Transcript Environmental Factors and Gene Expression

Environmental Factors and Gene
Expression
• Environmental factors can influence the
expression of certain traits
– Expression refers to what we can see (what gene
products are made)
– Environmental factors include:
• Diet
• Climate (or temperature)
• Chemicals!
– Air, food, anything that will come into contact with you
Lung Cancer and Tobacco Use
• Cigarette smoking is the number one risk factor for
lung cancer (Center for Disease Control and
Intervention)
– Almost 90% of lung cancers in the US
• Risk of lung cancer may be higher if a person's
parents, siblings (brothers or sisters), or children
have had lung cancer.
– This doubles the risk!!
– Habits and environment can contribute here
• Also smoking?
• Second-hand smoke?
Skin Cancer
There is a link between skin cancer and sun exposure.
Scientists often debate about the best way to prevent it
while still getting appropriate amounts of vitamins
• Vitamin D
– Vitamin D is essential for strong bones and a healthy
immune system.
– It can be obtained from the sun
• Some scientists believe that Vitamin D made by the body may
help prevent prostate, colon, breast, and other cancers, as
well as bone diseases (Skin Cancer Foundation)
• Folic Acid (A B vitamin)
– Eating foods with folic acid has been thought to help
prevent skin cancer
– Foods include romaine lettuce, spinach, asparagus,
turnip greens, parsley, collard greens, broccoli, and
cauliflower
Sun Exposure
• The risk for melanoma doubles is a person has had
5 or more sunburns (Skin Cancer Foundation)
Diabetes
• Diabetes refers to a group of diseases that affect
how your body uses blood glucose, commonly
called blood sugar.
• If you have diabetes, no matter what type, it means
you have too much glucose in your blood
– either because insulin production is inadequate, or
because the body's cells do not respond properly to
insulin
• Type 1
Diabetes
– 10% of people
– autoimmune disease in which the immune system, by
mistake, attacks its own insulin-producing cells so that
insufficient amounts of insulin are produced - or no
insulin at all (NobelPrize.org)
• Type 2
– 90 percent of diabetes cases, commonly affects patients
during the second half of their lives. The cells of the
body no longer react to insulin as they should.
Prediabetes
• The vast majority of patients with type 2 diabetes
initially had prediabetes. Their blood glucose
levels where higher than normal, but not high
enough to merit a diabetes diagnosis. The cells in
the body are becoming resistant to insulin (MNT)
• People with type 2 diabetes may be able to rid
symptoms with a lot of exercise and strict diet
Insulin
• The hormone insulin is a main regulator of the glucose
(sugar) levels in the blood. (NobelPrize.org)
• “Synthetic human insulin was the first golden molecule of
the biotech industry and the direct result of recombinant
DNA technology. Currently, millions of diabetics worldwide
use synthetic insulin to regulate their blood sugar levels.
Synthetic insulin is made in both bacteria and yeast.”
• It is estimated that 1/3 of Americans born in the year 2000
will develop diabetes.
Genetic Links to Diabetes?
• In most cases of type 1 diabetes, people need to
inherit risk factors from both parents
• Because most people who are at risk do not get
diabetes, researchers want to find out what the
environmental triggers are
– More common in areas with cold weather
– Viruses have been known to be triggers
– Diet?
American Diabetes Association
Genetic Links Continued…
• Type 2 diabetes has a stronger link to family history
and lineage than type 1, although it too depends on
environmental factors.
– Type 2 diabetes runs in families. In part, this tendency is
due to children learning bad habits — eating a poor diet,
not exercising — from their parents. But there is also a
genetic basis.
– Some scientists believe that a child's risk is greater when
the parent with type 2 diabetes is the mother. If both
you and your partner have type 2 diabetes, your child's
risk is about 1 in 2.
American Diabetes Association
PKU
• Phenylketonuria
• Autosomal recessive
• causes an amino acid called phenylalanine to build
up in your body due to a missing enzyme
• Foods that contain proteins
• Without the enzyme, levels of phenylalanine and
two closely-related substances build up in the body.
These substances are harmful to the central
nervous system and cause brain damage.
Diet
• The diet for PKU consists of a phenylalaninefree medical formula and carefully measured
amounts of fruits, vegetables, bread, pasta,
and cereals. Many people who follow a low
phenylalanine (phe) food pattern eat special
low protein breads and pastas.
Heart Disease
• Atherosclerosis is a condition that develops when a
substance called plaque builds up in the walls of the
arteries. This buildup narrows the arteries, making
it harder for blood to flow through. If a blood clot
forms, it can stop the blood flow. This can cause a
heart attack or stroke.
There are many
types of heart
disease
Heart Disease and Diet
• Comparisons between a diet low in saturated fats,
with plenty of fresh fruit and vegetables, and the
typical diet of someone living in the developed
world show that in the former there is a 73%
reduction in the risk of new major cardiac events
Heart Disease and Genetic Interactions
• There are many types of inherited heart disease
• Diseases that pertain to the structure of the heart
and arties
• People can be born with these diseases and control
them with screenings, medicine, and diet