Tortishell
Tortishell, a^mo/*
At least one copy of Melanistic gene.
Chromosome: Unknown
RVG description:
Tortishell are suspected to be caused by the a^mo gene as it seems to only be found in Melanistic lines.
Tortishell is thought to be apparent after the first few moults on a Melanistic rat. This means that Tortishell is rarely apparent from birth and only appears on Melanistic rats.
It seems it comes down to selection of the a^mo as it tends to vary from poor expression to good expression.
Sources:
At least one copy of Melanistic gene.
Chromosome: Unknown
RVG description:
Tortishell are suspected to be caused by the a^mo gene as it seems to only be found in Melanistic lines.
Tortishell is thought to be apparent after the first few moults on a Melanistic rat. This means that Tortishell is rarely apparent from birth and only appears on Melanistic rats.
It seems it comes down to selection of the a^mo as it tends to vary from poor expression to good expression.
Sources: