1. Gene Expression and Regulation

2. Nucleotide (DNA) to Gene Chromosome
Small to large
Nucleotide (DNA) to Gene Chromosome

3. Every human cell contains 46 chromosomes!
Human Genome Project
In April 2003 scientists finished mapping the human genome. They sequenced all of the bases (A, T, C & G) as well as what proteins those genes coded for.
It took 13 years to complete and cost
$1 billion dollars.
Every human cell contains 46 chromosomes!
(except sperm and egg)

4. What is a Gene?
GENE = sequence of DNA that codes for a specific protein

5. What is a Protein?
PROTEIN= sequence of amino acids that becomes functional once it folds into a 3D shape.

6. What do Proteins do? Hormonal=proteins can be hormones
Enzymes=proteins control chemical reactions
Structural=form muscles, bones, skin, hair, nails and teeth
Defensive=proteins make up part of your immune system
Contractile=proteins help you move
Plus many other jobs!

7. What is Gene Expression?
Gene expression is the process by which information from a gene is used in the synthesis (making) of a functional gene product. These products are often proteins.

8. Each cell has tens of thousands of potentially viable genes.
Every cell in the human body contains a complete copy of that person's DNA (all 46 chromosomes).
Each cell has tens of thousands of potentially viable genes.

9. All of these genes cannot be expressed (“turned on”) at once
All of these genes cannot be expressed (“turned on”) at once. Cells must decide which genes to turn on and which genes to turn off.
When a gene is expressed (turned on), that means it is making a protein.

10. Examples of gene expression
Cells become specialized when they each use a different part of the DNA they contain.
Example 1: The human liver contains many specialized cells that secrete bile. Only these cells produce bile because different cells use different parts of the genetic information they contain.
“Liver” genes are turned on (specific proteins are made)
All other genes are turned off (not making proteins)

11. Examples of gene expression
Example 2: a skin cell turns on the genes which make it a skin cell, while a bone cell would leave these genes turned off.
Neither of these cells would need the genes which allow a cell to differentiate into a neuron (brain cell), so these genes would be left off as well.

12. Factors affecting Gene Expression
Sex influenced traits – traits expressed differently between two sexes.
Ex. Male Pattern Baldness: males experience a higher rate of baldness due to higher levels of testosterone which triggers this gene.

13. Factors affecting Gene Expression
Environmental Factors
Drugs Temperature
Chemicals Light
Ex. Himalayan rabbits’ fur changes color in response to temperature.
Temperature turns on a gene for hair color.

14. Stem Cells Stem cells are cells that do not have specific jobs yet.
Stem cells can differentiate, or turn into many different types of cells.

15. Source: http://learn.genetics.utah.edu/content/epigenetics/memory/
Early in development, genes are "poised" like runners in the starting blocks, ready to jump to action
In a differentiated cell, only 10 to 20% of the genes are active. Different sets of active genes make a skin cell different from a brain cell
Environmental signals such as diet and stress can trigger changes in gene expression.

16. Gene Regulation
Gene regulation is a process in which a cell determines which genes it will express and when. In other words when genes will be turned on and off.

17. All mixed up and no place to go!
Gene Mutations
All mixed up and no place to go!
Mutations Brain Pop

18. Introduction
The word mutation describes sudden (random) and drastic alterations in the hereditary material (DNA).
A mutation is a change in a gene or DNA sequence.
Sickle Cell Anemia Video
One look around a room tells you that each person has slight differences in their physical make up — and therefore in their DNA. These subtle variations in DNA are called polymorphisms (literally "many forms"). Many of these gene polymorphisms account for slight differences between people such as hair and eye color. But some gene variations may result in disease or an increased risk for disease. Although all polymorphisms are the result of a mutation in the gene, geneticists only refer to a change as a mutation when it is not part of the normal variations between people.
(Cited:

19. Mutations
Mutations are like making a spelling mistake and then making photocopies of it.
When a mutation happens in the DNA of sex cells (gametes), a different message gets copied into future generations.

20. How do mutations happen?
Sometimes a piece of DNA gets deleted, inserted, inverted, or substituted and can’t be read, so it isn’t copied properly.
Mutation Clip

21. How can mutations affect us? Video
Mutant genes can produce a change in the structure of the proteins they make, thus affecting the organism.
Genes mutate naturally all of the time and not all mutations are bad
Genes can become incorporated into the gene pool (passed on to future generations).

22. Genetic Engineering
Today scientists purposely cause mutations using genetic engineering.
Examples:
Cloning
Pesticide resistant plants
Crops that grow faster or bigger (trees, tomatoes, corn)
Salmon that grow faster
Growing human parts for facial abnormalities

23. Types of Mutations – video clip
Mutations can affect the gene or the whole chromosome depending on the severity of the change
3 Types of Mutations
1. Point
2. Frameshift
3. Inversion
The sickle-cell disease occurs when the seventh amino acid (if the initial methionine is counted), glutamic acid, is replaced by valine to change its structure and function. Valine is hydrophobic, causing the hemoglobin to collapse in on itself occasionally. Sickle Cell Video Clip

24. Point Mutations 1. Point/Substitution
Only occur at a single point and may or
may not be harmful.
Normal: TAG-ACT-ACC-TAG-GAA
Mutation: TAG-TCT-ACC-TAG-GAA
Silent Mutation (No change in Protein)
A change within the DNA triplet that
has no effect on the resulting protein
Normal: DNA: TAG-ACA-ACC-TAG
mRNA: AUC-UGU-UGG-AUC
Amino Acid: ISO-CYS-TRY-ISO
Mutation: DNA: TAG-ACG-ACC-TAG
mRNA: AUC-UGC-UGG-AUC

25. 2. Types of Frameshift
Deletion -These mutations are deletions of a nucleotide(s) that usually results in a change in every amino acid after the mutation occurs because it changes how codons are grouped and read.
Normal
TAG
ACT
ACC
GAA
Mutation
CTA
CCT
AGG AA

26. 2. Types of Frameshift cont…
Insertion (Duplication) These mutations are additions of a nucleotide(s) that can result in a change in every amino acid after the mutation occurs.
Normal
TAG
ACT
ACC
GAA
Mutation
GGG

27. 3. Inversion
These mutations are reversals of nucleotides that have different results depending where they happen and how many bases are involved.
Normal
TAG
ACT
ACC
GAA
Mutation
CAT

28. Heredity
If a mutation occurs in a body cell, it will only impact that cell and any cells that are created from that cell so the impact can be smaller (skin cancer is an example). These mutations CANNOT be passed on to offspring.
ONLY SEX CELL MUTATIONS ARE PASSED ON TO OFFSPRING.
Video Clip (5:00)

29. This is a point mutation
Example 1
Original: It’s raining cats and dogs outside
Mutation: It’s ragning cats and dogs outnide
Substitution of g instead of i in raining
Substitution of n instead of s in outside.
This is a point mutation

30. This is a frameshift mutation
Example 2
Original: It’s raining cats and dogs outside
Mutation: It’s raining cats and frogs dogs outside
Added the word frogs
INSERTION!
This is a frameshift mutation

31. This is a frameshift mutation
Example 3
Original: It’s raining cats and dogs outside
Mutation: It’s raining raining cats and dogs outside
Duplication of the word raining a second time
INSERTION!
This is a frameshift mutation

32. This is a frameshift mutation
Example 4
Original: It’s raining cats and dogs outside
Mutation: It’s raining dogs outside.
The words cats and and are missing.
DELETION!
This is a frameshift mutation

33. Example 5 INVERSION Original: It’s raining cats and dogs outside
Mutation: It’s raining edistuo sgod dna stac.
cats and dogs outside is written backwards.
INVERSION