The Prebiotic Synthesis of Modified Purines and Their Potential Role in the RNA World Matthew LevyStanley L. Miller Pages: 631 - 637
N-Carbamoyl Amino Acid Solid–Gas Nitrosation by NO/NO x : A New Route to Oligopeptides via α-Amino Acid N-Carboxyanhydride. Prebiotic Implications Jacques TailladesHélène ColletAuguste Commeyras Pages: 638 - 645
Extensive Gene Duplication in the Early Evolution of Animals Before the Parazoan–Eumetazoan Split Demonstrated by G Proteins and Protein Tyrosine Kinases from Sponge and Hydra Hiroshi SugaMitsumasa KoyanagiTakashi Miyata Pages: 646 - 653
Multiple Protein Tyrosine Phosphatases in Sponges and Explosive Gene Duplication in the Early Evolution of Animals Before the Parazoan–Eumetazoan Split Kanako OnoHiroshi SugaTakashi Miyata Pages: 654 - 662
Evolution of Mhc–DRB Introns: Implications for the Origin of Primates Heike KupfermannYoko SattaJan Klein Pages: 663 - 674
Comparison Between Two Human Endogenous Retrovirus (HERV)-Rich Regions Within the Major Histocompatibility Complex Jerzy K. KulskiSilvana GaudieriRoger L. Dawkins Pages: 675 - 683
Characterization of Repetitive DNA Elements in Arabidopsis Stefan A. SurzyckiWilliam R. Belknap Pages: 684 - 691
Gene Contents and Organization of a Mitochondrial DNA Segment of the Squid Loligo bleekeri Junji SasugaShin-ichi YokoboriKimitsuna Watanabe Pages: 692 - 702
Mitochondrial DNA Phylogeny of the Family Cichlidae: Monophyly and Fast Molecular Evolution of the Neotropical Assemblage Izeni P. FariasGuillermo OrtíAxel Meyer Pages: 703 - 711
Compositional Correlation Between Open Reading Frames with Opposite Transcriptional Orientations in Escherichia coli Antonio MarínGabriel GutiérrezJosé L. Oliver Pages: 712 - 716
Intracellular Bacterial Symbionts of Aphids Possess Many Genomic Copies per Bacterium Kanako KomakiHajime Ishikawa Pages: 717 - 722
Detection of Seven Major Evolutionary Lineages in Cyanobacteria Based on the 16S rRNA Gene Sequence Analysis with New Sequences of Five Marine Synechococcus Strains Daiske HondaAkira YokotaJunta Sugiyama Pages: 723 - 739
Primary and Secondary Structure of the Small-Subunit Ribosomal RNA of the Naked, Marine Amoeba Vannella anglica: Phylogenetic Implications Gary P. SimsAndrew RogersonRobert Aitken Pages: 740 - 749
Primary Structure and Phylogenetic Relationships of a Malate Dehydrogenase Gene from Giardia lamblia Andrew J. RogerHilary G. MorrisonMitchell L. Sogin Pages: 750 - 755
DNA Polymerase C of the Thermophilic Bacterium Thermus aquaticus: Classification and Phylogenetic Analysis of the Family C DNA Polymerases Yi-Ping HuangJunetsu Ito Pages: 756 - 769
Phylogenetic Analysis of Components of the Eukaryotic Vesicle Transport System Reveals a Common Origin of Adaptor Protein Complexes 1, 2, and 3 and the F Subcomplex of the Coatomer COPI Kai SchledzewskiHenner BrinkmannRalf R. Mendel Pages: 770 - 778
The First Sexual Lineage and the Relevance of Facultative Sex Joel DacksAndrew J. Roger Pages: 779 - 783