Structure and evolution of organelle genomes.

INTRODUCTION ........................................................... 208 ORGANELLE GENOME SIZE AND SHAPE ........................................ 208 Size and Shape of Mitochondrial Deoxyribonucleic Acids (DNAs) ...... ............... 209 Size and Shape of Chloroplast DNAs.............................................. 212 GENE ARRANGEMENT IN ORGANELLE DNAs ......... .......................... 213 Mitochondrial DNA Gene Organizations........................................... 213 Comparative organization of unicellular eucaryotic mitochondrial DNAs ..... ........ 213 Comparative organization of animal cell mitochondrial DNAs ...... ................ 216 Organization of vascular plant cell mitochondrial DNAs ....... .................... 217 Chloropbst DNA Gene Organization.............................................. 219 Organization of unicellular eucaryotic chloroplast DNAs........................... 219 Organization of vascular plant chloroplast DNAs ......... ........................ 219 CONCLUSIONS ABOUT THE ORGANIZATION AND EVOLUTION OF ORGANELLE DNAs ........................................................ 220 Impetus of and Constraints on Organelle Genome Evolution ....... .................. 220 Introns: Old or New? ........................................................... 221 ORGANELLE GENETIC CODES.................................................. 221 ORIGIN OF ORGANELLE DNAs.................................................. 224 Current Formulations of the Hypotheses........................................... 224 Analysis of the Theories ......................................................... 224 Interpretation of the data...................................................... 224 Divergence patterns of organelle and nuclear DNAs ........ ....................... 225 Monophyletic origin versus polyphyletic origin ................................... 227 TENTATIVE PHYLOGENIES OF ORGANELLE DNAs ............. ................. 227 Evolutionary History of Chloroplast DNAs......................................... 227 Evolutionary History of Mitochondrial DNAs....................................... 228 LITERATURE CITED......................................... 230