I’m just wondering why Palmetto is listed as a recessive gene mutation in the Corn Snake category. Palmetto is an Incomplete Dominant gene mutation. Seems like this might be an easy fix :).
I’ve seen people on both sides of this argument. Never seen anyone prove it either way. What factors are you going off of when you say it’s inc dom?
1 Like
I did not realize this was in dispute. Het Palmettos pretty reliably possess differences in coloration from Normal Corns (i.e., they resemble Hypos). That is, if you breed a visual Palmetto to a wild type/Normal, the young do not look like Normals or Palmetto’s, which as far as I am aware, is consistent with how Inc. Dominant gene mutations are expressed in many other reptiles. Also, both Sarah Mohr’s book on Corn Snake morphs and Don Soderberg’s website state that Palmetto is Incomplete Dominant and I can’t think of 2 better sources. I’m curious about what evidence there is against it being Inc. Dominant?
4 Likes
I was asking more so you would extrapolate and provide a little more information for staff. And so it would be captured here for future inquisitors. Would it be possible for you to share some example pictures of Het Palmettos or a comparison photo?
The hobby at large obviously still has some debate, right or wrong. It is listed on many websites and I’ve heard it referred to by many keepers as recessive. Including one of the breeders I purchased one of mine from. I’m not saying I disagree with you, I’ve never produced them and only have visuals.
2 Likes
Here are the sources I have relied on. If you have links or can point me towards discussion of evidence that Palmetto is recessive I’d be grateful.
- Ians Vivarium lists Palmetto as Incomplete Dominant (and provides photos of the “hypo-ish” look of Het Palmettos described by S. Mohr below (Ians Vivarium - Het Palmetto Cornsnake).
- Cornsnake Cultivar Compilation v1 by S. Mohr says Palmetto “is incomplete dominant. Het Palmettos appear to be Hypos in many cases” (pg.24).
- Don Soderberg’s website says the following: “Mode of Genetic Inheritance: Incompletely dominant gene mutation; Morph Type: Incompletely dominant to wild-type”.
2 Likes
To my knowledge palmettos work the same as lucies. The “hets” are actually visual like rusty rat snakes. Super rusty is also called lucy. Palmettos even have the same eye deformity as lucy animals.
Again I wasn’t disputing your point, just asking for the information that you’ve now provided. Thank you for taking the time to add the details.
It’s all good. I didn’t think what you said came off as contrary/disputing at all. I could be wrong about this, but the sources I trust all seem to be in agreement. Again, I am genuinely interested in learning about and discussing evidence that Palmetto is recessive. I just dig genetics.
3 Likes
From what I have read, that’s exactly right. Leucism and bug-eyes in rat snakes, including corns of course, are both tied to the MITF gene… as well as pied (same gene different loci is the hypothesis I think). I’m no geneticist so someone out there please correct me if I’m wrong, but doesn’t Het Palmetto resulting in any phenotypic expression, and the fact that a homozygous Palmetto does not produce all Palmetto young when bred to a normal, fit exactly with expectations for incomplete dominance? I know we sometimes see, or think we see “Het Markers”, associated with recessive genes, which makes no sense and complicates things, but what Palmetto does seems quite different to me.
4 Likes
So are we in agreement that Palmetto is Incdom?
- Inc Dom
- Recessive
0 voters
Inc-Dom 
2 Likes
Democracy in action 
3 Likes
The page names are incorrectly named. Palmetto is inc-dom, but a homozygous animal isn’t considered a super palmetto. Het palmetto and palmetto should still work fine (like het red axanthic and red axanthic in ball pythons). It’s what people know and are used to. A lot of animals are being mistagged now because that naming system just isn’t used for palmettos. I was told that the calculator might be incorrect too, but I’m not sure on that part
5 Likes
I wondered about this issue as well. Someone please correct me if I am wrong, but it looks like the MM gene category “Inc/Dominant Genes” is a combination of “Incomplete Dominant” and “Dominant”. If so, these should really be made in to separate categories, as these are different modes of genetic inheritance. For example, dominant gene mutations like Tessera have a homozygous/super form, but there is no phenotypic difference between a Tessera (heterozygous) and a Super Tessera (homozygous). On the other hand, incomplete dominant gene mutations like Palmetto are partially expressed phenotypically even when the animal is only heterozygous for that mutation, but are fully expressed when homozygous for a mutation. Seems like there should be a “Dominant Gene” category that has “Het” & “Super” and an “Incomplete Dominant Gene” category that has “Het” and “Visual”. Of course it would be great if the genetic calculator was up to speed on all of this as well.
1 Like
I think the current tags work fine. Genetically wise (like for the calculator) it still works either way. The tags work as heterozygous and homozygous whether or not they’re dominant or inc-dom. I think palmetto’s name for each tag just needs to be changed. Het palmetto and palmetto, even if it’s inc-dom. Like I said before, it’s just like het red axanthic. Red axanthic’s page doesnt say super red axanthic
I’m sorry, but either the tags are correct or they are not. Incomplete dominant and dominant gene mutations are not the same. They do not have the same rules of inheritability, and should not be combined. If MM is passionate about doing things right, this should be fixed so that folks that don’t know the distinctions are not confused by the tags.
There are different names for it but the two forms (heterozygous and homozygous) still inherit the same. For example pinstripe (in ball pythons) is dominant (the homozygous looks the same as the heterozygous) but super pinstripes exist (even though they aren’t visibly differentiable from a heterozygous pinstripe). Recessive is similar (homozygous and heterozygous still inherit the same), but the only thing differentiating it is that it’s only visible in the homozygous form.
I think it’s fine the way it is, though I wouldn’t be opposed to the change being made. The morphpedia should help clear up confusion.
2 Likes
I agree that the calculator is essentially going to treat them the same, but I’d suggest that the reason we started this convo, that there is no such thing as “Super Palmetto”, is still a valid point. And Dominant and Incomplete dominant do not inherit the same, at least from the perspective of phenotype (i.e., a Het Inc. Dominant shows visually). IMO, dominant and incomplete dominant gene mutations need their own individualized sets of tags so that what is represented on MM is accurate based on science, and so that confusion is not created. MM could have left Palmetto in the recessive category and the calculator would correctly spit out the right progeny, but it would not be technically correct. MM could leave Inc. Dominant and Dominant combined, but it is not technically correct. I think MM is a great tool, and a great forum, and efforts like MorphMedia clearly show that the MM staff are passionate about educating users. I don’t think requesting that genetic info be correctly represented is an unreasonable request and in fact I think it is an important improvement that should be given consideration.
2 Likes
Palmetto is in fact coded as an inc dom, not a dominant. Our database makes such a distinction.
The legend in index page UI does not make such a distinction, which I imagine is where you are drawing this conclusion from. This decision was probably in part simply to keep the number of colors down to a reasonable number.
I will make a note for future redesign that it would be nice to have this distinction made. But if someone wants to learn about the gene, they can click on the (i) icon as it is next to Amelanistic, and I suspect will show up for Palmetto by tomorrow. 
4 Likes