Whole-genome resequencing provides insights into the diversity and adaptation to desert environment in Xinjiang Mongolian cattle

Background Xinjiang Mongolian cattle is an indigenous breed that inhabits the Taklimakan Desert and is characterized by its small body size. However, the genomic diversity, origin, and genetic basis underlying the adaptation to the desert environment have been poorly studied. Results We analyzed patterns of Xinjiang Mongolian cattle genetic variation by sequencing 20 genomes together with seven previously sequenced genomes and comparing them to the 134 genomes of nine representative breeds worldwide. Among the breeds of Bos taurus, we found the highest nucleotide diversity (0.0024) associated with the lower inbreeding coefficient (2.0110-6), the lowest linkage disequilibrium (r2 = 0.3889 at distance of 10 kb), and the highest effective population size (181 at 20 generations ago) in Xinjiang Mongolian cattle. The genomic diversity pattern could be explained by a limited introgression of Bos indicus genes. More importantly, similarly to desert-adapted camel and same-habitat sheep, we also identified signatures of selection including genes, GO terms, and/or KEGG pathways controlling water reabsorption and osmoregulation, metabolic regulation and energy balance, as well as small body size in Xinjiang Mongolian cattle. Conclusions Our results imply that Xinjiang Mongolian cattle might have acquired distinct genomic diversity by virtue of the introgression of Bos indicus, which helps understand the demographic history. The identification of selection signatures can provide novel insights into the genomic basis underlying the adaptation of Xinjiang Mongolian cattle to the desert environment

Additional file 1 of Whole-genome resequencing provides insights into the diversity and adaptation to desert environment in Xinjiang Mongolian cattle

Additional file 1. Supplementary Figure 1. The output produced by OptM. A total of 5 iterations were run for each possible number of migration edges, m = 1–10. (A) The mean and standard deviation (SD) for the composite likelihood L(m) (left axis, black circles) and proportion of variance explained (right axis, red “x”s). (B) The second-order rate of change (Δm) across values of m. The arrow indicates the peak in Δm at m = 2 edges. Supplementary Figure 2. Cross-validation plot for the 161 genomes. Supplementary Table 1. Summary of sequencing data. Supplementary Table 2. Functional classification of the detected SNPs. Supplementary Table 3. Functional classification of the exonic SNPs. Supplementary Table 4. list of selected regions in Xinjiang Mongolian cattle. Supplementary Table 5. The top ten significant GO terms from the enrichment analysis of selected candidate genes Supplementary Table 6. The top ten significant KEGG pathways from the enrichment analysis of selected candidate genes

Free-standing film based on dissolution and homogeneous compounding of carbon nitride for photocatalytic sterilization

Polymeric carbon nitride (p-CN) has attracted increasing interest as a metal-free photocatalyst in energy conversion and bacterial disinfection. However, due to its particulate and insoluble nature, compounding p-CN at the molecular level into a functional composite of high performance remains a grand challenge. Here, we report the dissolution of p-CN in polyphosphoric acid (PPA) and the homogeneous compounding with carbon nanotubes (CNTs) into a free-standing film simply by co-dissolution, precipitation, and filtration. Interestingly, the as-prepared p-CN-CNTs film exhibited superior film strength than the pristine CNTs and nearly complete inactivation of E. coli and S. aureus under simulated solar irradiation with superoxide radicals as the dominant intermediates. Mechanistic studies indicated that the acidity and viscosity of PPA play crucial roles in the dissolution. The universality of this finding was supported by the further successful discovery of a new type of solvent for p-CN using task-specific ionic liquids. This work would provide a general way to address the dissolution difficulties of p-CN, and pave the prospective application of p-CN in nanocomposites at the molecular level

Freezing-Extraction/Vacuum-Drying Method for Robust and Fatigue-Resistant Polyimide Fibrous Aerogels and Their Composites with Enhanced Fire Retardancy

In the rapid development of modern materials, there is a great need for novel energy-saving, time-saving, cost-saving, and facile approaches to fabricate light, low-density, and high-porosity aerogels with excellent mechanical and thermal performance. In this work, a freeze-extraction method combined with normal vacuum-drying (VD), using short electrospun polyimide (PI) fibers as a supporting skeleton, was developed to prepare high-performance PI fibrous aerogels (PIFAs) without the need for a special drying process. The resulting PIFAs exhibit low density (≤ 52.8 mg·cm−3) and high porosity (> 96%). The PIFAs are highly fatigue resistant, with cycling compression for at least 20 000 cycles and a low energy-loss coefficient. A thermal conductivity of 40.4 mW·m−1·K−1 was obtained for a PIFA with a density of 39.1 mg·cm−3. Further modification of the PIFAs with polysilazane led to enhanced fire resistance and a high residue (> 70%) in a nitrogen atmosphere. These excellent properties make PIFAs and their composites promising candidates for lightweight construction, thermal insulating, and fireproof layers for the construction industry, aviation, and aerospace industries, as well as for high-temperature reaction catalyst carriers. In addition, the proposed freezing-extraction/VD approach can be extended to other material systems to provide savings in energy, time, and costs

Multiformity of Photoelectron Storages in Functionalized Carbon Nitrides Enabling Reversible and Adaptable Colorimetric Sensing

Colorimetric sensing has been widely used for centuries across diverse fields, thanks to easy operation with no electricity and uncompromised high sensitivity. However, the limited number of chromogenic systems hampers its broader applications. Here, we reported that carbon nitride (CN), the raw materials-abundant and cheap semiconductors with photoelectron storage capability, can be developed as a new chromogenic platform for colorimetric sensing. Beyond most photoelectron storage materials that only demonstrated blue color in the excited state, CN could also exhibit brown color by terminal group functionalization. The experiments and DFT theoretical calculation revealed the origin of the unusual two types of color switches. Cyano and carbonyl terminal groups in CN elongated the centroids distance of electron/hole and stabilized the excited states through a physical and electrochemical pathway, respectively; meanwhile, the counter cations strengthened these processes. As a result, the CN-derived colorimetric O2 sensors demonstrated excellent reversibility in recycling hundreds of times for detection, and exhibited adaptable limit of detection and linear detection range, which was superior to commercial O2 sensors, especially for complex systems with broad variable concentrations

Lighting up Electrochemiluminescent Inactive Dyes by Intramolecular Resonance Energy Transfer

By virtue of near-zero optical background and photobleaching, electrochemiluminescence (ECL), an optical phenomenon excited by electrochemical reactions, has drawn extensive attention in both fundamental studies and wide applications especially of ultrasensitive bioassay. Developing diverse ECL emitters is crucial to unlock their multiformity and performances, but remains a formidable challenge, due to the rigorous requirements for ECL. Herein, we report a general intramolecular ECL resonance energy transfer (iECL-RET) strategy to light up ECL-inactive dyes in aqueous solutions using an existing high-performance ECL initiators. As a proof-of-concept, a series of luminol donor-dye acceptor based ECL emitters with near unity RET efficiency and coarse/fine tunable emission wavelengths were demonstrated. Different to previous exploitation of new molecule single-handedly to address all the prerequisites of ECL, each unit in the proposed ECL ensemble performed maximally its own functions. The iECL-RET strategy would greatly expand the family members of ECL emitters for more demanding future applications

Growth of Robust Carbon Nitride Films by Double Inoculation with Exceptionally Boosted Electrochemiluminescence

Electrochemically generated chemiluminescence (ECL) has attracted significant interest over decades, ranging from fundamental studies of highly efficient electron-to-photon interconversion to practical bioassays. Nonetheless, the ECL efficiency of most emitters is low, which greatly hampers further development. Herein, we report a highly robust carbon nitride film with an unusually boosted ECL efficiency (2256 times higher than that of the reference Ru(bpy)3Cl2/K2S2O8. Double inoculation, which provided the primary interaction of carbon nitride with the substrate and the succedent growth, played a crucial role in preparation. The improved ECL efficiency was ascribed to few pinholes suppressing futile co-reagent reduction, maintenance of more orbit-delocalized heptazine subunit improving ECL kinetics, and transparency avoiding self-absorption. As a result of the exceptionally high ECL efficiency, an ultrasensitive visual DNA biosensor by the naked eye was further successfully developed

Graphitic C6N6-supported Dual Cu/Zn Single-Atom Catalyst Mimicking Allosteric Regulation for Intelligent Switching Biosensing

Self-adaptability is highly envisioned for artificial devices such as robots with chemical noses. To this end, seeking catalysts with reversibly switchable functions is promising but generally hampered by mismatched initial valence state of transition metal active centers and electronic structures. Herein, we report a graphitic C6N6-supported dual Cu/Zn single-atom catalyst with a synergistic effect (Cu/Zn-C6N6). It could not only rely on the Cu(I)/Cu(II) redox reaction with promotion from Zn to exhibit a remarkable superoxide dismutase-like (SOD) performance, but also activate Cu(I)/Cu(0) redox reaction to highly switch a marginable peroxidase-like (POD) activity, in which the initial oxidation state was transformed by a photoreduction. The multiformity of the cycles between different valence states for the same catalytic active center makes the reaction activity capable of being reversible switch, the switch efficiency can reach more than 90%. As a proof-of-concept application, Cu/Zn-C6N6 was further confined to a microfluidic chip and applied to a single-interface biosensor with reversibly switched ability in detecting xanthine and glucose in vitro

Extended Conjugation Refining Carbon Nitride for Non-sacrificial H2O2 Photosynthesis and Hypoxic Tumor Therapy

Artificial photocatalysis offers a clean approach for producing H2O2. However, the poor selectivity and activity of H2O2 production hamper traditional industrial applications and emerging photodynamic therapy (PDT)/chemodynamic therapy (CDT). Here, we report a well-defined C5N2 photocatalyst with a conjugated C=N linkage for highly selective and efficient non-sacrificial H2O2 production both in normoxic and hypoxic systems. The strengthened delocalization of π-electrons by linkers in C5N2 significantly downshifted the band position, which eliminated the side photoreduction reaction of H2 evolution in thermodynamics and promoted water oxidation ability in kinetics. As a result, C5N2 had a competitive overall H2O2 production with solar-to-chemical conversion efficiency of 0.55% and more interestingly, exhibited the highest activity so far in hypoxic condition (698 μM/h). C5N2 was further applied to hypoxic PDT/CDT, exhibiting outstanding performance in conspicuous cancer cell death and synchronous bioimaging. It shed light on unlocking linker functions in electronic structure engineering of carbon nitrides for highly efficient overall photosynthesis of H2O2 and expanded the scope of their prospective application in health care