EPISTATIC GENE INTERACTIONS:

EPISTATIC GENE  INTERACTIONS: TYPE:

NO INTERACTION

RATIO:

EXAMPLE:

9:3:3:1

FLY EYE COLOR: (RED:BROWN:VERMILLION:WHITE )

DESCRIP TION: Normal expected dihybrid test cross

(B-V-):(bbV-):(B-vv):(bbvv)

COMPLEMENTARY GENE INTERACTION

DUPLICATE GENE INTERACTION

DOMINANT GENE INTERACTION

RECESSIVE EPISTASIS

DOMINANT EPISTASIS

9:7

SWEET PEA FLOWER COLOR (PURPLE:WHITE) (C-P-): (C-pp; ccP-; ccpp)

15:1

BEAN FLOWER COLOR (PURPLE:WHITE) (P-R-; P-rr; ppR):(pprr)

9:6:1

SQUACH FRUIT SHAPE (DISK:SPHERE:LONG) (A-B-):(A-bb or aaB-):(aabb)

9:3:4

12:3:1

Mutation of either genes produces a mutant phenotype (white). In order to be wildtype (purple) it must have both genes. Only homozygous recessive has mutant allele. Both dominant alleles can switch on the pigment gene. All Dominant produces 1 phenotype (A-B-). One Dominant and one Recessive produces another phenotype (aaBor A-bb). And aabb produces another phenotype.

(B-E-):(bbE-):(B-ee or bbee)

Recessive alleles mask/reduce the expression of the other alleles

FOXGLOVE FLOWER COLOR (WHITE:DARK RED:LIGHT RED)

Dominant allele masks the expression of another

LABRADOR RETRIEVER COAT (BLACK:CHOCOLATE:GOLDEN)

(D-W- or ddW-):(D-ww):(ddww)

DOMINANT SUPPRESSION

13:3

CHICKEN FEATHER COLOR (WHITE:COLORED) (C-I- or ccI- or ccii):(C-ii)

allele. Having the dominant allele for white flowers (W-) will produce white flowers even if dominant allele for red (D-) is present. Dominant gene suppresses another dominant gene