BIOLOGY 2C03 Lecture Notes - Wild Type, Phocomelia, Frameshift Mutation
Document Summary
Mutations anywhere along the gene can still give a loss of function, but are considered different alleles. Individual (diploid): only two alleles coexist in each cell. Example of the multiple alleles contributing to fur coloration in cats. Cb-: burmese (mutation at a particular locus) Cs: siamese (mutation at a different allele) If each individual has two alleles, the dominant/allelic series tells you which one will be dominant. Ex, for a cat to be siamese they must have the cs allele with either a c or ca allele. This represents a dominance series or allelic series. Important is the relationship between pairs of alleles. The c gene codes for an enzyme called tyrosinase. The albino allele (the most recessive allele in this series) contains a cytosine deletion in tyrosinase at position 975 in exon 2. Causes a frame shift resulting in a premature stop codon residues downstream from the mutation loss of a single nucleotide that alters the reading frame.