The plateau zokor ( Eospalax baileyi) is a species of subterranean rodent endemic to the Tibetan Plateau. It is well adapted to the cold and hypoxic and hypercapnic burrow. To study the oxygenation properties of plateau zokor hemoglobins (Hbs), we measured intrinsic Hb-O2 affinities and their sensitivities to pH (Bohr effect); CO2; Cl−, 2,3-diphosphoglycerate (DPG); and temperature using purified Hbs from zokor and mouse. The optimal deoxyHb model of plateau zokor was constructed and used to study its structural characteristics by molecular dynamics simulations. O2 binding results revealed that plateau zokor Hbs exhibit remarkably high intrinsic Hb-O2 affinity, low CO2 effects compared with human and the relatively low anion allosteric effector sensitivities (DPG and Cl−) at normal temperature, which would safeguard the pulmonary Hb-O2 loading under hypoxic and hypercapnic conditions. Furthermore, the high anion allosteric effector sensitivities at low temperature and low temperature sensitivities of plateau zokor Hbs would facilitate the releasing of O2 in cold extremities and metabolic tissues. However, the high Hb-O2 affinity of plateau zokor is not compensated by high pH sensitivity as the Bohr factors of plateau zokor Hbs were as low as those of mouse. The results of molecular dynamics simulations revealed the reduced hydrogen bonding between the α1β1- and α2β2-dimer interface of deoxyHb in zokor compared with mouse. It may be the primary mechanism of the high intrinsic Hb-O2 affinities in zokor. Specifically, substitution of the 131Ser→Asn in the α2-chain weakened the connection between α1- and β2-subunit.

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Water samples were collected in a main branch of upstream Yangtze river, Jialing river, from 5 sampling sites along Chongqing to study the significance of alkaline phosphatase activity to algal blooming in discharging stage of three Gorges reservoir. The seasonal evolution of phosphorus fraction, alkaline phosphatase activity, algal cells amount and enzymatic kinetic parameters were investigated from 2011 to 2012. Results showed the amount of algal cells was highest in discharging stages with low dissolved inorganic phosphorus and was lowest in flood stages with high dissolved inorganic phosphorus. An expected negative correlation (y = 0.0054x-1.6428 , R 2 = 0.5153) between alkaline phosphatase activity and dissolved inorganic phosphorus and positive correlation (y = 0.0821x +0.3867 , R 2 = 0.7266) between alkaline phosphatase activity and algal cells amount were found. However a higher ratio of total nitrogen and total phosphorus indicated phosphorus limitation during discharging stage. The co-occurring of high alkaline phosphatase activity and algal blooming can be explained that alkaline phosphatase activity induces dissolved organic phosphorus decomposition and mineralization into dissolved inorganic phosphorus, which is bio-available and supports algal growth when algal blooming occurs. The lower Km values and higher Vmax values during discharging stage indicated high substrate affinity and catalysis efficiency. The study covered a full operating period of three Gorges reservoir, focusing on phosphorus fraction, kinetic parameters and their relationship with algal blooming, provided possible explanations of the mechanism of algal blooming under phosphorus limiting conditions and highlighted the ecological significance of alkaline phosphatase activity.

Upslope range shifting has been documented in diverse species in response to global warming. Plasticity, which refers to the ability of organisms to alter their phenotypes in changing environments, is crucial for the survival of those that newly migrated to a high-altitude environment. The scope and mechanisms of plasticity across biological levels, however, have rarely been examined. We used two agama lizards (genus Phrynocephalus) as model systems and a transplant experiment to comprehensively assess their plasticity on multiple organization levels. Two low-altitude (934 m) agama species, Phrynocephalus axillaris (oviparous) and P. forsythii (viviparous), were transplanted to a high-altitude site (3,400 m). After acclimation for 6 weeks in seminatural enclosures, plasticity was measured from bite force, tail display behavior, gene expression, and metabolome. Both lizards were capable of acclimating to the high-altitude environment without sacrificing their performance in bite force, but they also showed high plasticity in tail display behavior by either decreasing the intensity of a specific display component (P. forsythii) or by the trade-off between display components (P. axillaris). Genes and metabolites associated with lipids, especially fatty acid metabolism, exhibited significant differentiation in expression, compared to individuals from their native habitats. Improved fatty acid storage and metabolism appeared to be a common response among animals at high altitudes. Despite distinct reproductive modes that may differ in response to physiological pressure, the two lizards demonstrated high concordance in plasticity when they faced a novel environment at high altitudes. Taken together, lizards likely acclimate to high-altitude environments by reducing behavioral activity and increasing energy efficiency after range shifting. Our results provide new insights into our understanding of phenotypic plasticity and its importance in today’s changing climate.

Ecological immunology involves the study of the immune function of wildlife, which is seldom compared with that of model animals. Here, we evaluated and compared the level of the innate immune response in the plateau zokor (Eospalax baileyi), an indigenous underground rodent from the Tibetan Plateau, with that in the bamboo rat (Rhizomys pruinosus) and Sprague‐Dawley (SD) rat (Rattus norvegicus). The spleen was observed by ordinary light and transmission electron microscopy, and the spleen index was calculated. After liposaccharide (LPS) challenge, the expression of Toll‐like receptor 2 (TLR2), TLR4, and hypoxia‐inducible factor 1α (HIF‐1α) in the spleen was detected by Western blot analysis and immunofluorescence. The expression of nuclear factor‐κB1 (NF‐κB1) and mitogen‐activated protein kinase 14 (MAPK14) in the spleen was detected by real‐time quantitative polymerase chain reaction, and the levels of interleukin 6 (IL‐6), tumor necrosis factor‐α (TNF‐α), and interferon‐β (IFN‐β) in the spleen were detected by enzyme‐linked immunoassay. The spleen index of the plateau zokor was lower than that of the bamboo rat and SD rat. The expression of TLR4, NF‐κB1, and MAPK14 and the levels of IL‐6 and TNF‐α in the spleen of the plateau zokor were lower than those of the bamboo rat and SD rat, while the expression of TLR2 and HIF‐1α and the level of IFN‐β were higher than those of the bamboo rat and SD rat. We speculate that suppression of the TLR4 signaling pathway in the plateau zokor is an adaptation to hypoxic tunnels that decreases antigenic risk and maintains immune homeostasis. Moreover, the spleen of the plateau zokor is reduced in size, reducing the innate immunity investment in the spleen. We also noted that high levels of HIF‐1α in the spleen of the plateau zokor suppressed crosstalk between HIF‐1α and TLR4, promoting the innate immune response.