HMB265H1 Lecture Notes - Lecture 20: Ectopic Expression, Dosage Compensation, Insulin-Like Growth Factor 2

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

Heritable modifications in gene function not due to changes in base sequence of dna. Many changes are actually heritable - which is contrary to the original thought. Thus, due to epigenetic changes: even twins can have vastly different phenotypes, despite same genotype, do not get epigenetics mixed with epistatic genetics. Mice and coat colour differences: same genotype of avy/a, changes can be influenced by the environment. Yellow mice can also be influenced by obesity, tumors, etc. Regulation of gene expression: iap - a retrotransposon insertion. If methylated, you normal development of the brown colour. Ectopic expression of the agouti gene and thus yellow colour: different degrees of methylation result in the gradient of coat colour. Mother"s diets and offspring epigenetic changes: genetically identical offspring can change depending on diet, different phenotypes seen at birth, when fed methyl donors, there is more methylation at the iap. Leads to more brown mice: these changes can be inherited in the f2 also.