Search

Abstract Background The genetic mechanisms that underlie phenotypic differentiation in breeding animals have important implications in evolutionary biology and agriculture. However, the contribution of cis-regulatory variants to pig phenotypes is poorly understood. Therefore, our aim was to elucidate the molecular mechanisms by which non-coding variants cause phenotypic differences in pigs by combining evolutionary biology analyses and functional genomics. Results We obtained a high-resolution phased chromosome-scale reference genome with a contig N50 of 18.03 Mb for the Luchuan pig breed (a representative eastern breed) and profiled potential selective sweeps in eastern and western pigs by resequencing the genomes of 234 pigs. Multi-tissue transcriptome and chromatin accessibility analyses of these regions suggest that tissue-specific selection pressure is mediated by promoters and distal cis-regulatory elements. Promoter variants that are associated with increased expression of the lysozyme (LYZ) gene in the small intestine might enhance the immunity of the gastrointestinal tract and roughage tolerance in pigs. In skeletal muscle, an enhancer-modulating single-nucleotide polymorphism that is associated with up-regulation of the expression of the troponin C1, slow skeletal and cardiac type (TNNC1) gene might increase the proportion of slow muscle fibers and affect meat quality. Conclusions Our work sheds light on the molecular mechanisms by which non-coding variants shape phenotypic differences in pigs and provides valuable resources and novel perspectives to dissect the role of gene regulatory evolution in animal domestication and breeding.

Because of the bad environment of wind farms in the far -reaching sea, the cost of power collector system is high. The contradiction between economy and reliability of the power collector system planning is particularly prominent. According to the particularity of the wind farm in the far-reaching sea and the demand of the power collector system on higher reliability, this paper proposes the definition of topological redundancy of the power collector system and develops a multi-objective optimization model based on the topological redundancy. Thus, the contradictory variables of economy and reliability are optimized. Taking a large-scale offshore wind farm as an example, based on the topological redundancy assessment, the topology of its power collector system is optimized from the perspective of life cycle cost. The results show that, although the initial cost of the optimal redundancy topology is slightly higher than that of the radial structure, the advantage of life cycle cost after 8 years of operations is obvious, which can meet the actual engineering requirements of the power collector system for the wind farm in the far-reaching sea.