Autonomy And Biogenesis Of Mitochondria And Chloroplasts

There are currently a growing number of laboratories actively studying the mechanism by which various biological membranes are assembled. This area of research is still relatively new to biochemists and molecular biologists, but in view of the rapid progress being made, a review of the field at this time is justified. The present volume focuses on the biogenesis of three related membranes. Mitochondria and chloroplasts are semiautonomous organelles whose biogenesis is carried out partly in the external cytoplasm and partly by the organelles themselves. Both membranes are principally concerned with the energy metabolism of the cell, and this commonality of function is reflected in a considerable degree of similarity in their ul trastructure and enzymatic composition. Although the bacterial cell membrane is a much more diversified structure, it also fulfills the basic energy requirements of the cell, and depending on the organism, this can take the form of photosynthesis or oxidative phosphorylation. The addi tional consideration that prokaryotic organisms may, in fact, be the evolu tionary ancestors of mitochondria and chloroplasts, makes it all the more compelling that those interested in biogenesis be aware of new develop ments in each of these three areas. In organizing this book, I felt that the contributors should summarize and bring up to date their own research and review the literature only in sofar as would be necessary to provide the proper perspective for their work.

Cytoplasmic Genes and Organelles is about cytoplasmic genes: what they are and what they do. It applies the concepts and methods of cytoplasmic genetics to the problems of cell and molecular biology to which they can uniquely contribute. It shows geneticists the many attractive problems in this area awaiting their attention; cell biologists and biochemists the usefulness of cytoplasmic genetic analysis in their endeavors; and students the potential power of an integrated experimental approach using cytoplasmic genes together with the more conventional tools of biochemistry and electron microscopy in the investigation of organelle biogenesis. The book treats the following aspects of cytoplasmic genetic systems: (1) the properties of cytoplasmic DNA; (2) the genetic analysis of cytoplasmic systems; and (3) the functions of cytoplasmic genes in organelle biogenesis. The opening chapter summarizes the principal findings to provide readers with a bird's eye view of the subject. Subsequent chapters cover topics such as cytoplastmic DNAs; cytoplasmic genes in Chlamydomonas; mitochondrial genetics of yeast; cytoplasmic genes in higher plants; the role of mitochondrial genes in mitochondrial biogenesis; and cytoplasmic genes and cell heredity.

Plant cell structure and function; Gene expression and its regulation in plant cells; The manipulation of plant cells.

In the past few years, the body of experimental work on the structure, function and assembly processes of mitochondria has expanded rapidly. No one person can believe himself or herself completely in control of the burgeoning literature without possessing serious omissions or blind spots. In the present monograph I have attempted a critical evaluation of the literature. I believe that the common thread of single authorship outweighs the shortcomings of one person presenting many disparate viewpo,ints. It is my hope that the end product represents a comprehensive and coordinated review of the subject matter to the present date. Although the bulk of this monograph was completed by October 1974, I have made some attempts to update several of the sections at later times. Albany, N. Y. , November 1975 H. TEDESCHI Contents A. Structure of Mitochondria 1. General Organization . a) Conventional Thin Section Electron Microscopy b) Negative Staining Techniques . 3 c) Freeze-Cleavage . . . . . . . 4 2. Special Organization and Inclusions 10 a) Prismatic or Atypical Cristae 10 b) Filaments and Tubules . . 11 c) Amorphous Inclusions 12 d) Intramitochondrial Granules 12 e) DNA Containing Fibers 14 3. Topography of the Mitochondrial Transducing Systems 15 B. The Assembly of Mitochondria 18 1. Mitochondrial DNA and Its Genetic Role 19 2. Transcription of the Mitochondrial DNA . 28 a) mRNA . . . . . . . . . . . . . . 30 b) The Machinery for Transcription and Translation 32 c) Turnover of Mitochondrial RNA 36 3. Protein Synthesis . . . . . . . . 37 a) Mitochondrial Protein Synthesis and Its Characteristics 37 b) Role of Mitochondrial Protein Synthesis . .

Our ambition in the organization of this book was to explore the current stus of knowledge about nucleic acids in plants. We wanted the reader to be able to learn how this research is being undertaken. Therefore, we asked the contributing authors to include details of approaches and methods. Where feasible, the have provided protocols that can be followed by those who wish to repeat results, extend data, make improvements, or use them in new applications.