Janis's Felines

See Feline Genetics, Cat Fanciers: Color Genetics or The Book of the Cat, Ed. M. Wright and S. Walters, Summit Books, NY for discussion of coat color inheritance. Note that the different sources disagree about whether deafness is associated with white spotting (piebald) gene or the White gene.

Puffy Mother of Wilbur, Spot, and Mombo. The orange-black tortoiseshell pattern indicates heterozygosity for X-linked orange gene, O=orange, o=not orange (ie genotype determined by Black gene on another chromosome). Orange patches result from inactivation of the X-chromosome with the o allele. Long haired, therefore two recessive long hair alleles, ll. Small white patch on chest (not visible here) indicates a dominant piebald allele for white spotting (S). Probably overall B- Oo Ss ll.

Wilbur Son of Puffy. When younger, all white with orange spot on head. The orange indicates he inherited Puffy's X-chromosome with the dominant O allele. Probably white due to piebald spotting (S-). Though some cats with the White gene (dominant allele W for white, recessive w for 'normal color') have small colored patches as kittens, he does not have blue or copper eyes, usually associated with White. Short-haired but must be heterozygous (Ll) since Puffy was long-haired.

Spot Son of Puffy. All white with black spot on head. He therefore inherited Puffy's X-chromosome with the recessive o allele, and can express the genotype at the Black locus (B-). Black spot has faded with time though not as much as Wilbur's orange spot. Short-haired, heterozygous (Ll) since Puffy was ll.

Mombo Daughter of Puffy. Obviously also heterozygous for orange, since she has patches of orange and black due to random X-chromosome inactivation of O (orange) and o (non-orange) alleles. White spotting (S-) makes her a traditional calico; and she is short-haired heterozygous (Ll).

Stretch Although Stretch was completely white as far as we could tell, it was not due to albino (recessive allele of full-pigmentation gene) since he had yellow/green not pink or pale blue eyes; probably not due to a dominant White allele, again because of eye color (not blue or copper) and because he was not deaf. Possibly it was a strong, homozygous, Piebald genotype (SS), causing extensive (ie 100%) white spotting. Short haired, therefore LL or Ll.

Io Our youngest addition. When a kitten she had some distinct black hairs on the top of her head; not albino since eyes are not pink or pale blue; may be White (W-) though not deaf nor is eye color that usually found with W; could be another extensive piebald spotting, possibly homozygous SS. Short haired, either homozygous or heterozygous. Mother is shorthaired L-, tortoiseshell Oo, some white patches (S-).

		Puffy Mother of Wilbur, Spot, and Mombo. The orange-black tortoiseshell pattern indicates heterozygosity for X-linked orange gene, O=orange, o=not orange (ie genotype determined by Black gene on another chromosome). Orange patches result from inactivation of the X-chromosome with the o allele. Long haired, therefore two recessive long hair alleles, ll. Small white patch on chest (not visible here) indicates a dominant piebald allele for white spotting (S). Probably overall B- Oo Ss ll.
		Wilbur Son of Puffy. When younger, all white with orange spot on head. The orange indicates he inherited Puffy's X-chromosome with the dominant O allele. Probably white due to piebald spotting (S-). Though some cats with the White gene (dominant allele W for white, recessive w for 'normal color') have small colored patches as kittens, he does not have blue or copper eyes, usually associated with White. Short-haired but must be heterozygous (Ll) since Puffy was long-haired.
		Spot Son of Puffy. All white with black spot on head. He therefore inherited Puffy's X-chromosome with the recessive o allele, and can express the genotype at the Black locus (B-). Black spot has faded with time though not as much as Wilbur's orange spot. Short-haired, heterozygous (Ll) since Puffy was ll.
		Mombo Daughter of Puffy. Obviously also heterozygous for orange, since she has patches of orange and black due to random X-chromosome inactivation of O (orange) and o (non-orange) alleles. White spotting (S-) makes her a traditional calico; and she is short-haired heterozygous (Ll).
		Stretch Although Stretch was completely white as far as we could tell, it was not due to albino (recessive allele of full-pigmentation gene) since he had yellow/green not pink or pale blue eyes; probably not due to a dominant White allele, again because of eye color (not blue or copper) and because he was not deaf. Possibly it was a strong, homozygous, Piebald genotype (SS), causing extensive (ie 100%) white spotting. Short haired, therefore LL or Ll.
		Io Our youngest addition. When a kitten she had some distinct black hairs on the top of her head; not albino since eyes are not pink or pale blue; may be White (W-) though not deaf nor is eye color that usually found with W; could be another extensive piebald spotting, possibly homozygous SS. Short haired, either homozygous or heterozygous. Mother is shorthaired L-, tortoiseshell Oo, some white patches (S-).