Biased ligand bonds to make right calls—laboratory of signal transduction reveals molecular mechanism for functional selectivity of GPCR

<正>In a recent study,Professor Rui-Ping Xiao and her research group at Institute of Molecular Medicine of Peking University has provided an essential experimental evidence to support the new paradigm of functional selectivity for G protein-coupled receptor(GPCR)signal transduction.The study was published online on May 15 in The Journal of Biological Chemistry[1].The GPCR superfamily,a class of membrane proteins     

Loud calls ofGalago crassicaudatus andG. garnettii and their relation to habitat structure

Long distance vocalizations have been shown to be good indicators of genetic species in primates. Here the loud calls of two recently identified greater galago taxa —Galago crassicaudatus andG. garnettii — are compared and analyzed statistically. Observed differences in call structures are investigated further as potential indicators of differences in the structures of habitats frequented by the two species. Although the calls share a repetitive structure, and show similar dominant frequency bands (1,000 – 1,500 Hz), they differ significantly in the number of units per call, unit duration, inter-unit interval, highest frequency, lowest frequency, dominant frequency band, first harmonic, and call duration. The duration of theG. crassicaudatus call is more than twice that ofG. garnettii. Strong intraspecific consistency is seen in the most energetic frequency bands (dominant frequency band and first harmonic), and durations of the individual units and inter-unit intervals. Information important to species recognition is thus most likely to be contained in these features. Individual recognition may be encoded in the relative emphasis of higher level harmonics. The frequency structures of the calls will reflect requirements for acoustical transmission in a forest environment, as well as structural constraints imposed by body size. Higher frequencies detected in theG. garnettii call (up to 8,500 Hz) may have a functional significance related to distance estimation, or may simply be a reflection of smaller body size. The greater modulation of theG. garnettii call suggests that its habitat constitutes a denser or more turbulent medium for sound transmission than does the habitat ofG. crassicaudatus.     

Acoustic Repertoire of Spawning Cod, Gadus morhua

We examine the vocal repertoire of spawning cod, Gadus morhua. Fish captured in northern Norway were allowed to spawn in tanks and we recorded sound during the spawning period. The cod's grunt repertoire contained more variation than previously suggested. Half of the grunts lasted more than 200ms including one grunt lasting nearly 1s and consisting of 52 pulses, which is far beyond previous reports. Moreover, increasing repetition period and increasing duration of pulses within a grunt from the first pulse towards pulses at the end of the grunt, has previously not been described. On the other hand, no knocks or series of knocks, and on average only one grunt per hour suggest that cod are less versatile vocalists than closely related gadid species, such as haddock, Melanogrammus aeglefinus.     

Food-associated calls in rhesus macaques (Macaca mulatta): I. Socioecological factors

Upon discovering food, free-living rhesus macaques (Macaca mulatta)on the island of Cayo Santiago, Puerto Rico, produce a complexof vocal signals consisting of five acoustically distinguishablecalls. This report examines the socioecological factors elicitingcall production and the information protentially conveyed toothers. The primary contexts for three vocalizations ("warbles," "harmonicarches, " and "chirps") are encounters with rareand highly preferred foods (e.g., coconut). Two other vocalizations("coos" and "grunts") are produced both in food (primarily provisionedchow) and in nonfood contexts, such as during mother-infantseparation and grooming interactions. Grunts given upon encounteringfood are acoustically distinct from those given in nonfood contexts.In contrast, coos associated with food are statistically indistinguishablefrom coos given in other contexts. When conspecitics hear thesefood-associated calls, they typically approach the caller. Coosare less likely to lead to approach than other food-associatedcalls, Results from all-day follows on adult males and adultfemales reveal that changes in hunger level influence call ratebut not call type; the different call types are produced throughoutthe day. We infer that the structure of food-associated callsprovides information about the quality of the food discovered,whereas call rate conveys information about the relative hungerlevel of the caller. In this population, adult males give fewerfood-associated calls than adult females. In addition, femaleswithin large matrilines call more than females within smallermatrilines, and males who are resident in a group are more vocalthan peripheral males.     

同一山洞中五种蝙蝠的回声定位比较及生态位的分化

对同一山洞中5种蝙蝠的回声定位叫声和外部形态作了比较分析,根据蝙蝠回声定位叫声,形态特征与捕食策略之间的联系,并结合部分的野外观察研究,推断其捕食生境及捕食策略,并对洞中5种共栖蝙蝠的生态位分化进行了分析;研究结果如下：（1）南蝠（Ia io)在地面或树冠中间的开阔空间捕食个体较大的昆虫;（2）大鼠耳蝠（Myotis myotis)主要以掠食性方式（gleaning) 捕食森林或草地地表面的昆虫;（3）黄大蹄幅（Hipposideros pratti)主要在树冠周围或树冠上方进行捕蝇器式（Fly-catching)（即倒挂于一固定枝条或地点,探索周围飞行或接近的昆虫,探索到后捕捉回原倒挂地点再进食）或飞行捕食,它主要捕食个体较大的甲虫;（4）角菊头蝠（Rhinolophus cornutus)主要在较密集树木中（枝叶间）,农田及树木周围捕食型较小的翼拍动昆虫;（5）三叶蹄幅（Aselliscus wheeleri)是在树木,灌丛或在其周围空间内捕食较小的翼拍动昆虫,但其食性可能菊头蝠不同,根据以上研究结果,认为这5种蝙蝠的取食生态位存在着明显的分化。     

Postnatal development of franciscana's (Pontoporia blainvillei) biosonar relevant structures with potential implications for function,life history,and bycatch

Franciscana dolphins (Pontoporia blainvillei) are the most endangered species of the western South Atlantic Ocean. The major cause of their vulnerability is incidental bycatch in fishery gill nets. Ontogenetic changes of biosonar relevant structures in Pontoporia were analyzed in five specimens (one female neonate, two male neonates and two male adults) using digital imaging technology (MRI, CT) and macroscopic dissections to compare structures involved in sound production and reception. These data were compared to an ontogenetic series of 69 macerated skulls of Pontoporia in order to elucidate the correlation between soft tissue structures and bones of the epicranial complex and to describe the development‐related changes in the mandible. Postnatal developmental shape changes of the posterior part of the right vestibular air sac followed bone formation and the melon with its right branch elongated, paralleling the flatter facial depression of adults. Minor postnatal developmental modifications were verified in the tympano‐periotic complex but a shape change of the mandible was visible by a ventral deviation of the posterior part of the mandible in adults. These results reveal postnatal changes in allometry and shape of biosonar relevant structures that may be one of the causes that increase bycatch of neonate and young Pontoporia individuals.     

Use of Olfaction During Prey Location by the Common Vampire Bat (Desmodus rotundus)1

The common vampire bat, Desmodus rotundus, feeds on mammalian blood and is a major agricultural pest in Latin America. One way to prevent bats from biting livestock is to understand how the bats locate the livestock. We confirmed the role of olfaction in foraging with a modified cafeteria trial. Bats significantly favored blood meals associated with scent (fur, feces) over meals lacking these olfactory cues. These results confirm earlier observations on the role of olfaction during prey location by this species, and have potential to facilitate eradication measures without extensive loss of other bat species.     

The inner ear morphology of the ‘condylarthran’ Hyopsodus lepidus

We describe the bony labyrinth morphology of the Eocene ‘archaic ungulate’ Hyopsoduslepidus (Bridgerian, North America) reconstructed from micro computed tomography scan data. Comparisons with the inner ear of the Eocene early diverging artiodactyl Diacodexis and perissodactyl Xenicohippus allow refining the picture of the ancestral inner ear morphology of Euungulates. These taxa are very close morphologically and mostly differ by slight differences in their semicircular canal angulations and profile. They all present a secondary crus and a low position of the plane of the lateral semicircular canal relative to the posterior semicircular canal. These two characters, considered as ancestral features for Theria, might be symplesiomorphies of Euungulata as well. Hyopsodus and Xenicohippus share characters also observed in other basal Equoidea, which would support the close relationship between these two taxa previously proposed in the literature. A functional study of the cochlea of Hyopsodus lepidus is also realised to discuss its putative ability of using terrestrial echolocation previously proposed in the literature. The morphology of the cochlea of Hyopsodus lepidus does not indicate a specialisation to sophisticated echolocation such as observed today in microchiropteran bats. However, its estimated audible range of frequencies (208 Hz to 76.8 KHz) would be compatible with terrestrial echolocation.     

人工神经网络在蝙蝠回声定位叫声识别方面的应用

近年来,人工神经网络被不断应用于野生动物的声学研究中,本文概括地介绍了人工神经网络的概念以及这项新技术的研究方法,并且重点介绍了它在蝙蝠回声定位叫声识别方面的应用。