Replies to post #4350 on GTC Biotherapeutics (fka GTCB)

[genisi]

I'm sure. cDNA constructs are lousy expressors because for unknown reasons mammalian cells require splicing for stability and efficient transcription. In many cases including the first intron is sufficient. In other cases you need more introns.

[gym gravity]

there are a few semi-truths here and there.

genomic promoters and enhancers are the best for tissue specific expression of a tissue specific geen.

introns (genomic DNA) often enhance expression levels over a cDNA.

goat mammary gland expression is driven by goat mammary gland promoters and enhancers, but the gene of interest, for efficiencies sake, is likely to be a cDNA. If you wanted to maximize expression, you would engineer a splice site into the 3'UTR of the construct because for some reason, having splicing machinery on the mRNA enhances translation.