1. WELCOME to
Bio 230: Genetics
Dr. Erin Gestl
Jan 24
Pages 1-28

2. On-line Resources http://darwin.wcupa.edu/faculty/gestl Syllabus
Powerpoint Lectures

3. TEXTBOOK Introduction to Genetic Analysis 11TH EDITION
Griffiths • Wessler • Carroll • Doebley

4. Quiz 1 Name Major List three things you know about genetics.
List three things that are controversial (in the news) concerning genetics.
List three things you hope to learn in class.
#3 Imagine you are a geneticist in the future….what could you be working on
addressing food shortages by genetically modifying plants to make them resistant to fungal infections
determining which single nucleotide polymorphisms are associated with human disorders
investigating which genes are involved in mammalian development from conception to birth
searching for mutations in genes that result in human diseases

5. Discuss as a class So what are some controversial topics in genetics?
What would you most like to learn?

6. Chapter 1: Genetics Revolution
Genetics – Study of inheritance

7. Genetic Inheritance Originally purposed as the Blending theory
Red x white flowers = pink flowers
Tall person x short person = average height person
It became clear very quickly this was not how nature worked

8. Mendel and his peas Gregor Mendel– 1863
Proposed Mendel’s particles not fluid (which are now called genes)
Peas had two copies of each gene in plant body (somatic cells) and only one copy in sex cells (gametes)
Introduced dominant vs recessive alleles
Explained why Pink x Pink flowers
yield white and red flowers

9. Complex Traits Single-Gene Traits Red x white flowers = pink flower
Person’s height

10. Mendel’s law of Equal Segregation
During the production of gametes the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent
Hereditary factors are called genes
Diploids have two copies of each gene
Genes come in different forms called alleles
Capital letter (A) allele is dominant, a is recessive
Members of a gene pair (Aa) separate equally into gamete

11. One of Mendel’s experiments

12. Model Organisms
A species used in experimental biology with the presumption that what is learned will hold true for other species.
Characteristics
Easy and inexpensive to maintain
Short generation time
Very simple to cross/mate
Produce ample numbers of offspring
Well suited to answer a scientific question

13. Model Organisms in Genetics
What makes a model organism a “model” organism?
What features are key?
Easy and inexpensive to maintain
Short generation time
Very simple to cross/mate
Produce ample numbers of offspring

23. Genetics Today
Farmers grow rice using controlled flooding Problem: In poverty areas water is not well regulated and the can kill the rice if it remains flooded
1. that is, individuals with a particular characteristic may reproduce better than others in a given environment.
2. (i.e., mutations).
3. Charles Darwin proposed that evolution occurred through the process of natural selection.

24. Genetics Today
A submerged resistant strain was identified, but it had a poor yield Solution: Cross the 2 strains to create a strain that is both high yield and submerged resistant American Chestnut
1. that is, individuals with a particular characteristic may reproduce better than others in a given environment.
2. (i.e., mutations).
3. Charles Darwin proposed that evolution occurred through the process of natural selection.

25. Genetics and Evolution
Evolution depends on natural selection
Evolution depends on genetic variation
Who purposed evolution occurs through natural selection?
For evolution to occur, allele frequencies in a population must change over several generations.
Gene variants arise from mutations
1. that is, individuals with a particular characteristic may reproduce better than others in a given environment.
2. (i.e., mutations).
3. Charles Darwin proposed that evolution occurred through the process of natural selection.

26. Single Nucleotide Polymorphisms SNPs
-a DNA nucleotide variation occurring in the genome between two members of the same species

27. Occurrance in Humans -1 in 1000 bases, 0.1%
-3 to 10 million SNPs in the
human genome

28. How does genetics influence our diet?
Any examples?
Celiac Disease
Can not digest gluten (lack the enzyme)
Yes this is Hereditary (Genetics)
This is different than “gluten intolerant”
Lactose intolerance
Lack Lactase enzyme to digest the sugar found in dairy known as lactose

29. Genetics associate with diet
T variant have persistent expression of the lactase gene into adulthood
C variant have their lactase gene switched off after childhood (lactose intolerant)
A protein called OCT1 can bind to the T variant and turn on lactase gene expression
Single nucleotide polymorphisms can be used to determine in which parental germ line (i.e., in egg cells or sperm cells) a new point mutation occurred.
Some human populations have lactase gene variants expressed in adults
People with the T variant have persistent expression of the lactase gene into adulthood, where as people with the C variant have their lactase gene switched off after childhood

30. Review Question
Which of the following traits is not ideal for a model organism?
Easy and inexpensive to maintain
Short generation time
A large complex genome that allows for the creation of billions of possible mutations
Very simple to cross/mate and produce ample numbers of offspring even though you my only need a couple progeny per project

31. In the news….
The octopus genome and the evolution of cephalopod neural and morphological novelties (Albertin et al., 2015)
What is something you learned from this video?