The potato (Solanum tuberosum L. ) tuber is a major food source in many countries of the world, and subsequently potato has been the target of a good deal of effort directed at engineering disease and herbicide tolerance, and improvements in various crop characteristics. Consequently investigations into the regulation of gene expression in tubers is relevant to these endeavours, as tubers are the main target organ for modification of gene expression. We have been interested in the regulation of genes in tubers for these reasons. Morphologically tubers are modified stems, which have enlarged radially by limited cell division and substantial expansion. At the molecular level, tuber development is characterised by a massive increase in starch deposition and the synthesis of a limited number of abundant proteins. These include proteinase inhibitors and a 40kd group of proteins called patatin, which are acyl hydrolases. Together these proteins account for over 50% of tuber proteins (reviewed by Bevan, 1991). The synthesis of these proteins has parallels to the synthesis of other somatic storage proteins, especially the VSP proteins of soybean. In both potato and soybean, removal of the sink for these proteins (tubers and pods, respectively) causes deposition in other tissues (Staswick, 1990). It is hypothesised that transcriptional control of the genes encoding these proteins is regulated in part by source-sink relationships of metabolites or other factors. In the case of VSPs, both amino acid levels and jasmonic acid play a major regulatory role (Staswick et aI.

This volume brings together the disciplines of plant and animal genome research, and serves as an opportunity for scientists from both fields to compare results, problems and prospects.

The results obtained to date involving the use of in ~ methods to facilitate wide hybridization in plants are voluminous and impressive. The techniques of embryo culture, ovule culture, and in~ pollination and fertilization represent an extension of the normal sexual hybridization process. Successes recorded in obtaining hybrids stem largely from circumventing prezygotic or postzygotic hybridization barriers. Numerous recent successful hybridizations were possible because of the development of improved tissue and cell culture systems for crop plants and attention given to genotypes used in hybridization attempts. Interspecific and intergeneric hybridization utilizing the process of protoplast fusion will bypass the limits set by all sexual me'thods. In addition to combining complete genomes from two different species through protoplast fusion, this system affords unique opportunities for creating novel cytoplasmic combinations, transfer of individual chromosomes, transfer of cytoplasmic organelles, manipulation of male sterility, and for single gene transfer. Some caution must be noted with regard to the extent of hybridization possible between distantly related species. Although practically no limit exists to the physical fusion of protoplasts from widely divergent species, the restrictions imposed by somatic incompatibility have not been adequately addressed. Regeneration of plants from the protoplast or single heterokaryon level is still a major hurdle for many important crop species before somatic cell fusion can be exploited to produce interspecific and intergeneric hybrids. Identification and selection of hybrids is also a limitation to the efficient application of cell fusion methods.

One outstanding question in biology is the problem of devel opment: how the genetic instructions encoded in the DNA become expressed in the morphological, physiological, and behavioral features of multicellular organisms, through an ordered sequence of events that extend from the first cell division of the zygote to the adult stage and eventual death. The problem is how a one dimensional array of instructions is transformed into a four dimensional entity, the organism that exists in space and time. Understanding this transformation is, nevertheless, necessary for mastering the process of evolution. One hundred and twenty-five years after The Origin of Species, we have gained some understanding of evolution at the genetic level. Genetic information is stored in the linear sequence of nucleotides in the DNA. Gene mutations, chromosomal reorganiza tions, and a host of related processes introduce variation in the sequence and the amount of DNA. The fate of these variations is determined by interactions within the genome and with the outside environment that are largely understood. We have recently gained a glimpse of how the genome of eukaryotes is organized and will learn much more about it in the future, now that we have the research tools for it."

This volume brings together the disciplines of plant and animal genome research, and serves as an opportunity for scientists from both fields to compare results, problems and prospects.

A Historical Perspective on the Study of Chromosome Structure and Function R. Appels Division of Plant Industry CSIRO P.O. Box 1600 A.C.T. AUSTRALIA "Modern physical science gives us no model to explain the re duplication of the gene-string in each cell generation, or to ex plain the production of effective quantities of specific enzymes or other agents by specific genes. The precise pairing and inter change of segments by homologous gene-strings at meiosis also suggest novel physical properties of this form of matter." Stadler (1954) The very strong influence of reductionism in the history of understanding chromosome structure and function is evident in the above quotation from Stadler's 1954 paper, "The gene." Earlyob servations on the constancy of the cytological appearance of chromo somes and their regular behaviour in cell division led to specula tion on their biological importance. As genetics became more refined in the early decades of the 20th century the genes-on-a string model of chromosomes developed and greater emphasis was placed on the further dissection of these structures. As a result, in the 1980's the reductionist approach is reaching a crest as extensive regions of the genetic material are being sequenced."

There are clearly many directions in which the further development of the GUS gene fusion system can progress. Some of these have been outlined above, but others can be imagined. There are no reasons to limit our conceptions of the use of GUS gene fusions to analysis and manipulation of single genes. We can envision numerous marked genes - perhaps with several new fusion systems - giving valuable information about gene interaction, or population structure. The study of plan- pathogen and plant symbiont interactions can progress rapidly with simple quantitative markers for genes and individuals. We can imagine ways of using gene fusions to report on crop physiology or other complex phenotypes, thereby enhancing the accuracy and speed of screening. Introduction of the biosynthetic pathway for glucuronide detoxification by expressing genes for the UDP-glucuronyl transferases in plants may result in novel mechanisms for plants to deal with xenobiotics such as insecticides or herbicides. Synthesis of substrates, which until now has been performed chemicall- resulting in expensive compounds - can be done biosynthetically. This should make the system not only the most powerful gene fusion system for agriculture, but also the most accessible.

In this well-illustrated text, the author explores the potential of brief psychotherapy through four paradigmatic modes of the patient's relationship to others: subservience, indecisiveness, control, and fundamental fault. Dr. Gustafson utilizes cognitive, behavioral, psychodynamic, psychoanalytic, and systems approaches to show clinical psychology practitioners and students how to decipher and respond to the narratives of patients' lives.

Genome Exploitation: Data Mining the Genome is developed from the 23rd Stadler Genetic Symposium. This volume discusses and illustrates how scientists are going to characterize and make use of the massive amount of information being accumulated about the plant and animal genomes. Genome Exploitation: Data Mining the Genome is a state-of-the-art picture on mining the Genome databases. This is one of the few times that researchers in both plants and animals will be working together to create a seminal data resource.

This volume brings together the disciplines of plant and animal genome research, and serves as an opportunity for scientists from both fields to compare results, problems and prospects.

The 19 papers include discussions of constructing an integrated genetic and physical map of rice, commonalities and contrasts in the organization of the maize and sorghum nuclear genomes, prospects for comparative genome analyses among mammals, genome analysis in farm animals, sense suppression of p

The potato (Solanum tuberosum L. ) tuber is a major food source in many countries of the world, and subsequently potato has been the target of a good deal of effort directed at engineering disease and herbicide tolerance, and improvements in various crop characteristics. Consequently investigations into the regulation of gene expression in tubers is relevant to these endeavours, as tubers are the main target organ for modification of gene expression. We have been interested in the regulation of genes in tubers for these reasons. Morphologically tubers are modified stems, which have enlarged radially by limited cell division and substantial expansion. At the molecular level, tuber development is characterised by a massive increase in starch deposition and the synthesis of a limited number of abundant proteins. These include proteinase inhibitors and a 40kd group of proteins called patatin, which are acyl hydrolases. Together these proteins account for over 50% of tuber proteins (reviewed by Bevan, 1991). The synthesis of these proteins has parallels to the synthesis of other somatic storage proteins, especially the VSP proteins of soybean. In both potato and soybean, removal of the sink for these proteins (tubers and pods, respectively) causes deposition in other tissues (Staswick, 1990). It is hypothesised that transcriptional control of the genes encoding these proteins is regulated in part by source-sink relationships of metabolites or other factors. In the case of VSPs, both amino acid levels and jasmonic acid play a major regulatory role (Staswick et aI.

This timely collection of 15 original essays written by expert scientists the world over addresses the relationships between human population growth, the need to increase food supplies to feed the world population, and the chances for avoiding the extinction of a major proportion of the world's plant and animal species that collectively makes our survival on earth possible. These relationships are highly intertwined, and changes in each of them are increasingly decreasing humankind's chances to achieve environmental stability on our fragile planet. The world population is projected to be nine to ten billion by 2050, signaling the need to increase world food production by more than 70 percent on the same amount of land currently under production-and this without further damaging our fragile environment. The essays in this collection, written by experts for laypersons, presents the problems we face with clarity and assess our prospects for solving them, calling for action but holding out viable solutions.