Lecture 13

Question 1

Thrifty phenotype hypothesis

Answer 1

created by David Barker in 1992
Observation: obesity is more frequent in adults that were undernourished as fetuses and infants
Q: how might early-life events define late-life health and disease?
A: conditions a fetus experiences during pregnancy can affect physiology throughout an individual’s life

Question 2

Some developmental and physiological processes are insensitive to

Answer 2

environmental changes
*subject to genetic changes

Question 3

Some developmental and physiological processes are _____ to environmental changes

Answer 3

sensitive

Question 4

During a pregnancy infection, the privilege change from the fetus to the

Answer 4

immune system
- comes at a price; disease of homeostasis in the fetus (insulin resistance and type 2 diabetes)

Question 5

type 2 diabetes a DOED (disease of exaggerated defense)

Answer 5

like other autoimmune disorders, obesity and type 2 diabetes have increased significantly

Question 6

in New Guinea, obesity is higher in

Answer 6

cities than jungles

Question 7

Aboriginal Aussies are more likely to have type 2 diabetes than

Answer 7

European Aussies

Question 8

The Dutch Hunger Winter of 1944

Answer 8

• end of WW2, Nazis blockaded the Dutch and tried to starve them to death
• individuals went down to a diet of less than 1000 cal a day

Question 9

The Dutch Hunger Winter of 1944 effects

Answer 9

early gestation: cardiovascular disease, general poor health
mid gestation: kidney disease associated with diabetes, lung disease
late gestation: insulin resistance (diabetes)
*These effects have also been seen in normal populations

Question 10

the physiological/homeostatic mechanisms that today are responsible for autoimmune disease (metabolic syndrome, obesity, and type 2 diabetes) are part of

Answer 10

an adjustable pathway that evolved under conditions of unpredictable food

Question 11

limited nutrition during prenatal development causes

Answer 11

an individual to switch to a starvation mode physiology for life

Question 12

the key feature of metabolic syndrome is

Answer 12

insulin resistance (cells fail to respond to normal action of the insulin)

Question 13

evolutionary effects of insulin resistance

Answer 13

• helps withstand starvation b/c muscle cells become less sensitive to insulin
• muscle cells use less glucose, which then gets moved to vital organs
• fat tends to be deposited in abdomen (can be quickly mobilized to provide energy when food is scarce)

Question 14

type 2 diabetes is an example of adaptive developmental plasticity as long as…

Answer 14

prenatal condition correlates well with conditions later on in life

Question 15

thrifty epigenotype hypothesis

Answer 15

environmental circumstances can alter the expression of genes over an individual’s lifetime
- the prenatal environment can modify the functionality of the fetus’s genome without affecting the underlying nucleotide sequence

Question 16

epigenetics

Answer 16

modification to DNA that is independent of the nucleotide sequence(histones, methylation, etc.)
an important way that cell types can diverge in a pattern of gene expression during development

Question 17

Some epigenetic effects can be transmitted

Answer 17

from parents to offspring, so their effects might persist for several generations

Question 18

Epigenetic state at birth predicts body composition in children

Answer 18

children w/ high levels of methylated RXRA are heavier
- RXRA is a retinoic acid receptor that mediates growth response
low maternal carbohydrate intake in early pregnancy is associated with higher RXRA gene promoter methylation

Question 19

beginning to establish a connection between a signal that is passed by the mother to the offspring to

Answer 19

set the gene expression in the offspring depends upon the quality of nutrition that the infant is getting

Question 20

all humans potentially have a thrifty genome, but phenotypic expression can

Answer 20

vary based on environmental input due to epigenetic modifications inherited across generations