1. Blood typing and genetics
February 8, 2017

2. Blood Groups
All cells in the body have genetically-determined glycoproteins on their surface; the combinations of these are unique to each individual and are involved in self / non-self recognition
Some of these proteins are also antigens – they cause an immune response in individuals that do not posses them
The proteins (blood factors) that cause the greatest immune response belong to the ABO and Rh groups.

3. Antigen – Antibody Reactions
Antigens are foreign substances that provoke an immune response, including the release of antibodies that bind to and attack them
Where are antigens found?
Surface of pathogens (e.g. viruses, bacteria, etc.)
Vaccines (that’s why they work!)
Allergens (e.g. pollen, dust, etc.)
Cancer cells (foreign b/c cell has mutated)
Transplanted tissue / organs
Antibodies are proteins produced by white blood cells that bind to and destroy antigens. Antibodies are specific to certain antigens
Which cells make antibodies? Lymphocytes! That is why they are #2 most abundant leukocyte in blood.

4. Agglutination
When antibodies bind to RBCs, they cause agglutination, or clumping
Why is this bad?
Initially, clumps clog small capillaries, causing pain and reduced blood flow
Later, RBCs that are bound to the antibodies lyse or break open, releasing hemoglobin into the blood – which can cause kidney failure

5. ABO blood group
In the ABO blood group, there are two antigens, “A” and “B”, found on the surface of RBCs
You can have one type of antigen, both types, or neither
You develop antibodies to the type of antigens you don’t have during infancy

6. Rh Blood Group
The Rh blood group describes ~45 different (but similar) antigens on RBCs. These antigens are called antigen “D”
People are Rh + if they have any of the various D antigens. They are Rh – if the do not have any D antigens.
Unlike the ABO system, Rh- people must be sensitized to the D antigen before developing antibodies. That means Rh- people will NOT have an agglutination reaction the first time they encounter Rh+ blood … but they will if they have it a second time.

7. Blood Type
Our ‘blood type’ is the combination of the antigens from the ABO and Rh groups – the two groups of antigens that cause the strongest immune response.
What blood type do you have if you have D antigens only? O+
If you have A- blood, what type(s) of antigens do you have? What type(s) of antibodies?
A antigens only; B and maybe D antibodies

8. Blood type compatibility
The key to transfusions:
You cannot give a person blood that has antigens for which they have antibodies, otherwise, their immune system will attack that blood.
Fill out the chart …
Which is the universal donor?
Which is the universal recipient?
Blood Type
Can donate to
Can receive from A+ A- B+ B-
AB+
AB- O+ O-
A+, AB+
A+, A-, O+, O-
A-, A+, AB-, AB+
A-, O-
B+, AB+
B+, B-, O+, O- O-
B-, B+, AB-, AB+
B-, O-
AB+
A+/-, B+/-, AB+/-, O+/-
AB-, AB+
A-, B-, AB-, O-
A+, B+, AB+, O+
O+, O-
A+/-, B+/-, AB+/-, O+/-
AB+ O-

9. Blood Type Compatibility & Pregnancy
For the most part, blood type compatibility is NOT a problem during pregnancy because the blood of the baby and the blood of the mom do not mix.
However, Rh+ babies carried by Rh- moms can face serious risks because the
mother’s Rh antibodies can
cross the placenta and attack
the babies blood.
Rh antibodies are IgG … which is the most abundant type, but only type to cross placenta
ABO are IgG and IgM, but cause minor / no disease in newborns.
If a mother is already sensitized to Rh and is pregnant with an Rh+ baby, the shot will not help. The baby will be closely monitored, and may receive blood transfusions in utero, and may be delivered early.

10. Blood Type Compatibility & Pregnancy
There are often no problems affecting the first Rh+ baby carried by an Rh- mom… why?
Because mom needs to be sensitized by having contact with
Rh+ blood before she will produce Rh antibodies. During labor
and delivery, the baby’s blood and mom’s blood often come into
contact, which sensitizes the mother.
If the mom becomes pregnant with
a second Rh+ baby, her immune
system will attack the baby’s blood,
causing brain damage or death to
the fetus.
This can be prevented by giving the
mother medicine that prevents her
from developing antibodies against
Rh antigens.
Rh antibodies are IgG … which is the most abundant type, but only type to cross placenta
ABO are IgG and IgM, but cause minor / no disease in newborns.
If a mother is already sensitized to Rh and is pregnant with an Rh+ baby, the shot will not help. The baby will be closely monitored, and may receive blood transfusions in utero, and may be delivered early.

11. Blood Typing
Antiserum is a solution that contains antibodies against a specific antigen (i.e. antiserum A contains type A antibodies). Blood type is determined by adding antiserum A, B, and D to blood and observing whether or not agglutination occurs. What does an agglutination reaction with a certain antiserum mean? It means that the blood contains that antigen. O+ O- A+ A- B+ B-
AB+
AB-

12. Just for Fun:

13. Genetics Refresher
We have two versions – or alleles – of every gene. One inherited from our mom, one from our dad.
The two alleles (genotype) interact to determine our trait (phenotype) in predictable ways.
Some alleles are dominant, some are recessive. Dominant genes show their trait and ‘cover up’ recessive genes.
IA (A) and IB (B) are dominant to i (O).
D (+) is dominant to d (–)
Some alleles are codominant. This means both alleles fully express their trait.
IA and IB are codominant with each other.

14. Genotype to Phenotype What blood type will result from each genotype?
IAiDD
iidd
IB IB Dd
IA IB dd
IB iDd

15. Genotype to Phenotype What blood type will result from each genotype?
IAiDD A+
iidd O-
IB IB Dd B+
IA IB dd AB-
IB iDd B+

16. Phenotype to Genotype
What are the possible genotypes for each blood type? A+
AB- O- B+

17. Phenotype to Genotype
What are the possible genotypes for each blood type?
A+ IAIADD, IAiDD, IAIADd, IAiDd
AB- IAIBdd
O- iidd
B+ IBIBDD, IBiDD, IBIBDd, IBiDd
More important vocab –
Homozygous – both alleles for one gene are the same (e.g. ii)
Heterozygous – the two alleles for one gene are different (e.g. Iai)

18. Punnett Squares
Punnett Squares are a tool for predicting the traits that will result from crossing certain genotypes.

19. Monohybrid Crosses i i IA i IA i i i IAi X ii IBIB X IAi Dd X dd
Note 1: By convention, you should always write the dominant allele in front of the recessive allele for each gene
Example #1: IAi X ii
Note 2: A Punnett square isn’t enough. You must summarize your answer, like below.
Mom’s eggs IA i
Dad’s sperm
i i i
IA i
Genotypic % Phenotypic %
Iai – 50% A – 50%
ii – 50% O – 50% i
IA i
i i

20. Monohybrid Crosses IAIB IAIB IB i IB i IAi X ii IBIB X IAi Dd X dd
Note 3: By convention, write the A allele in front of the B allele, when both are present
Example #2: IBIB X IAi
Mom’s eggs IB IB
Dad’s sperm
IAIB IA
IAIB
Genotypic % Phenotypic %
IaIB – 50% AB – 50%
IBi – 50% B – 50% i
IB i
IB i

21. Monohybrid Crosses dd Dd Dd dd IAi X ii IBIB X IAi Dd X dd
Example #3: Dd X dd
Mom’s eggs D d
Dad’s sperm dd d Dd
Genotypic % Phenotypic %
Dd – 50% Rh+ 50%
dd – 50% Rh- 50% d Dd dd

22. Dihybrid Crosses
IAiDd X iiDd
AB- X iiDD
IBiDd X IAiDD
IAidd X IBiDd

23. Dihybrid Crosses Example #1: IAiDd X iiDd IAiDd X iiDd AB- X iiDD
IBiDd X IAiDD
IAidd X IBiDd
Example #1: IAiDd X iiDd
Mom’s eggs
IAD
IAd iD id
IAiDD
IAiDd
iiDD
iiDd iD
Genotype Phenotype
IAiDD – 1/ A+ 3/8
IAiDd – ¼
Iadd – ¼ A- 1/8
iiDD – 1/8 O+ 3/8
iiDd – ¼
Iidd – 1/ O- 1/8
Dad’s sperm
IAiDd
iiDD
iiDd
IAiDD
FOIL for algebra problems – First, Outside, Inside, Last iD
IAiDd
IAidd
iiDd
iidd id
IAiDd
IAidd
iiDd
iidd id

24. Dihybrid Crosses Example #2: IAIBdd X iiDD IAiDd X iiDd AB- X iiDD
IBiDd X IAiDD
IAidd X IBiDd
Example #2: IAIBdd X iiDD
Mom’s eggs
IBd
IAd
IAd
IBd
IAiDd
IAiDd
IBiDd
IBiDd iD
Genotype Phenotype
IAiDd – 50% A+ 50%
IBiDd – 50% B+ 50%
Dad’s sperm
IAiDd
IAiDd
IBiDd
IBiDd iD
IAiDd
IAiDd
IBiDd
IBiDd iD
Shortcut!
IAiDd
IAiDd
IBiDd
IBiDd iD

25. Dihybrid Crosses Example #3: IBiDd X IAiDD IAiDd X iiDd AB- X iiDD
IAidd X IBiDd
Example #3: IBiDd X IAiDD
Mom’s eggs
IBD
IBd iD id
IAIBDD
IAIBDd
IAiDD
IAiDd
IAD
Genotype Phenotype
IAIBDD 1/ AB+ ¼
IAIBDd 1/8
IAiDD 1/ A+ ¼
IAiDd 1/8
IBiDD 1/ B+ ¼
IBiDd 1/8
iiDD 1/ O+ ¼
iiDd /8
Dad’s sperm
IAIBDD
IAIBDd
IAiDD
IAiDd
IAD
IBiDD
IBiDd
iiDD
iiDd iD
IBiDD
IBiDd
iiDD
iiDd iD

26. Dihybrid Crosses Example #4: IAidd X IBiDd IAiDd X iiDd AB- X iiDD
IBiDd X IAiDD
IAidd X IBiDd
Example #4: IAidd X IBiDd
Mom’s eggs
IAd id
IAd id
IAIBDd
IAIBDd
IBiDd
IBiDd
IBD
Genotype Phenotype
IAIBDd 1/ AB+ 1/8
IAIBdd 1/ AB- 1/8
IAiDd 1/ A /8
IAidd 1/ A /8
IBiDd 1/ B+ 1/8
IBidd 1/ B /8
iiDd 1/ O+ 1/8
iidd / O /8
Dad’s sperm
IAIBdd
IAIBdd
IBd
IBidd
IBidd
IAiDd
IAiDd
iiDd
iiDd iD id
IAidd
IAidd
iidd
iidd

27. Closure What were our objectives, and what did we learn?
What was our learner profile trait and how did we demonstrate it?
How does what we did today tie to our unit question?

28. Exit Ticket What blood type is shown?
What are the possible genotypes of this blood?
To which blood types could this person donate blood?
From which blood types could this person receive blood?
What are the genotypic and phenotypic ratios produced by the cross of IAiDD and IBIBdd?