BIOLOGY 1A03 Lecture Notes - Lecture 5: Proceedings Of The National Academy Of Sciences Of The United States Of America, Choline, Epigenomics

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Kim Dej

Document Summary

Chemical dna modifications that occur along the genome that change gene activity without altering the dna sequence. Epigenetic processes are essential for normal development, cell differentiation, and are increasingly being recognized as being involved in. Epigenomics: studying the epigenetic modifications across an individual"s entire genome. Signals can act on the epigenome to alter gene expression. Cancerous cells can have lower levels of methylation. I. e. can increase expression of genes that promote cell growth. Cancerous cells can also have higher levels of methylation. I. e. can decrease expression of genes that are needed to keep cell growth in check or repair dna, initiate programmed cell death etc. Cancer can begin when mutations change a cell"s dna sequence. In many cancers, some genes are turned up and turned down often in the very same cells. Agouti gene encodes protein that signals melanocytes to switch from producing black to yellow pigment. Agouti yellow mice have insertion in agouti gene, making them obese and yellow.