Exams back T 9/30 Bonus #1 is due 10/02

1. Regulating Gene Expression Exams back T 9/30 Bonus #1 is due 10/02

2. What makes us who we are? Nature and Nurture Based on “Nature via Nurture” by Matt Ridley (2003)

3. Genes Traits Genes code for proteins. These proteins give rise to traits…

4. Genes Traits Genes code for proteins. These proteins give rise to traits… It is rarely this simple.

5. Imprinting: exposure to movement (environment) sets “mother”

6. X/Y chromosomes in humans:genes = traits

7. This article, shows how even today people see nature and nurture as opposing each other: The Pathogenesis of the Glaucomas:Nature versus NurtureMackey, et al., Clinical & Experimental Opthamology vol 36, pg 297, April 2008

8. Twin studies have been used to determine the heritability of various traits.

9. Types of twins: http://pennhealth.com/health_info/pregnancy/000199.htm

10. Twin studies have been used to determine the heritability of various traits, but there are some caveats:How many twins have been studied? How different are the environments?

11. Correlation of weight (BMI) % Identical twins reared together 80 Identical twins reared apart 72 Fraternal twins reared together 43 Biological siblings 34 Parents and children living together 26 Adopted children and parents 4 Unrelated children living together 1 *But food preference shows little genetic correlation Correlation of weight and relatedness The nature of environmental influences on weight and obesity: A behavior genetic analysis. Grilo, Carlos M.; Pogue-Geile, Michael F.; Psychological Bulletin, Vol 110(3), Nov 1991. pp. 520-537. And two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

12. Intelligence Correlation of IQ Inheritance : % The same person tested twice 87 Identical twins reared together 86 Identical twins reared apart 76 Fraternal twins reared together 55 Biological siblings 47 Parents and children living together 40 Parents and children living apart 31 Adopted children living together 0 Unrelated people living apart 0 From two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

13. When the environment is equal (everyone has access to resources), genetic differences are magnified. When environments are different (only a few have access to resources), environmental differences are magnified.

14. Proof or disproof? Correlation of IQ Inheritance : % The same person tested twice 87 Identical twins reared together 86 Identical twins reared apart 76 Fraternal twins reared together 55 Biological siblings 47 Parents and children living together 40 Parents and children living apart 31 Adopted children living together 0 Unrelated people living apart 0 From two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

15. Can we see a genetic basis for complex behaviors?

16. Prairie Monogamous Both parents care for young Montane Nonmonogamous Mother cares for young briefly Voles

17. Oxytocin and Vasopressin (hormones) Encourages bonding between individuals Water/salt balance Contraction of womb and milk production

18. Hormones are molecules produced in one cell and signal another.

19. Oxytocin and Vasopressin (hormones) Encourages bonding between individuals Water/salt balance Contraction of womb and milk production

20. Prairie Monogamous Both parents care for young Montane Nonmonogamous Mother cares for young briefly Voles

21. Prairie Monogamous Both parents care for young Montane Nonmonogamous Mother cares for young briefly Voles Same levels of oxytocin and vasopressin

22. Hormones are molecules produced in one cell and signal another.

23. Prairie Monogamous Both parents care for young More receptors Montane Nonmonogamous Mother cares for young briefly Less receptors Voles Same levels of oxytocin and vasopressin

24. Prairie Monogamous Both parents care for young More receptors ? Montane Nonmonogamous Mother cares for young briefly Less receptors ? Voles Same levels of oxytocin and vasopressin Inject hormone into brain

25. Prairie Monogamous Both parents care for young More receptors Monogamous Montane Nonmonogamous Mother cares for young briefly Less receptors Nonmonogamous Voles Same levels of oxytocin and vasopressin Inject hormone into brain

26. Prairie Monogamous Both parents care for young More oxytocin receptors ? Montane Nonmonogamous Mother cares for young briefly Less oxytocin receptors ? Voles Same levels of oxytocin and vasopressin Block receptors

27. Prairie Monogamous Both parents care for young More oxytocin receptors Nonmonogamous Montane Nonmonogamous Mother cares for young briefly Less oxytocin receptors Nonmonogamous Voles Same levels of oxytocin and vasopressin Block receptors

28. Prairie Monogamous Both parents care for young More oxytocin receptors Monogamous Montane Nonmonogamous Mother cares for young briefly Less oxytocin receptors Monogamous Voles Same levels of oxytocin and vasopressin Increase levels of receptors (genetically) in ventral pallidum

29. Prairie Monogamous Both parents care for young More receptors Montane Nonmonogamous Mother cares for young briefly Less receptors Voles Same levels of oxytocin and vasopressin

30. Prairie voles Monogamous Both parents care for young Montane voles Nonmonogamous Mother cares for young briefly Why might these voles use different reproductive strategies?

31. Prairie voles: Resource poor habitat Monogamous Both parents care for young Montane voles: Resource rich habitat Nonmonogamous Mother cares for young briefly Why might these voles use different reproductive strategies?

32. We looked at the mechanisms of gene expression, now we will look at its regulation. Combinations of 3 nucleotides code for each 1 amino acid in a protein.

33. Exons are a very small part of DNA

34. Fig 15.1 Each step in gene expression presents an opportunity to regulate when and how much of a gene product will be produced.

35. Fig 15.1 • Why change gene expression? • Different cells need different components • Responding to the environment • Replacement of damaged/worn-out parts

36. Two points to keep in mind: • Cellular components are constantly turned-over. • Gene expression takes time: Typically more than an hour from DNA to protein. Most rapidly 15 minutes. Fig 15.1

37. Blood clotting must happen within minutes

38. mRNA levels change in response to cold acclimation Fowler and Thomashow The Plant Cell, Vol. 14, 1675-1690, 2002

39. DNA damage inhibits rRNA transciption Fig 1b The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaksNature Vol 447 pg 730-734 (7 June 2007)

40. Gene expression can be controlled at many points between DNA and making the final proteins. • Changes in the various steps of gene expression control when and how much of a product are produced. Fig 15.1