|Cornsnake Morph Guide ®||Pattern Formation||Charles Pritzel|
The milksnake phase and banded lines of corns appear to be the result of selective breeding for the opposite effect of motley: they increase the amount of lateral migration, making broader saddles. This could explain why some motley and other "clear belly" snakes from these lines end up with unexpected belly checkers.
Additional traits may affect the expansion rates of the different elements of the pattern. For example: larger saddles, larger borders, and larger ground areas. Traits along these lines appear to exist in ball pythons, currently known as "spider" and "mojave" morphs, which brings hope that similar patterns may appear in corns.
Different expansion rates can have a drastic effect on the pattern.
Piebald, which is not known to exist in cornsnakes yet, prematurely kills off or deactivates migrating cells. This is responsible for the areas where no color or pattern develop. Several different species are known to have piebald mutants at a locus that corresponds to the same locus in the other species. (The locus is known as the endothelin-B receptor.) As a result, it is very likely that a piebald mutant will appear in cornsnakes someday and create that same phenotype. However, many of the mutants that cause piebaldism also cause severe or lethal effects on homozygotes. As a result, "bad" piebaldism might be discovered several times in a species before a "good" version is found.
Other pattern mutations (which have not yet been discovered) could affect the lengths and/or widths of saddles, the distances between saddles, the number of saddles, the thickness of the black border areas, and many other effects. It is the author's belief that brindle, leucistic, piebald, and whitesided pattern genes (and probably many others) will eventually appear in cornsnakes. Perhaps pied-sided is the cornsnake equivalent of other whitesided genes...