The researchers disregarded known Mendelian colours - colourpoint, dilute, and silver - and focussed on the variation ranging from grey-brown to red-orange. Asip and Corin genes act on the same genetic pathway to regulate the type (black/brown eumelanin or red/yellow pheomelanin (Asip) and amount of pigment produced in hair follicles (Corin). In Bengal cats, AsipPb and CorinPb allele frequencies correlate with colour variation, but in opposite directions. ALC-Asip allele frequencies decrease and ALC-Corin allele frequencies increase as coat colour changes from grey-brown to red-orange tones across individuals. ALC introgression is associated with loss-of-function effects at multiple loci, and the combined effect contributes to this diversity.

GENETICS OF AGOUTI AND CORIN GENES

The researchers found a number of single nucleotide variations in the Bengal corin gene. Of the 19 protein-altering Corin variants in Bengal cats, 7 are not associated with colour variation. A corin allele of domestic cat origin also contributed to colour variation in Bengals.

The previously known Corin mutations are
CORIN:C.839G>A - extreme-sunshine Siberian cats.
CORIN:C.2383C>T - sunshine Siberian cats.
CORIN:C.2425C>T - copper/flaxen gold/akita British Shorthair/Longhair cats.
CORIN:C.1759C>T - golden tiger (big cat).

None of the three domestic cat Corin mutations were detected in Bengal cats. This means there are novel Corin mutations in Bengals referred to here as CorinPb.

- Christopher B. Kaelin, Kelly A. McGowan, Anthony D. Hutcherson, John M. Delay, Gregory S. Barsh, "Ancestry dynamics and trait selection in a designer cat breed," December 12, 2022.