Ebony Phenotype vs. Genotype

[poetrue]

So I think MOST chin breeders can agree that the ebony phenotype is not based on one simple dominant/recessive gene. My question to you all is how many genes do we think "ebony" consists of?

I believe that the ebony phenotype is a quantitative trait and polygenic, similar to skin color. I think in addition to that we have multiple types of what we commonly refer to as "ebony" in the US. Such as charcoal (recessive) and mahogany. Ebony seems to me to be a Does anyone know how many different types of "ebony" gene popped up in different areas of the world?

Cheryl

 

[Spoof]

I think in addition to that we have multiple types of what we commonly refer to as "ebony" in the US. Such as charcoal (recessive) and mahogany.

Even within the simple dominant ebony here I believe there are various mutations.

Does anyone know how many different types of "ebony" gene popped up in different areas of the world?

I don't know about the world but I read about four separate (almost simultaneous) occurrences on ranches in the old Empress magazines.

 

[poetrue]

I don't know about the world but I read about four separate (almost simultaneous) occurrences on ranches in the old Empress magazines.

Does it say in the magazine what they called each of the 4 occurences that popped up?

Cheryl

 

[mishalaa]

The Alice Kline book names 7 ebony mutations. They are Tasco (dominant), Busse (dominant), French Blue (dominant), Lester black (or Midwest City black, recessive), Sakrison (recessive), Treadwell (recessive), and charcoal (recessive).

However, this information is old. Mahogany is not even mentioned, though may be just a later name for Sakrison or an off-color charcoal.

I think this is what Spoof was referring to, pg 145-146 "The recessive charcoal mutation appeared almost simultaneously in several places in the United States in the 1956, '57, and '58 era. Some ranches of origin were those of Betty Broucke, Wes Olsen, Ramon Somavia, and W. Pohl in California, and also in the herd of Tom Ready in Bowling Green, Ohio." It goes on to say "They were all similar genetically, but each ranch produced them with just a little difference in their characteristics. Some charcoals had outstanding density; some had lovely texture. There were two main variants – a dark brown gray and a lighter brown."

 

[Spoof]

That's it Mish! Thanks, those magazines were at the WSU library and I haven't seen them in ages.

There was another article in a later mag that talked about one of the breeders working with the mutation. They had gotten up to a couple dozen and had all but two killed by dogs I think. They had written the article right afterwards. I always wondered what happened to the animals.

I also recall during that time that they had a male pool you could rent males from to diversify bloodlines. I'd be curious to know if any of them participated in that.

One of those males was an ebony that everyone - and I mean everyone - grabbed to use to make the veiling better. Every old Canadian breeder I talked to had used that lineage and were still having throwback "dirty bellies" 30-40 years later. They always culled them. I asked two of them to save me one if they got it, but they both sold out before they had any more. It would have been very interesting to work with.

I think mahogany is a different critter all together. Haven't seen one in six years, but the ones I did see would only show up if the chin was pure black. It was almost like it was tied to the chin being one uniform color. Parents would be normal tans or non-pure black ebonies. I would absolutely love to play with that mutation.

 

[poetrue]

The Alice Kline book names 7 ebony mutations. They are Tasco (dominant), Busse (dominant), French Blue (dominant), Lester black (or Midwest City black, recessive), Sakrison (recessive), Treadwell (recessive), and charcoal (recessive).
QUOTE]

And to think everyone in the US simply refers to them as ebony chins! I knew there were a few different genetics that made up the US "Ebony" but didn't realize there were that many different mutations that had popped up! I have been working with the ebony genes for quite awhile now and I definitely think that there is a lot going on in my chins. I know I have worked with chins that definitely had Charcoal recessive genes in their background. I also have a chin that has thrown kits very much like a simple dominant recessive. He is pure black, mated to all pure standards, and every single litter he throws always has one standard and one pure black ebony chin.

I think mahogany is a different critter all together. Haven't seen one in six years, but the ones I did see would only show up if the chin was pure black. It was almost like it was tied to the chin being one uniform color. Parents would be normal tans or non-pure black ebonies. I would absolutely love to play with that mutation.

I'm pretty sure that I've had a few "Mahogany" chins born here. The first time it happened I was a bit surprised and started asking the older ranchers/breeders if they had ever seen a kit with the unique color that I had. Based off my description and the photos I said I got told by a few individuals that the kit looked like a Mahogany. Since then I've had quite a few kits with similar phenotypes born here. In fact I ended up showing a few and the last one had 2 different judges comment that she seemed to be expressing Mahogany instead of just ebony. I have her younger brother growing out for show now and he looks just like her. It will be interesting to see if he gets the same comments on the show table as she did!

Cheryl

 

[SRSimpson]

Just a question, I have a background in genetics but not so much chin breeding, but I have read a lot on it. So could ebony genes possibly contain a genetic switch? I have heard that it can skip generations or chins can be ebony carriers and then when mated to a standard produce a light ebony. So if this is true, it's possible that the gene is turned off or not expressed then reactivated when the chromosomes divide in meiosis.

Or could it be an incomplete dominance or two genes? Where one is required for the other to be expressed? Such as having an ebony gene and then another gene which is needed for the ebony to show? Such as a promoter sequence to amplify the amount of the gene which is transcribed making more proteins. Since ebonies range in color so much, from light to extra dark. Yet all have the 'wrap', or no white belly. So maybe there is a gene or multiple genes for the wrap element, and then another set of genes which dictate the depth/darkness of color.

These are just thoughts.

 

[Amphy64]

Interesting stuff, ebony seems such a complex mutation to work with. Etherdale Chinchillas page describes the varieties (probably from the Alice Kline book?), along with a bit of speculating:

http://www.edchinchillas.co.uk/

Interesting that the French Blue and Lester Black are said to have a curliness/waviness of fur. So, would the particular strain of ebony in the Locken perhaps be one of these two, or a mix of both?

 

[Chin_Pig]

Has anyone done any genetic marker testing (which would be expensive...) or ideas on which line seem to produce extra dark, dark, medium or light? I'm curious because I have a male that is a med. ebony and I have bred him to a med eb. female and got an eb carrier, bred him to a beige female and got a std. eb carrier and then a std female (light or med phase not sure) and she gave me a med and light eb baby I think.... anyway I have read before that people know what lines of ebonies consistently produce different phases of eb. I understand that there are 7ish types of the charcoal gene possibly involved, but I would like to wrap my head around this a little better.

Thanks!

 

[Spoof]

or ideas on which line seem to produce extra dark, dark, medium or light?

I've found that ebony is a fairly accumulative gene - eg, if you bred him to another medium or a dark, kept one of the darker kits(G1) and bred that kit to a medium or a dark and kept a dark (G2) kit you would have a much higher chance of getting dark babies out of (G2) and any non-ebony female. Breeding G2 to a light ebony would likely almost always result in dark ebonies.

Part of the light/med/dark issue is in how people see their animals. I judge by the darkness of the belly, not by the top of the animal. You can show an ebony out of Shoots lines and it can get tossed into the extra dark ebony class because it is so black on top, yet it will have a light belly and not be capable of throwing those dark ebonies, just the dark veiling.

Food for thought. )

 

[threewingedfury]

You can show an ebony out of Shoots lines and it can get tossed into the extra dark ebony class because it is so black on top, yet it will have a light belly and not be capable of throwing those dark ebonies, just the dark veiling.

I've had no issue with getting dark / extra dark ebonies out of 1st or 2nd generation and I pair extra dark eb to dark standards. I get a crap shoot, from medium to extra dark. My darkest eb I've produced was out of a dark standard with crisp belly and an extra dark eb. I've taken my first generation offspring from the standard / eb pairs and paired them together (mostly medium eb paired to dark eb) and I tend to get lighter results.. mostly medium. I've then paired those to a dark standard, and I've gotten extra dark. Crazy how eb genes work.

 

[Chin_Pig]

so here is my ebony female, i was told she is a medium (ebony gene from doug wilson)


this is her belly (not been groomed in a while)


these two have me an eb carrier with as the judges put it "a nice clean belly" she looks like a light phase as well.

This is my male who i was told is med. eb also. (not been groomed) {ebony gene from strk but further back either 5R9 or RNJR}


his belly


Belly of darker baby and lighter baby from Std. (light maybe med. phase) mom and med. Eb. dad


i can add a picture of std mom too but phone is almost dead and i will have to send the picture to my computer.