A transgenic pig model expressing a ZsGreen1 reporter across an extensive array of tissues

Abstract

The advent of genetically engineered pig production has revealed a wide array of opportunities to enhance both biomedical and agricultural industries. One powerful method to develop these models is transgenesis; however, selection of a suitable promoter to drive transgene expression is critical. The cytomegalovirus (CMV) promoter is the most commonly used viral promoter as it robustly drives transgene expression in a ubiquitous nature. However, recent reports suggest that the level of CMV promoter activity is tissue-dependent in the pig. Therefore, the objective of this study was to quantify the activity of the CMV promoter in a wide range of porcine tissues. Swine harboring a CMV-ZsGreen1 transgene were utilized for this study. Thirty five tissue samples were collected from neonatal hemizygous (n = 3) and homozygous (n = 3) transgenic piglets and analyzed for ZsGreen1 abundance via immunoblot. ZsGreen1 was detected in all tissues examined; however, quantification revealed that the level of ZsGreen1 expression was tissue-specific. For example, ZsGreen1 was most abundantly produced in the salivary gland, moderately produced in the esophagus and lowly expressed in the stomach. Interestingly, expression of ZsGreen1 also differed within organ. For instance, levels were highest in the right ventricle compared with other chambers of the heart. The expression patterns of ZsGreen1 were similar between homozygous and hemizygous piglets. Ultimately, these results elucidate the tissuespecific activity of the CMV promoter in the neonatal pig.All rights reserved. No reuse allowed without permission.was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.