Introduction to Genetic Analysis, Chapter 1 PDF

Anthony J.F. Griffiths, John Doebley, Catherine Peichel, David A. Wassarman An Introduction to Genetic t Analysis TWELFTH EDITION Lecture Slides CHAPTER ONE Copyright © 2020, W.H. Freeman and Company  Key Concepts 1. The history o...

Anthony J.F. Griffiths, John Doebley, Catherine Peichel, David A. Wassarman An Introduction to Genetic t Analysis TWELFTH EDITION Lecture Slides CHAPTER ONE Copyright © 2020, W.H. Freeman and Company  Key Concepts 1. The history of discovery in genetics 2. The review of molecules involved in storage and expression of genetic information 3. The review of basic tools for genetic research 4. The influence and impact of genetics to our society 1.1 The Birth of Genetics (1 of 11) Children resemble their parents  1.1 The Birth of Genetics (2 of 11) Gregor Mendel and his experiments, 1856–1863 1.1 The Birth of Genetics (3 of 11) Gregor Mendel’s conclusions: 1. Genes behave like particles and do not blend together. 2. One allele is dominant to the other. 1.1 The Birth of Genetics (4 of 11) The rediscovery of Mendelism and the birth of the genetics revolution, 1904 Genetics—the study of inheritance. Bateson, 1904.  1.1 The Birth of Genetics (5 of 11) Historical milestones in genetics: Thomas, H. Morgan discovered Mendel’s genes are located on chromosomes. 1910. Ronald Fisher discovered that multiple Mendelian factors can explain continuous variation for traits, founding the field of quantitative genetics. 1916. Edward Tatum and George Beadle proposed the one-gene–one- polypeptide hypothesis. 1941. James Watson and Francis Crick, using data produced by Rosalind Franklin and Maurice Wilkins, determined that DNA forms a double helix. 1953. Francis Crick introduced the phrase “central dogma” to represent the flow of genetic information within cells from DNA to RNA to protein. 1958.  1.1 The Birth of Genetics (6 of 11) Historical milestones in genetics: 1961: François Jacob and Jacques Monod proposed that enzyme levels in cells are controlled by feedback mechanisms. 1961–1967: Marshall Nirenberg, Har Gobind Khorana, Sydney Brenner, and Francis Crick “cracked” the genetic code. 1977: Fred Sanger, Walter Gilbert, and Allan Maxam invented methods for determining the nucleotide sequences of DNA molecules. 2001: The sequence of the human genome is first published. 2012: Genome editing with the modified CRISPR-Cas9 system.  1.1 The Birth of Genetics (7 of 11) Multiple Mendelian factors can explain continuous variation for traits, founding the field of quantitative genetics. Ronald Fisher, 1916.  1.1 The Birth of Genetics (8 of 11) Edward Tatum and George Beadle proposed the one- gene–one-polypeptide hypothesis. 1941.  1.1 The Birth of Genetics (9 of 11) In 1953 James Watson and Francis Crick, using data produced by Rosalind Franklin and Maurice Wilkins, determined that DNA forms a double helix. 1.1 The Birth of Genetics (10 of 11) Francis Crick introduced the phrase “central dogma” in 1958 to represent the flow of genetic information within cells from DNA to RNA to protein. 1.1 The Birth of Genetics (11 of 11) In 1961, François Jacob and Jacques Monod proposed that enzyme levels in cells are controlled by feedback mechanisms. 1.2 After Cracking the Code (1 of 5) Model organisms 1.2 After Cracking the Code (2 of 5) Model organisms Genetic discoveries made in a model organism are often true of related species and may even apply to all forms of life. Small size, small genome, large numbers of offspring, and short generation time are the common features for model organisms. 1.2 After Cracking the Code (3 of 5) Tools for genetic analysis The enzymatic machinery for copying, pasting, cutting, and transcribing DNA: DNA polymerases Nucleases Ligases 1.2 After Cracking the Code (4 of 5) Tools for genetic analysis DNA cloning in E. coli Transformation and genetically modified organism (GMO) 1.2 After Cracking the Code (5 of 5) Tools for genetic analysis Hybridizing DNA molecules to one another or to RNA molecules Using molecular and computational tools to analyze the entire genome of an organism—genomics  1.3 Genetics Today (1 of 12) From classical genetics to medical genomics A patient of arterial calcification due to deficiency of CD73, an autosomal recessive condition.  1.3 Genetics Today (2 of 12) From classical genetics to medical genomics A patient of arterial calcification due to deficiency of CD73, an autosomal recessive condition. The patient is the child of a marriage between two third cousins.  1.3 Genetics Today (3 of 12) Investigating mutation and disease risk Study and compare complete genome sequences of “trios”—a family group of a mother, a father, and their child.  1.3 Genetics Today (4 of 12) Investigating mutation and disease risk The correlation between the father’s age and disease risk— older fathers were more likely to have new point mutations.  1.3 Genetics Today (5 of 12) When rice gets its feet a little too wet  1.3 Genetics Today (6 of 12) When rice gets its feet a little too wet In FR13A plants that become submerged, genes involved in stem and leaf elongation are switched off, as are genes involved in mobilizing the energy reserves (carbohydrates) needed to fuel the escape strategy, so that plants can survive under flooding.  1.3 Genetics Today (7 of 12) Recent evolution in humans: adaptation to life at high altitude Native Tibetans are far less likely to experience pulmonary hypertension and the associated formation of blood clots that underlie it.  1.3 Genetics Today (8 of 12) Recent evolution in humans: adaptation to life at high altitude The Tibetan version of EPAS1 is expressed at a lower level than the lowland version, so their bodies are not as stimulated by EPAS1 to overproduce RBCs at high altitude, and thus they avoid the associated blood clots and pulmonary hypertension. Remarkably, a single SNP in a regulatory element for EPAS1 seems to be the key genetic variant for this adaptation.  1.3 Genetics Today (9 of 12) Recent evolution in humans: the complex genetics of color blindness  1.3 Genetics Today (10 of 12) Recent evolution in humans: the complex genetics of color blindness The opsin gene for blue light detection is located on an autosome. The opsin genes for red and green light detection are neighbors located on X chromosome.  1.3 Genetics Today (11 of 12) Recent evolution in humans: the complex genetics of color blindness The opsin genes for red and green light detection are neighbors located on X chromosome. Unequal crossing over can produce hybrid opsin in women, in which either the green opsin is missing, or a hybrid gene is formed. Either of these causes red-green color blindness in women.  1.3 Genetics Today (12 of 12) Recent evolution in humans: the complex genetics of color blindness Red-green color-blind monkey The monkey treated with gene therapy and can distinguish red from green color.