Rabbit Genetics Question

[Sassy07]

So I recently bred my broken blue Rex doe to what I thought was a purebred Californian buck. She produced four kits, one of which is a REW. If my Californian were purebred he wouldn’t carry that recessive “c,” would he?

 

[Bunnylady]

Himi/Cali/Pointed White kits are born solid white; the darker points develop a bit later. This color is temperature dependent. The dark pigment only appears on cooler areas of the skin, which is why it normally only shows up on the extremities. Does often get dark patches on their dewlaps when they pull fur and the skin cools as a result (not a fault on the show table, as long as the dewlap is the only place the dark marks appear). Himi kits that get chilled in the nest box may develop a dark band in the part of the hair that was growing at the time of the chilling; this dark ticking can be so pronounced, they almost look like some sort of Chinchilla (though the ticking will grow out with the next molt). Himis frequently show smaller/lighter points during warmer weather, with the points growing darker/larger during cooler months.

Another thing that can put smaller points on a Himi is genetics. The expression of the middle genes of the C series is a sort of sliding scale, and a chc Himi shows the influence of the REW gene by having much smaller and often lighter points than a chch Himi has. The nose marking of a chc Himi seldom covers more than just the nose itself; if the rabbit in your avatar is the Cali buck in question, the size of his nose marking sure makes it look like he has two copies of the Himalayan gene (ch). Do you know whether your Rex doe has REW or Cali (in the Rex, this color is called Californian, in this case, I mean the color, not the breed) in her background?

 

[Sassy07]

Himi/Cali/Pointed White kits are born solid white; the darker points develop a bit later. This color is temperature dependent. The dark pigment only appears on cooler areas of the skin, which is why it normally only shows up on the extremities. Does often get dark patches on their dewlaps when they pull fur and the skin cools as a result (not a fault on the show table, as long as the dewlap is the only place the dark marks appear). Himi kits that get chilled in the nest box may develop a dark band in the part of the hair that was growing at the time of the chilling; this dark ticking can be so pronounced, they almost look like some sort of Chinchilla (though the ticking will grow out with the next molt). Himis frequently show smaller/lighter points during warmer weather, with the points growing darker/larger during cooler months.

Another thing that can put smaller points on a Himi is genetics. The expression of the middle genes of the C series is a sort of sliding scale, and a chc Himi shows the influence of the REW gene by having much smaller and often lighter points than a chch Himi has. The nose marking of a chc Himi seldom covers more than just the nose itself; if the rabbit in your avatar is the Cali buck in question, the size of his nose marking sure makes it look like he has two copies of the Himalayan gene (ch). Do you whether your Rex doe has REW or Cali (in the Rex, this color is called Californian, in this case, I mean the color, not the breed) in her background?

I am completely unsure of my Rex’s ancestry as she was a dumped bunny at a local farm that I took in. My Cali buck is not as nicely marked as the doe in my avatar. Here is a pic of him from yesterday.

 

[Bunnylady]

These show typical markings for chc rabbits. With the color spilling over onto the whisker pads, your buck looks chch to me.

 

[Sassy07]

I see. He has never produced anything like that with my Cali doe. And 2 of the 4 kits, the two smaller ones, do show some of the grey ticking. I was not aware they would color whole body like that during cold. My purebreds have never done so, but they have always been born into bigger litters. Thank you for the information!

 

[Bunnylady]

Purebred Calis can be full of surprises when they get outcrossed to another breed, because they can be carrying genes (like Steel) that you might not expect, and wouldn't be able to see without the genes that come from the other breed.

 

[Sassy07]

I attempted to research for hours last night, but was always getting confused about which gene would hide which other gene. I breed for meat so it really doesn’t matter, now I’m even more curious though!

 

[Bunnylady]

Lots of people have addressed the subject on blogs and other websites, with varying degrees of clarity. I don't know if it will help, but I started this thread on BYC's sister site:
https://www.backyardherds.com/threads/rabbit-coat-color-101.38256/#post-562256

Be warned - you want to avoid Steel until you have a solid grasp of the rest of the genome. I don't know why Californians and NZW's should have Steel, but they often do, and the odd behavior of Steel can make for some real head-scratchers!

 

[CoturnixComplex]

Thank you guys! You just figured out my doe's genetics for me too! I know Mom and Dad both carried REW but didn't know that was what was making her points so light.

On a side note, I am very jealous OP. I am currently scouring the ends of the Earth to find: a broken blue rex doe.