GENE 3200 Lecture Notes - Lecture 1: Tyrosinase, Melanin, Mutation
Document Summary
Complementation testing: you cross two pure breeding lines. If you get white flowers, the mutation is at the same locus. If same locus: do not complement: recessive (aa) x recessive (aa) recessive offspring (aa) If different loci: complement: recessive (aabb) x recessive (aabb) dominant offspring (aabb) Extensions of mendel"s rules: mendel"s rules hold, but additional factors are in play such as, multiple alleles, some loci have multiple alleles giving different phenotypes when homozygous. There can be 4 alleles at one locus (a, g, c, t): for examples rabbits- c locus affects tyrosinase which is important in melanin production. It is incomplete when the heterozygote has a phenotype intermediate between those of two parental homozygotes. In codominance, the heterozygote exhibits traits of both parental homozygotes: the type of dominance does not affect the inheritance of an allele; it does affect the phenotypic expression of the allele.
