YB Complex Decoded & Tests Available

We are excited to announce that Dr. Hannah Seidel and team have just published a scientific paper in which they present the details of the Yellowbelly (YB) complex that they have decoded.

First, they were able to show that there are TWO mutations in the same gene that cause the YB morph. Either of these mutations can cause a yellowbelly, and Ivories can be two copies of either one of these mutations, or one copy of each. So, the YBs and Ivories we are all used to seeing as keepers and breeders are technically not all the same genetically.

Their research further explained the mutations that cause YB and Ivory are mutations that completely alter the genetic product (i.e., protein) and likely render it totally inactive. Whereas the mutations that cause Spark and Specter cause less of a change to the resulting protein, and the protein is still able to partially do its job (hence the difference between an Ivory and a Super Specter).

Finally, the mutations that cause Asphalt and Gravel change the normal protein even less than Specter and Spark, so their effects are less severe than what you see in an Ivory or a Super Spark or Super Specter.

Because of this amazing work by Eastern Michigan, RGI has now added ball python morph tests for Yellowbelly, Spark, Specter, Gravel, & Asphalt, bringing the total number of ball python morph tests to 11. Order tests for your animals today.


"The animals lacking these deletions were further tested to determine whether they carried any of the other variants associated with alleles in the Yellowbelly series—i.e., L152F (spark), R315P (specter), and the G-to-A substitutions in splice donors (gravel and asphalt). One animal was found to be heterozygous for L152F (S2 Table). The other animals did not carry any of these variants (S2 Table). Thus, of the 130 animals described as yellowbelly heterozygotes, 98 were correctly described, one was a spark homozygote, and the remainder carried only putatively wildtype copies of EDNRB1. These findings confirm the skepticism surrounding heterozygote descriptions for alleles in the Yellowbelly series. They suggest that approximately one in four animals described as a yellowbelly heterozygote is mis-labeled. "


Oh wow! This is super exciting to hear!

Crazy to think there were actually so many things going on and that YB was actually two possible genes with the same results


This is fantastic work. I believe we will start to see many other types show up not as expected, when testing expands to other morphs. This will have breeders shocked and scrambling to make changes. But testing will have to be done on the breeders to see what type they are. This will also lead to buyers expecting to see test to verify the true line, especially if price is the determining factor. These test are either going to flip this hobby upside down or, not be utilized and keep things as is. It is going to be interesting to see how this plays out in the long run.



Genetic info is so interesting to me but I swear my brain glazes over when I try to read papers about it :joy: