Mammals, well that could incite a complete thread hijack...
All I will say here is that I was the first person to DNA colour test a DNA profiled (parentage proven sire, dam, and full brother) Australian Cattle Dog. Terribly long but interesting story (for me), told shorter; the quicker and slick method...
<<Apologies on some of the photo qualities...yeh, some pics are 14 years young...some are photos scanned too.>>
Red from Blues; HyBlade on left, full brother Dusty on right
March 2000; Two Blues (Blue, Black and Tan-homo for agouti a"t" or black-and-tan allele) ACDogs produced two Red pups (both male) and seven Blue pups. Impossible in the (agouti) A-series since "red" (commonly a"y" - sable or fawn sometimes with black hair tips) is dominant to blue (a"t"). How can two recessive Blues throw two dominant Reds was the puzzler? DNA profiled, so here we now could say, NOT a mismating...very important when we are dissecting a puzzle that could simply be...this roo and this hen never produced these chicks--easy to dismiss.
In 2000, I took on one of the red pups, HyBlade. In 2001, I sent in a cheek swab (very CSI!) for DNA testing and results were that HyBlade was B/B and e/e. Labrador Retrievers that are e/e are "golden" labs.
What I figured out is that HyBlade was a Blue, Black and Tan ACD that could NOT express black (eumelanin) pigments completely...so basically he was White (the blue dog colour in this case was a mix of black and white hairs), NO Black, and Tan. A Blue, Black, and Tan ACD in his pyjamas; HyBlade was TAN AND WHTE.
Makins on left, HB on right
All the tan points you saw in a Blue, Black and Tan ACDs were there on HyBlade (eye brows, cheeks/muzzle, throat, diamonds on the chest, feet on up legs, and belly) and they were just a smidgen darker than the rest of his coat colours. Basically the term TAN or RED being phaeomelanin pigments made the most sense to me...no eumelanin was allowed but we did see BLACK hair tips. The black hair tips were puzzling as it was like the melanocytes did not switch fast enough from eumelanin to phaeomleanin...a lag time that produced black tips on the red hairs. Usually e/e dogs had no black on them...they were red/yellow.
Keep in mind, that black pigments are produced faster than red pigments...I like to remember which pigment is made the quickest by looking at the feathers in the Mille de Fleur variety: tip of the feather goes from NO pigment (white)--->eumelanin (black)--->phaeomelanin (red). So when told that after no pigment to express the pigments...makes perfect sense to see a white spangle, then black then slower pigment red on MDF feathers.
MDF Booted Bantam Vulture hocks
HyBlade was whelped with a JET BLACK nose that faded as he grew up. Called a "snow nose" and common in Siberian Huskies.
HyBlade's nose would darken up in summer and pale out in winter.
Like the warmer temperatures made his pigments darken. We see expression of this phenomena completely backwards in Siamese c@ts ...the extremities which are furthest from the body core (tail, feet, face, etc.) would be the "coldest" and are the darkest.
HyBlade had a right eye ring on his face (dark red eyelashes on the ringed eye and lighter eyelashes on the non-ringed eye) and he also had some black pigment inside his mouth along the gum line and one toe nail remained black striped his entire life. I was told some rather interesting causes for his "snow nose." Plastic dishes would make his nose brown (he drank and ate out of stainless steel) and other outlandish things like I must feed him sea weed/Dulse (Palmaria palmata) to darken his snoot...in the ACD standard, no matter WHAT colour the dog, the nose was to be black. His was NOT...
HyBlade and one of my females Makins (Blue, Black and Tan) were the stars of my genetic canine colour seminars and the three of us taught over 450 Biology 30 high school students. Much to our delights, not a single student failed their biology exams after attending one of our presentations...dogs in school helped make genetic study REAL and memorable! It brought to light how the differences in one gene can make such a huge stark visual image. Makins and HyBlade are both homo for a"t" but HB is e/e and Makins is not.
Odd man out...HB is the only not black nose in my herd of five...even the two crossbred ACD rescues have BLACK noses!
I showed HyBlade in confirmation and he easily earned his Championship title in just two weekends of showing...12 points, 6 majors under six different sanctioned judges. Gorgeous boy, just a little strange coloured for a red ACD.
This is Fixins, Makins' daughter. She is a Red Speckled Australian Cattle Dog.
I showed and titled HyBlade because I had been told by people (even a biologist of all things) that I need to KILL him...yes, that "snow nose" of his was incorrect and he should die for that. Hilarious! On all 450+ surveys from the Biology students, I asked the question if HyBlade's "not black" nose was a concern to them...not one student EVER replied the "not black" nose was a problem to them.
So before I get my fingees smacked hard for having answered some of the question on how this relates to mammals...I will now revert back to the topic of black pigments and how this relates to chooks.
Things of interest to the black chickeners...HyBlade was MALE (was he lighter because of his gender like is seen in male chooks?), his pigment FADED over time and fluctuated with seasonal temperatures, and he was DNA proven e/e.
If I may pass on only one thing to people in pursuit of colour perfection...no good animal is EVER a bad colour.
Since we in poultry may have any breed (shape) in any variety (colour pattern), while I understand the drive to get the blackest of blacks...but please never become so wrapped up in your obsession where things like temperament, longevity, disease resistance, fertility, vigour and production take a complete back seat to phenotype (looks; shape and colour). There is way more to a GOOD Ayam Cermani or Silkie than just how black they be!
No good chicken is a bad colour...I GET your journey to get black black chickens...a worthy endeavour, but balance your expectations and enjoy the ride getting there too. Have FUN!!!!!!!!!!!!!!!!!
Doggone & Chicken UP!
Tara Lee Higgins
Higgins Rat Ranch Conservation Farm, Alberta, Canada
