Below is an updated version of this page from my original website.

ch, chch Theory:As in c(h) or c(h)c(h) = gx

There has been many discussions that ch or chch are involved. I have known for a very long time, This just wasn’t the case. It was one of the first things I tried checking for. Many of the Satins were CC. Many of the Slates that carried gx were Cc(chm) due to one parent being a Cp Slate or a Burmese. I have some Cch Slates with gx due to the same reason.In otherwords I had placed those colorpoint genes there due to test breeding. Some Satins also have c(chm) & ch for the same reason. The colorpoints seem to make little difference.

I am currently working on and planning pure lines of Agouti and Blacks. This is done to see if the gx alone has any effect on the coat color without interference of other recessive genes.

It seems to me it is a  simple recessive gene, not a Semi-Dominant or Dominant one. It also seems to be similar acting to several recessives genes like c(h), e, e(f) and of course p. Somewhat similar to dd as it has the ability to bleach the coat and eye color. One g(x) genewill dilute a Slate leaving a darker tail and often facial points and / or mask. Although the feet seem to remain light.  I have noticed this “point” effect in specimens of blue gerbils.

The Satins and Whites (some) seem to have an ever so slight darkness in their tails.

Note:

Young Satins and Doves can be easily confused to the inexperienced eye. Especially if the Dove carries the e gene. So can Siamese. The Siamese tend to have a darker eye slit

More Thoughts…

Recently I began to ponder if the positioning of g(x) on the allele would make a difference in shading.

This could also explain why the Satins come in darker or lighter shades.

Given any gerbil with homozygous genes, the offspring will be guaranteed to have one of the genes.

I have toyed with the same idea with c(chm)c(h) gerbils.  Keep in mind everything at this time is based on theory. As far out as it may seem at times, It is only speculation. My expertise does have it’s limitations.

With a Slate x Satin pairing, you have gg, g(x)g(x), resulting in the offspring probablities being g(x)g or gg(x). One way being near normal and the other resulting in a much lighter shade.  They would produce Slates Dilute (Azure Slate) , but no Satins unless the Slate has g(x).  I suppose you could go as far as saying it’s possible it’s (x)g. g(x) makes a notable difference most Slates.

I have since then learned from Ed that polygenes may play a good part in the above statement. Polygenes coupled with other hidden recessives can account for much of the shade variability that I have seen in my breeding.  Although I feel another variant of this gene may be involved, I do not have enough data to prove it at this time. Future plans will be made to test this.

Ed’s input at the time we first began going over this gene together.

Input is from Ed Cope of e-gerbil when we first started corresponding.

Re: Thoughts on this gene…
« Message sent on Nov 18, 2007, 3:13am »

Hi,

Sorry for the late reply but I’ve been snowed under with work at the moment!

I saw the pics in the photobucket, and I’m sure there is something going on with the coat colour, but from the gerbils in your photobucket they all look like examples of how it dilutes aa types. I can see how they are diluting the black pigments, but have you got any examples of what it does with an agouti background? I would expect even if it only reduces the black pigments, that you would see some minor dilution to the ticking on A* types too, and also slight dilution to the black pigment in the eye, have you seen any of this occurring? Are the ones you call “satins” a dilution of dove or lilac? Do they have solid bellies?

The other thing I found confusing was in your forum post where you suggested the mystery allele maybe on the Grey locus, and the Grey locus itself reduces Yellow pigments, and only slightly dilutes the black pigments to slate by minor clumping of the pigment granules themselves. So I would expect that a further mutation on this locus to have a similar effect. For example if you take the C locus, then look at which protein that it effects, you will see that all the variant alleles do something similar to the protein. With C locus, the protein is tyrosinase. It is mutations here that cause disorders in pigment synthesis on the chinchilla gene (C locus) which leads to either semi -functional or non-functiona tyrosinase enzyme. Although not present in gerbils, cc animals are pure white because the gene completely knocks out tyrosinase. In gerbils we have c(h) and c(chm) which again are on the same locus as C , so it affects tyrosinase, this time making it temperature sensitive, so increased temps make it only semi-functional. You can see by the fact that it reduces pigments on the body, but not on the points. So by this, I would imagine that anything on the Gene locus will act in a similar way to gg, ie reduces yellow pigments, but I can’t see this in your gerbils, as it looks from the examples that the yellow pigments remain largely unaffected. You can see this on other animals too, say for example Grey fading in the horse, which produces a grey animal, which fades with age (A similar effect to schimmel but this time on the G locus)

As to a guess which coat colour (gene) candidate this could be, I would strongly suggest that you look into dilution genes.  Not dilute (d) or variants, that’s entirely down the wrong path I think, but the type of dilution that causers albinism (coat and eyes) such as C and P mutations.  These are many, but below i’ll set out a guide that should help narrow down candidates.  The big problem though is that you not only need a colour match for your mutation, but a corresponding colour match to our Grey Agouti and Slate (If as you suggest, your mutation is an allele of the Grey locus!)  This effectively means we need to properly identify an entire locus as it isn’t the G locus.

Genes I would explore as candidates would be as follows:

OCA mutations such as Tyr,P , Tyrp 1, MATP.  All these mutations dilute coat and eyes.  Here I would look more closely at genes such as Brown (b) underwhite (uw) Oa1 (oa1)

Hermansky- Pudlack syndromes (1 to8) such as HPS1, APB31 , HPS3, HPS4. All these mutations dilute coat and eyes.  Candidates here could be pearl (pe), Mocha(mh) reduced pigmentation(rp) Sandy (sdy) Cappucino (cno) pale ear (ep) cocoa (coa) light ear (le) ruby eye 1 & 2 (ru)

Chediak-Higashi syndrome-  These also dilute coat and eyes. Candidates here are beige (bg)

Of course there are other possible, but you should exhaust these avenues i’m suggesting before exploring others.

Thanks for taking time out to email me it’s much appreciated , and if I can help in any way, don’t hesitate to drop me a line.

Kind regards,

Ed

Why I don’t believe this is dd.

Wow that would be so awesome if it were dd. But I really never thought it was although many suggested this.  I believe the Blue’s nails are dark mine are not. I would think with the many genetically planned pairings I did, for example a Satin and a normal Cp Slate I should have gotten Blacks. I received more Slates. It’s as simple as that.
Nowhere can I find in the Blue’s history any records of “Satin” gerbils showing up.  When I first started learning gerbils and genetics, I came across an article (I can’t seem to find it again) It stated that dd came from a pair of Blacks out Osnabrueck University. Later I found the same information that dd was similiar to a gene developed at the Osnabrueck University out of a pair of Grey Agouti’s. I have tried contacting the University to no avail, no answer. There’s seems to be much history of the origins of the Blues and the gene from the University missing or I just cannot find it. A bit confusing given my gene came out Black gerbils

I have since located this report again on the Gerbil information page!

http://www.gerbil.info/html/dilute.htm

More detailed genetics info on the dilute mutation can be found at the genetics section of the eGerbil website.

http://www.egerbil.com/dilution.html

How does it feel to discover something new?

That really is a loaded question. I think I went through all the emotions and then some. For much and most of the time I have been working on this gene , I have had little to no real help with it. So frustration was probably the biggest thing I felt during these periods.  There were times I just wanted to throw in the towel. Defeat, the times I just gave-up.  The thrill of being the first with a mutation. Tears, when problems struck the kennel.  The pull to continue even though I could only locate the gene , and not actually figure out the cause.  Finally,  exhilaration ,after 8 years knowing now what the  gene  actually is.

My recommendations to all breeders

One thing I have learned is to never never give up on your dreams. Firstly, learn gerbil genetics. There is so much more information out there now than when I had first begun breeding gerbils. Secondly, learn something about Mouse genetics if you can; you might come across an unusual colour never before seen in gerbils, but you can bet it likely that the colour has appeared in mice!  Thirdly, always document your findings, and whenever possible, take the best photos you can.  Lastly, always make sure you have fun and enjoy your Gerbils.