PCB 3063 Lecture Notes - Lecture 21: Twin, Cell Potency, Dna Methyltransferase
Document Summary
Epigenetics: changes to structure of dna and chromatin, but not to dna sequence: affect traits that are passed on to other cells or even future generations, influences by environment. Dna methylation: addition of a methyl group to cytosine base in cpg or cpnpg islands: maintaining methylation after cell division: after dna replication, only old strand remains methylated- Hemimethylated: dna methylation represses transcription- inhibits binding of proteins for transcription. Attracts histone deacetylase enzymes- leads to inhibition of gene expression and phenotypic changes. Environmental epigenetics: air food, water all affect dna methylation and histone modification in gamete cells, leading to changes in reproduction and offspring. Maternal increase in cpg methylation in avy fat and yellow. Dad"s diet may also shape chromatins of his sperm, embryos and children: ex- father"s high sugar diet increases obesity susceptibility in his offspring through dna methylation reprogram. **epigenetic effects can be seen in both mothers and fathers**