Homozygous Spider Morph

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Here are definitions taken from three genetics texts. They differ in definitions and how they classify the various examples. How the sickle cell gene is classified depends on the test used.

How would each text classify the spider mutant gene (assuming spider is not dominant to normal)?

For what it's worth, I follow Miller because that definition is the simplest for a breeder to use.

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Atherly, et al. (1999):
codominance -- a form of dominance relationship between two alleles of one gene in which the heterozygote shows the phenotypes of both alleles. Example -- A, B, and AB human blood types; sickle cell trait in humans.

incomplete dominance -- progeny that possess a phenotype that is approximately intermediate between the homozygous parents. Example -- red, white, and pink flowers; sickle cell trait in humans; Siamese, Burmese, and Tonkinese cat coat colors.

overdominance -- a dominance relationship in which the heterozygote has a greater or more extreme phenotype than individuals homozygous for either allele. Example -- a heterozygous plant that is larger than either homozygous parental type; sickle cell trait in humans.
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Zubey (1987):
codominance -- A situation in which the phenotype is the additive function of two alleles. Both alleles are expressed. Example -- A, B, and AB human blood types; sickle cell trait in humans; Siamese, Burmese, and Tonkinese cat coat colors.

incomplete dominance -- A situation in which only one allele is expressed, and the amount of expression is directly proportional to gene dosage. Example -- red, white, and pink flowers.

overdominance -- the situation in which the heterozygote a more extreme form of a trait than either homozygote. Example -- a heterozygous plant that is larger than either homozygous parental type; sickle cell trait in humans.
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Miller (1991):
Codominance -- the heterozygote's phenotype can be distinguished from either homozygote's phenotype. This allows each of the three genotypes to be inferred from its phenotype. Synonyms -- incomplete dominance, overdominance, many others. Examples -- A, B, and AB human blood types; sickle cell trait in humans; red, white, and pink flowers; Siamese, Burmese, and Tonkinese cat coat colors; a heterozygous plant that is larger than either homozygous parental type.
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References:
Atherly, Alan G., Jack R. Girton, and John F. McDonald. The Science of Genetics. Saunders College Publishing, Fort Worth, TX. 1999, 704 pp.

Miller, Wilmer J. A Survey of Genetics. Ginn Press, Needham Heights, MA. 2nd ed., 1991, 328 pp.

Zubay, Geoffrey. 1987. Genetics. The Benjamin/Cummings Publishing Co., Menlo Park, CA. 1987, 973 pp.

I dont think that anyone is really doubting the way genetics actually work technically speaking, only that for the purposes of ball pythons we use them pretty basically to make things more simple. Its more application and trial and error, many of morphs out there havnt really been explored or combined with every different morph so nothing is known until proven many times over. The example of mice isnt really the same thing, ball python patterns and color mutations are a little harder to predict than a black and white mouse makes grey or a black and white mouse, any person with any sense could resonably asume that would be the case, and mice can breed months after they are born and balls can take up to 3 years which makes it a little more difficult to prove out genetics. Only time will tell. But for the mean time the misnomers for the names we label genetic traits seems to work for its purpose. Essentially too many morphs, not all have been combined, lack of extensive genetic experimentation, this gene usually does this, we havent seen that gene do that yet=just call it this trait for now and if its proven something else later, change it.