the environment, including physical features such as obstacles, and biologically relevant cues related to food, mates, hosts and predators. The antennae, the principal sensory organs of insects, house an array of sensory receptors for olfaction, gustation, audition, nociception, balance, stability, graviception, static electric fields, and thermo-, hygro- and mechanoreception. The antennae, being the anteriormost sensory appendages, play a prominent role in social interactions with conspecifics that involve primarily chemosensory and tactile stimuli. In the German cockroach (Blattella germanica) antennal contact during social interactions modulates brain-regulated juvenile hormone production, ultimately accelerating the reproductive rate in females. The primary sensory modality mediating this social facilitation of reproduction is antennal mechanoreception. We investigated the key elements, or stimulus features, of antennal contact that socially facilitate reproduction in B. germanica females. Using motor-driven antenna mimics, we assessed the physiological responses of females to artificial tactile stimulation. Our results indicate that tactile stimulation with artificial materials, some deviating significantly from the native antennal morphology, can facilitate female reproduction. However, none of the artificial stimuli matched the effects of social interactions with a conspecific female.     

中华真地鳖断触角再生的研究

【目的】研究中华真地鳖Eupolyphaga sinensis(Walker)断触角再生特征及再生临界期。【方法】选取1~10龄健康的初龄若虫一条触角除基部3节外剪除,蜕皮后观察并统计触角的节数。选取生长一致健康的初龄4龄若虫,于第0~19日龄进行断触角处理,蜕皮后观察触角的再生情况和触角的节数。【结果】不同虫龄的初龄若虫断去触角蜕皮后,均能通过再生使触角的节数增加。1~10龄的若虫一条触角除基部3节外剪除,蜕皮后下一龄的触角节数分别为5、8、12、13~15、15~17、16~19、18~20、13~15、20~23、22~25、24~28节。4龄的初龄若虫一条触角分别除基部0~2、3、5、10、15、20节外剪除,蜕皮后触角的节数分别为11~12、13~15、18~21、19~25、24~27节,其中一条触角除基部20节外剪除蜕皮后基本恢复正常节数。不同日龄的4龄若虫一条触角除基部3节外剪除蜕皮后,0~8日龄的处理若虫蜕皮后触角节数为13~15节,而12日龄及以后的处理若虫蜕皮后触角节数为5~6节。4龄若虫的断触角再生临界期为9~11日龄。【结论】中华真地鳖在再生临界期内断触角后能够再生触角。     

Antennal movements induced by odour and central projection of the antennal neurones in the honey-bee

Movements of the antennae induced by odour were investigated. Odour presented to the antenna of one side induced both antennae to move to that side. The EMGs recorded from the flexor muscles of both scapes showed that the latency of the movement of the ipsilateral flagellum when induced by odour was about 71 msec shorter than that of the contralateral flagellum. Recording electrical activities from the antennal nerve showed that there are more than 14 neurones in the antenno-motor externus.The distribution of the antennal nerve in the brain was investigated histologically by the injection of fluorescent dye. Antennal sensory neurones terminated at the glomeruli in the antennal lobe, in the dorsal lobe, in the protocerebrum, and in the commissural part of the suboesophageal ganglion. Injection of the fluorescent dye into the antennal nerve after degeneration of the antennal sensory neurones showed that the antennal motoneurones run in the ventral side of the antennal and dorsal lobes, and terminate in the marginal region of the ipsilateral oesophageal connective.The difference in latency of odour-induced flagellar movements is discussed in relation to the histological results and the unitary responses in the brain reported previously.     

Antennal and ovipositor sensilla of Pseudoligosita yasumatsui (Hymenoptera: Trichogrammatidae)

Pseudoligosita yasumatsui Viggiani and Subba Rao 1978 (Hymenoptera: Trichogrammatidae) is a common egg parasitoid of rice insect pests. The surface morphology of the antenna and ovipositor on P. yasumatsui was examined using scanning electron microscopy. The antenna of P. yasumatsui is geniculate in shape, hinged at the scape-pedicel joint, approximately 190 μm in length and consists of seven antennomeres. In total, the male and female antennae have ten different types of sensilla: trichoid sensilla type 1, 2, 3, 4, 5, 6, campaniform sensilla, basiconic sensilla, and placoid sensilla type 1 and 2. The flagellum of the female antenna is covered with cuticular pores, which are absent on the male antennal flagellum. The distal extremity of its ovipositor stylet has campaniform sensilla and styloconic sensilla. Trichoid sensilla found on its apical abdomen part may play a role in the host detection and egg placement. The types and distribution of antennal and ovipositor sensilla on the parasitoid were discussed.     

The antennal motor system of the stick insect Carausius morosus: anatomy and antennal movement pattern during walking

The stick insect Carausius morosus continuously moves its antennae during locomotion. Active antennal movements may reflect employment of antennae as tactile probes. Therefore, this study treats two basic aspects of the antennal motor system: First, the anatomy of antennal joints, muscles, nerves and motoneurons is described and discussed in comparison with other species. Second, the typical movement pattern of the antennae is analysed, and its spatio-temporal coordination with leg movements described. Each antenna is moved by two single-axis hinge joints. The proximal head-scape joint is controlled by two levator muscles and a three-partite depressor muscle. The distal scape-pedicel joint is controlled by an antagonistic abductor/ adductor pair. Three nerves innervate the antennal musculature, containing axons of 14-17 motoneurons, including one common inhibitor. During walking, the pattern of antennal movement is rhythmic and spatiotemporally coupled with leg movements. The antennal abduction/adduction cycle leads the protraction/retraction cycle of the ipsilateral front leg with a stable phase shift. During one abduction/adduction cycle there are typically two levation/depression cycles, however, with less strict temporal coupling than the horizontal component. Predictions of antennal contacts with square obstacles to occur before leg contacts match behavioural performance, indicating a potential role of active antennal movements in obstacle detection.     

Dramatic changes in patterning gene expression during metamorphosis are associated with the formation of a feather-like antenna by the silk moth, Bombyx mori

Many moths use sex pheromones to find their mates in the dark. Their antennae are well developed with lateral branches to receive the pheromone efficiently. However, how these structures have evolved remains elusive, because the mechanism of development of these antennae has not been studied at a molecular level. To elucidate the developmental mechanism of this type of antenna, we observed morphogenesis, cell proliferation, cell death and antennal patterning gene expression in the branched antenna of the silk moth, Bombyx mori. Region-specific cell proliferation and almost ubiquitous apoptosis occur during early pupal stages and appear to shape the lateral branch cooperatively. Antennal patterning genes are expressed in a pattern largely conserved among insects with branchless antennae until the late 5th larval instar but most of them change their expression dramatically to a pattern prefiguring the lateral branch during metamorphosis. These findings imply that although antennal primordium is patterned by conserved mechanisms before metamorphosis, most of the antennal patterning genes are reused to form the lateral branch during metamorphosis. We propose that the acquisition of a new regulatory circuit of antennal patterning genes may have been an important event during evolution of the sensory antenna with lateral branches in the Lepidoptera.     

External morphology of the antennae of Damalinia ovis (Phthiraptera: Trichodectidae)

The antennae of adult Damalinia ovis, the sheep louse, were studied using light and scanning electron microscopy. Sensory structures are located on all three antennal segments with the predominant sensilla type being tactile. Nine different types of sensilla are described on the basis of external appearance. One of the sensilla, designated a "pit organ" because of its unusual shape, has not been described previously. A pair of these sensilla are present on each antenna, and their function is unknown. A group of 11 sensilla on the tip of each antenna contains olfactory and chemosensory pegs, and a possible thermohygroreceptor. The antennae are sexually dimorphic, the male having more tactile sensilla, two well-developed terminal hooks, and a different cuticular architecture on the posterior surface of antennal segment 1.