Isn't this genetically impossible?

[Robochelle]

Isn't a rabbit supposed to be either dilute or not dilute? How does she have left face black and right face gray?

Is there something I am missing about fur color? Same thing with second rabbit, Isn't he supposed to be steel all over rather than in a splotch here and there?

 

[ladysown]

it's not grey, it's just washed out black from the orange coat.

And the other might not be the steel gene at work, could be another gene completely. is the fur tipped or are they random white/gold hairs?

 

[Robochelle]

What's meant by washed out? Is this a common occurrence?

On the second guy, yes the fur is consistently tipped inside the splotch, consistently not tipped the rest of the face.

 

[RabbitsOfTheCreek]

It doesn't look half and half, but if it was, it's called a Chimera

 

[Robochelle]

Chimerism is very rare, isn't it? There's got to be a different rationale.

For the steel gene, it isn't improbable for the black guy to have it- the orange is his half sister, and she has consistent gold tips on her orange fur (but isn't tipped on the black or gray)

 

[ladysown]

it's quite normal to have different shadings of black on japanese. The colour gets diluted, particularly if there is tort/shaded in the background.

sometimes damage to an area can affect the hair just in the spot.

 

[MsTemeraire]

Chimerism is very rare, isn't it? There's got to be a different rationale.

Chimerism is rare, yes. But somatic mutation is much more common. It often expresses similarly to the Harlequin pattern, caused by the way the pigment cells of the two different colours migrate.

 

[reh]

Rabbits with strange color distributions
on heterocygote colors, if the dominant gene get lost in one cell, on proliferation it developes one or more patches of the recessive color.

the steel gene in combination with other Extension alleles beside E may cause black color.. I am not sure if EeJ will show as black or as harlequinized black/steel.

 

[judymac]

Both of the issues you describe are common to the harlequin e(j) allele. There is a book available online at Rabbitcolors.info by Roy Robinson called Genetic Studies of the Rabbit. Rabbitcolors - Literature Some of what you describe is noted in his book on rabbit genetics (p. 450): "The dark or 'steel' pattern which develops in agoutis of genotype Ee(j) shows that the black part of the Japanese (the 'j' part of e(j) stands for Japanese, the original name for harlequin) pattern is not fully recessive. PUNNETT, indeed, suggests that the black of the e(j) is more closely akin to that of the E(D) than to that occuring in E animals." On page 251 of the same book, he states: "The peculiar relationship of expression of the yellow and black pattern of the Japanese has prompted CASTLE (1922, 1950) to suggest that the e(j) allele is a compound of the alleles e and E(S) or E(D)". I have noticed in my harlequin line rabbits that some dark patches are a much deeper black than others, and have read on other websites about the same condition on their harlequins. It is suspected that these sections are actually dominant black E(D)

If you go to Green Barn Farm's page on the effects of the various E extension alleles at A/E Gene Combinations you'll see that mixing steel with harlequin E(S)e(j) can cause ticking only in patches, the other condition you noted.