HMB265H1 Lecture Notes - Lecture 19: X-Inactivation, Nature Reviews Genetics, Insulin-Like Growth Factor 2

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

Document Summary

Epigenetics: heritable modi cations in gene function not due to changes in the base sequence of dna. Encompasses anything that can not be explained by traditional genetics. Note: do not confuse it with epistatic effects! Normal development: epigenetic modi cations are required for normal dna development. These ways of regulating gene expression result in the variety of cell types that we see in the body, ultimately giving rise to a phenotype. Slide 6: molecular mechanisms of epigenetics: dna methylation: covalent modi cation at cpg sequences > represses gene expression, covalent histone modi cation: covalent modi cation of histones. (acetylation, methylation, ubiquitination, non-covalent histone modi cation: chromatin remodelling, histone variants, non-coding rnas: transcriptional silencing. These rnas control when and how much of a gene is expressed. The environment can have an effect on epigenetic modi cations. Iap region: whether or not this is methylated determines the coat colour. The agouti gene is downstream of this iap region.