Efficient and stable expression of foreign genes in cells and transgenic animals is important for gain-of-function studies and the establishment of bioreactors.Safe harbor loci in the animal genome enable consistent o...Efficient and stable expression of foreign genes in cells and transgenic animals is important for gain-of-function studies and the establishment of bioreactors.Safe harbor loci in the animal genome enable consistent overexpression of foreign genes,without side effects.However,relatively few safe harbor loci are available in pigs,a fact which has impeded the development of multi-transgenic pig research.We report a strategy for efficient transgene knock-in in the endogenous collagen type I alpha 1 chain(COL1A1)gene using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)system.After the knock-in of a 2A peptide-green fluorescence protein(2A-GFP)transgene in the last codon of COL1A1 in multiple porcine cells,including porcine kidney epithelial(PK15),porcine embryonic fibroblast(PEF)and porcine intestinal epithelial(IPI-2I)cells,quantitative PCR(qPCR),Western blotting,RNA-seq and CCK8 assay were performed to assess the safety of COL1A1 locus.The qPCR results showed that the GFP knock-in had no effect(P=0.29,P=0.66 and P=0.20 for PK15,PEF and IPI-2I cells,respectively)on the mRNA expression of COL1A1 gene.Similarly,no significant differences(P=0.64,P=0.48 and P=0.80 for PK15,PEF and IPI-2I cells,respectively)were found between the GFP knock-in and wild type cells by Western blotting.RNA-seq results revealed that the transcriptome of GFP knock-in PEF cells had a significant positive correlation(P<2.2e–16)with that of the wild type cells,indicating that the GFP knock-in did not alter the global expression of endogenous genes.Furthermore,the CCK8 assay showed that the GFP knock-in events had no adverse effects(P_(24)h=0.31,P_(48)h=0.96,P_(72)h=0.24,P_(96)h=0.17,and P_(120)h=0.38)on cell proliferation of PK15 cells.These results indicate that the COL1A1 locus can be used as a safe harbor for foreign genes knock-in into the pig genome and can be broadly applied to farm animal breeding and biomedical model establishment.展开更多
The safe harbor rule was introduced to exempt Internet service providers(ISPs)from liability for copyright infringement committed by ISP users.Nevertheless,the safe harbor rule was crafted for ISPs that provide passiv...The safe harbor rule was introduced to exempt Internet service providers(ISPs)from liability for copyright infringement committed by ISP users.Nevertheless,the safe harbor rule was crafted for ISPs that provide passive,content-neutral service to distribute copyrighted works.Therefore,the safe harbor rule is difficult to accommodate UGC(user-generated-content)platforms due to their active role in facilitating the distribution and even the creation of copyrighted works.The uncertainty of UGC platforms’liability has led copyright owners to directly target individual UGC creators.In order to unleash the creativity of users without harming the interests of copyright owners,a levy scheme should be introduced.Under the levy scheme,users are allowed to freely use copyrighted works to create UGC for non-commercial purpose.UGC platforms are required to remunerate the copyright owners of the copyrighted works used in the UGC posted on the platforms based on the popularity of the UGC.展开更多
基金supported by the Major Scientific Research Tasks for Scientific and Technological Innovation Projects of the Chinese Academy of Agricultural Sciences(CAAS-ZDRW202006)the National Transgenic Breeding Project(2018ZX08010-10B)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(ASTIP-IAS05).
文摘Efficient and stable expression of foreign genes in cells and transgenic animals is important for gain-of-function studies and the establishment of bioreactors.Safe harbor loci in the animal genome enable consistent overexpression of foreign genes,without side effects.However,relatively few safe harbor loci are available in pigs,a fact which has impeded the development of multi-transgenic pig research.We report a strategy for efficient transgene knock-in in the endogenous collagen type I alpha 1 chain(COL1A1)gene using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)system.After the knock-in of a 2A peptide-green fluorescence protein(2A-GFP)transgene in the last codon of COL1A1 in multiple porcine cells,including porcine kidney epithelial(PK15),porcine embryonic fibroblast(PEF)and porcine intestinal epithelial(IPI-2I)cells,quantitative PCR(qPCR),Western blotting,RNA-seq and CCK8 assay were performed to assess the safety of COL1A1 locus.The qPCR results showed that the GFP knock-in had no effect(P=0.29,P=0.66 and P=0.20 for PK15,PEF and IPI-2I cells,respectively)on the mRNA expression of COL1A1 gene.Similarly,no significant differences(P=0.64,P=0.48 and P=0.80 for PK15,PEF and IPI-2I cells,respectively)were found between the GFP knock-in and wild type cells by Western blotting.RNA-seq results revealed that the transcriptome of GFP knock-in PEF cells had a significant positive correlation(P<2.2e–16)with that of the wild type cells,indicating that the GFP knock-in did not alter the global expression of endogenous genes.Furthermore,the CCK8 assay showed that the GFP knock-in events had no adverse effects(P_(24)h=0.31,P_(48)h=0.96,P_(72)h=0.24,P_(96)h=0.17,and P_(120)h=0.38)on cell proliferation of PK15 cells.These results indicate that the COL1A1 locus can be used as a safe harbor for foreign genes knock-in into the pig genome and can be broadly applied to farm animal breeding and biomedical model establishment.
基金This work was supported by Guangdong Planning Office of Philosophy and Social Sciences 2020(project no.GD20YFX05).
文摘The safe harbor rule was introduced to exempt Internet service providers(ISPs)from liability for copyright infringement committed by ISP users.Nevertheless,the safe harbor rule was crafted for ISPs that provide passive,content-neutral service to distribute copyrighted works.Therefore,the safe harbor rule is difficult to accommodate UGC(user-generated-content)platforms due to their active role in facilitating the distribution and even the creation of copyrighted works.The uncertainty of UGC platforms’liability has led copyright owners to directly target individual UGC creators.In order to unleash the creativity of users without harming the interests of copyright owners,a levy scheme should be introduced.Under the levy scheme,users are allowed to freely use copyrighted works to create UGC for non-commercial purpose.UGC platforms are required to remunerate the copyright owners of the copyrighted works used in the UGC posted on the platforms based on the popularity of the UGC.
