Learning to understand coat colour outcomes in Afghan Hounds.

          We will never fully understand the basics of coat colour genetics.  It is equally correct that one can, by empirical knowledge, and an understanding of Mendelian principles, elucidate the modes of inheritance of base colours, in most canine breeds.  These predictors are remarkably reliable in most litters.  The challenge is to understand how multiple genes interact, and how some genes act as inhibitors in some circumstances, and extenders or reduction genes in others.  This crucible of variables is responsible for the diverse range of colours, tints and tones within this breed, and thus presents an interesting challenge: to try to unravel these complex inter-relationships.
             The last decade has seen the canine genome unfold, largely in North American Academic Institutions, with considerable developments in re-examination of Clarence Little's monumental work of genetic allocations of the early '50s.  Little's work provided an alphabetic structure, where he attributed specific colours and their states, being epistatic (dominant), hypostatic (recessive) or incomplete.  Many of these allocations have subsequently been altered.  In this programme, I have maintained the standard conventions, e.g. epistatic, homozygous genes commence with upper case letters, recessives, heterozygous or hypotstatis, lower case, and have adopted alphabetic symbols, of the renamed genes.  In the case of currently unallocated genes like domino and several black overlay factors, I have provided alphabetic codes.
              The main differences with this approach, which I acknowledge as not unique (as many other colour breeders and enthusiasts of this subject have made similar observations) is that I am presenting these ideas in a graphic format.  Personally, I have not prioritised colour when breeding, structural soundness and disposition is far more important.  This colour exercise is an academic project.

             Attributes are as follows:

                    1 : The Base Colour, "ay"
              2 : Overlays
                3 : Modifiers
                4 : Spotting genes

             The  "ay" gene is the base colour gene of naturally evolving sighthounds.  "ay" is Little's designated colour for yellow, be it ochre, sand, or gold (modifiers determine the final colour).  Other colours are the result of the three other variables.
            1 : Overlays: fall into three categories, black, brindle, and black and tan.  I have also included the black spotting overlays in this section. e.g. black mask, black ear fringes, brow and tail etc.
            2 : Modifiers: these genes modify the base colour and overlays, by extension, or more commonly, reduction of pigment.   Most modifiers are recessives (heterozygous genes) and need to be provided by both parents to manifest phenotypically, or physically.  Where only one parent is a carrier, some genetic modifiers may provide tell tale indicators of their presence.
            3 : Spotting genes: White spots are the more complex and amorphous colour phenotypic manifestations in nature.  Fortunately the Afghan Hound is blessed with solid colours, with the exception of the white bib or chest spots, and the tip hairs on the tail.  All other facial or neck spots are considered not desirable.  The Afghan Hound breed standard notes all colours to be acceptable, and white spots are normally not defined as a colour gene.             Extreme dilution to pure white is not to be confused with white spotting.  Little's work on white spotting genes is of contemporary relevance.

            The first graphic provides definitions.   As you scroll over different genes, definitions of how they may manifest will present, and likewise, be removed as you move off a particular gene button. If you wish to use that gene in the lower display, left click upon it. if you wish to remove the gene, double left click.
           There is both a Sire and Dam's profile.  Combinations of genes, if selected, will present in a gene profile panel on the bottom section of the graphic, facilitating printing.  I have included a section of black point overlays.  These are particularly relevant to the Afghan Hound because the black mask, ear fringes and tail etc. accentuate the classic image of this breed's remarkable coat type and pattern. 
            This breed possesses unique permutations, as it has a short, close saddle, accompanied by long fine, or silky feathering (undercoat).  This feature generates the numerous and fascinating phenotypic manifestations of the breed: of tints and tones not observed in other canid breeds. It is also possible the undercoat which mutated some time past, to long continuous growing hair may infact manifest genetically differently from other sighthounds, as students will attest, the long flowing coat provides a range of coat characteristics not seen in other breeds.
             There are nine main currently known genes which impact upon Afghan colour, these are allocated to being
either Heterozygous - Homozygous by the colour coded panel in which they reside. There are also three surround rings on several genes, this indicates only one of these two can be allocated to offspring.
             You will find gene switching as you select different overlay genes, the colour swatches make this easier to observe.
             Read the text for each gene then try to apply it to actual litters. Build colour profiles of individual canines,
check and see if they abide by your calculations when mated..
             Coat colour genetics is a fascinating pass time. See if you can decipher other breeds and where they fit in the scheme of the different colours, first you will have to get a handle on the nine basic genes.

This Australian dog has a slightly different coat type where the feathering is equally impacted by the underlying coat colour, look and one can imagine a certain common overlay pattern, similar to a beagle saddle pattern.

This head study shows the mask is not the classic white ghost mask. This is the result of carrying "Ee" instead of the normal "ee"
If she had "EE" this would have produced a remarkable red sable domino, the "EE" would further extended the pigment.

The sire, a tee bar black and cream dog of the litter shown below to the above Domino Afghan bitch, also carries "Ee" This allows
for an unusual array of colour.

This image shows six of the more common seven black points which present in the Afghan Hound. 1: Black mask 2: Black Brow 3: Black Ear Fringes 4: Black Tail 5: Feet and Chest,  6: Black Saddle. 7: B/T sable overlay.