Genomic analysis of Tibetan ground tits identifies molecular adaptations associated with cooperative breeding.

Cooperative breeding is a sophisticated altruistic social behavior that helps social animals to adapt to harsh environments. The Tibetan ground tit, Pseudopodoces humilis, is a high-altitude bird endemic to the Tibetan plateau. Recently, it has become an exciting system for studying the evolution of facultative cooperative breeding. To test for molecular adaptations associated with cooperative breeding, we resequenced the whole genome of ground tits from 6 wild populations that display remarkable variation in the frequency of cooperative breeding. Population structure analyses showed that the 6 populations were divided into 4 lineages, which is congruent with the major geographical distribution of the sampling sites. Using genome-wide selective sweep analysis, we identified putative positively selected genes (PSGs) in groups of tits that displayed high and low cooperative breeding rates. The total number of PSGs varied from 146 to 722 in high cooperative breeding rate populations, and from 272 to 752 in low cooperative breeding rate populations. Functional enrichment analysis of these PSGs identified several significantly enriched ontologies related to oxytocin signaling, estrogen signaling, and insulin secretion. PSGs involved in these functional ontologies suggest that molecular adaptations in hormonal regulation may have played important roles in shaping the evolution of cooperative breeding in the ground tit. Taken together, our study provides candidate genes and functional ontologies involved in molecular adaptations associated with cooperative breeding in Tibetan ground tits, and calls for a better understanding of the genetic roles in the evolution of cooperative breeding.

A 35-Year-Old Man With Fever and Pulmonary Cavity.

CASE PRESENTATION: A 35-year-old man was hospitalized with fever, chest pain, and cough of 2 weeks' duration. These symptoms persisted despite 4 days of antibiotic treatment with IV ceftriaxone sodium 2 g/d. The patient was a nonsmoker with an unremarkable medical history who worked as a herdsman and lived in the Shigate region of Tibet, China.

Vulture Genomes Reveal Molecular Adaptations Underlying Obligate Scavenging and Low Levels of Genetic Diversity.

Obligate scavenging on the dead and decaying animal matter is a rare dietary specialization that in extant vertebrates is restricted to vultures. These birds perform essential ecological services, yet many vulture species have undergone recent steep population declines and are now endangered. To test for molecular adaptations underlying obligate scavenging in vultures, and to assess whether genomic features might have contributed to their population declines, we generated high-quality genomes of the Himalayan and bearded vultures, representing both independent origins of scavenging within the Accipitridae, alongside a sister taxon, the upland buzzard. By comparing our data to published sequences from other birds, we show that the evolution of obligate scavenging in vultures has been accompanied by widespread positive selection acting on genes underlying gastric acid production, and immunity. Moreover, we find evidence of parallel molecular evolution, with amino acid replacements shared among divergent lineages of these scavengers. Our genome-wide screens also reveal that both the Himalayan and bearded vultures exhibit low levels of genetic diversity, equating to around a half of the mean genetic diversity of other bird genomes examined. However, demographic reconstructions indicate that population declines began at around the Last Glacial Maximum, predating the well-documented dramatic declines of the past three decades. Taken together, our genomic analyses imply that vultures harbor unique adaptations for processing carrion, but that modern populations are genetically depauperate and thus especially vulnerable to further genetic erosion through anthropogenic activities.

Loss of sweet taste despite the conservation of sweet receptor genes in insectivorous bats.

The evolution of taste perception is usually associated with the ecology and dietary changes of organisms. However, the association between feeding ecology and taste receptor evolution is unclear in some lineages of vertebrate animals. One example is the sweet taste receptor gene Tas1r2 Previous analysis of partial sequences has revealed that Tas1r2 has undergone equally strong purifying selection between insectivorous and frugivorous bats. To test whether the sweet taste function is also important in bats with contrasting diets, we examined the complete coding sequences of both sweet taste receptor genes (Tas1r2 and Tas1r3) in 34 representative bat species. Although these two genes are highly conserved between frugivorous and insectivorous bats at the sequence level, our behavioral experiments revealed that an insectivorous bat (Myotis ricketti) showed no preference for natural sugars, whereas the frugivorous species (Rousettus leschenaultii) showed strong preferences for sucrose and fructose. Furthermore, while both sweet taste receptor genes are expressed in the taste tissue of insectivorous and frugivorous bats, our cell-based assays revealed striking functional divergence: the sweet taste receptors of frugivorous bats are able to respond to natural sugars whereas those of insectivorous bats are not, which is consistent with the behavioral preference tests, suggesting that functional evolution of sweet taste receptors is closely related to diet. This comprehensive study suggests that using sequence conservation alone could be misleading in inferring protein and physiological function and highlights the power of combining behavioral experiments, expression analysis, and functional assays in molecular evolutionary studies.

Surveillance of death causes among residents in Shannan City of Tibet Autonomous Region in 2018 / 公共卫生与预防医学

Objective To explore the mortality and main causes of death of residents in Shannan City. Methods Death data in Shannan City in 2018 were collected. The data was encoded and classified according to the International Classification of Diseases (ICD-10). The 2010 standard population was used to standardize the mortality rate. Results In 2018, the mortality rate of residents in Shannan City was 359.53/100 000, and the standardized mortality rate was 421.446/100 000. The top 5 causes of death were cerebrovascular disease, heart disease, malignant tumor, respiratory disease and digestive system disease, accounting for 74.91% of the total deaths. Tuberculosis and hepatitis B were the main lethal infectious diseases, accounting for 90% of their total deaths. Conclusion Chronic non-communicable diseases were the main causes of death in Shannan City. Tuberculosis and hepatitis B among all infectious diseases are the focus of prevention. Targeted intervention measures should be taken to reduce the incidence of disease and death.