Stop cassette optimization

<div>During my early experimentation with the <i>ROSA26^Ai14</i> allele mice, I noticed some basal fluorescence in the V-SVZ cells.</div><div><br></div><div>While constructing some constructs here and there, figured out what is going on.</div><div><br></div><div>Some self-explanatory data from the tests of 3x repeats of an SV40 polyadenylation sequence from a Clontech plasmid as stop cassette. An illustration of what I mean by 3pA "leaks in vivo" (as noted in https://www.addgene.org/133574/).</div><div><br></div><div>Then I tried to "fix" the basal fluorescence.</div><div><br></div><div>Because the bGH pA - 3x SV40 pA doesn't leak in vivo, a truncated version of that stop cassette with one less copy of SV40 pA was constructed (to make the length similar to 3x SV40 pA).</div><div><br></div><div>Finally, there may be reasons why the basal fluorescence may be beneficial. Since the <i>ROSA26^Ai14</i> allele works so well, I don't think there is a good reason to spend the time, effort, and the resources to find out with another new reporter allele. So I haven't tested this construct as a knock-in yet, but is deposited for anybody interested at https://www.addgene.org/133576/. It may be useful for other purposes.</div><div><br></div><div>The <i>ROSA26-CAG-LSL-Mitochondrial miniSOG-T2A-tdTomato</i> mouse line was a project initiated by Dr. Dimitri Tränkner, and conducted in collaboration by Drs. Hyung-song Nam, Emanuele Panza, and Dimitri Tränkner.</div>