Time was when you could bite a tomato and not ingest fish genes. Time was when you could eat french fries and just worry about the fat and salt, not the bacterial genes that produce insecticides in the potato. Those times are over, thanks to corporate control over both genetic engineering and the lack of food-labeling. Unless you are a “hard core” consumer of organic foods, you eat genetically engineered foods everyday. While 80-90% of US consumers believe genetically engineered foods (...) should be labeled, only 3% know they already on the market.[1] Today 60-70% of the food in a grocery store contains components from genetically modified crops. Moreover, this technology was unleashed on over 45 million acres of US farmland last year alone, after having been commercially introduced only four years ago.[2] Here we will provide a brief background on the types of genetically engineered crops that are being surreptitiously forced upon consumers, then argue against their current widespread use. (shrink)

Early last year, the GenEthics Consortium (GEC) of the Washington Metropolitan Area convened at George Washington University to consider a complex case about genetic testing for Alzheimer disease (AD). The GEC consists of scientists, bioethicists, lawyers, genetic counselors, and consumers from a variety of institutions and affiliations. Four of the 8 co-authors of this paper delivered presentations on the case. Supplemented by additional ethical and legal observations, these presentations form the basis for the following discussion.

In an effort to assess the latest thinking in the Roman Catholic Church on economic matters, we examine the newest encyclical by Pope Benedict XVI, Caritas in Veritate (Charity in Truth) for guidance concerning marketing and business strategy. Core ethical values, consistent with historical Catholic Social Teachings (CST), are retained. However, some important nuances are added to previous treatments, and, reflecting the mind of the current Pontiff, certain points of emphasis are shifted to account for recent global developments. Key areas (...) of consistency and differences (as we perceive them) are spelled out along with some brief commentary on the evolution of the CST position on matters of importance to business decision makers. We close our analysis with a brief discussion of how the lessons of the encyclical can be applied to selected marketing problems embedded with ethical issues, including some criteria for evaluating marketing programs. Finally, we note some editorial commentary published in the wake of the letter’s release along with our own summation. (shrink)

Some suggest that gene editing human embryos to prevent genetic disorders will be in one respect morally preferable to using genetic selection for the same purpose: gene editing will benefit particular future persons, while genetic selection would merely replace them. We first construct the most plausible defence of this suggestion—the benefit argument—and defend it against a possible objection. We then advance another objection: the benefit argument succeeds only when restricted to cases in which the gene-edited child would (...) have been brought into existence even if gene editing had not been employed. Our argument relies on a standard account of comparative benefit which has recently been criticised on the grounds that it succumbs to the so-called ‘pre-emption problem’. We end by considering how our argument would be affected were the standard account revised in an attempt to evade this problem. We consider three revised accounts and argue that, on all three, our critique of the benefit argument stands. (shrink)

Some suggest that gene editing human embryos to prevent genetic disorders will be in one respect morally preferable to using genetic selection for the same purpose: gene editing will benefit particular future persons, while genetic selection would merely replace them. We first construct the most plausible defence of this suggestion—the benefit argument—and defend it against a possible objection. We then advance another objection: the benefit argument succeeds only when restricted to cases in which the gene-edited child would (...) have been brought into existence even if gene editing had not been employed. Our argument relies on a standard account of comparative benefit which has recently been criticised on the grounds that it succumbs to the so-called ‘pre-emption problem’. We end by considering how our argument would be affected were the standard account revised in an attempt to evade this problem. We consider three revised accounts and argue that, on all three, our critique of the benefit argument stands. (shrink)

Definitions of the term gene typically superimpose molecular genetics onto Mendelism. What emerges are persistent attempts to regard the gene as a unit of structure and/or function, language that creates multiple meanings for the term and fails to acknowledge the diversity of gene architecture. I argue that coherence at the molecular level requires abandonment of the classical unit concept and recognition that a gene is constructed from an assemblage of domains. Hence, a domain set (1) conforms (...) more closely to empirical evidence for genetic organization of DNA regions capable of transcription and (2) has ontological properties lacking in the traditional unit definition. (shrink)

Germline Gene Editing has enormous potential both as a research tool and a therapeutic intervention. While other types of gene editing are relatively uncontroversial, GGE has been strongly resisted. In this article, we analyse the ethical arguments for and against pursuing GGE by allowing and funding its development. We argue there is a strong case for pursuing GGE for the prevention of disease. We then examine objections that have been raised against pursuing GGE and argue that these fail. (...) We conclude that the moral case in favour of pursuing GGE is stronger than the case against. This suggests that pursuing GGE is morally permissible and indeed morally desirable. (shrink)

According to a recent suggestion, the names of gene taxa should be conceived of as referring to individuals with concrete genes as their parts, just as the names of biological species are often understood as denoting individuals with organisms as their parts. Although prima facie this suggestion might advance the debate on gene concepts in a similar way as the species-are-individuals thesis advanced the debate on species concepts, I argue that the principal arguments in support of the (...) class='Hi'>gene-individuality thesis are much less compelling than the parallel arguments in the species case. In addition, I argue that the notion of biological function invoked in the gene-individuality thesis (selected effect) is not the one that biologists actually use when individuating genes. Contra the gene-individuality thesis, I argue that gene names refer to kinds, defined primarily (though not exclusively) by causal-role functions. (shrink)

Although the great majority of genes are not subject to cell‐cycle controls, those that are could play a very important role in regulation of the cell cycle itself. The tubulin and histone genes of the naturally synchronous myxomycete, Physarum polycephalum, provide an excellent paradigm for such regulation. The transcription of both is highly periodic within the Physarum cycle, and curiously, both sets of genes appear to be activated at the same time. This activation appears to function as part of a (...) developmental program, since it serves to meet future needs for each gene's product. The significance of this activation event for cell‐cycle regulation is discussed with particular regard to the nature of the mitotic oscillator. (shrink)

There is nothing like a little controversy to generate publicity for your new book. In May of 2016, two weeks before the release of The Gene: An Intimate History, author and physician Siddhartha Mukherjee published a New Yorker article that generated a firestorm of criticism. His subject was epigenetics, a newly popular subdiscipline of genetics that seeks to explain how an organism’s traits can be affected by factors other than its genes. The conventional view within biology is that an (...) organism’s physical traits are specified by its genetic information. Genotype determines pheno-type, and different phenotypes imply different genotypes. But findings within epigenetics suggest... (shrink)

Cancer is most commonly viewed as resulting from somatic mutations enhancing proliferation and invasion. Some hypotheses further propose that these new capacities reveal a breakdown of multicellularity allowing cancer cells to escape proliferation and cooperation control mechanisms that were implemented during evolution of multicellularity. Here we critically review one such hypothesis, named “atavism,” which puts forward the idea that cancer results from the re‐expression of normally repressed genes forming a program, or toolbox, inherited from unicellular or simple multicellular ancestors. This (...) hypothesis places cancer in an interesting evolutionary perspective that has not been widely explored and deserves attention. Thinking about cancer within an evolutionary framework, especially the major transitions to multicellularity, offers particularly promising perspectives. It is therefore of the utmost important to analyze why one approach that tries to achieve this aim, the atavism hypothesis, has not so far emerged as a major theory on cancer. We outline the features of the atavism hypothesis that, would benefit from clarification and, if possible, unification. (shrink)

In the multidisciplinary field of developmental cognitive neuroscience, statistical associations between levels of description play an increasingly important role. One example of such associations is the observation of correlations between relatively common gene variants and individual differences in behavior. It is perhaps surprising that such associations can be detected despite the remoteness of these levels of description, and the fact that behavior is the outcome of an extended developmental process involving interaction of the whole organism with a variable environment. (...) Given that they have been detected, how do such associations inform cognitive-level theories? To investigate this question, we employed a multiscale computational model of development, using a sample domain drawn from the field of language acquisition. The model comprised an artificial neural network model of past-tense acquisition trained using the backpropagation learning algorithm, extended to incorporate population modeling and genetic algorithms. It included five levels of description—four internal: genetic, network, neurocomputation, behavior; and one external: environment. Since the mechanistic assumptions of the model were known and its operation was relatively transparent, we could evaluate whether cross-level associations gave an accurate picture of causal processes. We established that associations could be detected between artificial genes and behavioral variation, even under polygenic assumptions of a many-to-one relationship between genes and neurocomputational parameters, and when an experience-dependent developmental process interceded between the action of genes and the emergence of behavior. We evaluated these associations with respect to their specificity, to their developmental stability, and to their replicability, as well as considering issues of missing heritability and gene–environment interactions. We argue that gene–behavior associations can inform cognitive theory with respect to effect size, specificity, and timing. The model demonstrates a means by which researchers can undertake multiscale modeling with respect to cognition and develop highly specific and complex hypotheses across multiple levels of description. (shrink)

This review provides a current perspective on the insertion of genes into plants. Some of the knowledge on the structure and control of plant genes gained recently from genetic engineering approaches is described, together with developments that can be expected to emerge from further exploitation of gene transfer techniques.

Griffiths and Stotz’s Genetics and Philosophy: An Introduction offers a very good overview of scientific and philosophical issues raised by present-day genetics. Examining, in particular, the questions of how a “gene” should be defined and what a gene does from a causal point of view, the authors explore the different domains of the life sciences in which genetics has come to play a decisive role, from Mendelian genetics to molecular genetics, behavioural genetics, and evolution. In this review, I (...) highlight what I consider as the two main theses of the book, namely: genes are better conceived as tools; genes become causes only in a context. I situate these two theses in the wider perspective of developmental systems theory. This leads me to emphasize that Griffiths and Stotz reflect very well an on going process in genetics, which I call the “epigenetization” of genetics, i.e., the growing interest in the complex processes by which gene activation is regulated. I then make a factual objection, which is that Griffiths and Stotz have almost entirely neglected the perspective of ecological developmental biology, and more precisely recent work on developmental symbioses, and I suggest that this omission is unfortunate in so far as an examination of developmental symbioses would have considerably strengthened Griffiths and Stotz’s own conclusions. (shrink)

The publication of the first study to use gene editing techniques in human embryos (Liang et al., 2015) has drawn outrage from many in the scientific community. The prestigious scientific journals Nature and Science have published commentaries which call for this research to be strongly discouraged or halted all together (Lanphier et al., 2015; Baltimore et al., 2015). We believe this should be questioned. There is a moral imperative to continue this research.

A number of debates in philosophy of biology and psychology, as well as in their respective sciences, hinge on particular views about the relationship between genotypes and phenotypes. One such view is that the genotype-phenotype relationship is relatively straightforward, in the sense that a genome contains the ?genes for? the various traits that an organism exhibits. This leads to the assumption that if a particular set of traits is posited to be present in an organism, there must be a corresponding (...) number of genes in that organism's genome to account for those traits. This assumption underlies what can be called the ?counting argument,? in which empirical estimates of the number of genes in a genome are used to support or refute particular hypotheses in philosophical debates about biology and psychology. In this paper, we assess the counting argument as it is used in discussions of the alleged massive modularity of the brain, and conclude that this argument cannot be upheld in light of recent philosophical work on gene concepts and empirical work on genome complexity. In doing so, we illustrate that there are those on both sides of the debate about massive modularity who rely on an incorrect view of gene concepts and the nature of the genotype-phenotype relationship. (shrink)

ESTs or ‘expressed sequence tags’ are DNA sequences read from both ends of expressed gene fragments. The Merck‐WashU EST Project and several other public EST projects are being performed to rapidly discover the complement of human genes, and make them easily accessible. These ESTs are widely used to discover novel members of gene families, to map genes to chromosomes as ‘sequence‐tagged sites’ (STSs), and to identify mutations leading to heritable diseases. Informatic strategies for querying the EST databases are (...) discussed, as well as the strengths and weaknesses of the EST data. There is a compelling need to build on the informatic synthesis of human gene data, and to devise facile methods for determining gene functions. (shrink)

This book engages with some of the most pressing ethical issues that arise from the use of animals in various business practices, providing interdisciplinary approaches to improving the nonhuman and human lives in animal-related industries. The chapters in this volume provide conceptual, theoretical and practical analyses of these issues that will shape the future direction of business ethics to more fully reflect the impacts and implications of animal-based businesses on society, its members, and nature. The authors in this volume engage (...) with topics including animal suffering and emotions, the commodification of animals, vegetarian and vegan businesses and diets, technological innovations such as gene editing and lab-cultured meat, as well as captivity, corporate disclosure of animal welfare policies, and the possibility of humane jobs as well as the consideration of animals as stakeholders. (shrink)

Thomas Weber's book comprises a series of biographical reflections about people who influenced Gandhi, and those who were, in turn, influenced by him. Whilst previous literature tended to focus on Gandhi's political legacy, Weber's book explores the spiritual, social and philosophical resonances of these relationships, and it is with these aspects of the Mahatma's life in mind, that the author selects his central protagonists. These include friends such as Henry Polak and Hermann Kallenbach, who are not as well known (...) as those usually cited, but who left a deep impression nevertheless, and motivated some of Gandhi's major life changes. Conversely, the work of luminaries such as E. F. Schumacher and Gene Sharp reveal the Mahatma's influence in arenas which are not traditionally associated with his thinking. Weber's book offers intriguing insights into the life and thought of one of the most significant figures of the twentieth century. (shrink)

La brevetabilité du vivant suscite d’importantes questions car elle confronte le droit des brevets à certaines de ses limites comme, la non brevetablité des découvertes, l'interdiction d'appropriation du corps humain et la protection de l'intégrité du génome humain. Le présent article identifie ces limites et d'autres problématiques connexes, dans l'attente d'un article de fond plus complet sur le sujet.

Over the last decades, it has become evident that highly complex networks of regulators govern post‐transcriptional regulation of gene expression. A novel class of Argonaute (Ago)‐associated RNA molecules, the agotrons, was recently shown to function in a Drosha‐ and Dicer‐independent manner, hence bypassing the maturation steps required for canonical microRNA (miRNA) biogenesis. Agotrons are found in most mammals and associate with Ago as ∼100 nucleotide (nt) long RNA species. Here, we speculate on the functional and biological relevance of agotrons: (...) (i) agotrons could serve as non‐promiscuous miRNA‐like regulators with reduced off‐targeting or (ii) agotrons could encompass other putative functions, such as protecting Ago proteins from taking up aberrant short RNAs or by rescuing and stabilizing otherwise unloaded Ago‐proteins from degradation. Collectively, agotrons have emerged as a novel class of interesting non‐coding RNA molecules, but their full functional potential and biological impact still remain to be disclosed. (shrink)

Every cartilage and bone in the vertebrate skeleton has a precise shape and position. The head skeleton develops in the embryo from the neural crest, which emigrates from the neural ectoderm and forms the skull and pharyngeal arches. Recent genetic data from mice and zebrafish suggest that cells in the pharyngeal segments are specified by positional information in at least two dimensions, Hox genes along the anterior‐posterior axis and other homeobox genes along the dorsal‐ventral axis within a segment. Many zebrafish (...) and human mutant phenotypes indicate that additional genes are required for the development of groups of adjacent pharyngeal arches and for patterning along the mediolateral axis of the skull. The complementary genetic approaches in humans, mice and fish reveal networks of genes that specify the complex morphology of the head skeleton along a relatively simple set of coordinates. (shrink)

The ability of medical science to clone and perhaps even predetermine characteristics of certain species conflicts dramatically with many claims of the religious establishment. Opening with a description of various developments in plant, animal, and human genetics, Made in Whose Image? highlights the progress genetic research has achieved, its future promise, and its social impact. The developments are analyzed from the perspective of Christian ethics, as expounded by Roman Catholic and Protestant theorists, to give an overview of crucial ethical issues. (...) In reviewing the advances of genetic research, noted religion and ethics professor Thomas A. Shannon covers general ethical themes, such as the value of life, materialism, freedom, individuality, the concept of nature, and health and disease. In addition, he discusses problems in genetic engineering and misconceptions of the church. Shannon explores prenatal diagnosis, gene therapy, genes and behavior, freedom and responsibility, and the Human Genome Project. The book concludes with a powerful and groundbreaking methodological discussion of how to approach ethical problems in genetic engineering. (shrink)

This article focuses on the role of the interchromatin compartment (IC) in shaping nuclear landscapes. The IC is connected with nuclear pore complexes (NPCs) and harbors splicing speckles and nuclear bodies. It is postulated that the IC provides routes for imported transcription factors to target sites, for export routes of mRNA as ribonucleoproteins toward NPCs, as well as for the intranuclear passage of regulatory RNAs from sites of transcription to remote functional sites (IC hypothesis). IC channels are lined by less‐compacted (...) euchromatin, called the perichromatin region (PR). The PR and IC together form the active nuclear compartment (ANC). The ANC is co‐aligned with the inactive nuclear compartment (INC), comprising more compacted heterochromatin. It is postulated that the INC is accessible for individual transcription factors, but inaccessible for larger macromolecular aggregates (limited accessibility hypothesis). This functional nuclear organization depends on still unexplored movements of genes and regulatory sequences between the two compartments. (shrink)

Cheating evolves constantly. Dozens of athletes were barred from the Winter Olympics for taking banned substances. Gene doping is on the horizon. Questions have arisen about which athletes count as “female.” What does it take to keep sports fair? And what does fairness require?

Definition of the problem: Recent progress in the pharmacological sciences provides a first glimpse of the development of an individual, genotype-based drug therapy in order to improve the efficiency of drug utilization. Genotyping of genetic polymorphisms in genes involved in drug response promises to optimize drug therapy fundamentally by identifying patients for whom a pharmaceutical agent may be effective and safe or contraindicated because of expected adverse drug reactions. Arguments: The new pharmacogenomic treatment strategies raise complex bioethical issues, because genetic (...) screening for drug therapy may identify asymptomatic patients who are at risk for a particular adverse outcome. Thus, pharmacogenomics will affect the relationship between the treating physician and the patient which is traditionally based on privacy, confidentiality, beneficience and non-maleficience. Conclusion: In the article presented some ethical aspects of these new pharmacogenomic approaches concerning the physician-patient relationship are discussed. (shrink)

“Antibiotic resistance is usually associated with a fitness cost” is frequently accepted as common knowledge in the field of infectious diseases. However, with the advances in high‐throughput DNA sequencing that allows for a comprehensive analysis of bacterial pathogenesis at the genome scale, including antibiotic resistance genes, it appears that this paradigm might not be as solid as previously thought. Recent studies indicate that antibiotic resistance is able to enhance bacterial fitness in vivo with a concomitant increase in virulence during infections. (...) As a consequence, strategies to minimize antibiotic resistance turn out to be not as simple as initially believed. Indeed, decreased antibiotic use may not be sufficient to let susceptible strains outcompete the resistant ones. Here, we put in perspective these findings and review alternative approaches, such as preventive and therapeutic anti‐bacterial immunotherapies that have the potential to by‐pass the classic antibiotics. (shrink)

Here, we propose that the heterogeneity of mutational types in populations underpins alternative pathways of evolutionary adaptation. Point mutations, deletions, insertions, transpositions and duplications cause different biological effects and provide distinct adaptive possibilities. Experimental evidence for this notion comes from the mutational origins of adaptive radiations in large, clonal bacterial populations. Independent sympatric lineages with different phenotypes arise from distinct genetic events including gene duplication, different insertion sequence movements and several independent point mutations. The breadth of the mutational spectrum (...) in the ancestral population should be viewed as a form of bet‐hedging, reducing the risk of evolutionary dead ends and complementing the phenotypic and epigenetic heterogeneities that improve the survival capabilities of a population. Different mutational events arise from distinct cellular processes and are subject to separate environmental impacts, so the availability of any particular type of mutation may constrain or promote adaptive pathways in populations. (shrink)

In the recent past a number of empirical studies provided evidence that increasing genetic knowledge leads to new forms of exclusion, disadvantage and stigmatisation. As a consequence, many states have inaugurated special legislation to fight "genetic discrimination".This article focuses on some theoretical, normative and practical problems in the scientific and political debate on genetic discrimination. It puts forward the thesis that the existing antidiscrimination approach is based on the implicit idea that genes are the essence of (human) life. Since genes (...) are held responsible for individual development and personal identity, genetic discrimination is granted a privileged legal status in comparison to other forms of discrimination. As a result the analytical and political concentration on processes of genetic discrimination may reinforce the "geneticization" of body, illness and deviance. (shrink)

A diploid human genome contains approximately six billion nucleotides. This enormous amount of genetic information can be replicated with great accuracy in only a few hours. However, because DNA strands are oriented antiparallel while DNA polymerization only occurs in the 5′ → 3′ direction, semi‐conservative replication of double‐stranded DNA is an asymmetric process, i.e., there is a leading and a lagging strand. This provides a considerable opportunity for non‐random error rates, because the architecture of the two strands as well as (...) the DNA polymerases that replicate them may be different. In addition, the proteins that start or finish chains may well be different from those that perform the bulk of chain elongation. Furthermore, while replication fidelity depends on the absolute and relative concentrations of the four deoxyribonucleotide precursors, these are not equal in vivo, not constant throughout the cell cycle, and not necessarily equivalent in all cell types. Finally, the fidelity of DNA synthesis is sequence‐dependent and the eukaryotic nuclear genome is a heterogeneous substrate. It contains repetitive and non‐repetitive sequences and can actually be considered as two subgenomes that differ in nucleotide composition and gene content and that replicate at different times. The effects that each of these asymmetries may have on error rates during replication of the eukaryotic genome are discussed. (shrink)

In diesem Aufsatz wird der jeweils mögliche Beitrag verschiedener Experten, insbesondere von Fachphilosophen und Naturwissenschaftlern, zu einer allgemeinen Diskussion derjenigen ethischen und rechtlichen Fragen erörtert, die sich in Verbindung mit dem Genomprojekt stellen. Wir kommen zu dem Ergebnis, daß man die tatsächlich schon betriebene Forschung keinesfalls wird aufhalten können, sondern allenfalls bestimmte für bedenklich gehaltene Anwendungen der neuen Techniken verzögern oder verhindern kann. Wir stellen verschiedene Probleme vor, die die Wirksamkeit der philosophischen Reflexion in solchen Fragen zweifelhaft erscheinen läßt, die (...) mit der grundsätzlichen Unzulänglichkeit der traditionellen Verfahren angewandter Ethik, aber auch mit der Pluralität der Grundnormen in einer modernen Gesellschaft zu tun haben. So fällt der empirischen Wissenschaft eine entscheidende Rolle bei der Beurteilung der Angemessenheit bestimmter Verfahren im Hinblick auf die eine Norm zu, die allgemein vorausgesetzt werden darf, nämlich die über die Bedeutung des handgreiflichen Eigeninteresses, da dieses am ehesten in der Lage ist, die voraussichtlichen Möglichkeiten und Gefahren einer bestimmten Technik einzuschätzen. Wir behaupten, daß die bisherigen Erfahrungen mit anderen Organismen innerhalb und vor allem außerhalb von Laborato-rien auf eine Komplexität der Interaktionen der Gene untereinander und der genetischen Erbmasse mit der Umgebung hindeuten, die eine Vorhersage des Resultats beim Menschen als sehr ungewiß erscheinen läßt. Angesichts dieser Ungewißheit einerseits und des entgegengesetzten finanziellen Interesses seitens des Anbieters der neuen Techniken andererseits mag das amerikanische Zivilrecht vielleicht den stärksten Anreiz für den Anbieter darstellen, die Risiken realistisch einzuschätzen und bei der Anwendung mit der angemessenen Vorsicht zu Werke zu gehen. Noch wirksamer als jeglicher moralischer Appell mögen die finanziellen Gefahren für den überoptimistischen Anbieter sein, die Menschen als seine "Kunden" vor Schaden zu bewahren. Schließlich weisen wir auf die Schwierigkeit der Kommunikation der Ergebnisse philosophischer und wissenschaftlicher Überlegungen im Zeitalter der Massenmedien hin. Die Rationalität der Diskussion muß soweit wie möglich allererst hergestellt werden, statt daß man sie voraussetzen könnte. Dafür ist eine der größten Gefahren die Einbindung der modernen Naturwissenschaft gerade in die Industrien, deren Leistungen oder Risiken sie eigentlich beurteilen soll. (shrink)

Selection operates at many levels. Some of the most obvious cases are organismic, such as changes in coloration under the influence of predation (cf. Kettlewell 1973; also Endler 1986). It also operates at other levels. Meiotic drive involves selection for a gene, independently of its effect on the organism. At a higher level, there may also be selection for patterns of colony growth in social insects, again under the influence of predation (cf. Wilson 1971). The appropriate level of selection (...) is a matter of the causal patterns exhibited, or the target of selection. It can also be understood as a question of the appropriate level at which to seek explanatory laws.Robert Brandon (1982, 1990) first clearly distinguished the question of the level of selection from debates over the units of selection. In doing so, he argued that the phenotype is commonly the target of selection, whatever the unit of selection might be. (shrink)

The final assembly of the protein synthesis machinery occurs during translation initiation. This delicate process involves both ends of eukaryotic messenger RNAs as well as multiple sequential protein–RNA and protein–protein interactions. As is expected from its critical position in the gene expression pathway between the transcriptome and the proteome, translation initiation is a selective and highly regulated process. This synopsis summarises the current status of the field and identifies intriguing open questions. BioEssays 25:1201–1211, 2003 © 2003 Wiley Periodicals, Inc.

Peptides serve as important signalling molecules in development and differentiation in the simple metazoan Hydra. A systematic approach (The Hydra Peptide Project) has revealed that Hydra contains several hundreds of peptide signalling molecules, some of which are neuropeptides and others emanate from epithelial cells. These peptides control biological processes as diverse as muscle contraction, neuron differentiation, and the positional value gradient. Signal peptides cause changes in cell behaviour by controlling target genes such as matrix metalloproteases. The abundance of peptides in (...) Hydra raises the question of whether, in early metazoan evolution, cell–cell communication was based mainly on these small molecules rather than on the growth‐factor‐like cytokines that control differentiation and development in higher animals. BioEssays 23:420–427, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Heterotrimeric G proteins, consisting of α, β, and γ subunits, couple ligand-bound seven transmembrane domain receptors to the regulation of effector proteins and production of intracellular second messengers. G protein signaling mediates the perception of environmental cues in all higher eukaryotic organisms, including yeast, Dictyostelium, plants, and animals. The nematode Caenorhabditis elegans is the first animal to have complete descriptions of its cellular anatomy, cell lineage, neuronal wiring diagram, and genomic sequence. In a recent paper, Jansen et al.(1) used sequence (...) searches of the C. elegans genome database to identify all heterotrimeric G protein genes (20 Gα, 2 Gβ, 2 Gγ). C. elegans encodes one ortholog of each of the four Gα classes found in metazoans and 16 new Gα genes. The orthologous genes are widely expressed, whereas 14 of the divergent Gα genes are almost exclusively expressed in sensory neurons where they may regulate perception and chemotaxis.BioEssays 21:713–717, 1999. © 1999 John Wiley & Sons, Inc. (shrink)