Case Study: The world wide distribution of lactose intolerance - PowerPoint Presentation

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Case Study: The world wide distribution of lactose intolerance

University of Kentucky: Andrew BouwmaPeter MirabitoJeffrey Osborn

Stanford University:Shyamala MalladiPatricia Seawell

University of Miami: Douglas L. CrawfordMarjorie F. Oleksiak

Facilitators:

Kimberly Tanner,

San Francisco State Univ.

Langdon Martin,

Univ Wisconsin

Classroom Setting

Sophomore Genetics Course Students have been introduced to GenesMolecular Mechanisms of TranscriptionTranscriptional RegulationMolecular Mechanisms of TranslationTranslational Regulation

Learning Goals –

Measurable OutcomeStudents will understandStudents will be able to(1) the concept of a gene- Sketch a representation of a gene and label its parts (promoter, intron, exon, termination signal)

- Relate Mendel’s inheritable traits to a gene(2) the mechanism of transcription

- List, order and define the active players in transcription (or diagram)- contrast the structure of nuclear DNA and hnRNA with cytoplasmic mRNA(3) the regulation of transcription

- how does exercise lead to larger muscle mass

- predict which genes might be expressed under conditions of exercise or hypoxia (low blood oxygen)

- how does eating more sugar lead to more absorption of sugars

(4) the mechanism of translation

- Generate a strip sequence that describes the process/mechanism of translation

- Describe how some antibiotics kill bacteria

(5) the regulation of translation

- compare and contrast global vs mRNA specific regulation

- imagine five ways that protein synthesis can be regulated

(6) how genes affect phenotypes

- explain how skin becomes darker when exposed to the sun

- describe how DNA affects the production of hemoglobin

- - explain why a person of northern European descent can drink milk, while a majority of the world population cannot

(7) and engage in specific components of the scientific process.

- read and interpret

biogeographical

maps

- read and apply appropriate information from the primary literature to a scientific problem or question.

Learning Goal6) Genotype

 Phenotype7) Engagement in the Scientific ProcessOutcomes:Interpret the biogeographical mapsRead and apply appropriate information from the primary literature to address a scientific problem. Students will explain why specific populations maintain the ability to drink and digest milk through adulthood.

What do you think is the percentage of adults around the world who are lactose intolerant?

A:0-20% B: 20-40% C: 40-60% D: 60-80% E:>80%

Lactose is milk sugar, a disaccharide in all mammalian milkLactose intolerance is the inability to digest lactose, because of a lack of the required enzyme lactase in the digestive system.

Drinking milk without having an active lactase enzyme produces gastro-intestinal distress (e.g.,diarrhea).It is estimated that 75% of adults worldwide show lactose intolerance.Lactose and Lactose Intolerance

Adult Worldwide Milk Intolerance

due to the Inability to Digest Lactose

Milk

Intolerance

Adapted from http://en.wikipedia.org/wiki/Lactose_intolerance

Native Americans

Aboriginal Australians

Adult Worldwide Lactose Intolerance

What do these data say about the worldwide distribution of the ability to drink and digest milk as an adult?Think & Write 1 minutePair-Share 2 minutes

Milk

Intolerance

Predict

What would you predict is the relationship between the world wide distribution of adult and infant lactose intolerance?A: SameB: OppositeC: UnrelatedD: Same except for North America

Milk

Intolerance

Discuss Convince your neighbor and revote

What is the relationship between the world wide distribution of adult and infant lactose intolerance?

A: Same

B: OppositeC: UnrelatedD: same except for North America

What is the relationship between the world wide distribution of adult and infant lactose intolerance?

Frequency of Lactose Intolerance in Infants

>90% Tolerance

Milk

Intolerance

Brainstorm

Given these data:75% of adults worldwide cannot drink and digest milkYet nearly all infants are able to digest milkPropose molecular mechanisms to explain why only a few populations have the ability to drink and digest milk throughout adulthood.

Choose a hypothesis

The molecular mechanism that explains why only a few populations have the ability to drink and digest milk throughout adulthood includes variation in:A: the coding region of the lactase geneB: the regulatory region of the lactase geneC: transcription factorsD: the post-translational modification of the enzyme lactaseE: None of the above

For your final assessment Read the Genetics paper on “Lactose Intolerance”

Write a short essay (250 words) to defend one hypothesis and refute one other > Paper will be posted on Blackboard. > Potential hypotheses will be posted. > Biogeographic map will be posted.

Diversity: Not using red-green map colors

Population diversity Teaching methods addresses a diversity of learning styles Possible discussion of “Got Milk”Activity/AssessmentTopicTimeClickerThink about people you know who are lactose intolerant1 minute

Map InterpretationAnalysis of biogeographical data2 minutesThink and WritePair-Shore

How much diversity is there in lactose intolerance3 minutesClickerPredict infant milk intolerance1 minute

Clicker

Discuss and revote

2 minutes

Brainstorm and write

Propose

molecular mechanisms to explain lactose intolerance

1 minute

Clicker pre-assessment

Vote

on molecular mechanisms to explain lactose intolerance

1 minute

Final

assessment

Defend and refute hypotheses

Homework