Schnauzer Color Genetics
By Cathy Tarlton, updated 03-22-2001
Before we get into the particulars of color inheritance, a brief overview of the terms geneticists use to describe colors in dogs is in order. As well as an overview of all color genes present in Miniature Schnauzers.
This discussion for the most part, [other than the overview] will be confined to White Mini Schnauzers.
Each series of genes involved in creating different aspects of creating the coat color we see, is represented by a letter of the alphabet. Each series is called a locus. Each gene within a series is called an allele. Every dog carries two (2) alleles at each locus.
Series
The A Series--A stands for AREAS of dark pigment. Sometimes referred to as "pattern" genes. As=solid (in our breed, generally black**, sometimes brown); Aw=Agouti, or "wild color"commonly referred to in this breed as S/P; FOR A DESCRIPTION OF natural "Wild color" (from which the term was derived,) CLICK HERE. ay = red-sable and At=tan-points, expressed as black/silver
The B Series--B=Black; b=brown
The C Series--This series is one of the two factors that are involved in producing the white miniature schnauzer. They will be discussed in detail below.
The E Series--This is the second of the two series involved in creating the white miniature schnauzer. It will also be discussed in great detail below. Other e series members (generally considered to belong to this string) but not noted in this breed are Em (masking gene -- as in fawn pugs) and Ebr (brindle -- as in Bouviers, Bullmastiffs, etc.) However, these may indeed be at the "new" K series.
The G Series--G=Progressive fading from birth; g=coat remains at full color strenth for the life of the animal.
The K Series -- A NEW THEORY see LINKS at the bottom of this page for Sue Bowling's article
The S Series--S stands for Spotting. All dogs not parti-color carry S the highest allele. The other alleles are, in order, si=Irish spotting; sp=parti color spotting; swh=extreme white piebald.
The T series--T is for Ticking. T=ticked; t=non-ticked.
****
How the Series are expressed in a full genetic formula for a dog
The typical, homozygous salt and pepper mini carrying no recessives for white, brown, or parti-color would be as follows:
aw aw B B cch ce E E G g S S t t
The C and the E series and how they create the white miniature schnauzer
We are going to start with the E series as it is easier to understand and lays the basis for forming the white miniature schnauzer.
E stands for Extension of dark pigment. E is the dominant allele; present in all miniature schnauzers not white, cream, red (more on this later in C series.) E is carried by all Salt/Peppers, Black/Silvers, Blacks, partis, & browns. If a "colored" mini is carrying white factors, he is Ee at that locus. If he meets in breeding another Ee, the two will produce whites. The e is recessive. The double ee recessive restricts the dark pigment to eyes, nose, & pads. What color is left when the dark pigment is restricted to those areas? That is determined by the C series.
C is Color Strength determiners. The most important thing to remember about the C series is that IT HAS NO EFFECT ON BLACK ("dark"--black or brown) pigmentation. It ONLY affects what geneticists refer to as "blonde" pigment. (for our purposes in this discusson-- the light areas on S/P and B/S; (including both the 'furnishings' as well as the
Before we get into the particulars of color inheritance, a brief overview of the terms geneticists use to describe colors in dogs is in order. As well as an overview of all color genes present in Miniature Schnauzers.
This discussion for the most part, [other than the overview] will be confined to White Mini Schnauzers.
Each series of genes involved in creating different aspects of creating the coat color we see, is represented by a letter of the alphabet. Each series is called a locus. Each gene within a series is called an allele. Every dog carries two (2) alleles at each locus.
Series
The A Series--A stands for AREAS of dark pigment. Sometimes referred to as "pattern" genes. As=solid (in our breed, generally black**, sometimes brown); Aw=Agouti, or "wild color"commonly referred to in this breed as S/P; FOR A DESCRIPTION OF natural "Wild color" (from which the term was derived,) CLICK HERE. ay = red-sable and At=tan-points, expressed as black/silver
The B Series--B=Black; b=brown
The C Series--This series is one of the two factors that are involved in producing the white miniature schnauzer. They will be discussed in detail below.
The E Series--This is the second of the two series involved in creating the white miniature schnauzer. It will also be discussed in great detail below. Other e series members (generally considered to belong to this string) but not noted in this breed are Em (masking gene -- as in fawn pugs) and Ebr (brindle -- as in Bouviers, Bullmastiffs, etc.) However, these may indeed be at the "new" K series.
The G Series--G=Progressive fading from birth; g=coat remains at full color strenth for the life of the animal.
The K Series -- A NEW THEORY see LINKS at the bottom of this page for Sue Bowling's article
The S Series--S stands for Spotting. All dogs not parti-color carry S the highest allele. The other alleles are, in order, si=Irish spotting; sp=parti color spotting; swh=extreme white piebald.
The T series--T is for Ticking. T=ticked; t=non-ticked.
****
How the Series are expressed in a full genetic formula for a dog
The typical, homozygous salt and pepper mini carrying no recessives for white, brown, or parti-color would be as follows:
aw aw B B cch ce E E G g S S t t
The C and the E series and how they create the white miniature schnauzer
We are going to start with the E series as it is easier to understand and lays the basis for forming the white miniature schnauzer.
E stands for Extension of dark pigment. E is the dominant allele; present in all miniature schnauzers not white, cream, red (more on this later in C series.) E is carried by all Salt/Peppers, Black/Silvers, Blacks, partis, & browns. If a "colored" mini is carrying white factors, he is Ee at that locus. If he meets in breeding another Ee, the two will produce whites. The e is recessive. The double ee recessive restricts the dark pigment to eyes, nose, & pads. What color is left when the dark pigment is restricted to those areas? That is determined by the C series.
C is Color Strength determiners. The most important thing to remember about the C series is that IT HAS NO EFFECT ON BLACK ("dark"--black or brown) pigmentation. It ONLY affects what geneticists refer to as "blonde" pigment. (for our purposes in this discusson-- the light areas on S/P and B/S; (including both the 'furnishings' as well as the