Hartl, Jones - Genetics. Principlers and analysis - 1998, страница 4

Burke, Georges F. Carle,and Maynard V. Olson 1987Washington University,St. Louis, MissouriCloning of Large Segments of ExogenousDNA into Yeast by Means of ArtificialChromosome VectorsScience 236: 806–812Carol W. Greider andElizabeth H. Blackburn1987University of California,Berkeley, CaliforniaThe Telomere Terminal Transferaseof Tetrahymena Is a Ribonucleoproteinwith Two Kinds ofPrimerSpecificityCell 51:887–898Micheline Strand1, Tomas A.Prolla2, R. Michael Liskay2,and Thomas D.

Petes1 19931University of North Carolina,Chapel Hill, North Carolina2Yale University,New Haven, ConnecticutDestabilization of Tracts of SimpleRepetitive DNA in Yeast by MutationsAffecting DNA Mismatch RepairNature 365: 274–276The Huntington's DiseaseCollaborative Research Group 1993Comprising 58 authors among9 institutionsA Novel Gene Containing a TrinucleotideRepeat That is Expanded and Unstable onHuntington's Disease ChromosomesCell 72: 971–983Jeffrey C.

Murry and26 other investigators 1994University of Iowa and 9 otherresearch institutionsA Comprehensive Human Linkage Mapwith Centimorgan DensityScience 265: 2049–2054Ian Wilmut, Anagelika E.Schnieke, Jim McWhir, Alex J.Kind, and Keith H. S. Campbell 1997Roslin Institute, Roslin, Midlothian,ScotlandViable Offspring Derived from Fetal andAdult Mammalian CellsNature 385: 810–813Page xvPrefaceThis book is titled Genetics: Principles and Analysis, Fourth Edition, because it embodies our beliefthat a good course in genetics should maintain the right balance between two important aspects ofthe science. The first aspect is that genetics is a body of knowledge pertaining to genetictransmission, function, and mutation.

This constitutes the Principles. The second aspect is thatgenetics is an experimental approach, or a kit of "tools," for the study of biological processes suchas development or behavior. This is Analysis.The overall aim of Genetics: Principles and Analysis, Fourth Edition, is to provide a clear,comprehensive, rigorous, and balanced introduction to genetics at the college level.

It is a guide tolearning a critically important and sometimes difficult subject. The rationale of the book is that anystudent claiming a knowledge of genetics must:• Understand the basic processes of gene transmission, mutation, expression, and regulation;• Be able to think like a geneticist at the elementary level of being able to formulate genetichypotheses, work out their consequences, and test the results against observed data;• Be able to solve problems of several types, including problems that ask the student to verbalizegenetic principles in his or her own words, single-concept exercises that require application ofdefinitions or the basic principles of genetics, genetic analysis in which several concepts must beapplied in logical order, and quantitative problems that call for some numerical calculation;• Gain some sense of the social and historical context in which genetics has developed and iscontinuing to develop; and• Have some familiarity with the genetic resources and information that are available through theInternet.Genetics: Principles and Analysis, Fourth Edition, incorporates many special features to helpstudents achieve these learning goals.

The text is clearly and concisely written in a somewhatrelaxed prose style without being chummy or excessively familiar. Each chapter is headed by a listof Principles that are related at numerous points to the larger whole. Each chapter contains two orthree Connections in which the text material is connected to excerpts of classic papers that reportkey experiments in genetics or that raise important social, ethical, or legal issues in genetics. EachConnection has a brief introduction of its own, explaining the importance of the experiment and thehistorical context in which it was carried out.

At the end of each chapter is a complete Summary,Key Terms, GeNETics on the web exercises that guide students in the use of Internet resources ingenetics, and several different types and levels of Problems. These features are discussedindividually below.In recent decades, both the amount of genetic knowledge and its rate of growth have exploded.Many of the new discoveries have personal and social relevance through applications of genetics tohuman affairs in prenatal diagnosis, testing for carriers, and identification of genetic risk factors forcomplex traits, such as breast cancer and heart disease. There are also ethical controversies: Shouldgenetic manipulation be used on patients for the treatment of disease? Should human fetuses be usedin research? Should human beings be cloned? There are also social controversies—for example,when insurance companies exclude coverage of people because of their inherited risks of certaindiseases.Inspired in part by the controversies and the publicity, many of today's students come to a course ingenetics with great enthusiasm.

The challenges for the teacher are:• To sustain this enthusiasm;• To help motivate a desire to understand the principles of genetics in a comprehensive and rigorousway;• To guide students in gaining an understanding that genetics is not only a set of principles but alsoan experimental approach to solving a wide range of biological problems; and• To help students learn to think about genetic problems and about the wider social and ethicalissues arising from genetics.While addressing these challenges in Principles and Analysis, we have also tried to show the beauty,logical clarity, and unity of the subject. Endlessly fascinating, genetics is the material basis of thecontinuity of life.Chapter OrganizationIn order to help the student keep track of the main issues and avoid being distracted by details, eachchapter begins with a list of the Principles that provide the main focus of the chapter.

There is alsoan Outline, showing step by step the path along the way. An opening paragraph gives an overviewof the chapter, illustrates the subject with some specific examples, and shows how the material isconnected to genetics as a whole. The text makes liberal use of numbered lists and "bullets" in orderto help students organize their learning, as well as summary statements set off in special type inorder to emphasize important principles.

Each chapter ends with a Summary and list of Key Termsas well as the Problems. There is aPage xviConcise Dictionary of Genetics at the end of the book for students to check their understanding ofthe Key Terms or look up any technical terms they may have forgotten. The Dictionary includes notonly the Key Terms but also genetic terms that students are likely to encounter in exploring theInternet or in their further reading. The Dictionary also includes page references for terms defined inthe text.ContentsThe organization of the chapters is that favored by the majority of instructors who teach genetics.

Itis the organization we use in our own courses. An important feature is the presence of anintroductory chapter providing a broad overview of genes—what they are, how they function, howthey change by mutation, and how they evolve through time. Today, most students learn about DNAin grade school or high school; in our teaching, we have found it rather strange to pretend that DNAdoes not exist until the middle of the term. The introductory chapter serves to connect the moreadvanced concepts that students are about to learn with what they already know. It also serves toprovide each student with a solid framework for integrating the material that comes later.Throughout each chapter, there is a balance between observation and theory, between principle andconcrete example, and between challenge and motivation.

Molecular, classical, and evolutionarygenetics are integrated throughout. A number of points related to organization and coverage shouldbe noted:• Chapter 1 is an overview of genetics designed to bring students with disparate backgrounds to acommon level of understanding. This chapter enables classical, molecular, and evolutionarygenetics to be integrated in the rest of the book. Included in Chapter 1 are the basic concepts ofgenetics: trait, gene, genotype, phenotype, gene interaction, and so forth.

Chapter 1 also includes adiscussion of the experimental evidence that DNA is the genetic material, as well as a description ofDNA structure and how DNA codes for proteins.• Chapters 2 through 4 are the core of Mendelian genetics, including segregation and independentassortment, the chromosome theory of heredity, mitosis and meiosis, linkage and chromosomemapping, and tetrad analysis in fungi. Also included is the basic probability framework ofMendelian genetics and the testing of genetic models by means of the chisquare test.An important principle of genetics, too often ignored or given inadequate treatment, is that of thecomplementation test and how complementation differs from segregation or other geneticprinciples.

Chapter 2 includes a clear and concise description of complementation, with examples,showing how complementation is used in genetic analysis to group mutations into categoriescorresponding to genes. This chapter also introduces the use of molecular markers, especially withreference to human genetic analysis, because these are the principal types of genetic markers oftenused in modern genetics.• Chapters 5 and 6 deal with the molecular structure and replication of DNA and with themolecular organization of chromosomes. A novel feature is a description of how basic research thatrevealed the molecular mechanisms of DNA replication ultimately led to such important practicalapplications as DNA sequencing and the polymerase chain reaction.