HMB265H1 Lecture Notes - Demethylation, Epigenome, Twin
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HMB265H1 Full Course Notes
Verified Note
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Document Summary
Genotype=phenotype these twins are identical but if you look closely, there are still subtle differences between them even with monozygotic twins, differences can become more apparent as they age especially in terms of health. But, these mice are genetically identical all have genotype =avy/a differences due to epigenetic changes but a fat mice and yellow coat and these have wild grey coat colour but same dna/same genes allele combinations. Epigenetics heritable modifications in gene function not due to changes in the base sequence of. Dna such that one allele is expressed and other isn"t. Molecular mechanisms: 1) dna methylation at cpg (dinucleotides) islands-repression of gene expression . 2) covalent modification of histones- e. g. acetylation, methylation, ubiquitination, etc these modifications can lead to repression or activation of transcription. 3) non-covalent modification of histones-chromatin remodeling, histone variants due with chromatin remodeling complexes. Epigenetic changes cause coat colour differences as well as other differences thes changes can be influcneced by the environment.
