天牛成虫信息素及嗅觉感受机制研究进展

评述了天牛成虫信息素及嗅觉感受机制的研究进展。天牛雌、雄成虫均可释放性信息素,迄今已对31种天牛的性信息素进行了研究,其中完成组分鉴定的有13种。天牛性信息素包括长距离、短距离和接触性信息素3种类型。天牛性信息素存在变异现象,同种天牛分布在不同地区,其性信息素组分之间存在差异。触角是天牛感受性信息素的主要器官,也是判别成虫通讯方式的形态指标,性信息素发达的种类其触角常具显著的性二型现象。天牛利用寄主信息素（如萜烯类、醇类和酯类）寻找寄主。性信息素和寄主信息素在林间复合使用可提高诱捕率。天牛信息素还包括异种信息素、忌避信息素和产卵干扰素,能够提高天牛寄主定位效率。天牛触角嗅觉感受的神经细胞（RNs）有3类,气味信息经神经细胞群传输至中枢神经系统,神经信号按标记路线或交叉纤维样式输导。天牛气味结合蛋白（OBP）方面的研究尚未见报道。     

Volatile terpenes – mediators of plant-to-plant communication

Plants interact with other organisms employing volatile organic compounds (VOCs). The largest group of plant-released VOCs are terpenes, comprised of isoprene, monoterpenes, and sesquiterpenes. Mono- and sesquiterpenes are well-known communication compounds in plant–insect interactions, whereas the smallest, most commonly emitted terpene, isoprene, is rather assigned a function in combating abiotic stresses. Recently, it has become evident that different volatile terpenes also act as plant-to-plant signaling cues. Upon being perceived, specific volatile terpenes can sensitize distinct signaling pathways in receiver plant cells, which in turn trigger plant innate immune responses. This vastly extends the range of action of volatile terpenes, which not only protect plants from various biotic and abiotic stresses, but also convey information about environmental constraints within and between plants. As a result, plant–insect and plant–pathogen interactions, which are believed to influence each other through phytohormone crosstalk, are likely equally sensitive to reciprocal regulation via volatile terpene cues. Here, we review the current knowledge of terpenes as volatile semiochemicals and discuss why and how volatile terpenes make good signaling cues. We discuss how volatile terpenes may be perceived by plants, what are possible downstream signaling events in receiver plants, and how responses to different terpene cues might interact to orchestrate the net plant response to multiple stresses. Finally, we discuss how the signal can be further transmitted to the community level leading to a mutually beneficial community-scale response or distinct signaling with near kin.     

Contexts and messages in macaque social communication

Using a previously developed quantitative scale of social behavior, interactions between group members in seven groups of rhesus macaques were studied. Analysis of 636 behavior chains showed that the large number of different chain sequences (445) was due in part to the large number of contexts in which interactions were occurring. A catalog of 33 contexts of interaction was empirically developed. Particular behaviors were found to have different frequencies of occurrence in different contexts. These frequency differences can be accounted for by the verbal message statements derived for each behavior.     

Symplast domains in extrastelar tissues of Egeria densa Planch.

A set of hydrophilic fluorescent dyes of known molecular weight has been used to determine the molecular exclusion limit and the extent of apical, epidermal and cortical symplasts in the root, stem and leaf of Egeria densa. These dyes are unable to pass the plasmalemma, so that any cell-to-cell movement of injected dye must occur via the symplast. The shoot-apex symplast has a high molecular exclusion limit, excluding dyes with a molecular weight of 749 dalton (fluorescein hexaglycine) and greater but allowing dyes of up to 665 dalton (fluorescein diglutamic acid) to pass. The leaf epidermal symplast is similar to that in the apex: fluorescein pentaglycine (674 dalton) moves to a limited extent, but fluorescein hexaglycine is immobile. Stem and root epidermal cells have a lower molecular exclusion limit, only the dye 6-carboxyfluorescein (376 dalton) is able to move from cell-to-cell. Cortical and epidermal tissues in both the stem and the root have similar symplast permeabilities. However, a barrier to dye (6-carboxyfluorescein) movement is found between the epidermis and the cortex in both organs. Barriers are also found at the nodes between expanded internodes. The stem barriers are not found in the unexpanded nodes near the shoot tip; apparently they are formed early during internode expansion. In the root tip, a barrier to the movement of dye is found between the root cap and the remainder of the root. Plasmodesmata are found linking all cell types studied, even cells where barriers to dye movement occur. Thus, the plant, far from being one uniform symplast, consists of a large number of symplast domains, which may or may not differ in molecular exclusion limit.Abbreviations F fluorescein isothiocyanate isomer I - Glu l-glutamic acid - (Glu)₂ l-glutamylglutamic acid - (Gly)₅ l-pentaglycine - (Gly)₆ l-hexaglycine     

Luteinizing hormone-releasing hormone in olfactory bulbs of primates

This immunohistochemical study of luteinizing hormone-releasing hormone (LHRH) in the olfactory bulbs in primates was undertaken in order to see whether there was an LHRH innervation in these species similar to that found in rodents. One old world (Macaca fascicularis) and two new world (Saimiri sciureus and Aotus trivirgatus) monkeys were studied. Aotus trivirgatus was of particular interest as it is noctural and so presumably more dependent upon olfactory cues. Animals were perfused with fixative, olfactory bulbs removed and sectioned, and tissues reacted immunocytochemically using LR1 (Benoit) antiserum to LHRH. Some LHRH innervation was found in the olfactory bulbs of all three species, comprising a few LHRH neurons and many fibers that ramified within the bulbs. The accessory bulb (not present as a distinct entity in old world primates) had more LHRH innervation than did the main olfactory bulb. Aotus trivirgatus had the greatest representation of LHRH of the three species. The layer of the olfactory bulb with the greatest number of LHRH fibers was the external plexiform layer. This is also true in rodents. There is evidence that LHRH has a role in the mediation of olfactory cues in reproductive behavior in rodents. It is not known how LHRH functions within the olfactory system in primates. However, the fact that it is distributed similarly in the two groups suggests that it may serve a similar function.     

Tumor-derived extracellular vesicles and microRNAs: Functional roles,diagnostic, prognostic and therapeutic options

In the last few years cancer research more and more highlighted the importance of cell to cell communication in tumor progression. Among many other functional mechanisms, results evidenced the importance of miRNAs loaded into exosomes and their actions as mediators in intercellular communication, either in the tumor microenvironment or at distant sites. Deregulation of miRNA levels is a prerogative of cancer cells and is reflected in the miRNA cargo of tumor derived exosomes. Thus, learning of circulating miRNA activities add the missing piece we need to understand some unclear aspects of cancer biology.Here we summarized the current knowledge on exosome transfer capabilities between cancer cells and all the cells constituting tumor microenvironment with a particular focus on their miRNA cargos and regulatory functions. The clinical relevance of these molecular aspects is emphasized by numerous cell interactions that ultimately result in normal cell function defeat, relevant to increase tumor malignancy. The quantitative and qualitative evaluation of circulating miRNAs offers new perspective for better diagnosis and prognosis of cancer patients, eventually improving their management.     

Protistological science dissemination

It is rare to meet protistologists who are not passionate about their study subject. The vast majority of people, however, never get the chance to hear about the work of these researchers. Although every researcher working on protists is likely to be aware of this situation, efforts made and tools employed for dissemination of knowledge are rarely documented. Following a proposal by the Italian Society of Protistology, a workshop at the 2019 VIII European Congress of Protistology in Rome, Italy, was dedicated to protistological knowledge dissemination. Through the many interventions, we discovered the diversity of efforts to reveal the protistan world to the general public, including museum exhibitions and activities, public understanding of science events, citizen science projects, specific book publications, the use of protists in teaching at all levels from primary school children to university undergraduate students, and to a global audience via social media. The participation of the workshop delegates in the discussions indicated that presentations on the wonderful world of protists to the public not only increase the visibility and accessibility of protistology research but are also very important for the scientific community. Here we report on some of the key aspects of the presentations given in the dissemination workshop.