BIOLOGY 2C03 Lecture Notes - Lecture 4: Tyrosinase, List Of Minor Characters In Judge Dredd, Wild Type
Document Summary
Individual (diploid): only two alleles coexist in each cell. Example: multiple alleles contributing to fur colouration in cats: C > cb = cs > c > ca. ">" indicates dominance and "=" indicates incomplete dominance or codominance cb / cs: mink. C gene codes for an enzyme called tyrosinase. Cytosine deletion in tyrosinase at position 975 in exon 2 causes frameshift resulting in premature stop codon 9 residues downstream from mutation. Result in non-functional protein, allele described as loss of function allele. Haplosufficient allele - 1 allele is enough to make functional protein to drive a reaction e. g. r+ is dominant to r. R+/r+ ad r+/r genotypes produce a wildtype phenotype because they make enough protein for the cell to function (r/r does not) Example: c/c genotype, half as much tyrosinase is synthesized, but is sufficient to achieve full colouration.