Basic Color Genetics: Blue and Blue Tort

Blue tort is the non-extended color of blue. They are in the “black gene” family. 

We have seen this photo a few days ago when we discuss black and blue:
Northern California Angora Guild: Basic Color Genetics: Black and Blue (ncag.blogspot.com)
The color genes of the blue is
aaB-C-D-ddE-
Blue is the dilute of black.

It is in the "black gene family", it is full colored, the E extends the grayish blue color to the entire body.  The dd dilute gene makes the dark black into grayish blue.

What if the blue lacks the E to extend the grayish blue color to the entire body?  We have a blue tort: 
aaB-C-ddee
If you compare the blue and blue tort, the difference is the ee part.  Blue has E- while blue tort is ee.  

 

The non-extension recessive gene ee restrict the grayish blue color to the points.  For English Angora, the most visible blue points are on the face and the ears.   The rest of the body is light beige or light tan.

These two English Angora does are littermates, the blue is Chu’s Talia and the blue tort is Chu’s Tianna. Photos taken when they were seniors.