When, nearly 20 years ago, I was participating in the organization of a workshop held in Palermo entitled "Regulation of Transcription in Sea Urchin Embryos" (see Fig. 1), under the expert direction of Prof. G. Giudice, at the time Director of both the University and CNR Institutes for Developmental Biology, I was not aware of the extent to which echinoderms (sea urchins) contribute to the advancement of science. It was spring 1986 and, among other well-known and those who would one day be well-known in the field, Tim Hunt (R. Timothy Hunt) presented his lecture on the "Role of maternal mRNA in the regulation of cell division in early cell cycles of the sea urchin embryos". I am sure that at the moment most, if not all, of the audience found the way in which a messenger RNA could promote the synthesis of a protein which was going up and down during cell cycles very bizarre. Many years later, his efforts, together with those of Paul M. Nurse and Leland H. Hartwell, were appreciated worldwide. They were awarded the Nobel Prize in Physiology and Medicine 2001 for "their discoveries of key regulators of the cell cycle". In fact, their work led to the discovery of cyclins, proteins widespread in the animal kingdom, that oscillate throughout the cell cycle, binding and activating cyclin-dependent kinases. Needless to say that nowadays everybody knows what cyclins are and how studies on their regulation are inspiring new therapies against human cancer. However, very few people remember that this all stemmed from a lesson from the sea urchin, just one example of how precious simple marine organisms can be in teaching scientists how to improve human health.

With this in mind, it was with great pleasure that I accepted the kind invitation of Prof. Müller to assemble a book that, by examining the recent productive research in support of marine biotechnology, would encourage further studies on the sustainable exploitation of biologically active compounds from echinoderms. Echinodermata, a phylum that appeared back in the Pre-cambrian age, accounting for more than 7,000 living species, belongs to the branch of the animal kingdom known as the deuterostomes, a group that also includes man. Since they are phylogenetically more related to chordates than to other invertebrate groups, it is not surprising that echinoderms possess regulatory mechanisms rather similar to those of vertebrates. This explains the flourishing interest of scientists in the fields of developmental biology, molecular genomics and molecular evolution.

However, as many of the contributors to this book have pointed out, despite the incredible amount of research accomplished during the past centuries using echinoderms as a model organism in the fields of zoology, ecology, embryology, cell biology, molecular biology, etc., modest efforts of the echin-oderm scientific community have been directed towards studies on the development of the sustainable production of bioactive compounds from echino-derms and their application in biomedicine.

This book illustrates the progress made in the exploitation of natural products from marine invertebrates (echinoderms) at a specialized high level. Studies describe: (1) the discovery of new potential therapeutic tools for human health; (2) the introduction of new biomolecular and biocellular sensors for the detection of environmental contamination; (3) the development of new composite materials for biomedical applications; and (4) the improvements and limitations of aquacultural techniques and farming. Past and recent findings are reported in the format of reviews on general topics or detailed explanations where the description of a recently defined method is needed.

Environmental and health issues are addressed by the 2004-2010 Action Plan of the European Community which focuses on: (1) an integrated environmental and health monitoring system; (2) the standardization of methods of analysis; and (3) common sampling and sample preparation procedures. Taking these points into consideration, I decided to invite only European scientists, with only one exception, to contribute their work and thoughts, most of them being involved in EU R&D projects which encourage and support multidisciplinary research with the aim of ensuring the rapid transfer of technology.

For all the above-mentioned reasons, I am particularly grateful to the Marine Molecular Biotechnology Series Editor, Prof. Werner Müller, who gave me the opportunity to select those studies which I think will be able to promote discussion in this rapidly growing field and open new routes for research on innovative bioactive compounds to be used in environmental and medical research.

Many thanks are extended to all the contributors to this book; I am confident that the high scientific value of their reviews on past and current findings will serve as a forum of ideas for the exploitation of echinoderm as a bioresource and will promote the development of studies in the new exciting field of marine molecular biotechnology.

I am also very grateful to the invaluable and friendly collaboration and assistance of all the actual members of the group (see Fig. 2) whose daily hard work and professional skills were part of the success of this enterprise. Special warm thanks go to my colleagues Francesca Zito and Rosa Bonaventura for their continuous and generous collaboration, support and assistance throughout all the difficulties related to the editorial work.

Fig. 1. Original sketch of a sea urchin, engaged in "transcribing", drawn by G. Giudice and used for the cover of the scientific program of the workshop on "Regulation of Transcription in Sea Urchin Embryos", held in Palermo in 1986

Fig. 1. Original sketch of a sea urchin, engaged in "transcribing", drawn by G. Giudice and used for the cover of the scientific program of the workshop on "Regulation of Transcription in Sea Urchin Embryos", held in Palermo in 1986


Finally, I express my gratitude to my husband Benedetto and my daughter Laura for their continuous intellectual and practical support. In spite of the time it took me away from them, their intelligent and open-minded attitude was invaluable in this scientific endeavour.

In closing, I would like to recall the words of Prof. Monroy, who used to say: "Science is one of the best ways for mutual understanding. Its language is universal and pays no attention to national barriers. This is to say that science is one of the best approaches to peace".

Valeria Matranga

As Director of the Institute of Biomedicine and Molecular Immunology "Alberto Monroy", I am pleased to introduce this book on the marine molecular biotechnology of echinoderms, edited by Dr. Valeria Matranga, with the precious help of her team, who dedicated much time and effort. I know and appreciate the dedication of Valeria Matranga to her work on cell biology, especially her research on cell-environment interactions and on the validation of the role played by cellular and molecular biology in the detection and assessment of environmental pollution. I am confident that this book will have a great impact on our understanding of biological markers and their different functions in the cell. In addition, the advancements described here will be extremely useful for the evaluation of environmental risk. Moreover, this research field ultimately addresses issues on the protection of human health, since we can now monitor potentially dangerous changes in the sea environment along the coast where degradation products from the earth accumulate.

The topics addressed in the book, Echinodermata, will be of interest to scientists in various fields:

• Cell biologists will find it useful to study cell responses to stress factors;

• Marine biologists will be able to evaluate the damage to cells and organisms caused by coastal water pollution, as well as the role of monitoring such phenomena;

• Researchers dedicated to Nutritional Sciences will appreciate the "warning messages" provided by the environmental monitoring of seawater;

• Environmental scientists will take advantage of an additional way to fight seawater pollution, which could possibly be useful in the prevention and adequate correction of problems originating from ground pollution.

Finally, I wish Valeria Matranga and her team continuing success in their engrossing and promising research field.

Istituto di Biomedicina e Immunologia Molecolare (IBIM) "Alberto Monroy" Palermo, Italy

Professor Giovanni Bonsignore (Director)

Biology owes a great deal to Echinodermata, especially in the field of development. Sea urchins have actually represented one of the main and one of the first biological materials on which the history of developmental biology was built.

Fertilization and parthenogenesis were, in fact, first clearly and correctly described in sea urchins. Oskar Hertwig, working at the Zoological Station of Naples, wrote in 1875: "I was lucky enough, by studying the egg of Toxop-neustes lividus, to find an object in which phases and intimate phenomena of fertilization were clearly visible, that is: following fertilization, few minutes after semen addition, around the sperm head, lodged in the cortex, a series of rays was formed". The description of a series of important observations followed, which allowed him to conclude: "And therefore I was able to formulate the low: the fertilization rests on the union of two sexually different cells".

Again, with regard to sea urchins, Edmund B. Wilson (1906) wrote: "Fertilization accordingly consists of two distinct phenomena: first the introduction into the egg of the paternal hereditary characteristics potentially contained in some unknown manner in the substance of the sperm nucleus or of the chromosomes in which resolves itself. Second in the introduction into the egg of a centrosome which gives rise to the mechanisms by means of which the egg divides and the hereditary substance is distributed to the resulting cells". Thus, the concept of the centrosome is also due to sea urchins.

In 1895 it was again Hertwig who described parthenogenesis in sea urchins, while Jacque Loeb in 1909 showed that it is possible to induce parthenogenesis in sea urchins also by chemical treatments such as hypertonic seawater. This caused public surprise and also some concern, such that some people even advised women to avoid bathing in seawater owing to the danger of parthenogenesis!

Furthermore, genetics, in spite of a long-lasting metamorphosis, owes some crucial initial experiments to sea urchins. It suffices here to recall the experiments of Theodor Bovery, who in 1889 studied sea urchin hybrids, again at the Zoological Station of Naples, and concluded that chromosomes are qualitatively responsible for genetic character transmission, after observ ing the fate of hybrid merogones in which some chromosomes were selectively lacking.

Although not being the elective material for genetic studies, sea urchins represented and still represent a very important model for studies of molecular biology and molecular genomics. The story started with the demonstration by Alberto Monroy that, following fertilization, there is an activation of protein synthesis in the sea urchin egg. This demonstration was achieved by Eizo Nakano and Alberto Monroy in Palermo by preloading the amino acid pool of the unfertilized sea urchin egg with radioactive amino acids (which was carried out by injecting the labeled amino acids into the coelomic cavity of the adult female), and showing that immediately following fertilization, but not before, there was a quick transfer of the amino acids from the pool to the proteins. This injection of amino acids into the adult sea urchin was depicted by a cartoonist (myself, at that time one of Monroy's students; Fig. 1).

The story of molecular genetics has continued in sea urchins, especially in the USA, where many research groups flourished, especially that of Eric Davidson at Caltech, of which I will only recall here the regulatory gene networks described in sea urchins. It has continued also in Europe, e.g. in Palermo with Monroy's former students, including myself and younger coworkers, both at the University and at the National Research Council of Palermo. It has also continued at the Zoological Station of Naples and elsewhere, e.g. in Villefranche sur Mer, just to quote an example. Other groups are studying molecular genomics of sea urchins in Japan.

It should be noted here that the hypothesis of a role for DNA methylation in differentiation was first proposed in sea urchin embryos in 1958 by Edoardo Scarano and by colleagues still working in Naples.

It is also worth recalling the contribution of sea urchins to the field of cell interaction. Curt Herbst, in 1891, working at the Zoological Station of Naples, found that lowering the calcium concentration of seawater brought about a loosening of contacts between sea urchin blastomeres, which remained inside the fertilization envelope and continued to develop, although with a "krank-like" aspect. This observation allowed Hans Driesch to easily separate the first two blastomeres and to show that each gave rise to an entire, albeit smaller,

Fig. 1. Original sketch by G. Giudice representing a furious sea urchin chasing Prof. Eizo Nakano, armed with a syringe, and Prof. Alberto Monroy, first in the row, at the time of their joint experiments in the mid-1950s.

pluteus. Many years later, in 1961,1 succeeded in dissociating sea urchin blas-tulae into single cells, essentially by removing calcium. These cells were able to reaggregate and to develop into pluteus-like structures, which represented the first example of entire larvae of any kind of embryos reconstituted from dissociated cells. These studies were followed by those of some colleagues of mine, e.g. Letizia Vittorelli and Valeria Matranga, and by others, including Yukio Yokota, Hans Noll and David McClay.

The theory of morphogen gradients, so popular in developmental biology, also originated in the study of sea urchins, following the beautiful microtransplantation experiments done by Sven Horstadius in 1928 and by the intelligent speculations of John Runnstrom.

Finally, the beginning of so-called chemical embryology can be attributed to studies on sea urchins: it was in fact Otto Waburg who discovered in 1908 that following fertilization of sea urchin eggs there was a sudden increase in oxygen consumption.

I am aware that many important results obtained not only using sea urchins, but using echinoderms in general have not been included here. I hope, however, to have succeeded in giving an idea of the contribution that studies on sea urchins have provided to developmental biology in the past in places like Naples Zoological Station, Woods Hole MBL, Stockholm Carolin-ska Institute, Sugashima Marine Station and Villefranche sur Mer Marine Station, and continue to provide especially in places like the USA (i.e. the MBL in Woods Hole, Caltech, Pennsylvania and so on), Italy (Naples and Palermo), France and Japan.

Dipartimento di Biologia Cellulare e dello Professor G. Giudice

Sviluppo "Alberto Monroy", Universita di Palermo Palermo, Italy

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