[Jacob-list] Chocolate Lilacs--Purity?

[ranchrat at telusplanet.net]

Heel low Neal and list:

Quoting Neal and Louise Grose <nlgrose at yadtel.net>:

> When we cross our lilac Jacob sheep to homozygous white longwool sheep, we
> get piebald black and white lambs. I have done enough test crossing that I
> am reasonably sure that the black is the dominant Jacob black.

We are fortunate to have people here willing to do breedings to help answer 
our "why's" and "what's."  Thank you for sharing!
 
> I have never seen a crossbred lilac sheep. In my experience, the sheep has
> to be at least 3/4 Jacob in order for lilac to be expressed at all.
> 
> This is going to be a little uncomfortable to say, but "lilac" expression
> is "proof" that the animal is "purebred Jacob".

Cool!  I can only say that your "uncomfortableness" really does help put MY 
mind at ease.  :-/

Yet another PLUS I figure for the lilacs if this color helps to prove a measure 
of pureness.
 
> If the question is: "How does the gene cause the expression of  lilac?"
> Then I haven't a clue. We're working on it.

No way!  I already know better than to ask just yet for the explanation on what 
makes the lilac Jacob LILAC!  I do however hear that common theory is that 
lilac is inherited similar to the "dun" color in cattle.  What gene series the 
lilac comes from...well that is anyone's guess just yet.

To keep this all straight in my mind, I figure so far that lilac is basically a 
simple recessive (l for lilac gene, B for dominant BLACK; homozygous "l" (ll) 
gives pheno & geno lilac, "Bl" gives pheno black and geno lilac factor and "BB" 
is dominant black pheno/geno).  I am able to think in this manner only because 
by breeding and watching the color of the resulting progeny (F1 and following 
generations), this SEEMS to be what is happening.  What exactly IS happening 
genetically in regards to which series is responsible, I am not sure about but 
so far we are able to predict the outcomes reasonably well...llxll=100% ll, 
DDxll=100% Dl, Dl's will throw the occassional lilac when matched to similars 
or with ll's.  To me this IS something we are able to use and didn't Mendel 
started out with cross breeding plants and trying to predict the outcomes...I 
suppose we have the lilac question half beat knowing what percentiles to expect 
out of our matchings--get those Punnett squares out peoples!

We had a color geneticist do a re-write on their website because "us" breeders 
were producing conflicting results to their theories in regards to the affects 
of homozygous "e" and the fact that we were DNA parentage proving we could 
produce rare pheno reds from geno/pheno blues (a"t").  The findings in the Labs 
have to stand up in our whelping and lambings to be true proven genetic 
research!

Where the fading lilacs come from (maybe incomplete dominance or modification 
from another series or +/- factors, or roaning?), or the fact that some lilacs 
have black extremities (legs, facial markings--maybe like the Collie markings 
where a set of colored portions-head, tail, legs- is packaged up and inherited 
separately than what the body coloration will be--this is how one gets a rare 
red headed blue ACDog or blue headed red ACDog) is out of my league of 
expertise and maybe no one has done any scientific study to any degree yet.  I 
do know that the lilac may have an affect upon the whole body (similar to 
homozygous "e"-- plueotropic???...ah heck...at the moment I forget the proper 
genetic term--sigh!) with the horns being "greyish" and the iris color not 
quite amber, not marble or blue, but greyish also.

With the completion just last month of the human genome mapping...now maybe all 
those great minds will be freed up to go work on more DNA testing for the 
public.  You will hear my shout for joy all the way up here when they announce 
there is a test for mutations in the agouti series.  I've had my canines marker 
tested for the b and e color mutations and do an annual presentation for the 
local grade 12 Biology classes based on these findings.  I am already hinting 
at the prof that I just might do my next seminar with Jacob Sheep as the lab 
specimens instead of my Australian Cattle Dogs.  A lilac and a lilac factor 
oughta sparkle some eyes and bring home the real meaning of genentics.  Color 
genetics rock as we get to see our results in true living color!  We might not 
yet understand the entire genetics of our lilacs...but we sure have alot of 
breeder information on how to produce the lilac on the farm.

Speaking about testing, has anyone DNA tested the Jacob to prove that it is NOT 
a cross developed historically from a goat and a sheep as some rumour to have 
occurred?  This theory has some merit in the phenotype of the Jacob, that there 
have been goat/sheep crosses that have lived and shepherds of old kept both 
together.  I would like to be able to reply back to those who inquire about 
this that a DNA test HAS been done saying that the Jacob Sheep is descended 
from the Mouflon and is not a hybrid goat/sheep.

Doggone,

Tara
--
     ____(\                Tara Lee Higgins                  /)____
    (_____~>        Rat Ranch - An ACD is for LIFE          <~_____)
   ( ``  ``          ranchrat at telusplanet.net                ``  `` )
    \                       Alberta Canada                         /
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