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

摘要

Since genetic engineering of pigs can benefit both biomedicine and agriculture,selecting a suitable gene promoter is critically important.The cytomegalovirus(CMV)promoter,which can robustly drive ubiquitous transgene expression,is commonly used at present,yet recent reports suggest tissue-specific activity in the pig.The objective of this study was to quantify ZsGreen1 protein(in lieu of CMV promoter activity)in tissues from pigs harboring a CMV-ZsGreen1 transgene with a single integration site.Tissue samples(n=35)were collected from neonatal hemizygous(n=3)and homozygous(n=3)piglets and ZsGreen1 abundance was determined via immunoblotting.ZsGreen1 was detected in all tissues,except hypothalamus,kidney cortex and oviduct.The expression patterns of homozygous and hemizygous piglets were similar(P>0.05).However,quantification revealed that ZsGreen1 protein levels were tissue-specific.Within neural/endocrine tissues,ZsGreen1 abundance was highest in the anterior pituitary gland,intermediate in the cerebellum and lowest in the cerebrum,spinal cord and posterior pituitary(P<0.05).In the digestive system,ZsGreen1 was more abundant in the salivary gland than esophagus,stomach,pancreas,duodenum,jejunum,ileum,spleen,colon,gallbladder and liver(P<0.05).Interestingly,ZsGreen1 amounts also differed within an organ(i.e.,the right ventricle had 3-fold higher levels than the other heart chambers;P<0.05).These results provide useful information for the use of the CMV promoter to drive transgene expression in the pig.Moreover,this swine model represents a novel resource of ZsGreen1-labeled organs and a valuable tool to advance genome editing research.