ABO genotype alters the gut microbiota by regulating GalNAc levels in pigs.

The composition of the intestinal microbiome varies considerably between individuals and is correlated with health1. Understanding the extent to which, and how, host genetics contributes to this variation is essential yet has proved to be difficult, as few associations have been replicated, particularly in humans2. Here we study the effect of host genotype on the composition of the intestinal microbiota in a large mosaic pig population. We show that, under conditions of exacerbated genetic diversity and environmental uniformity, microbiota composition and the abundance of specific taxa are heritable. We map a quantitative trait locus affecting the abundance of Erysipelotrichaceae species and show that it is caused by a 2.3 kb deletion in the gene encoding N-acetyl-galactosaminyl-transferase that underpins the ABO blood group in humans. We show that this deletion is a ≥3.5-million-year-old trans-species polymorphism under balancing selection. We demonstrate that it decreases the concentrations of N-acetyl-galactosamine in the gut, and thereby reduces the abundance of Erysipelotrichaceae that can import and catabolize N-acetyl-galactosamine. Our results provide very strong evidence for an effect of the host genotype on the abundance of specific bacteria in the intestine combined with insights into the molecular mechanisms that underpin this association. Our data pave the way towards identifying the same effect in rural human populations.

Confinement Effect and 3D Design Endow Unsaturated Single Ni Atoms with Ultrahigh Stability and Selectivity toward CO2 Electroreduction.

Developing single-atomic catalysts with superior selectivity and outstanding stability for CO2 electroreduction is desperately required but still challenging. Herein, confinement strategy and three-dimensional (3D) nanoporous structure design strategy are combined to construct unsaturated single Ni sites (Ni-N3) stabilized by pyridinic N-rich interconnected carbon nanosheets. The confinement agent chitosan and its strong interaction with g-C3N4 nanosheet are effective for dispersing Ni and restraining their agglomeration during pyrolysis, resulting in ultrastable Ni single-atom catalyst. Due to the confinement effect and structure advantage, such designed catalyst exhibits a nearly 100% selectivity and remarkable stability for CO2 electroreduction to CO, exceeding most reported state-of-the-art catalysts. Specifically, the CO Faradaic efficiency (FECO) maintains above 90% over a broad potential range (-0.55 to -0.95 V vs. RHE) and reaches a maximum value of 99.6% at a relatively low potential of -0.67 V. More importantly, the FECO is kept above 95% within a long-term 100 h electrolyzing. Density functional theory (DFT) calculations explain the high selectivity for CO generation is due to the high energy barrier required for hydrogen evolution on the unsaturated Ni-N3. This work provides a new designing strategy for the construction of ultrastable and highly selective single-atom catalysts for efficient CO2 conversion.

One-Step Syntheses of 3,4-Disubstituted Isochroman-1-ones by the Annulation of Benzoic Acids with Nitroalkenes.

The Rh(III)-catalyzed annulation of benzoic acids with nitroalkenes was disclosed to afford a wide range of 3,4-disubstituted isochroman-1-ones with excellent regioselectivity and high catalytic efficiency. Both aromatic and aliphatic nitroalkenes participated in this cyclization reaction successfully. The synthetic value of 3,4-disubstituted isochroman-1-ones was proven by a series of derivatizations. Furthermore, a reliable mechanism is outlined on the basis of experimental investigations and related precedents.

Identification of postnatal development dependent genes and proteins in porcine epididymis.

BACKGROUND: The epididymis is a highly regionalized tubular organ possesses vectorial functions of sperm concentration, maturation, transport, and storage. The epididymis-expressed genes and proteins are characterized by regional and developmental dependent pattern. However, a systematic and comprehensive insight into the postnatal development dependent changes in gene and protein expressions of porcine epididymis is still lacking. Here, the RNA and protein of epididymis of Duroc pigs at different postnatal development stages were extracted by using commercial RNeasy Midi kit and extraction buffer (7 M Urea, 2 M thiourea, 3% CHAPS, and 1 mM PMSF) combined with sonication, respectively, which were further subjected to transcriptomic and proteomic profiling. RESULTS: Transcriptome analysis indicated that 198 and 163 differentially expressed genes (DEGs) were continuously up-regulated and down-regulated along with postnatal development stage changes, respectively. Most of the up-regulated DEGs linked to functions of endoplasmic reticulum and lysosome, while the down-regulated DEGs mainly related to molecular process of extracellular matrix. Moreover, the following key genes INSIG1, PGRMC1, NPC2, GBA, MMP2, MMP14, SFRP1, ELN, WNT-2, COL3A1, and SPARC were highlighted. A total of 49 differentially expressed proteins (DEPs) corresponding to postnatal development stages changes were uncovered by the proteome analysis. Several key proteins ACSL3 and ACADM, VDAC1 and VDAC2, and KNG1, SERPINB1, C3, and TF implicated in fatty acid metabolism, voltage-gated ion channel assembly, and apoptotic and immune processes were emphasized. In the integrative network, the key genes and proteins formed different clusters and showed strong interactions. Additionally, NPC2, COL3A1, C3, and VDAC1 are located at the hub position in each cluster. CONCLUSIONS: The identified postnatal development dependent genes and proteins in the present study will pave the way for shedding light on the molecular basis of porcine epididymis functions and are useful for further studies on the specific regulation mechanisms responsible for epididymal sperm maturation.

Regulating Zinc Storage Behaviors of Tunnel Structure Cathodes Via Tungsten Induction.

Aqueous zinc-ion batteries have received continuous interests because of applying low-cost and eco-friendly aqueous electrolytes and having high safety. Beyond energetically to explore new-type cathode materials, it is of great significance to regulate the zinc storage behavior of the existing cathodes in order to understand the underlying working mechanism. Therefore, as a proof of concept, this work achieves the regulation of zinc storage behaviors of the tunnel structure tunnel structure B-phase vanadium dioxide (VO2 (B)) and vanadium oxide (V6 O13 ) cathodes via a simple chemical tungsten-doping induction approach. Under low-concentration tungsten-doping induction of 1, 2 and 3 at.%, the tunnel sizes of VO2 (B) can be controlled readily. Moreover, the V6 O13 with large size tunnels can be achieved by medium-concentration tungsten induction of 6 and 9 at.%. It is demonstrated that tungsten induced VO2 (B) can achieve zinc storage without lattice structure change via operando X-ray diffraction analyses. Remarkably, via operando and non-operando analyses, tungsten induced V6 O13 with lager size tunnels can realize the oriented 1D zinc ion intercalation/deintercalation. The further kinetics analysis shows that the zinc storage is mainly diffusion control, which is different from most of vanadium-based cathodes with capacitance control. This viable tungsten-doping induction strategy provides a new insight into achieving the controllable regulation of zinc storage behaviors.

Influence of electron donor and acceptor substituents on tuning the nonlinear optical properties of zinc phthalocyanine derivatives.

Four phthalocyanine derivatives with different electron donor and acceptor substituents (B1, B2, B3, and B4) were synthesized by a solid-phase melting method. The influence of substituent type on the nonlinear optical properties of the materials was investigated in detail. In the case of similar conjugated structures, B3, which has amino electron-donor groups, presents high intramolecular charge transfer, a low energy gap (2.05 eV), and good nonlinear optical properties. Compared with B3, B4 has a larger π-conjugated structure and its energy gap is 0.04 eV smaller. Moreover, B4 has stronger reverse saturation absorption (7 × 10-12 m/W) and optical limiting performance. The four phthalocyanine derivatives exhibit third harmonic generation (THG) characteristics. Furthermore, the third harmonic strengths of B1, B2, B3, and B4 are 4 times, 9 times, 11 times, and 21 times that of SiO2, respectively. So, B4 has the best application potential in laser protection and frequency conversion.

Synthesis and nonlinear optical properties of polyurethane composites containing a pyrene derivative.

The pyrene derivative (PD) was synthesized with pyrene-1-carboxaldehyde and p-aminoazobenzene by a Schiff base reaction. Then the obtained PD was dispersed in polyurethane (PU) prepolymer to prepare polyurethane/pyrene derivative PU/PD materials with good transmittance. The nonlinear optical (NLO) performances of the PD and PU/PD materials were studied by the Z-scan technique under picosecond and femtosecond laser pulses. The PD has reverse saturable absorption (RSA) properties under the excitation of 532 nm 15 ps pulses, 650 and 800 nm 180 fs pulses, and a low optical limiting (OL) threshold (0.01J/c m 2). The PU/PD has a larger RSA coefficient than that of the PD under 532 nm 15 ps pulses. With the enhanced RSA, the PU/PD materials exhibit excellent OL (OL) performance. Good NLO properties, high transparency, and easy processing performances make the PU/PD an excellent choice for use in OL and laser protection fields.

Sensitive detection of Escherichia coli in diverse foodstuffs by electrochemical aptasensor based on 2D porphyrin-based COF.

The two-dimensional porphyrin-based covalent organic framework (denoted by Tph-TDC-COF) was used as the sensitive layerto build an aptamer-based electrochemical sensor for the detection of Escherichia coli (E.coli). Tph-TDC-COF produced with 5,10,15,20-tetrakis(4-aminophenyl)-21H, 23H-porphine (Tph) and [2,2'-bithiophene]-2,5'-dicarbaldehyde (TDC) as building blocks exhibited a highly conjugated structure, outstanding conductivity, large specific surface area, and strong bioaffinity towards aptamers. The adoption of Tph-TDC-COF-modified electrode resulted in improved sensing performance and increased anchoring affinity toward the E.coli-targeted aptamer. Under optimal conditions, the Tph-TDC-COF-based electrochemical aptasensor demonstrated an extremely low detection limit of 0.17 CFU mL-1 for E.coli detection within a linear range of 10 to 1 × 108 CFU mL-1, accompanied by good stability, excellent reproducibility and regeneration ability, and wide practical applications. The current electrochemical aptasensing technique has the potential to be extended to detect different foodborne bacteria using specific aptamer, therefore widening the application of COFs in biosensing and food safety fields.

Ultra-sensitive H2S sensor based on sunflower-like In-doped ZnO with enriched oxygen vacancies.

Metal oxide sensors face the challenge of high response and fast recovery at low operating temperatures for the detection of toxic and flammable hydrogen sulfide (H2S) gases. Herein, novel In-doped ZnO with a sunflower-like structure and tunable surface properties was rationally synthesized. The substitutional In atom in the ZnO crystal can dramatically enhance the concentration of oxygen vacancies (Ov), the In-ZnO sites are responsible for fast recovery, and the formation of sub-stable sulfide intermediates gives rise to the high response towards H2S. As a result, the response of the optimized 4In-ZnO sensor is 3538.36 to 50 ppm H2S at a low operating temperature of 110 °C, which is 106 times higher than that of pristine ZnO. Moreover, the response time and recovery time to 50 ppm H2S are 100 s and 27 s, respectively, with high selectivity and stability. First-principles calculations revealed that 4In-ZnO with rich Ov exhibited higher adsorption energy for the H2S molecule than pristine ZnO, resulting in effortless H2S detection. Our work lays the foundation for the rational design of highly sensitive gas sensors through precise doping of atoms in oxygen-rich vacancies in semiconductor materials.

Cocrystallization Enabled Spatial Self-Confinement Approach to Synthesize Crystalline Porous Metal Oxide Nanosheets for Gas Sensing.

Crystalline metal oxide nanosheets show exceptional catalytic performance owing to the large surface-to-volume ratio and quantum confinement effect. However, it is still a challenge to develop a facile and general method to synthesize metal oxide nanosheets. Herein, we report a cocrystallization induced spatial self-confinement approach to synthesize metal oxide nanosheets. Taking the synthesis of SnO2 as an example, the solvent evaporation from KCl and SnCl2 solution induces the cocrystallization of KCl and K2 SnCl6 , and the obtained composite with encapsulated K2 SnCl6 can be in situ converted into SnO2 nanosheets confined in KCl matrix, after water washing to remove KCl, porous SnO2 nanosheets can be obtained. Notably, a series of metal oxide nanosheets can be obtained through this general and efficient green route. In particular, porous CeO2 /SnO2 nanosheets with improved surface O- species and abundant oxygen vacancies exhibit superior gas sensing performance to 3-hydroxy-2-butanone.

Multifunctional DyIII Enantiomeric Pairs Showing Enhanced Photoluminescences and Third-Harmonic Generation Responses through the Coordination Role of Homochiral Tridentate N,N,N-Pincer Ligands.

By utilizing Dy(hfac)3(H2O)2 to react with enantiomerically pure tridentate N,N,N-pincer ligands, namely (-)/(+)-2,6-bis(4',5'-pinene-2'-pyridyl)pyridine (LR and LS), respectively, homochiral DyIII enantiomeric pairs formulated as Dy(hfac)3LR/Dy(hfac)3LS (R-1/S-1) (hfac- = hexafluoroacetylacetonate) were achieved and structurally characterized. Meanwhile, their magnetic, photoluminescent (PL), and chiroptical properties were probed. The PL test results indicate that the precursor Dy(hfac)3(H2O)2 only shows very weak emission, while R-1 exhibits characteristic DyIII f-f transition emission bands at room temperature. Furthermore, the nonlinear optical responses of Dy(hfac)3(H2O)2, LR/LS, and R-1/S-1 were investigated in detail based on crystalline samples. The results reveal that LR and LS present the coexistence of second- and third-harmonic generation (SHG and THG) responses with more intense signals for SHG responses; and Dy(hfac)3(H2O)2 merely displays weak THG responses, while R-1 and S-1 also only exhibit THG responses. However, the THG intensities of R-1 and S-1 are more than six times larger than that of Dy(hfac)3(H2O)2 under the identical measurement conditions. These results demonstrate that introducing homochiral N,N,N-pincer ligands to replace two H2O molecules of Dy(hfac)3(H2O)2 results in significant improvements of both PL performances and THG responses of resultant R-1/S-1 enantiomers. R-1 and S-1 integrate PL, THG, and chiral optical activity in one molecule, suggesting their multifunctional merits. In particular, a convenient method is introduced to simultaneously test THG and SHG responses of molecular materials based on crystalline samples in this work.

Effect of host breeds on gut microbiome and serum metabolome in meat rabbits.

BACKGROUND: Gut microbial compositional and functional variation can affect health and production performance of farm animals. Analysing metabolites in biological samples provides information on the basic mechanisms that affect the well-being and production traits in farm animals. However, the extent to which host breeds affect the gut microbiome and serum metabolome in meat rabbits is still unknown. In this study, the differences in phylogenetic composition and functional capacities of gut microbiota in two commercial rabbit breeds Elco and Ira were determined by 16S rRNA gene and metagenomic sequencing. The alternations in serum metabolome in the two rabbit breeds were detected using ultra-performance liquid chromatography system coupled with quadrupole time of flight mass spectrometry (UPLC-QTOFMS). RESULTS: Sequencing results revealed that there were significant differences in the gut microbiota of the two breeds studied, suggesting that host breeds affect structure and diversity of gut microbiota. Numerous breed-associated microorganisms were identified at different taxonomic levels and most microbial taxa belonged to the families Lachnospiraceae and Ruminococcaceae. In particular, several short-chain fatty acids (SCFAs) producing species including Coprococcus comes, Ruminococcus faecis, Ruminococcus callidus, and Lachnospiraceae bacterium NK4A136 could be considered as biomarkers for improving the health and production performance in meat rabbits. Additionally, gut microbial functional capacities related to bacterial chemotaxis, ABC transporters, and metabolism of different carbohydrates, amino acids, and lipids varied greatly between rabbit breeds. Several fatty acids, amino acids, and organic acids in the serum were identified as breed-associated, where certain metabolites could be regarded as biomarkers correlated with the well-being and production traits of meat rabbits. Correlation analysis between breed-associated microbial species and serum metabolites revealed significant co-variations, indicating the existence of cross-talk among host-gut microbiome-serum metabolome. CONCLUSIONS: Our study provides insight into how gut microbiome and serum metabolome of meat rabbits are affected by host breeds and uncovers potential biomarkers important for breed improvement of meat rabbits.

Dynamic distribution of gut microbiota in meat rabbits at different growth stages and relationship with average daily gain (ADG).

BACKGROUND: The mammalian intestinal tract harbors diverse and dynamic microbial communities that play pivotal roles in host health, metabolism, immunity, and development. Average daily gain (ADG) is an important growth trait in meat rabbit industry. The effects of gut microbiota on ADG in meat rabbits are still unknown. RESULTS: In this study, we investigated the dynamic distribution of gut microbiota in commercial Ira rabbits from weaning to finishing and uncover the relationship between the microbiota and average daily gain (ADG) via 16S rRNA gene sequencing. The results indicated that the richness and diversity of gut microbiota significantly increased with age. Gut microbial structure was less variable among finishing rabbits than among weaning rabbits. The relative abundances of the dominant phyla Firmicutes, Bacteroidetes, Verrucomicrobia and Cyanobacteria, and the 15 predominant genera significantly varied with age. Metagenomic prediction analysis showed that both KOs and KEGG pathways related to the metabolism of monosaccharides and vitamins were enriched in the weaning rabbits, while those related to the metabolism of amino acids and polysaccharides were more abundant in the finishing rabbits. We identified 34 OTUs, 125 KOs, and 25 KEGG pathways that were significantly associated with ADG. OTUs annotation suggested that butyrate producing bacteria belong to the family Ruminococcaceae and Bacteroidales_S24-7_group were positively associated with ADG. Conversely, Eubacterium_coprostanoligenes_group, Christensenellaceae_R-7_group, and opportunistic pathogens were negatively associated with ADG. Both KOs and KEGG pathways correlated with the metabolism of vitamins, basic amino acids, and short chain fatty acids (SCFAs) showed positive correlations with ADG, while those correlated with aromatic amino acids metabolism and immune response exhibited negative correlations with ADG. In addition, our results suggested that 10.42% of the variation in weaning weight could be explained by the gut microbiome. CONCLUSIONS: Our findings give a glimpse into the dynamic shifts in gut microbiota of meat rabbits and provide a theoretical basis for gut microbiota modulation to improve ADG in the meat rabbit industry.

Advances in Doped ZnO Nanostructures for Gas Sensor.

Gas sensors based on metal oxides semiconductor (MOS) have attracted extensive attention from both academic and industry. ZnO, as a typical MOS, exhibits potential applications in toxic gas detection, owning to its wide band gap, n-type transport characteristic and excellent electrical performance. Meanwhile, doping is an effective way to improve the sensing performance of ZnO materials. In this review, the effects of different types of doping on morphology, crystal structure, band gap and depletion layer of ZnO materials are comprehensively discussed. Theoretical analysis on the strategies for enhancing the sensing properties of ZnO is also provided. This review puts forward the reasonable insight for designing efficient n-type ZnO-based semiconductor oxide sensing materials.

Highly enhanced photocatalytic H2 evolution of Cu2O microcube by coupling with TiO2 nanoparticles.

A Cu2O/TiO2 p-n heterojunction composite was created via a facile, controllable, one-pot hydrothermal method based on cubic Cu2O and TiO2 nanoparticles in the presence of dioctyl sulfosuccinate sodium salt (AOT) surfactant. The TiO2 nanoparticles with an average edge length of ∼10.1 nm were uniformly distributed on the crystal surface of a Cu2O cube {100}. The photocatalytic performance of the composite was effectively tuned by controlling the amount of TiO2. The Cu2O/TiO2 (60 wt%, labeled as CT-60) exhibits the highest enhanced photocatalytic activity in hydrogen production with H2 evolution of 3002.5 µmol g-1. The yield remained around 92.6% after three cycles. Hydrogen production of the CT-60 is 103 and 8.5 fold higher than the cubic Cu2O and TiO2 nanoparticles, respectively. The improvement in photocatalytic performance could be attributed to the formation of p-n heterojunction. Furthermore, the interface effect of Cu2O and TiO2 caused a broader absorbance in the visible-light region and the lower recombination of photogenerated electron-hole pairs. It is believed that the Cu2O/TiO2 p-n heterojunction composites could provide an alternative method to design highly efficient photocatalysts for solar energy.

Double-platelet Pd@ZnO microcrystals for NO2 chemical sensors: their facile synthesis and DFT investigation.

Double-platelet, single-platelet and spherical ZnO microcrystals were fabricated via a facile and controllable hydrothermal method. The morphology of the ZnO microcrystals and the exposure ratio of the (001) crystal surface were regulated by adjusting the pH of the solution. The ZnO microcrystals were modified with Pd nanoparticle loading by simple calcining, and the interaction of Pd nanoparticles (NPs) on the ZnO crystal surface increased its oxygen vacancy content. A micro-amount (0.05 wt%) of Pd NP-doped ZnO double-platelets (D-ZnO-0.05) enhanced the gas sensing of the sensor to 3.5 times that of pure double-platelet ZnO. The gas sensing results indicate that D-ZnO-0.05 exhibits a high response (71.2 for NO2 with 25 ppm), fast response/recovery (25 s/21 s), and superior long-term stability (remained at around 95.5% after 35 days). The enhancement in the gas sensing could be attributed to the catalysis of Pd NPs and the increase in the number of oxygen vacancies as a result of Pd loading. The band structure of D-ZnO-0.05 could be effectively tuned by introducing Pd nanoparticles, as shown in density functional theory (DFT) calculations. The Pd dopant and oxygen vacancies reduce the band gap of the ZnO(001) crystal materials, resulting in excellent sensor performance. It is believed that the D-ZnO-0.05 microcrystals could provide inspiration for crystal growth studies and high NO2 gas sensing.

Age-based dynamic changes of phylogenetic composition and interaction networks of health pig gut microbiome feeding in a uniformed condition.

BACKGROUND: The gut microbiota impacts on a range of host biological processes, and the imbalances in its composition are associated with pathology. Though the understanding of contribution of the many factors, e.g. gender, diet and age, in the development of gut microbiota has been well established, the dynamic changes of the phylogenetic composition and the interaction networks along with the age remain unclear in pigs. RESULTS: Here we applied 16S ribosomal RNA gene sequencing, enterotype-like clustering (Classification of the gut microbiome into distinct types) and phylogenetic co-occurrence network to explore the dynamic changes of pig gut microbiome following the ages with a successive investigation at four ages in a cohort of 953 pigs. We found that Firmicutes and Bacteroidetes are two predominant phyla throughout the experimental period. The richness of gut microbiota was significantly increased from 25 to 240 days of age. Principal coordinates analysis showed a clear difference in the gut microbial community compositions between pre-weaning piglets and the pigs at the other three age groups. The gut microbiota of pre-weaning piglets was clearly classified into two enterotypes, which were dominated by Fusobacterium and p-75-a5, respectively. However, Prevotella and Treponema were the main drivers of the enterotypes for pigs at the age of 80, 120 and 240 days. Besides the piglets, even some adult pigs switched putative enterotypes between ages. We confirmed that the topological features of phylogenetic co-occurrence networks, including scale, stability and complexity were increased along with the age. The biological significance for modules in the network of piglets were mainly associated with the utilization of simple carbohydrate and lactose, whereas the sub-networks identified at the ages of 80, 120 and 240 days may be involved in the digestion of complex dietary polysaccharide. The modules related to the metabolism of protein and amino acids could be identified in the networks at 120 and 240 days. This dynamic change of the functional capacities of gut microbiome was further supported by functional prediction analysis. CONCLUSIONS: The present study provided meaningful biological insights into the age-based dynamic shifts of ecological community of porcine gut microbiota.

Evaluating the profound effect of gut microbiome on host appetite in pigs.

BACKGROUND: There are growing evidences showing that gut microbiota should play an important role in host appetite and feeding behavior. However, what kind of microbe(s) and how they affect porcine appetite remain unknown. RESULTS: In this study, 280 commercial Duroc pigs were raised in a testing station with the circadian feeding behavior records for a continuous period of 30-100 kg. We first analyzed the influences of host gender and genetics in porcine average daily feed intake (ADFI), but no significant effect was observed. We found that the Prevotella-predominant enterotype had a higher ADFI than the Treponema enterotype-like group. Furthermore, 12 out of the 18 OTUs positively associated with the ADFI were annotated to Prevotella, and Prevotella was the hub bacteria in the co-abundance network. These results suggested that Prevotella might be a keystone bacterial taxon for increasing host feed intake. However, some bacteria producing short-chain fatty acids (SCFAs) and lactic acid (e.g. Ruminococcaceae and Lactobacillus) showed negative associations with the ADFI. Predicted function capacity analysis showed that the genes for amino acid biosynthesis had significantly different enrichment between pigs with high and low ADFI. CONCLUSIONS: The present study provided important information on the profound effect of gut microbiota on porcine appetite and feeding behavior. This will profit us to regulate porcine appetite through modulating the gut microbiome in the pig industry.

Hydrogen Bond Induces Hierarchical Self-Assembly in Liquid-Crystalline Block Copolymers.

Microphase-separated structures of block copolymers (BCs) with a size of sub-10 nm are usually obtained by hydrogen-bond-induced self-assembly of BCs through doping with small molecules as functional additives. Here, fabrication of hierarchically self-assembled sub-10 nm structures upon microphase separation of amphiphilic liquid-crystalline BCs (LCBCs) at the existence of hydrogen bonds but without any dopants is reported. The newly introduced urethane groups in the side chain of the hydrophobic block of LCBCs interact with the ether groups of the hydrophilic poly(ethylene oxide) (PEO) block, leading to imperfect crystallization of the PEO blocks. Both crystalline and amorphous domains coexist in the separated PEO phase, enabling a lamellar structure to appear inside the PEO nanocylinders. This provides an elegant method to fabricate controllable sub-10 nm microstructures in well-defined polymer systems without the introduction of any dopants.

Copy number variation in the MSRB3 gene enlarges porcine ear size through a mechanism involving miR-584-5p.

BACKGROUND: The size and type of ears are important conformation characteristics that distinguish pig breeds. A significant quantitative trait locus (QTL) for ear size has been identified on SSC5 (SSC for Sus scrofa chromosome) but the underlying causative gene and mutation remain unknown. Thus, our aim was to identify the gene responsible for enlarged ears in pig. RESULTS: First, we narrowed down the QTL region on SSC5 to a 137.85-kb interval that harbors only the methionine sulfoxide reductase B3 (MSRB3) gene. Then, we identified a 38.7-kb copy number variation (CNV) that affects the last two exons of MSRB3 and could be the candidate causative mutation for this QTL. This CNV showed complete concordance with genotype at the QTL of the founder animals in a white Duroc × Erhualian F2 intercross and was found only in pigs from six Chinese indigenous breeds with large ears and from the Landrace breed with half-floppy ears. Moreover, it accounted for the significant association with ear size on SSC5 across the five pig populations tested. eQTL mapping revealed that this CNV was significantly associated with the expression of the microRNA (miRNA) miR-584-5p, which interacts with MSRB3, one of its target genes. In vivo and in vitro experiments confirmed that miR-584-5p inhibits the translation of MSRB3 mRNA. Taken together, these results led us to conclude that presence of the 38.7-kb CNV in the genome of some pig breeds affects ear size by altering the expression of miR-584-5p, which consequently hinders the expression of one of its target genes (e.g. MSRB3). CONCLUSIONS: Our findings shed insight into the underlying mechanism of development of external ears in mammals and contribute to a better understanding of how the presence of CNV can regulate gene expression.