Revisit: Those Mysterious Modifiers: Rufus (Rufous)

 

This post about Rufus was originally posted on February 23, 2019.

In this picture there are two babies that are identified as red and fawn.  What is red?  Red is not a part of the ABCDE genetics, it is a modifier that makes the fawn color turn reddish.   It is currently an identified modifier thus it is not as mysterious as Umbros.       

These are bunnies come from Casey's efforts of breeding Red English Angora.  Of the four colored ones, second and fourth from the left are expressing the effect of Rufus while the very right one shows a regular tort.   Of the three that have reddish color, only one can be called "Red".  Why? According to SOP, Red is under the "Wide Band Group" and the wild band group is agouti patterned.   The two on the left are tort and chocolate tort, so they would not be considered as red, they are just tort and chocolate that have the rufus modifier.  

Here is another group of the bunnies that come from Casey's effort of breeding red English Angora.   The second and the fourth can be called Red as they have the reddish wool and agouti patterned.   The first one is a tort with the rufus modifier but not considered as red as it is a self.   Then the middle and the very right bunnies do not seem to be affected by the rufus modifier, they look like a regular tort and a cream.   

Unlike the Umbros modifier, the Rufus modifier can affect both agouti and non-agouti coats.   Though the rufus is not as mysterious as the Umbros darkening modifier, it is still quite unpredictable as it could affect the bunnies in the same litter differently. 

By the way these photos are from many years ago.   Casey is no longer working on the red English Angora.  

Revisit: Those Mysterious Modifiers: Umbros (Umbrous)

 

The topic of how modifiers affect the color of our bunnies have been discussed quite a few times in 2016 and 2019.     This topic has come up recently again, we are revisiting two of the previous posts, one on "Umbros" that darkens the color and another on "Rufus" that is reponsible for Red.   Today's post was originally posted February 22, 2019.  

A while ago I had a French Angora litter with two chestnut and three chocolate agouti bunnies.   Mom is a black based fawn and dad a chocolate agouti. 

The three chocolate agouti bunnies grew up to be chocolate agouti adults, the color on all three look about the same.  

The two chestnut grew up to be very different looking.   If you go back to the top photo, they looked about the same as days-old bunnies but now very different.   

This photo shows the back of the two chestnut that have very different colors.  

I had a discussion with our color genetics guru Candy Haenszel, here is her assessment:

"It looks like your chestnuts go from the extreme one way to the extreme the other way.  The more yellowish one is the sandy type of chestnut, and is caused by wide-band genes.  I don't know if a rabbit has to have two wide-band genes to be expressed, but I think so.  Wide-band genes widen the yellowish tan band on an agouti.  I can see in the photos, that the dark gray band is a lot wider on the wild gray, and the tan band is a lot wider on the "sandy" chestnut.  Wide-band genes are a wonderful thing to have in fawn and cream, because non extension genes usually leave just a faint grayish color band, and wide-band genes make the yellowish color take over more of the wool, getting rid of the grayish, and making a much better/cleaner fawn/cream.  What I have always heard, is that wild gray is caused by umbros darkening modifiers.  They darken the grayish band of a chestnut into a very dark bluish gray color.  I don't know if they also widen the grayish band, but they must, or that dark bluish gray color wouldn't almost take over the whole color of the wool.  Maybe there is another modifier that is closely linked to umbros that widens the grayish band, or narrows the yellowish band.  I don't know.  I just know that umbros modifiers darken the grayish band into that very dark color.  I wish I knew more about how that grayish band is widened."  

According to a summary in the "Journal of Genetics" on

https://link.springer.com/article/10.1007/BF02982492

The Umbros darkening gene only expresses on agouti patterned mice, no visual effect on non-agouti mice.   We are not sure whether such can be applied to rabbits.  If applied to rabbits, then Umbros would not be a viable modifier that darkening my tort bunnies.  Then what is the modifier that accounts for the orangey wool and grayish wool on the tort bunnies? I don't know.   There are many modifiers out there that we don't understand.   We'll conclude by saying "those darn mysterious modifiers"!

Carol's Office Assistants: Boo and Dallas

Carol is still working at SRI, some days she works at her office, some days remote.  On the days when she works at home, she has two assistants. 

Dallas and Boo. 

The two assistant s take breaks frequently. 

With such cute faces, no one could question their work ethics. 

Vianna Longing for a Show

Vianna has been successful in shows.  She is getting restless, there has not been any shows for over 6 weeks.

Vianna says that she's ready.  Good news, she'll get a chance to go to King City in a few days.

Vianna promises that she's a good girl, will behave well at the show.

Frosty American Fuzzy Lop

Carol and Nate held the COD Frosty American Fuzzy Lop.  They were so successful in presentation that every single vote was a big YES.  Instead of the regular 3 showings, they got an exemplary pass after 2 showings.    Frosty AFL will be eligible to compete on December 1, 2024.   Look at this frosty buck's big head!

Profile of the handsome frosty AFL.

 

How about some Frosty French Angora?  Frosty boy will love to have a French Angora girl friend.
Mama Carol says NO!  You two can admire either other from afar.

 

Jasabeau and Princess Ga Ga's Beautiful Family

Handsome boy Jasabeau meets beautiful girl ...

 

...Princess Ga Ga and they have a love match.   A beautiful family is formed...

Aurelia is the only daughter of the four kids.

Alexander is the big brother.

Anchor is the middle brother.

Arlo is the little brother.

If anyone wonders why none of the kids is white, the obvious genetic reason is the Jasabeau does not carry the white gene, he is a CC while Priness Ga Ga is cc.  Since the ruby eye white (REW) gene c is recessive to the colored gene C, all four kids have the appearance of colored but all four carry the REW gene c.  They are all Cc, that means in the next generation they can produce REW offspring if the mate carries REW gene c.

Princess Ga Ga Regrowing Her Coat

Princess Ga Ga had her litter of 4 in late March and raised all 4, Aurelia whose photos were on blog a few days ago is her daughter.    Some said English Angoras do not grow second or subsequent coats.  Here is Princess Ga Ga with her second coat.   Still a bit more guard hairs than desired but the rest are growing well.  She even won a BOB over Vianna in one of the five shows at San Jose.