WHAT'S NEW IN THE SECOND EDITION?

Since genetics is a rapidly changing discipline, a major goal of the second edition has been to update the entire book. In some cases, this has involved minor content changes, while in other cases entire sections have been added. These major changes are described under the heading, Content Changes. In addition, the following general improvements have been made:

• Illustrations - As mentioned earlier in the Preface, all of the illustrations in the second edition have been newly drawn using state-of-the-art technology. These illustrations have been drawn with an eye toward completeness, clarity, consistency and realism.
• Problem sets - A large number of new and challenging problems have been added to the problem sets of every chapter.
• Animations - The student and instructor CD-ROM contains 43 animations.
• Website (Online Learning Center) - As described previously in this Preface, the Website for the instructor and students contain a much wider variety of resources and activities.

CONTENT CHANGES (major changes)

• Chapter 4 (Extensions of Mendelian Inheritance) - A greater emphasis has been placed on the molecular mechanisms that underlie the various patterns of inheritance.
• Chapter 6 (Genetic Transfer and Mapping in Bacteria and Bacteriophages) - The process of bacterial conjugation has been updated and more realistically illustrated.
• Chapter 7 (Non-Mendelian Inheritance)- The molecular mechanisms that underlie X-inactivation and genomic imprinting have been substantially updated.
• Chapter 10 (Chromosome Organization and Molecular Structure) - The structure of eukaryotic chromosomes has been greatly updated including descriptions of the nuclear matrix, chromatin remodeling proteins, and two multiprotein complexes called condensin and cohesin, which play a critical role in chromosomal condensation and sister chromatid alignment.
• Chapter 11 (DNA Replication)- Descriptions are presented of newly discovered DNA polymerases, such as lesion-replicating polymerases, along with updates regarding the molecular mechanisms of the DNA polymerases that play a major role in DNA replication.
• Chapter 12 (Gene Transcription and RNA Modification) - This chapter contains updated information regarding the structure of RNA polymerase, the functions of general transcription factors, and the role of chromatin remodeling during transcription.
• Chapter 15 (Gene Regulation in Eukaryotic) - This area has changed considerably since the first edition. New information regarding the roles of TFIID and mediator, which communicate the effects of regulatory transcription factors, has been added, along with the importance of chromatin remodeling for transcriptional activation and silencing. A new subsection on RNA interference has also been added.
• Chapter 16 (Gene Mutation and DNA repair) - A new subsection has been added that explains some of the chemical changes that underlie spontaneous mutations. Also, a subsection has been added that concerns the roles of translesion DNA polymerases in the replication of damaged DNA.
• Chapter 19 (Biotechnology) - The topic of stem cells has received considerable attention in the news lately. In a new subsection, which contains three figures and one table, the genetic issues that underlie the proliferative capacities of stem cells are discussed, along with their potential applications and societal concerns.
• Chapter 20 (Structural Genomics) - Since the first edition, the area of genomics has expanded to the point where it needs to be divided into two chapters. Chapter 20 contains the updated methods that are used to dissect genomes and sequence them.
• Chapter 21 (Functional Genomics, Proteomics, and Bioinformatics) - The first two sections of this chapter are new to the second edition. Functional genomics includes updates to topics such as EST libraries, subtractive libraries, and the applications of DNA microarrays. The Proteomics section explains the techniques of 2D gel electrophoresis, mass spectrometry, and protein microarrays. The Bioinformatics section is supplemented with tools at our Online Learning Center, where students can actually download files and run programs to analyze those files. These include programs that can translate a DNA sequence, generate a multiple sequence alignment, or search databases for homologous sequences (i.e., a BLAST search).
• Chapter 23 (Developmental Genetics) - An entire new section regarding Sex Determination has been added. This section describes the genetic pathways that govern sex determination in Drosophila, C. elegans, mammals, and dioecious plants.
• Chapter 26 (Evolutionary Genetics) - The UPGMA method for constructing phylogenetic trees is described. In addition, a new subsection regarding the role of horizontal gene transfer in the evolution of species has been added.