BIO 325 Lecture Notes - Lactose Intolerance, Mendelian Inheritance, Genomic Imprinting
29 Sep 2013
School
Department
Course
Professor
Document Summary
Mendel"s principle of independent assortment applies to situations in which two modes of inheritance occur simultaneously, provided that the genes controlling each character are not linked on the same chromosome. Gene interaction - the cellular function of numerous gene products contributes to the development of a common phenotype. Many traits characterized by a distinct phenotype are affected by more than one gene. Epistasis - effect of one gene or gene pair modifies or masks the effect of another gene or gene pair. The gene that modifies is known as the epistatic gene. The gene that gets modified is hypostatic gene. Example: bombay phenotype: mutation of fut1 affected the expression of the main gene. Often arise because two or more different proteins participate in a common cellular function: example: enzymatic pathway. Colorless precursor ----------(enzyme c)---------> colorless intermediate ---------(enzyme. Novel phenotypes - gene interaction produces new phenotypes in the f2 generation in addition to producing a modified dihybrid ratio.
