What is incomplete autosomal dominant inheritance?
In its simplest form, it involves 1 pair of genes with the
wild type/normal gene "a" being recessive to the mutant/dominant gene
"A". Since the mutation is incomplete or not fully dominant, a
combination of the two gene types will result in an intermediate form between
the wild type and mutant forms. If the wild type/natural colour of a bird is
green and the mutant form is dark green, the following will be true:
kk = Green Bird
Kk = Medium Green Bird
KK = Dark Green Bird
In the following example, one gene, we will call it
"K", is responsible for colour. The "K" gene comes in 2
forms: "K" and "k". When the "K" gene is a
capital "K", it is responsible for the dark green colour and
classified as dominant. When the "K" gene is a small "k",
it is responsible for the regular/wild type green colour and is classified as
recessive. The are always 2 copies of the "K" gene in each
individual. If an individual is kk, then it is green/normal/wild type or is a
homozygote (the pair of genes are the same) for the green gene. Green is the
recessive form. If an individual is KK, then it is dark green or in its
dominant form. "KK" is a homozygote for the dark green gene. Most autosomal dominant mutations are
incomplete (as is this one) meaning that the Split / heterzygote have a
different phenotype (or appearance) than both the homozygous dominant form (KK)
and the homozygous recessive for (kk). The phenotype for a Kk individual is a
mix of the dark and regular/light green colours resulting in a medium green
bird. It is still a Split to dark green, but it appears almost as a new
mutation since it is a different colour than the wild type form and full
mutation.
"K" = dark green gene
"k" = green gene
KK = dark green individual
Kk = medium green / split to dark green individual
kk = green individual
(1) Dark Green (KK) X Dark Green (KK) = All Dark Green (KK)
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K |
K |
KK |
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K |
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(2) Green (kk) X Green (kk) = All Green (kk)
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k |
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k |
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(3) Dark Green (KK) X Green (kk) = All Medium Green/Split to Dark Green (Kk)
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K |
K |
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(4) Medium Green/Split to Dark Green (Kk) X Medium
Green/Split to Dark Green (Kk) = 25% Dark Green (KK), 50%Medium Green/Split to
Dark Green (Kk), & 25% Green (kk)
kk
(5) Medium Green/Split to Dark Green (Kk) X Dark Green (KK)
= 50% Dark Green (KK) & 50% Medium Green/Split to Dark Green (Kk)
k
(6) Medium Green Split to Dark Green (Kk) X Green (kk) = 50% Medium Green/Split to Dark Green (Kk) & 50% Green (kk)
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Blue Series in Lineolated Parakeets
Genes Involved
B = Green
b = Blue
Understanding Dominance Factors
DD = Dominant Phenotype - 2 copies leads to the darkest
phenotype (either mauve or olive)
Dd = Incomplete Dominant Phenotype - 1 copy leads to an
intermediate phenotype (either cobalt or dark green)
dd = Wild Type - no copies leads to one of the phenotypes
associated with the "B" gene (either green (Normal bird [BB] or Split
to Blue [Bb]) or Blue [bb])
Mutation Legend
BdBd = Green Bird
BDBd = Dark Green Bird
BDBD = Olive Bird
Bdbd = Split to Blue Bird. It is a regular green bird that
carries one blue gene and no dominance factors.
BDbd = Dark Green Split to Blue Bird. It can also be called
a Dark Green Split to Cobalt bird because it contains 1 dominant factor and
when this bird reproduces, it is capable of contributing a blue gene or a
cobalt gene. However,the resulting colour of the offspring is dependent on the
genotype of the other parent and the genes that it contributes. It is a Dark
Green Bird that carries one blue gene and one dominant gene.
BDbD = Olive Split to Blue Bird. It can also be called an
Olive Split to Mauve bird because it contains 2 dominant factors and when this
bird reproduces, it is capable of contributing a mauve gene. However,the
resulting colour of the offspring is dependent on the genotype of the other
parent and the genes that it contributes. It is an Olive Bird that carries one
blue gene and two dominant genes.
bdbd = Blue Bird
bDbd = Cobalt Bird
bDbD = Mauve Bird
1) Blue (bdbd) x Blue (bdbd) = 100% Blue (bdbd) Offspring
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2) Blue (bdbd) x Cobalt (bDbd) = 50% Blue (bdbd) & 50%
Cobalt (bDbd)
bd bD bd bbdd bbdd
3) Blue (bdbd) x Mauve (bDbD) = 100% Cobalt (bDbd)
bD bD
4) Blue (bdbd) x Green (BdBd) = 100% Split to Blue (Bdbd)
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bd |
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Bbdd |
Bbdd |
Bd |
Bbdd |
Bbdd |
5) Blue (bdbd) x Dark Green (BDBd) = 50% Split to Blue
(Bdbd) & 50% Dark Green Split to Blue (BDbd)
bd Bbdd BbDd BbDd
6) Blue (bdbd) x Olive (BDBD) = 100% Dark Green Split to Blue (BDbd)
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bd |
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BbDd |
BbDd |
7) Blue (bdbd) x Split to Blue (Bdbd) = 50% Blue (bdbd)
& 50% Split to Blue (Bdbd)
Bd Bbdd bbdd
8) Blue (bdbd) x Dark Green Split to Blue (BDbd) = 25% Dark Green Split to Blue (BDbd), 25% Cobalt (bDbd), 25% Split to Blue (Bbbd), & 25% Blue (bdbd)
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Bd |
Bb |
B |
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bbdd |
bbdd |
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9) Blue (bdbd) x Olive Split to Blue (BDbD) = 50% Dark Green
Split to Blue (BDbd) & 50% Cobalt (bDbd)
BbDd BbDd bbDd bbDd
10) Cobalt (bDbd) x Cobalt (bDbd) = 25% Blue (bdbd), 50%
Cobalt (bDbd) & 25% Mauve(bDbD)
bbdd
11) Cobalt (bDbd) x Mauve (bDbD) = 50% Cobalt (bDbd) &
50% Mauve (bDbD)
bd bD bbDd bbDd
12) Cobalt (bDbd) x Green (BdBd) = 50% Dark Green Split to
Blue (BdbD) & 50% Split to Blue (Bbbb)
bD bd Bd BbDd Bbdd Bd BbDd Bbdd
13) Cobalt (bDbd) x Dark Green (BDBd) = 25% Olive Split to
Blue (BDbD), 50% Dark Green Split to Blue (BdbD), & 25% Split to Blue
(Bbbb)
bd BbDd Bbdd BbDD BbD
14) Cobalt (bDbd) x Olive (BDBD) = 50% Olive Split to Blue
(BDbD) & 50% Dark Green Split to Blue (BdbD)
bD bd BbDD BbDd
15) Cobalt (bDbd) x Split to Blue (Bdbd) = 25% Dark Green
(BDbd), 25% Split to Blue (Bdbd), 25% Cobalt (bDbd), & 25% Blue (bdbd)
bd BbDd Bbdd bd bbDd bbdd
16) Cobalt (bDbd) x Dark Green Split to Blue (BDbd) = 12.5%
Olive Split to Blue (BDbD), 25% Dark Green Split to Blue (BDbd OR BdbD), 12.5%
Split to Blue (Bdbd), 12.5% Mauve (bDbD), 25% Cobalt (bDbd), & 12.5% Blue
(bdbd)
BbDd BD BbDD bD bbDD
17) Cobalt (bDbd) x Olive Split to Blue (BDbD) = 25% Olive
Split to Blue (BDbD), 25% Dark Green Split to Blue (BDbd), 25% Mauve (bDbD),
& 25% Cobalt (bDbd)
bD BD bbDD bbDd
18) Mauve (bDbD) x Mauve (bDbD) = 100% Mauve (bDbD)
bD bbDD
19) Mauve (bDbD) x Green (BdBd) = 100% Dark Green Split to
Blue (BDbd)
BbDd BbDd BbDd
20) Mauve (bDbD) x Dark Green (BDBd) = 50% Olive Split to
Blue (BDbD) & 50% Dark Green Split to Blue (BdbD)
21) Mauve (bDbD) x Olive (BDBD) = 100% Olive Split to Blue
(BDbD)
BD BbDD BbDD BD BbDD
22) Mauve (bDbD) x Split to Blue (Bdbd) = 50% Dark Green
(BDbd) & 50% Cobalt (bDbd)
Bd bbDd
23) Mauve (bDbD) x Dark Green Split to Blue (BDbd) = 25%
Olive Split to Blue (BDbD), 25% Mauve (bDbD), 25% Dark Green Split to Blue
(BdbD), & 25% Cobalt (bDbd)
BbDd BbDd bd bbDd bbDD
24) Mauve (bDbD) x Olive Split to Blue (BDbD) = 50% Olive
Split to Blue (BDbD) & 50% Mauve (bDbD)
bD bbDD
25) Split to Blue (Bdbd) x Green (BdBd) = 50% Green (BdBd)
& 50% Split to Blue (Bdbd)
bd Bd BBdd Bbdd Bd BBdd Bbdd
26) Split to Blue (Bdbd) x Dark Green (BDBd) = 25% Green
(BdBd), 25% Dark Green (BDBd), 25% Dark Green Split to Blue (BDbd), & 25%
Split to Blue (Bdbd)
Bd BBdd Bbdd BBDd
27) Split to Blue (Bdbd) x Olive (BDBD) = 50% Dark Green
(BDBd) & 50% Dark Green Split to Blue (BDbd)
bd BD BBDd BbDd
28) Split to Blue (Bdbd) x Split to Blue (Bdbd) = 25% Green
(BdBd), 50% Split to blue (Bdbd), & 25% Blue (bdbd)
bd BBdd Bbdd bbdd
29) Split to Blue (Bdbd) x Dark Green Split to Blue (BDbd) = 12.5% Green (BdBd), 12.5% Dark Green (BDBd), 25% Dark Green Split to Blue (BDbd OR BdbD ), 25% Split to Blue (Bdbd), 12.5% Cobalt (bDbd), & 12.5% Blue (bdbd)
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bd |
BBdd |
Bbdd |
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Bbdd |
bbdd |
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BBDd |
BbDd |
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BbDd |
bbDd |
30) Split to Blue (Bdbd) x Olive Split to Blue (BDbD) = 25%
Dark Green (BDBd), 50% Dark Green Split to Blue, & 25% Cobalt (bDbd)
bd Bbdd BbDd
31) Dark Green Split to Blue (BDbd) x Green (BdBd) = 25%
Dark Green (BDBd), 25% Dark Green Split to Blue (BDbd), 25% Green (BdBd), &
25% Split to Blue (Bdbd)
BBDd Bbdd BbDd BBdd BBDd BbDd
32) Dark Green Split to Blue (BDbd) x Dark Green (BDBd) =
12.5% Olive (BDBD), 25% Dark Green (BDBd), 12.5% Green (BdBd), 25% Dark Green
Split to Blue (BDbd), 12.5% Split to Blue (Bdbd), & 12.5% Olive Split to
Blue (BDbD)
bd BBDd Bbdd BbDd BbDd
33) Dark Green Split to Blue (BDbd) x Olive (BDBD) = 25%
Olive (BDBD), 25% Dark Green (BDBd), 25% Dark Green Split to Blue (BDbd), &
12.5% Olive Split to Blue (BDbD)
BBDd BBDD B BbDD
34) Dark Green Split to Blue (BDbd) x Dark Green Split to
Blue (BDbd) = 6.75% Olive (BDBD), 12.5% Dark Green (BDBd), 6.75% Green (BdBd),
12.5% Olive Split to Blue (BDbD), 12.5% Dark Green Split to Blue (BDbd), 12.5%
Split to Blue (Bdbd), 6.75% Mauve (bDbD), 12.5% Cobalt (bDbd), & 6.75% Blue
(bdbd)
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BBdd |
BBDd |
Bbdd |
BbDd |
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BBDD |
BbDd |
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Bbdd |
BbDd |
bbdd |
bbDd |
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35) Dark Green Split to Blue (BDbd) x Olive Split to Blue
(BDbD) = 12.5% Olive (BDBD), 25% Olive Split to Blue (BDbD), 12.5% Dark Green
(BDBd), 25% Dark Green Split to Blue (BDbd), 12.5% Mauve (bDbD), & 12.5%
Cobalt (bDbd)
BBDD BbDd bD bbDD
36) Olive Split to Blue (BDbD) x Green (BdBd) = 50% Dark
Green (BDBd) & 50% Dark Green Split to Blue (BDbd)
bD BBDd BbDd BBDd BbDd
37) Olive Split to Blue (BDbD) x Dark Green (BDBd) = 25%
Olive (BDBD), 25% Dark Green (BDBd), 25% Dark Green Split to Blue (BDbd), &
25% Olive Split to Blue (BDbD)
BBDD
38) Olive Split to Blue (BDbD) x Olive (BDBD) = 50% Olive
(BDBD), & 50% Olive Split to Blue (BDbD)
BBDD BbDD
39) Olive Split to Blue (BDbD) x Olive Split to Blue (BDbD)
= 25% Olive (BDBD), 50% Olive Split to Blue (BDbD), & 25% Mauve (bDbD)
BBDD BbDD bbDD