How does the annelid Alvinella pompejana deal with an extreme hydrothermal environment?

Alvinella pompejana, the so-called Pompeii worm (Desbruyères and Laubier, 1980), is found exclusively in association to high temperature venting, at the surface of hydrothermal chimneys of the East Pacific Rise. The main characteristics of this emblematic species is its tolerance to high temperature but its ability to colonize extremely hot substrates has been the subject of much controversy. In the last decade, new tools allowing in situ and in vivo investigation have been determinant in the understanding of the strategies and adaptations required to colonize such an extremely hot environment. New data relative to the characterization of the animal habitat conditions, on one hand, to the molecular adaptations of this organism and the colonization processes by this species, on the other hand, are now available. Advanced methods and tools, that have fostered the physico-chemical characterization of vent habitats in recent years, are first reviewed. Factors controlling the physico-chemical variability of vent habitats and the threats A. pompejana might effectively face are discussed. The exceptional thermotolerance of this species and the maximum temperature it could sustain are then considered in the light of molecular data relative to its collagen stability. Life history traits as well as biological controls on tube micro-habitat conditions are discussed on the basis of new in situ and in vivo experiments and characterization. Finally, the current knowledge and opened questions related to the molecular adaptations to chemical stresses are briefly stated. The ability of Alvinella pompejana to colonize these substrates is far from being fully understood, but the exceptional properties of its extracellular biopolymers and the behavior of the worm can be now considered as major clues in the colonization process. Alvinella pompejana could thus stand at the limits authorized for its biological machinery in a highly dynamic environment where temperature can readily reach lethal values, but where temperature regulation by the animal itself would prevent exposure to deleterious thermal spikes. The dynamic system associating this pioneer species and its associated microflora might be viewed as a key to the subsequent colonization of these environments by less tolerant species, highlighting A. pompejana as a new type of ecosystem bioengineer.     

Increased extreme drought events in south–central China since the last century：Evidence from oxygen isotope signatures preserved in tree ring cellulose

Tree-ring cellulose oxygen isotope ratios (δ¹⁸O) is a well-established proxy for hydroclimatic conditions in monsoon Asia. We reconstructed June–October relative humidity (RH_J–O) variations from 1808 to 2017, based on tree-ring cellulose δ¹⁸O data, which explain 46.2% of the actual RH variance in the Nanyue region, south–central China. Extreme wet events occurred frequently prior to the 1900s, but there have been more extreme dry events since the 1900s, apart from the late 1930s and early 1950s. Periodicity analysis revealed that the reconstructed RH_J–O records show obvious 15–30 years cycles from the 1830–1970s. The multi-decadal signals may reflect the effect of the Pacific Decadal Oscillation (PDO) on hydroclimate. In the positive PDO phase, there is drying in south–central China, which is related to a weaker East Asian summer monsoon (EASM) via the Pacific–Japan teleconnection. The decadal signal has weakened since the 1970s. In addition, the reconstructed RH_J–O record shows strong interannual variations, which may be related to the Central Pacific El Niño–Southern Oscillation (CP ENSO). During extreme CP El Niño events, there is a weaker EASM due to the Pacific–Japan teleconnection, and the study site experienced drought. Our reconstructed moisture record is characterized by a decreasing influence from the PDO and increasing influence from the CP ENSO in recent decades. Moreover, the frequency of CP ENSO events is projected to increase under anthropogenic warming. Consequently, more extreme droughts which are related to CP ENSO events may increase in the south–central China in near future.     

Identification of novel loci influencing refractive error in East Asian populations using an extreme phenotype design

The global “myopia boom” has raised significant international concerns. Despite a higher myopia prevalence in Asia, previous large-scale genome-wide association studies (GWASs) were mostly based on European descendants. Here, we report a GWAS of spherical equivalent (SE) in 1852 Chinese Han individuals with extreme SE from Guangzhou (631 < ?6.00D and 574 > 0.00D) and Wenzhou (593 < ?6.00D and 54 > ?1.75D), followed by a replication study in two independent cohorts with totaling 3538 East Asian individuals. The discovery GWAS and meta-analysis identify three novel loci, which show genome-wide significant associations with SE, including 1q25.2 FAM163A, 10p11.22 NRP1/PRAD3, and 10p11.21 ANKRD30A/MTRNR2L7, together explaining 3.34% of SE variance. 10p11.21 is successfully replicated. The allele frequencies of all three loci show significant differences between major continental groups (P < 0.001). The SE reducing (more myopic) allele of rs10913877 (1q25.2 FAM163A) demonstrates the highest frequency in East Asians and much lower frequencies in Europeans and Africans (EAS = 0.60, EUR = 0.20, and AFR = 0.18). The gene-based analysis additionally identifies three novel genes associated with SE, including EI24, LHX5, and ARPP19. These results provide new insights into myopia pathogenesis and indicate the role of genetic heterogeneity in myopia epidemiology among different ethnicities.     

Genetic structure and domestication footprints of the tusk,coat color,and ear morphology in East Chinese pigs

The domestication and artificial selection of wild boars have led to dramatic morphological and behavioral changes, especially in East Chinese (ECN) pigs. Here, we provide insights into the population structure and current genetic diversity of representative ECN pig breeds. We identify a 500-kb region containing six tooth development-relevant genes with almost completely different haplotypes between ECN pigs and Chinese wild boars or European domestic pigs. Notably, the c.195A>G missense mutation in exon 2 of AMBN may cause alterations in its protein structure associated with tusk degradation in ECN pigs. In addition, ESR1 may play an important role in the reproductive performance of ECN pigs. A major haplotype of the large lop ear-related MSRB3 gene and eight alleles in the deafness-related GRM7 gene may affect ear morphology and hearing in ECN pigs. Interestingly, we find that the two-end black (TEB) coat color in Jinhua pigs is most likely caused by EDNRB with genetic mechanisms different from other Chinese TEB pigs. This study identifies key loci that may be artificially selected in Chinese native pigs related to the tusk, coat color, and ear morphology, thus providing new insights into the genetic mechanisms of domesticated pigs.     

Prevalence and species richness of trematode parasites only partially recovers after the 2011 Tohoku,Japan, earthquake tsunami

Trematode parasites have complex life cycles and use a variety of host species across different trophic levels. Thus, they can be used as indicators of disturbance and recovery of coastal ecosystems. Estuaries on the Pacific coast of northeastern Japan were heavily affected by the 2011 Tohoku earthquake tsunami. To evaluate the effect of the tsunami on the trematode community, we examined trematodes in the mud snail, Batillaria attramentaria, at five study sites (three sites severely exposed to the tsunami and two sites sheltered from the tsunami) in Sendai Bay for 2 years prior to and 8 years after the tsunami. While the trematode prevalence decreased at all study sites, the species richness decreased only at the sites exposed to the tsunami. Although parasitism increased over the study period post-tsunami, the community had not fully recovered 8 years after the event. Trematode community structure has changed every year since the tsunami and has not stabilised. This could be explained by the alteration of first and second intermediate host communities. Our study suggests that it will take more time for the recovery of the trematode community and the associated coastal ecosystem in the Tohoku region.     

Contrasting patterns of genetic structure and phylogeography in the marine agarophytes Gelidiophycus divaricatus and G. freshwateri (Gelidiales,Rhodophyta) from East Asia

The evolutionary and population demographic history of marine red algae in East Asia is poorly understood. Here, we reconstructed the phylogeographies of two upper intertidal species endemic to East Asia, Gelidiophycus divaricatus and G. freshwateri. Phylogenetic and phylogeographic inferences of 393 mitochondrial cox1, 128 plastid rbcL, and 342 nuclear ITS2 sequences were complemented with ecological niche models. Gelidiophycus divaricatus, a southern species adapted to warm water, is characterized by a high genetic diversity and a strong geographical population structure, characteristic of stable population sizes and sudden reduction to recent expansion. In contrast, G. freshwateri, a northern species adapted to cold temperate conditions, is genetically relatively homogeneous with a shallow population structure resulting from steady population growth and recent equilibrium. The overlap zone of the two species roughly matches summer and winter isotherms, indicating that surface seawater temperature is a key feature influencing species range. Unidirectional genetic introgression was detected at two sites on Jeju Island where G. divaricatus was rare while G. freshwateri was common, suggesting the occurrence of asymmetric natural hybrids, a rarely reported event for rhodophytes. Our results illustrate that Quaternary climate oscillations have left strong imprints on the current day genetic structure and highlight the importance of seawater temperature and sea level change in driving speciation in upper intertidal seaweed species.     

Is it God Speaking? Agency of Deities in the Western Himalaya

ABSTRACT

In many ethnographies, deities reflect social structures, represent power relations, or serve as a resource for individuals. However, believers usually do not doubt the existence of deities and their agency: that is, their ability to act and initiate change. The gap between these points of view narrows in the religious experiences in the Indian Himalayas. There, the local population, who communicate with local deities via mediums, face an epistemological problem: how to be certain that they are, indeed, talking with their gods. Furthermore, the believers are aware that they play a role in the decisions of the gods. These two aspects of the religious experience are expressed in the gradual transition of the gods from a Pahā?ī to a pan-Hindu identity, an indication of the way in which the agency of the gods is being challenged and is subject to negotiation by the locals.     

Quantification and characterization of vegetation and functional trait diversity of the riparian zones in protected forest of Kashmir Himalaya,India

Globally, riparian zones along river banks are widely recognized for their vital role in water regulation and conservation of biodiversity. Here, we specifically investigated the floristic and functional diversity of the vegetation of the riparian zones of protected forests in Kashmir Himalaya, India. A random sampling method was used for site selection while a transect method was used for data collection. Data obtained from the field was subjected to taxonomic and functional classification. Floristic analysis revealed a total of 78 species belonging to 68 genera in 40 families, suggesting an unequal distribution of species among families. Nine families contributed half of the species: Rosaceae was the dominant family with nine (12%) species followed by Asteraceae with eight species (10%), while 23 families were monotypic. In terms of functional trait diversity, herbaceous and perennial taxa dominated, and the biological spectrum showed a dominance of the therophytic life form, indicative of disturbed vegetation. The phenological spectrum revealed that the maximum flowering periods starts in March and extends into May, in which a total of 61% of the species were observed to flower. The leading leaf size spectra were mesophyll with 35%, followed by microphyll (31%). Most (64%) of the species had a simple leaf lamina type. The results of the present study serve as a means to evaluate best management practices, assess restoration and mitigation projects, prioritize riparian related resource management decisions, and establish aquatic life use standards.     

Impacts of large mammals on movements of the pouched mouse (Saccostomus mearnsi) in central Kenya

Populations of large wild mammals are declining worldwide, while the abundance of livestock is increasing. The absence of large mammals frequently leads to increases in the abundance of small mammals such as rodents, but little is known about how the loss of large mammals affects the behaviour of small mammals. To investigate this question, we analysed long‐term data collected at the Kenya Long‐term Exclosure Experiment, which excludes different combinations of large mammals from a savannah ecosystem in central Kenya. We investigated the effects of excluding large mammals, both wild and domestic, on the movements of the pouched mouse (Saccostomus mearnsi), the most common species of small mammal in this habitat. Mice moved ~20% more in the presence of wildlife, but their movements were not significantly affected by the presence of cattle. An index of intraspecific contacts between mice was higher at higher mouse densities, and these high densities were more likely when wildlife and cattle were absent. The results suggest that the absence of large mammals led to higher densities of small mammals, which resulted in a greater probability of intraspecific contacts, despite lower average movement distances.     

东亚-澳大利西亚候鸟迁飞区中杓鹬 的迁徙追踪

追踪候鸟的迁徙活动是全面认识其生活史年周期的重要途径。中杓鹬(Numeniusphaeopus)在全球广泛分布,但在东亚-澳大利西亚候鸟迁飞区的迁徙活动一直缺乏追踪研究。2018年2月,在澳大利亚西北部的布鲁姆为捕捉到的中杓鹬成鸟佩戴平台发射终端或全球定位系统-全球移动通讯系统追踪器,以确定其迁徙日程、迁徙路线以及迁徙停歇地和繁殖地的地理位置。我们从成功追踪的7只个体获取了6 378条精度高于1 km的位点数据。分析结果表明,在春季,中杓鹬的迁徙时长为(36±4)d,其间在1～3个迁徙停歇地的停留日期为(23±2)d,从越冬地到繁殖地的迁徙距离为(9 795±346)km(n=7)。追踪的中杓鹬在俄罗斯东部和中部区域繁殖,不同个体的繁殖地纬度相近而经度范围较广。在秋季,中杓鹬的迁徙时长为(90±27)d,相比春季迁徙时长更长;其间,在2～4个迁徙停歇地停留(79±29)d,从繁殖地到越冬地的迁徙距离为(10 101±520)km(n=5)。无论在春季还是秋季迁徙,迁徙停歇地广泛分布于东亚、东南亚沿海及内陆区域。大部分个体春季和秋季的迁徙路线相近,成功追踪的个体均在秋季返回了上一年的越冬地,这表明中杓鹬对越冬地具有很高的忠诚度。