B wild type allele is designated with superscript

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Unformatted text preview: -mutant gene has no superscript. 43 Complementary gene action - 2 genes Phenotypic ratio 9:7 Flower colour is a heterogeneous trait that can be complemented 44 45 For heterogeneous traits: To determine if 1 gene or 2+ genes are involved in producing a particular phenotype, we must use complementation testing Complementation testing can also be used to determine if 2 individuals have mutations in the same gene 46 Mutations in different genes; complementation Gene 1 Gene 2 Parents Gene 1 Gene 2 X Offspring Gene 1 Gene 1 Gene 2 Gene 2 47 Mutation in the same gene; no complementation Parents Gene Gene A 2 A X 2 Offspring A 2 48 Pedigrees can be used to determine the genetic basis of particular traits Albinism can result from mutations in more than one gene 49 - genetic heterogeneity Epistasis A gene interaction in which the effects of an allele at one gene hide the effects of alleles at another gene Epistatic = control over another gene 50 Recessive epistasis e.g., coat colour in Labrador retrievers 51 Phenotypic ratio 9:3:4 indicates recessive Epistasis Purebreeding BE Be bE be BE BBEE BBEe BbEE BbEe Be BBEe BBee BbEe Bbee bE BbEE BbEe bbEE bbEe be BbEe Bbee bbEe B_ = black bb = brown E_ = expression of gene B ee = no expression of gene B bbee Phenotypic ratio 9:3:4 ee is epistatic to gene B ee is always yellow, no matter what B/b is 52 pale eyes and nose bbee is a very light colour, eyes are blue, and nose and around eyes and paws are very pink (rejects) To figure out genetics of a golden lab, use a brown EE lab. Can two blood type O parents have a type A child? Type O would be ii ii x ii = ii 53 Recessive epistasis e.g., h Bombay allele in blood type hh is...
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This document was uploaded on 02/25/2014.

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