I'm not actually looking to get long tails right now, I was actually looking into short tails some day far off in the future, when I have the time/space to dedicate to another line. Reading someone's discussion on tailless mice got me thinking about what governs the tail length, and I suppose, the "set." The difference in what I'm trying to ask is basically - are mice likely to already HAVE the gene forms they need for tail length, and they just need to be selectively picked out and purified, or can you never get a long or short tail from an average mouse? Do you specifically have to bring in ("actively include") a certain gene form for tail length that is simply not present in your average population? I can't make a satin mouse appear out of nowhere. Is it equally impossible to manipulate the tail length if it hasn't been considered before, and might therefore be het at whatever loci it might involve? Or are the modifiers around and just need to be poked at?
When I worked at the lab, some of the mice had notably shorter tails, and it definitely seemed to be genetic, albeit unimportant at the time. I just wasn't sure if you could bring out the same difference in a separate or random selection of mice, by breeding the shortest or longest tailed, or if you needed a starter mouse to bring it in. I'm also not sure if it's linked to any other condition, either of coat type or color, or health conditions (especially regarding the spine), or anything like that. I don't know if that makes sense, heh.