In other species: Garter snake , gilthead seabream , Oujiang color common carp , White's rock-skink , rainbow trout

Mendelian trait/disorder: yes

Considered a defect: unknown

Key variant known: no

Species-specific description: Wang et al. (2021): "We identified 4 types of pigment cells: melanophores, xanthophores, iridophores and erythrophores, and characterized their first appearance in wild-type fish. We mutated 25 genes involved in melanogenesis, pteridine metabolism, and the carotenoid absorption and cleavage pathways. Among the 25 mutated genes, 13 genes had a phenotype in both the F0 and F2 generations. None of F1 heterozygotes had phenotype. By comparing the color pattern of our mutants with that of red tilapia (Oreochromis spp), a natural mutant produced during hybridization of tilapia species, we found that the pigmentation of the body and eye is controlled by different genes. Previously studied genes like mitf, kita/kitlga, pmel, tyrb, hps4, gch2, csf1ra, pax7b, and bco2b were proved to be of great significance for color patterning in tilapia."

Wang et al. (2022) "found that most fishes have two pmel genes arising from the teleost-specific whole genome duplication. Both pmela and pmelb were expressed at high levels in the eyes and skin of Nile tilapia. We mutated both genes in tilapia using CRISPR/Cas9. ... our results indicate that, while both pmel genes are important for the formation of body color in tilapia, pmela plays a more important role than pmelb. ... Studies on these mutants suggest new strategies for breeding golden tilapia, and also provide a new model for studies of pmel function in vertebrates."

Inheritance: CRISPR/Cas9 gene editing was used to create mutations (GMO).