BISC 202 Lecture Notes - Lecture 20: Lethal Allele, Null Allele, Wild Type
Document Summary
Bisc202 lecture 20: more gene interactions for 1-2 genes and biosynthetic pathways. 2 pure-breeding recessive mutant strains are mated together. If all wild type: complementation occurred so the mutations affect different genes. If not all wild type: complement failure so the mutations affect the same gene. Null mutations: mutation for one essential step in the gene pathway. Consider 2 wingless mutations (a and b mutations) for different genes for drosophila, many steps are essential to make wings. A mutation has a null mutation in a gene that"s needed for one step. B mutation has a null mutation in a gene that"s required for a different step. If 2 pure-breeding strains of these mutations mate with each other, the offspring will be able to have wings because these mutations affect different genes (they will each have a copy of the wild type allele)