Chapter 16, Problem 26P

You are studying a transgenic mouse strain that expresses a GFP reporter gene under the control of cis-acting regulatory elements that normally control a gene needed for the early development of mice. Previous evidence from transcriptome sequencing (RNA-Seq) indicates that mRNA for the gene of interest can be identified between days 8.5 and 10.5 of gestation. In your strain, GFP fluorescence can be seen from about day 8.75 until at least day 12.

a.	Explain the discrepancy between mRNA and protein expression.
b.	Would you expect GFP protein expression to indicate more accurately the normal onset of activity for this gene or the normal cessation of this gene’s activity? Explain.