What's New and Exciting About This EditionFocus on Genomics - Of SNPs, Chips, and More
While Mendel's laws, the DNA double helix, protein synthesis and population dynamics will always form the foundation of genetics, the gradual shift to a genomic view opens many new research doors, and introduces new ways of thinking about ourselves. Completion of the human genome draft sequence has catapulted human genetics from the one-gene-at-a-time approach of the last half of the last century to a more multifactorial view. Genes and the environment interact to mold who we are. It is a little like jumping from listening to individual instruments to experiencing a symphony created by an entire orchestra.
The fourth edition of Human Genetics: Concepts and Applications introduced genomics; in the fifth edition, the impact of this new view of genes is so pervasive that it is integrated into many chapters, rather than saved for a final chapter. Rather than bludgeon the reader with details, acronyms and jargon, the approach to genomics is in context - association studies in chapter 7, human genome annotation in chapter 10, filling in chromosome details in chapter 12, and glimpses into human evolution in chapter 15. Immunity is presented in chapter 16 from the point of view of the pathogen, courtesy of genomes. Because of the integration of the genomic view throughout the text, the final chapter is free to tell the story of how this view came to be - and where it will go. New Chapter on Behavior
The evolution of genetic thought, from a Mendelian paradigm to a much broader consideration of genes against a backdrop of environmental influences, is perhaps nowhere more evident than in the study of human behavior. With each edition, coverage of behavior has expanded until, like a cell accumulating cytoplasm, a division was in order. The resulting binary fission of the fourth edition's chapter 7 - Multifactorial and Behavioral Traits - naturally yielded a chapter on methods and basic concepts, and another on specific interesting behaviors.
Chapter 7 in this fifth edition, Multifactorial Traits, retains the classical adoption/twin/empiric risk approaches, and introduces association studies, which are critical in analyzing the traits and disorders described in depth in chapter 8, The Genetics of Behavior.
The topics for chapter 8 came from two general sources - my curiosity, and information from several human genome conferences held since 2000. The chapter opens with a focus on new types of evidence about the role of genes in behavior, then applies these new tools to dissect the genetic underpinnings of:
Eating disorders
Sleep
Intelligence
Drug addiction
Mood disorders (depression and bipolar disorder)
Schizophrenia
The chapter is entirely new, with many compelling examples from the biomedical literature and interviews with researchers.Fabulous New Art
Long-time users of Human Genetics: Concepts and Applications will note at a glance that all of the art is new. Vibrant new colors and closer attention to clarity of concepts ease the learning experience and make studying this complex subject less intimidating. Some of the figures are also available as Active Art, which enables the learner to manipulate portions of the illustration to review the steps to a process. Entirely new illustrations include:
7.11 Association studies are correlations of SNP profiles
8.6 How alcohol alters gene expression in the brain
16.19 M cells set up immunity in the digestive tract
19.1,2,3 Three gene therapies
20.9 The global GM foods picture
22.4 Two routes to the human genome sequence
22.9 Genome sequencing, from start to finish
22.10 Comparative genomics
Several new photos put faces on genetic diseases.Tables Tell the Tale
A student reviewing for an impending exam should be able to get the gist of a chapter in 10 minutes by examining the tables - if the tables are appropriately chosen and presented, as they are in this book. Table 8.5, for example, reviews every behavioral trait or disorder discussed in this new chapter, in the order of the subsections.
Most tables summarize and organize facts, easing studying. A few tables add information (table 12.1 Five Autosomes, table 14.1 Founder Populations; table 16.8 Sequenced Genomes of Human Pathogens), and some provide perspective (table 1.1 Effects of Genes on Health). Chapter 10, Gene Action and Expression, a top candidate for "toughest chapter," illustrates how the tables tell the tale:
Table 10.1 How RNA and DNA Differ
Table 10.2 Major Types of RNA
Table 10.3 Deciphering RNA Codons and the Amino Acids They Specify
Table 10.4 The Genetic Code
Table 10.5 The Non-protein Encoding Parts of the Genome
The final table in chapter 10 is new, a summary of answers to the question, certain to be posed by students and instructors alike, "If less than 2 percent of the genome encodes protein, what does the rest of it do?" This is a table that will obviously evolve with each edition as we learn more.New "In Their Own Words"
and Bioethics Boxes
"In Their Own Words" essays are written by individuals who experience inherited disease, as patients, family members, or researchers. New essays in the fifth edition introduce:
Patricia Wright, who only recently discovered that she has had signs and symptoms of alkaptonuria all her life. (chapter 5)
Francis Barany, a microbiologist who nearly burned his leg off searching for heat-loving bacteria with useful enzymes in a Yellowstone Park hot springs. (chapter 9)
Toby Rodman, an immunologist and octogenarian who discovered a new source of antibodies that may protect against HIV infection. (chapter 16)
They join from past editions Don Miller, the first recipient of gene therapy for hemophilia; Stefan Schwartz, who has Klinefelter disease, and Kathy Naylor, whose little girl died of cri-du-chat syndrome.
Bioethics: Choices for the Future essays continue their look at controversies that arise from genetic technology. These essays explore population databases (chapter 1), cloning and stem cell research (chapter 3), sex reassignment (chapter 6), xenotransplants (chapter 16), Canavan disease as a test of fair use of genetic tests (chapter 19) and GM foods (chapter 20). Bioethical issues weave throughout the narrative as well. New section 21.4, for example, examines the dilemma of what to do with in vitro fertilized "spares." Significant Changes
in Content
The two obvious changes in content are the addition of a chapter devoted to behavior, and a substantial new section in chapter 10, "The Human Genome Sequence Reveals Unexpected Complexity." This section is essentially a summary of the mid-February 2001 issues of Science and Nature, which covered the annotation of the draft human genome sequence, aka "the golden path." The rest of the chapter has been rewritten to embrace the new genome information as well.
Favorite examples and stories have been retained, and new ones added, many gleaned from my articles in The Scientist. They include:
A breast cancer DNA "chip" that predicts which drugs will work on which women (chapter 1)
Greatly expanded coverage of stem cells (chapters 2 and 3)
Relationship between Mendel's second law and DNA microarrays (chapter 4)
Clearer coverage of mitochondrial genes (chapter 5)
Moved and expanded coverage of DNA repair (chapter 11)
Updates on chromosome structure with new coverage of centromeres and subtelomeres (chapter 12)
Applications of DNA fingerprinting to events of 9-11-01 (chapter 13)
New coverage of genetic basis of resistance to AIDS drugs (chapter 14)
New section on genome distinctions between humans and chimps
(chapter 15)
Genome information applied to immunity, with new sections on crowd diseases, bioweapons, and pathogen genomes (chapter 16)
Genetic modification of pig excrement to reduce pollution (chapter 18)
Gene therapy for Canavan disease (chapter 19)
Impact of genomics on agricultural biotechnology (chapter 20)
History of the human genome project (chapter 22)
To obtain an instructor login to the Online Learning Centers, ask your local sales representative.
If you're an instructor thinking about adopting this textbook, request a free copy for review.
2003 McGraw-Hill Higher Education