This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Lecture 5 1/22/2008 1 Biosc 0350 Genetics Lecture 5 - Phenotypes and gene interactions (2) 1) Extensions to Mendel for multifactorial inheritance B) Verifying patterns of inheritance C) Complementation test D) Not all phenotypes are expressed at 100% E) Polygenic traits 1/22/08 Martens. Biosc 0350, University of Pittsburgh 2 IF two genes control the same trait AND the genes are unlinked AND there is complete dominance at both gene pairs THEN the following ratios are produced in a dihybrid cross: Ratio Name of interaction 9:3:3:1 None (Four distinct phenotypes) 9:7 Complementary gene action 9:6:1 Duplicate interaction 15:1 Duplicate dominant interaction 12:3:1 Dominant epistasis I 13:3 Dominant epistasis II 9:3:4 Recessive epistasis You ARE expected to use the correct terminology for these interactions on exams. Interactions between two genes Lecture 5 1/22/2008 2 1/22/08 Martens. Biosc 0350, University of Pittsburgh 3 Breeding studies can confirm patterns of inheritance P: Purebreeding brown and albino mice X F 1 : all black F 2 : black, brown, albino 90 40 30 Example: Mouse coat color Pattern of inheritance? Pattern of inheritance?...
View Full Document
This note was uploaded on 04/07/2008 for the course BIOSC 0350 taught by Professor Josephmartens during the Spring '08 term at Pittsburgh.
- Spring '08