Sex Ratio and Sexual Size Dimorphism in a Toad-headed Lizard, Phrynocephalus guinanensis

Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism (SSD) is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P. guinanensis. Our results indicated that the sex ratio of males to females was 1:2.8. Males had a lower survival rate (6%) than females (14%) across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates

Elevation as a selective force on mitochondrial respiratory chain complexes of the Phrynocephalus lizards in the Tibetan plateau

Animals living in extremely high elevations have to adapt to low temperatures and low oxygen availability (hypoxia), but the underlying genetic mechanisms associated with these adaptations are still unclear. The mitochondrial respiratory chain can provide >95% of the ATP in animal cells, and its efficiency is influenced by temperature and oxygen availability. Therefore, the respiratory chain complexes (RCCs) could be important molecular targets for positive selection associated with respiratory adaptation in high-altitude environments. Here, we investigated positive selection in 5 RCCs and their assembly factors by analyzing sequences of 106 genes obtained through RNA-seq of all 15 Chinese Phrynocephalus lizard species, which are distributed from lowlands to the Tibetan plateau (average elevation >4,500 m). Our results indicate that evidence of positive selection on RCC genes is not significantly different from assembly factors, and we found no difference in selective pressures among the 5 complexes. We specifically looked for positive selection in lineages where changes in habitat elevation happened. The group of lineages evolving from low to high altitude show stronger signals of positive selection than lineages evolving from high to low elevations. Lineages evolving from low to high elevation also have more shared codons under positive selection, though the changes are not equivalent at the amino acid level. This study advances our understanding of the genetic basis of animal respiratory metabolism evolution in extreme high environments and provides candidate genes for further confirmation with functional analyses

Evolutionary analysis of mitochondrially encoded proteins of toad-headed lizards, Phrynocephalus, along an altitudinal gradient.

BACKGROUND: Animals living at high altitude must adapt to environments with hypoxia and low temperatures, but relatively little is known about underlying genetic changes. Toad-headed lizards of the genus Phrynocephalus cover a broad altitudinal gradient of over 4000 m and are useful models for studies of such adaptive responses. In one of the first studies to have considered selection on mitochondrial protein-coding regions in an ectothermic group distributed over such a wide range of environments, we analysed nineteen complete mitochondrial genomes from all Chinese Phrynocephalus (including eight genomes sequenced for the first time). Initial analyses used site and branch-site model (program: PAML) approaches to examine nonsynonymous: synonymous substitution rates across the mtDNA tree. RESULTS: Ten positively selected sites were discovered, nine of which corresponded to subunits ND2, ND3, ND4, ND5, and ND6 within the respiratory chain enzyme mitochondrial Complex I (NADH Coenzyme Q oxidoreductase). Four of these sites showed evidence of general long-term selection across the group while the remainder showed evidence of episodic selection across different branches of the tree. Some of these branches corresponded to increases in altitude and/or latitude. Analyses of physicochemical changes in protein structures revealed that residue changes at sites that were under selection corresponded to major functional differences. Analyses of coevolution point to coevolution of selected sites within the ND4 subunit, with key sites associated with proton translocation across the mitochondrial membrane. CONCLUSIONS: Our results identify mitochondrial Complex I as a target for environment-mediated selection in this group of lizards, a complex that frequently appears to be under selection in other organisms. This makes these lizards good candidates for more detailed future studies of molecular evolution

Electrocatalytic upcycling of nitrogenous wastes into green ammonia: advances and perspectives on materials innovation

Abstract Ammonia serves as an irreplaceable raw material for nitrogen fertilizers, which is essential for global food production. In addition, it has been recently endowed with a new function as a carrier of renewable energy, demonstrating significant research prospects. However, the highly developed ammonia industry results in abundant nitrogenous wastes in nature, thus causing severe nitrogen pollution and disrupting the global nitrogen cycle. The environmentally friendly electrocatalytic technologies for upcycling nitrogenous wastes to green ammonia represent a highly valuable transformation strategy. In this review, we present three effective pathways for the electrocatalytic reduction of nitrogenous wastes to green ammonia, including nitrate reduction reaction (NO3RR), nitrite reduction reaction (NO2RR), and nitric oxide reduction reaction (NORR). Furthermore, achievements and challenges associated with electrocatalysts for green ammonia synthesis are discussed in terms of noble metal-based electrocatalysts, non-noble metal-based electrocatalysts, and metal-free electrocatalysts. Moreover, this review provides a systematic perspective on reaction mechanisms, catalyst design, and future developments, offering new insights and prospects for the value-upgrading cycle of nitrogenous substances. By exploring the potential of green ammonia synthesis, we aim to contribute to the development of sustainable and environmentally friendly ammonia production

Exploring the Structure and Mechanism of China's E-Commerce Express Logistics Network: Based on Space of Flows

Based on the space of flows theory, this study adopts China Smart Logistics Network big data to build China's e-commerce express logistics network, and explores the spatial structure characteristics of the e-commerce express logistics network, summarizes the regularity of the express logistics flows, finally reveals the formation mechanism of the network through complex network analysis, machine learning algorithms and other methods. The results are as follows: From the node dimension,the spatial inequality characteristics of the importance of e-commerce express logistics in Chinese cities are significant. Taking Heihe-Tengchong Line(Hu Line) as the boundary, the most important cities in the network are distributed within the four major urban agglomerations east of the boundary. The results based on random forest method show that express logistics export-oriented cities form the "e-commerce express logistics export belt" in the southeast coast. Macau and Taiwan receive express logistics input from Beijing-Tianjin-Hebei Urban Agglomeration and Yangtze River Delta Urban Agglomeration respectively on a small scale while Hong Kong plays an important role in logistics distribution function in the network as a high-equilibrium express logistics area. Additionally, from the dimensions of edges and overall network, the network density value is 0.927 0, and the average least connections value is 1.1375, indicating a wide network coverage and relatively complete express logistics routes between cities. Besides, China's e-commerce express logistics network has a small-world effect and high efficiency of the factor flows. A diamond-structured network is also formed with Shanghai, Guangzhou, Chongqing, and Beijing as the four core nodes. In comparison, the Yangtze River Delta Urban Agglomeration is more balanced in the development of e-commerce express logistics; Beijing-Tianjin-Hebei and Chengdu-Chongqing Urban Agglomerations are more dependent on the internal core cities; Guangdong-Hong Kong-Macao Greater Bay Area has the lowest network cohesion, and the express logistics links among Hong Kong, Macao and the other nine cities in the Pearl River Delta are weak. Overall, the network formation is influenced by the development of urban agglomerations. Driven by information technology, traditional and new infrastructure construction, etc., the network is less dependent on the distance factor. Express logistics elements mainly follow the hierarchical diffusion mechanism. This research expands the application of logistics big data in the field of urban network research, reveals the structural characteristics and formation mechanism of China's e-commerce express logistics network, helps enrich the theory of "space of flows", and is also of great significance for understanding the city correlation under the digital economy and the shaping of urban space by modern logistics elements, and promoting the digital transformation and high-quality development of express logistics

Mass Spectrometry Chromatography-Based Metabolomics: The Effect of Long-Term Aerobic Exercise on Learning Ability and the Metabolism of Intestinal Contents in Mice with Alzheimer’s Disease

This study aimed to investigate the effect of long-term aerobic exercise on the metabolism of intestinal contents in APP/PS1 mice was studied using a non-targeted metabolomics technique based on high-performance liquid chromatography-mass spectrometry (HPLC-MS) coupling, providing a theoretical basis for exercise to regulate the metabolism of Alzheimer’s disease (AD) organisms. Three-month-old male C57BL/6JNju mice, six wild-type (NC, n = 6); 12 APP/PS1 double transgenic species in total, were randomly divided into AD model (AM, n = 6) and AD model exercise (AE, n = 6) groups. The mice in the NC group were fed naturally, the mice in the AM group were statically placed on a running platform, and the mice in the AE group received a 20-week long-term moderate intensity running platform exercise intervention. Following the exercise intervention, the cecum contents of the mice in each group were collected and analyzed using the HPLC-MS technique, with those meeting both variable important in projection (VIP)> 1.5 and p < 0.05 being screened as differential metabolites. A total of 32 different metabolites were detected between the AM and NC groups, with 19 up-regulated in the AM group such as phosphatidic acid (PA) (18:4(6Z,9Z,12Z,15Z)/21:0) and 13 down-regulated in the AM group, such as 4,8-dimethylnonanoyl, compared to the NC group; 98 different metabolites were found between the AM and AE groups, 41 of which were upregulated such as Lyso phosphatidylcholine (LysoPC) and 57 of which were downregulated compared to the AM group such as Phosphatidylinositol (PI). The regulation of linoleic acid metabolism, glycerophospholipid metabolism, bile secretion, phenylalanine metabolism, and other pathways was predominantly regulated by nine metabolites, which were subsequently identified as indicators of exercise intervention to enhance metabolism in AD mice. The metabolomic technique can identify the metabolic problems of intestinal contents in AD mice and initially screen the biomarkers of exercise to improve the metabolic disorders in AD. These findings can help us better understand the impact of aerobic exercise on AD metabolism

Additional file 3: of Evolutionary analysis of mitochondrially encoded proteins of toad-headed lizards, Phrynocephalus, along an altitudinal gradient

Multiple sequence alignment was used in statistical coupling analyses for ND proteins. (XLS 224 kb

Additional file 4: of Evolutionary analysis of mitochondrially encoded proteins of toad-headed lizards, Phrynocephalus, along an altitudinal gradient

ML tree for Phrynocephalus inferred from 15,417 bp of mtDNA (6 partitions; GTRGAMMA model for each). Values on nodes are bootstrap proportions (2000 bootstraps). (DOCX 172 kb