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Transgenic pigs play an important role in biomedicine and agriculture. The "safe harbor" locus maintains consistent foreign gene expression in cells and is important for transgenic pig generation. However, as only several safe harbor loci(Rosa26, pH11 and Pifs501) have been identified in pigs, meeting the needs of the insertion of various foreign genes is difficult. In this study, we develop a novel strategy for the efficient knock-in of gene-of-interest fragments into endogenous beta-actin(ACTB) gene via CRISPR/Cas9 mediated homologous recombination with normal expression of ACTB. Thus, we provide an alternative strategy to integrate exogenous genes into the pig genome that can be applied to agricultural breeding and biomedical models.

Most previous studies aim to predict ecosystem sustainability from the perspective of a sole human or natural system and have frequently failed to achieve their desired outcome. Based on the coupled human and natural system (CHANS) and its interaction with other systems, we attempted to analyze the effectiveness of the Grain to Green Program and predict future trends in the Hexi Corridor, the hub of the ancient silk road of China. At different scales, we applied a metacoupling framework to investigate the flows, effects, and causes of the complex CHANS. Three typical inner river watersheds within the corridor at three different geographic scales (local, regional and national) were estimated and compared. The Telecoupling Geo App, additional models, and software tools were employed to evaluate the CHANS series of the focal system (Hexi Corridor, local), adjacent system (Gansu Province, regional), and distant system (China, national). The results showed that most flows can be screened and quantitatively analyzed across focal, adjacent and distant systems. The social and economic transformations in adjacent and distant systems could affect the possibility and whereabouts of labor transfer in the focal system. Moreover, the labor migration increased the implementation efficiency of the Grain to Green Program as a Payment for Ecosystem Services (PES) strategy, thereby improving its ecological benefits. For the first time, we established a metacoupled model to quantitatively evaluate aspects of ecosystem sustainability in China, providing insight to the theory and application of sustainability science.

Improving meat quality is a crucial purpose of commercial production and breeding systems. In this study, multiomics techniques were used to investigate the molecular mechanisms that impact the excessive diversity of meat quality in Enshi black pigs. The results suggest that 120 differentially expressed genes (DEGs) and 171 significantly changed metabolites (SCMs) contribute to the content of intramuscular fat (IMF) through the processes of fat accumulation and regulation of lipolysis. A total of 141 DEGs and 47 SCMs may regulate meat color through the processes of nicotinate and nicotinamide metabolism. Herein, we found some candidate genes associated with IMF and meat color. We also presented a series of metabolites that are potentially available biological indicators to measure meat quality. This research provides further insight into the detection of intramuscular fat accumulation and meat color variation and provides a reference for molecular mechanisms in the regulation of IMF and meat color.

Colostrum quality is a vital factor in mortality and growth performance for piglets. Lactoferrin is an immuno-active milk protein that contributes to the formation of a protective layer above intestinal mucosa, possesses the antibacterial and antiviral activities that are favorable for piglet development. However, there is a notable reduction in lactoferrin in sow milk during lactation after the first few days, which causes many piglets to fail to ingest enough colostrum thereby leading to an increase in piglet mortality. In this study, we successfully constructed genome-edited Large-White pigs with marker-free site-specific knock-in of lactoferrin gene in the 3′-end of Casein alpha-s1 via CRISPR/Cas9 mediated homologous recombination. Thus, the lactoferrin protein can be expressed in the mammary gland in the control of Casein alpha-s1 promoter. As expected, the lactoferrin protein in genetically modified pigs sustained high expression in both colostrum and milk when compared with wild-type pigs. Moreover, the bacterial plate assay indicated that the milk from genetically modified pigs showed bacteriostatic effects when compared with control pigs. Taken together, our study demonstrated that the milk from genetically modified pigs had antibacterial activity which may reduce the costs of veterinary drug and improve the surviving rate of piglets, which is promising for pig breeding.

Since Donald proposed ideotype breeding in 1968, agronomists and breeders have endeavoured to develop ideotype-oriented breeding methods to improve the dryland wheat production. Several scholars have discussed methods to reduce growth redundancy and improve the ideotype of crops, and have made some progress on dryland wheat breeding strategies and model innovation for cultivation management. Nevertheless, the evaluation of crop ideotype is not the same in different ecological zones, and progress on a specific crop ideotype for a particular ecological zone is not universally accepted. In this paper, the recent progress in ideotype research for the dryland wheat is reviewed and the evolutionary trend in growth redundancy in roots, stems and tiller number studied. At the same time, based on the data that has been collected under rainfed agricultural systems on Loess Plateau over the past two decades, we conducted regression analysis between root biomass, above-ground biomass, height and yield. On the Loess Plateau, spring wheat still has a high root/shoot ratio and removal of some root biomass can improve seed production, implying that there is a high incidence of growth redundancy in modern crop cultivars. The excessive growth of individual organs results in decreased yields. Further ecological mechanism of growth redundancy and interaction between ideotype and growth 基金项目:国家自然科学基金(31070372); 国家科技支撑计划(2012BAD14B10); 甘肃省科学院开发与应用基金项目(2012JK-03); 科技部国际合作项目 (2013DFA30950) ; 国家星火计划项目(2012GA860003); 国家公益性行业(气象)科研专项(GYHY201106029-2); 中央高校基本科研业务费专项 (lzujbky-2012-220) * 通讯作者 Corresponding author. E-mail: xiongyc@lzu.edu.cn 