Epigenetics, Environment And Inheritance

Question 1

What is the major mouse model example of how nutrition (folate) can impact epigenetic phenotype

Answer 1

Agouti mouse

Question 2

What is the avy allele downstream of which affects avy expression if methylated

Answer 2

Retrotransposon iav

Question 3

What happens when the avy gene not methylated vs when folate given

Answer 3

Yellow coat and obese

Hypermethtlation and avy repression if folate taken

Question 4

Which chemical which is harmful to humans when mice exposed gave then the avy coat and obesity

Answer 4

BPA - through reduced cpg methylation

Question 5

What environmental factor led to increased t2d in rats - example of gestational exposure

Answer 5

Maternal intake of a low protein diet/suboptimal diet = t2d risk

Question 6

Which gene did the low protein diet methylate

Answer 6

Hnf2awhxih is needed for pancreatic differentiation and glucose homeostasis

Question 7

What did post natal smoking cause methylation of which was similar to lung cancer bronchial epi cells

Answer 7

Dapk and p16

Question 8

Which methyl donor do things like b12,b6 and folate increase availability of for methylation

Answer 8

SAM

Question 9

Which genetic snp in what gene reduces folate serum levels so can’t influence methylation

Answer 9

Mthfr

Question 10

What is lamarcks theory of acquired inheritance which makes sense for epigentic

Answer 10

If an organism adapts to better suit its needs eg giraffe long neck then this is inherited by the offspring as advantageous

Question 11

What is weismanns germ plasm theory

Answer 11

The germ plasm is the essential component of egg and sperm which then passes on its hereditary material to the soma

Question 12

Why is classic Darwinism wrong

Answer 12

Variations don’t just occur through genetic mutations. They can occur trough epi genetics

Question 13

What is the issue with inherited methylation theories

Answer 13

They don’t account for the 2 reprogramming erase stages in development of a foetus

Question 14

When are the 2 reprogramming stages

Answer 14

Upon zygote (egg) fertilisation

Upon establishing PGCs (progenitors of gametes in the embryo)

Question 15

Why is methylation reestablished after reprogramming

Answer 15

For the differentiation of cells to form the embruo

Question 16

Which genetic elements can escape programming

Answer 16

Retrotransposons

Question 17

What did the overkalix study find which shows trans generational inheritance (evidence for lamarkian inheritance)

Answer 17

That during slow growing period (8-12 years) if the grandfather had too much food this caused increased diabetes mortality in the grandchild

If the father of the proband was exposed to lack of food, there were less cvd mortality in pro bands

Question 18

Which chemical/fungicide when exposed can recuensperm count

Answer 18

Vinclozolin

Question 19

Explain how vinclozolin exposure in mice of 3 generations showed epi genetic inheritance over 3 gens

Answer 19

5 genes in sperm cells of mice when the f0 mam was injected had differential methylation patterns

In f1 generation it reduced sperm count and the same pattern of methylation seen in 3 generations

The paternally imprinted sperm genes were hypermethylated vs maternal were hypomethylated

Question 20

What did the mouse study on how f0 liver damage can protect and adapt the liver in the generations after show

Answer 20

There were different methylation patterns where antifibrotic genes were hypomethylated vs profibrogenic were hypermethylated

The mice had adapted their liver to not respond to liver damage via ccl4 with fibrosis development

= trans generational epigentic inheritance