Book excerpt: Mechanisms of Eukaryotic DNA Recombination is a collection of papers that discusses advances in eukaryotic genetic recombination. Papers address issues in eukaryotic genetic recombination, particularly DNA integration in mammalian genomes, genetic recombination in Drosophila or Caenorhabditis; the manipulation of the mouse genome; genome organization; and genetic recombination in protozoa. One paper discusses chromatid interactions during intrachromosomal recombination in mammalian cells, namely, intrachromatid and sister chromatid. Another paper analyzes the implication for chromosomal recombination and gene targeting; results on extrachromosomal recombination show that circles are inefficient substrates for recombination even if only one of two substrates in an intermolecular reaction is circular. One author discusses the genetics and molecular biology of recombination, citing the work of Watson and Crick, stating that crossing-over occurs between genes (not within them). He also explains that the formation and resolution of recombination intermediaries depend on enzyme or other proteins. This book will prove invaluable to cellular biologists, microbiologists, and researchers engaged in genetics and general biology.