Patterns of Inheritance

1. Patterns of Inheritance Pedigrees

2. Pedigrees • Visually displays inheritance patterns across a family tree • Useful for tracing the inheritance patterns of disease and other genetic abnormalities • Autosome: A non-sex chromosome, equal number of copies of these chromosomes in males an females • 22 autosomal pairs in humans + 1 pair sex chromosomes

3. Pedigree Basics • Females represented by circles • Males represented by square Unaffected or Carrier Affected Unaffected or Carrier Affected

4. Pedigree Basics Parents • Horizontal lines connect parents • Vertical lines denote descendants of parents • All offspring of the same parents are connected by horizontal lines Offspring

5. Pedigree Basics • Individuals are numbered left to right starting from the first line and continue down the whole pedigree 1 2 1 3 4 5 6 7

6. Analyzing a Pedigree • Autosomal Dominant Inheritance • Trait usually does not skip generations • An affected person married to an unaffected person should have approximately 50% of the offspring being affected. • Affected individual is heterozygous for the trait • Distribution of the trait should be close to equal distribution among the sexes. http://csm.colostate-pueblo.edu/biology/dcaprio/350/pedrules.html

7. Analyzing a Pedigree • Autosomal Recessive Inheritance • Trait can skip generations. • Distribution of the trait should be close to equal distribution among the sexes. • Traits are often found in pedigrees with consanguineous marriages (Marriage among close relatives). • If both of the parents are affected, all of the children should be affected. • Most affected individuals have "normal" parents who were carriers. • When an unaffected person is married to an affected individual, all of the children are normal • The normal parent is homozygous dominant • If a heterozygous carrier is married to an affected individual, then approximately half of the children should be affected. • Showing that the "normal" parent is heterozygous http://csm.colostate-pueblo.edu/biology/dcaprio/350/pedrules.html

8. Carriers • Carriers of a trait will not express the trait but their offspring may exhibit the trait

9. Blood Types • Important to know blood type because giving someone the wrong blood type leads to severe complications and death • Individuals carry antibodies to non-self blood types

10. Blood Types • Basic rules: • Type A : AA or AO • Antibodies against type B • Type B: BB or BO • Antibodies against type A • Type O: OO • Universal donor, no antigens • Type AB: AB • Universal acceptor, no antibodies http://learn.genetics.utah.edu/content/begin/traits/blood/images/ABObloodsystem.gif

12. Lab Exam • Lab exam 2 Next Week • Know everything that is on the study guide

13. Exam 2 Review • Cell cycle lab • Know the phases of mitosis and be able to calculate time spent in each cell cycle (remember, 16 hours is not a constant!) • Punnet squares • Know how to analyze genetic crosses • Know how to calculate genotypic and phenotypic ratios, percentages, etc… • Pedigrees • Be able to draw and analyze a pedigree

14. Exam 2 Material • PCR • Understand what is happening in the reaction • Know what each reagent does and what role each plays in the reaction • Know the rules of primer design, and be able to make both forward and reverse primers • Know what is happening and the temperatures during denaturation, annealing, and elongation.

15. TA Evaluations

16. Next Lab • Exercise 6 on pedigrees due • Lab quiz 2 • If you are taking BSC 196 DO NOT SELL BACK YOUR TEXTBOOKS! You will use the same textbook that you used for this class.