In this study , we aimed to generate marker - free pbd-2 knock - in pigs
that expression levels of PBD-2 in different tissues of transgenic ( TG ) piglets were significantly higher than those of their wild - type ( WT ) littermates .
In this study , we aimed to generate marker - free pbd-2 knock - in pigs using the CRISPR / Cas9 and Cre / loxP systems .
Immunohistochemistry and immunofluorescence analyses indicated that expression levels of PBD-2 in different tissues of transgenic ( TG ) piglets were significantly higher than those of their wild - type ( WT ) littermates .