Epigenetics

Question 1

What did the effects of paternal grandparent diet on grandchildren mortality risk find?

Answer 1

poor diet during slow growth period of grandparents showed decrease in mortality of grandchildren (protective effect of genes). opposite for good diet during slow growth period

Question 2

what did the rat experiment that fed methyl donor ingredients to increase methylation of DNA in rats find?

Answer 2

mother fed methyl donor ingredients made a mouse that was smaller and didn’t like to eat compared to the other

Question 3

what are the 4 characteristics of epigenetics?

Answer 3

1. different gene expression pattern/phenotype, identical genome
2. inheritance through cell division, even through generations
3. like a switch: ON/OFF
4. erase-able (inter-convertible)

Question 4

what characteristic of epigenetics is a potential therapeutic target?

Answer 4

the fact that the genome is erasable (de-methylate)

Question 5

what is Waddington’s landscape as epigenetic visualization?

Answer 5

ball at top of hill, chooses to go downhill because its the easiest route, goes either left or right. once it chooses its path it can only stay in that valley and cannot differentiate into a different type of cell

Question 6

what is proper imprinting?

Answer 6

one maternal/paternal gene on

one maternal/paternal gene off

Question 7

what are the steps of proper imprinting through gametogenesis?

Answer 7

1. meiosis
2. erasure (de-methylation)
3. sex-specific gene silencing (methylation)
4. fertilization

Question 8

how does DNA methylation lock in the repressed state?

Answer 8

DNA methylation occurs by DNMT at CpG islands, methyl group gets added to the 5’ group of cytosine

Question 9

how is imprinting kept present after DNA replication in somatic cells?

Answer 9

the daughter strand must be methylated

Question 10

what are 2 problems with maintaining the epigenetic state in regards to DNA methylation and histone modifications?

Answer 10

DNA is half old/half new
histones are half old/ half new

Modifications to both the DNA and the histones must be performed to maintain the imprinting

Question 11

how can methylation lead to cancer?

Answer 11

tumor suppressor genes can become methylated through age/environment,mutation leading to inactivation of the tumor suppressor gene