Detection of Selection Signatures in Anqing Six-End-White Pigs Based on Resequencing Data.

As a distinguished Chinese indigenous pig breed that exhibits disease resistance and high meat quality, the Anqing six-end-white (AQ) pig represents a valuable germplasm resource for improving the quality of the pig breeding industry. In this study, 24 AQ pigs that were distantly blood-related and 6 Asian Wild Boar (AWB) were selected for 10× deep-genome resequencing. The signatures of the selection were analyzed to explore the genetic basis of their germplasm characteristics and to identify excellent germplasm-related functional genes based on NGS data. A total of 49,289,052 SNPs and 6,186,123 indels were detected across the genome in 30 pigs. Most of the genetic variations were synonym mutations and existed in the intergenic region. We identified 275 selected regions (top 1%) harboring 85 genes by applying a crossover approach based on genetic differentiation (FST) and polymorphism levels (π ratio). Some genes were found to be positively selected in AQ pigs' breeding. The SMPD4 and DDX18 genes were involved in the immune response to pseudorabies virus (PRV) and porcine reproductive and respiratory syndrome virus (PRRSV). The BCL6 and P2RX6 genes were involved in biological regulation of immune T cells and phagocytes. The SLC7A4 and SPACA4 genes were related to reproductive performance. The MSTN and HIF1A genes were related to fat deposition and muscle development. Moreover, 138 overlapping regions were detected in selected regions and ROH islands of AQ pigs. Additionally, we found that the QTLs with the most overlapping regions were related to back fat thickness, meat color, pH value, fatty acid content, immune cells, parasitic immunity, and bacterial immunity. Based on functional enrichment analysis and QTLs mapping, we conducted further research on the molecular genetic basis of germplasm traits (disease resistance and excellent meat quality). These results are a reliable resource for conserving germplasm resources and exploiting molecular markers of AQ pigs.

Identification of Candidate Genes and Regulatory Competitive Endogenous RNA (ceRNA) Networks Underlying Intramuscular Fat Content in Yorkshire Pigs with Extreme Fat Deposition Phenotypes.

Intramuscular fat (IMF) content is vital for pork quality, serving an important role in economic performance in pig industry. Non-coding RNAs, with mRNAs, are involved in IMF deposition; however, their functions and regulatory mechanisms in porcine IMF remain elusive. This study assessed the whole transcriptome expression profiles of the Longissimus dorsi muscle of pigs with high (H) and low (L) IMF content to identify genes implicated in porcine IMF adipogenesis and their regulatory functions. Hundreds of differentially expressed RNAs were found to be involved in fatty acid metabolic processes, lipid metabolism, and fat cell differentiation. Furthermore, combing co-differential expression analyses, we constructed competing endogenous RNAs (ceRNA) regulatory networks, showing crosstalk among 30 lncRNAs and 61 mRNAs through 20 miRNAs, five circRNAs and 11 mRNAs through four miRNAs, and potential IMF deposition-related ceRNA subnetworks. Functional lncRNAs and circRNAs (such as MSTRG.12440.1, ENSSSCT00000066779, novel_circ_011355, novel_circ_011355) were found to act as ceRNAs of important lipid metabolism-related mRNAs (LEP, IP6K1, FFAR4, CEBPA, etc.) by sponging functional miRNAs (such as ssc-miR-196a, ssc-miR-200b, ssc-miR10391, miR486-y). These findings provide potential regulators and molecular regulatory networks that can be utilized for research on IMF traits in pigs, which would aid in marker-assisted selection to improve pork quality.

Boosting the OER Performance of Nitrogen-Doped Ni Nanoclusters Confined in an Amorphous Carbon Matrix.

Nanoclusters are ideal electrocatalysts due to their high surface activity. However, their high activities also lead to serious agglomeration and performance attenuation during the catalytic process. Here, highly dispersed Ni nanoclusters (∼3 nm) confined in an amorphous carbon matrix are successfully fabricated by pulsed laser deposition, followed by rapid temperature annealing treatment. Then, the Ni nanoclusters are further doped with nitrogen element through a clean N2 radio frequency plasma technology. It is found that the nitrogen-doped Ni nanoclusters obtained under optimized conditions showed superior OER performance with a very low overpotential of 240 mV at a current density of 10 mA/cm2, together with good stability. The excellent OER performance of the nanoclusters can be attributed to the unique confined structure and nitrogen doping, which not only provide more active sites but also improve the conductivity. Our work provides a controllable method for the construction of a novel confined structure with controllable nitrogen doping, which can be used as a high-efficiency OER electrocatalyst.