title: Advances in site-specific integration of transgene in animal genome.
abstract: The traditional transgenic technologies, such as embryo microinjection, transposon-mediated integration, or lentiviral transfection, usually result in random insertions of the foreign DNA into the host genome, which could have various disadvantages in the establishment of transgenic animals. Therefore, a strategy for site-specific integration of a transgene is needed to generate genetically modified animals with accurate and identical genotypes. However, the efficiency for site-specific integration of transgene is very low, which is mainly caused by two issues. The first one is the low efficiency of inducing double-strand break (DSB) at the target site of host genome in the initial process. The second one is the low efficiency of homologous recombination repair (HDR) between the target site and the donor plasmid carrying homologous arm and foreign genes. HDR is the most common mechanism for site-specific integration of a transgene. DSBs can stimulate DNA repair mainly by two competitive mechanisms, HDR and nonhomologous end joining (NHEJ). Hence, activation of HDR or inhibition of NHEJ can promote the HDR in the integration processes, thereby optimizing a specific targeting of the transgene. In this review, we summarize the recent advances in strategies for improving the site-specific integration of foreign transgene in transgenic technologies.
authors.affiliation: National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Guo-ling
authors.initials: GL
authors.lastname: Li
authors.affiliation: National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Cui-li
authors.initials: CL
authors.lastname: Zhong
authors.affiliation: National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Jian-xin
authors.initials: JX
authors.lastname: Mo
authors.affiliation: National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Quan
authors.affiliation: 1. National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; 2. Guangdong Wens Foodstuff Co., Ltd., Xinxing 527439, China.
authors.forename: Zhen-fang
authors.initials: ZF
authors.lastname: Wu
authors.affiliation: National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Zi-cong
authors.initials: ZC
authors.lastname: Li
authors.affiliation: 1. National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; 2. Guangdong Wens Foodstuff Co., Ltd., Xinxing 527439, China.
authors.forename: Hua-qiang
authors.initials: HQ
authors.lastname: Yang
authors.affiliation: 1. National Engineering Research Center for Swine Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; 2. Guangdong Wens Foodstuff Co., Ltd., Xinxing 527439, China.
authors.forename: Xian-wei
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D053903:DNA Breaks, Double-Stranded; D059767:Recombinational DNA Repair; D019076:Transgenes