Metaseiulus occidentalis is a representative of an important family of mites (Arthropoda: Chelicerata: Acari: Phytoseiidae) that are effective predators of pest mites in agricultural crops around the world. Like many arthropods, this mite contains multiple genomes, including the genomes of several microbial symbionts as well as its own mitochondrial and nuclear genomes. The mitochondrial genome is “mitey” large at 25 kb, due to duplication and triplication of genes. By contrast, the nuclear genome is “mitey” small at (...) 88 Mb. This mite has a parahaploid genetic system, tolerates inbreeding, and has a haploid chromosome number of 3. This predator was genetically improved for use in agriculture by developing strains that lacked the ability to overwinter in diapause or were resistant to multiple pesticides, and can be genetically modified using recombinant DNA methods. Sequencing the nuclear genome would provide useful insights that could enhance genetic improvement programs that would result in improved pest management, could provide genes needed to resolve the evolutionary relationships of this family, and could serve as a model for understanding the evolution and genetics of chelicerate arthropod predators. (shrink)

Recently two developments have had a major impact on the field of ancient DNA (aDNA). First, new advances in DNA sequencing, in combination with improved capture/enrichment methods, have resulted in the recovery of orders of magnitude more DNA sequence data from ancient animals. Second, there has been an increase in the range of tissue types employed in aDNA. Hair in particular has proven to be very successful as a source of DNA because of its low levels of contamination and high (...) level of ancient endogenous DNA. These developments have resulted in significant advances in our understanding of recently extinct animals: namely their evolutionary relationships, physiology, and even behaviour. Hair has been used to recover the first complete ancient nuclear genome, that of the extinct woolly mammoth, which then facilitated the expression and functional analysis of haemoglobins. Finally, we speculate on the consequences of these developments for the possibility of recreating extinct animals. (shrink)

Genomes are defined by their primary sequence. The functional properties of genomes, however, are determined by far more complex mechanisms and depend on multiple layers of regulatory control processes. A key emerging contributor to genome function is the architectural organization of the cell nucleus. The spatial and temporal behavior of genomes and their regulatory proteins are now being recognized as important, yet still poorly understood, control mechanisms in genome function. Combined cell biological, molecular and computational analysis of (...) architectural aspects of genome function has added a further dimension to the investigation of some of the most fundamental cellular processes including transcription and maintenance of genome integrity. The complete elucidation of the contribution that nuclear architecture makes to gene expression will be required to fully understand physiological processes such as differentiation, development and disease at the cellular level. Here I give an overview of some of the emerging concepts in the study of in vivo genome organization and function. BioEssays 27:477–487, 2005. Published 2005 Wiley Periodicals, Inc. (shrink)

In this article, I argue that there is no compelling therapeutic ‘need’ for human nuclear genome transfer to prevent mitochondrial diseases caused by mtDNA mutations. At most there is a strong interest in this technology on the part of some women and couples at risk of having children with mitochondrial disease, and perhaps also a ‘want’ on the part of some researchers who see the technology as a useful precedent – one that provides them with ‘a quiet way (...) station’ in which to refine the micromanipulations techniques essential for other human germline interventions and human cloning. In advance of this argument, I review basic information about mitochondrial disease and novel genetic strategies to prevent the transmission of mutated mitochondria. Next, I address common features of contemporary debates and discussions about so-called mitochondrial replacement. First, I contest the cliché that science-and-technology is fast outpacing ethics. Second, I dispute the accuracy of the term ‘mitochondrial replacement’. Third, I provide a sustained critique of the purported ‘need’ for genetically-related children. In closing, I call into question the mainly liberal defense of human nuclear genome transfer. I suggest an alternative frame of reference that pays particular attention to issues of social justice. I conclude that our limited resources should be carefully expended in pursuit of the common good, which does not include pandering to acquired desires. (shrink)

We review a recent paper in Genome Research by Guantes et al. showing that nuclear gene expression is influenced by the bioenergetic status of the mitochondria. The amount of energy that mitochondria make available for gene expression varies considerably. It depends on: the energetic demands of the tissue; the mitochondrial DNA (mtDNA) mutant load; the number of mitochondria; stressors present in the cell. Hence, when failing mitochondria place the cell in energy crisis there are major effects on gene (...) expression affecting the risk of degenerative diseases, cancer and ageing. In 2015 the UK parliament approved a change in the regulation of IVF techniques, allowing “Mitochondrial replacement therapy” to become a reproductive choice for women at risk of transmitting mitochondrial disease to their children. This is the first time that this technique will be available. Therefore understanding the interaction between mitochondria and the nucleus has never been more important. (shrink)

New concepts may prove necessary to profit from the avalanche of sequence data on the genome, transcriptome, proteome and interactome and to relate this information to cell physiology. Here, we focus on the concept of large activity-based structures, or hyperstructures, in which a variety of types of molecules are brought together to perform a function. We review the evidence for the existence of hyperstructures responsible for the initiation of DNA replication, the sequestration of newly replicated origins of replication, cell (...) division and for metabolism. The processes responsible for hyperstructure formation include changes in enzyme affinities due to metabolite-induction, lipid-protein affinities, elevated local concentrations of proteins and their binding sites on DNA and RNA, and transertion. Experimental techniques exist that can be used to study hyperstructures and we review some of the ones less familiar to biologists. Finally, we speculate on how a variety of in silico approaches involving cellular automata and multi-agent systems could be combined to develop new concepts in the form of an Integrated cell (I-cell) which would undergo selection for growth and survival in a world of artificial microbiology. (shrink)

Advances in biochemistry, chemistry and engineering have enabled the development of a new gene expression assay. This ‘chip‐based’ approach utilizes microscopic arrays of cDNAs printed on glass as high‐density hybridization targets. Fluorescent probe mixtures derived from total cellular messenger RNA (mRNA) hybridize to cognate elements on the array, allowing accurate measurement of the expression of the corresponding genes. Array densities of >1,000 cDNAs per cm2 enable quantitative expression monitoring of a large number of genes in a single hybridization. A two‐color (...) fluorescence detection scheme allows rapid and simultaneous differential expression analysis of independent biological samples. Mass‐produced microarrays provide a new tool for genome expression analysis that may revolutionize genetic dissection, drug discovery and human disease diagnostics. (shrink)

Giulia Cavaliere and César Palacios-González argue that lesbian couples should have access to human nuclear genome transfer so that both members of the couple can have a genetic link to the child they intend to parent. Their argument is grounded in an appeal to reproductive freedom. In this Response, I address a number of concerns with their argument. These concerns relate to nomenclature, treating like cases alike, genetic-relatedness and the limits of reproductive rights. On this last point, I (...) insist that we should not mistake ‘wants’ for ‘needs’ or ‘rights’. I maintain that there is no right to biological parenthood, there is no compelling need for human nuclear genome transfer to satisfy a so-called need for genetically-related children, and we ought not to pander to an acquired desire for genetic filiation. (shrink)

The phenomenal proliferation of scientific studies into the nature of induced pluripotent stem (iPS) cells following publication of the findings of Takahashi and Yamanaka little more than 2 years ago, have significantly expanded our understanding of cellular mechanisms relating to cell lineage, differentiation, and proliferation. While the full potential of iPS cell lineages for both scientific tool and therapeutic applications is as yet unclear, findings from several lines of investigation suggests that multipotential and terminally differentiated cells from an array of (...) cell types are competent to undergo epigenetic reprogramming to a pluripotential state. The nature of this pluripotential state appears to be similar to, but not identical with that previously described for embryonic stem (ES) cells. Understanding the nature of this induced reprogrammed state will be critical to determining the full potential of iPS cells. Recently, this issue has been examined through an integrated analysis of the genome in fully and partially reprogrammed iPS cell lineages. These results provide a window onto the temporal components of reprogramming and suggest mechanisms by which the efficacy of reprogramming can be enhanced. (shrink)

For more than a decade, Iran has been referring to a fatwa issued by its Supreme Leader, Ali Khamenei, proscribing nuclear weapons. The fatwa, however, not only failed to influence the process that led to the resolution of Iran’s nuclear crisis, but also has been met with a good deal of skepticism. The most commonly held suspicions about the credibility of the fatwa can be summed up in five central questions: Has the nuclear fatwa actually been issued? (...) Does the fatwa apply to all the aspects of nuclear weapons including their production, possession and use? What is the juridical status of the fatwa? Was the nuclear fatwa issued only to deceive other nations? Is the fatwa really irreversible? This article tries to answer these questions by providing a chronological review of the fatwa and analyzing all the relevant statements by Khamenei. The analysis is conducted against the background of Islamic principles, Shi’a jurisprudence and the history of the Islamic Republic of Iran. The article concludes that the fatwa is a credible religious decree and could indeed contribute to the cause of nuclear disarmament. (shrink)

Delivering high quality genomics-informed care to patients requires accurate test results whose clinical implications are understood. While other actors, including state agencies, professional organizations, and clinicians, are involved, this article focuses on the extent to which the federal agencies that play the most prominent roles — the Centers for Medicare and Medicaid Services enforcing CLIA and the FDA — effectively ensure that these elements are met and concludes by suggesting possible ways to improve their oversight of genomic testing.

It is probable that, increasingly, genome investigations are going to be based on statistical formalization. This review summarizes the state of art and potentiality of using statistics in microbial genome analysis. First, I focus on recent advances in functional genomics, such as finding genes and operons, identifying gene conversion events, detecting DNA replication origins and analysing regulatory sites. Then I describe how to use phylogenetic methods in genome analysis and methods for genome‐wide scanning for (...) positively selected amino acids. I conclude with speculations on the future course of genome statistical modeling. BioEssays 25:266–273, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

The introduction of genomics and biobanking methodologies to the African research context has also introduced novel ways of doing science, based on values of sharing and reuse of data and samples. This shift raises ethical challenges that need to be considered when research is reviewed by ethics committees, relating for instance to broad consent, the feedback of individual genetic findings, and regulation of secondary sample access and use. Yet existing ethics guidelines and regulations in Africa do not successfully regulate research (...) based on sharing, causing confusion about what is allowed, where and when. In order to understand better the ethics regulatory landscape around genomic research and biobanking, we conducted a comprehensive analysis of existing ethics guidelines, policies and other similar sources. We sourced 30 ethics regulatory documents from 22 African countries. We used software that assists with qualitative data analysis to conduct a thematic analysis of these documents. Surprisingly considering how contentious broad consent is in Africa, we found that most countries allow the use of this consent model, with its use banned in only three of the countries we investigated. In a likely response to fears about exploitation, the export of samples outside of the continent is strictly regulated, sometimes in conjunction with regulations around international collaboration. We also found that whilst an essential and critical component of ensuring ethical best practice in genomics research relates to the governance framework that accompanies sample and data sharing, this was most sparingly covered in the guidelines. There is a need for ethics guidelines in African countries to be adapted to the changing science policy landscape, which increasingly supports principles of openness, storage, sharing and secondary use. Current guidelines are not pertinent to the ethical challenges that such a new orientation raises, and therefore fail to provide accurate guidance to ethics committees and researchers. (shrink)

As evidenced by high-throughput sequencers, genomic technologies have recently undergone radical advances. These technologies enable comprehensive sequencing of personal genomes considerably more efficiently and less expensively than heretofore. These developments present a challenge to the conventional framework of biomedical ethics; under these changing circumstances, each research project has to develop a pragmatic research policy. Based on the experience with a new large-scale project—the Genome Science Project—this article presents a novel approach to conducting a specific policy for personal genome (...) research in the Japanese context. In creating an original informed-consent form template for the project, we present a two-tiered process: making the draft of the template following an analysis of national and international policies; refining the draft template in conjunction with genome project researchers for practical application. Through practical use of the template, we have gained valuable experience in addressing challenges in the ethical review process, such as the importance of sharing details of the latest developments in genomics with members of research ethics committees. We discuss certain limitations of the conventional concept of informed consent and its governance system and suggest the potential of an alternative process using information technology. (shrink)

Mammalian telomeres have evolved safeguards to prevent their recognition as DNA double‐stranded breaks by suppressing the activation of various DNA sensing and repair proteins. We have shown that the telomere‐binding proteins TRF2 and RAP1 cooperate to prevent telomeres from undergoing aberrant homology‐directed recombination by mediating t‐loop protection. Our recent findings also suggest that mammalian telomere‐binding proteins interact with the nuclear envelope to maintain chromosome stability. RAP1 interacts with nuclear lamins through KU70/KU80, and disruption of RAP1 and TRF2 function (...) result in nuclear envelope rupture, promoting telomere‐telomere recombination to form structures termed ultrabright telomeres. In this review, we discuss the importance of the interactions between shelterin components and the nuclear envelope to maintain telomere homeostasis and genome stability. (shrink)

The nuclear envelope shapes the functional organization of the nucleus. Increasing evidence indicates that one of its main components, the nuclear lamina, dynamically interacts with the genome, including the promoter region of specific genes. This seems to occur in a manner that accords developmental significance to these interactions. This essay addresses key issues raised by recent data on the association of nuclear lamins with the genome. We discuss how lamins interact with large chromatin domains and (...) with spatially restricted regions on gene promoters. We address the relationship between these interactions, chromatin modifications and gene expression outcomes. Lamin‐genome contacts are redistributed after cell division and during stem cell differentiation, with evidence of lineage specificity. Thus, we also speculate on a developmental role of lamin interactions with specific genes. Finally, we highlight how concepts arising from this recent work lay the foundations of future challenges and investigations. (shrink)

The relationship between kinetochores and nuclear pore complexes (NPCs) is intimate but poorly understood. Several NPC components and associated proteins are relocated to mitotic kinetochores to assist in different activities that ensure faithful chromosome segregation. Such is the case of the Mad1‐c‐Mad2 complex, the catalytic core of the spindle assembly checkpoint (SAC), a surveillance pathway that delays anaphase until all kinetochores are attached to spindle microtubules. Mad1‐c‐Mad2 is recruited to discrete domains of unattached kinetochores from where it promotes the (...) rate‐limiting step in the assembly of anaphase‐inhibitory complexes. SAC proficiency further requires Mad1‐c‐Mad2 to be anchored at NPCs during interphase. However, the mechanistic relevance of this arrangement for SAC function remains ill‐defined. Recent studies uncover the molecular underpinnings that coordinate the release of Mad1‐c‐Mad2 from NPCs with its prompt recruitment to kinetochores. Here, current knowledge on Mad1‐c‐Mad2 function and spatiotemporal regulation is reviewed and the critical questions that remain unanswered are highlighted. (shrink)

The existence and properties of the chloroplast genome were established by a combination of genetic methods which identified chloroplast mutations and placed them into a linear sequence or map; and by chemical methods, CsCl density gradient ultracentrifugation and base analysis, which identified non‐nuclear DNA extracted from isolated chloroplasts. These studies, carried out in the 1950s and 1960s, primarily with Chlamydomonas, as well as parallel studies of mitochondrial DNA with yeast and Neurospora, laid the framework for distinguishing organelle (...) and nuclear genomes. On this basis, the coding and regulatory functions of three genomes – nuclear, chloroplast, and mitochondrial – are being addressed in modern plant molecular biology. (shrink)

Large-scale whole genome sequencing (WGS) studies promise to revolutionize cancer research by identifying targets for therapy and by discovering molecular biomarkers to aid early diagnosis, to better determine prognosis and to improve treatment response prediction. Such projects raise a number of ethical, legal, and social (ELS) issues that should be considered. In this study, we set out to discover how these issues are being handled across different jurisdictions.

High‐capacity sequencing technologies have dramatically reduced both the cost and time required to generate complete human genome sequences. Besides expanding our knowledge about existing diversity, the nature of these technologies makes it possible to extend knowledge in yet another dimension: time. Recently, the complete genome sequence of a 4,000‐year‐old human from the Saqqaq culture of Greenland was determined to 20‐fold coverage. These data make it possible to investigate the population affinities of this enigmatic culture and, by identifying several (...) phenotypic traits of this individual, provide a limited glimpse into how these people may have looked. While undoubtedly a milestone in ancient DNA research, the cost to generate an ancient genome, even from such an exceptionally preserved specimen, remains out of reach for most. Nonetheless, recently developed DNA capture methods, already applied to Neanderthal and fossil human mitochondrial DNA, may soon make large‐scale genome‐wide analysis of ancient human diversity a reality, providing a fresh look at human population history. (shrink)

Background The rise in genomic and biobanking research worldwide has led to the development of different informed consent models for use in such research. This study analyses consent documents used by investigators in the H3Africa (Human Heredity and Health in Africa) Consortium. Methods A qualitative method for text analysis was used to analyse consent documents used in the collection of samples and data in H3Africa projects. Thematic domains included type of consent model, explanations of genetics/genomics, data sharing and feedback (...) of test results. Results Informed consent documents for 13 of the 19 H3Africa projects were analysed. Seven projects used broad consent, five projects used tiered consent and one used specific consent. Genetics was mostly explained in terms of inherited characteristics, heredity and health, genes and disease causation, or disease susceptibility. Only one project made provisions for the feedback of individual genetic results. Conclusion H3Africa research makes use of three consent models—specific, tiered and broad consent. We outlined different strategies used by H3Africa investigators to explain concepts in genomics to potential research participants. To further ensure that the decision to participate in genomic research is informed and meaningful, we recommend that innovative approaches to the informed consent process be developed, preferably in consultation with research participants, research ethics committees and researchers in Africa. (shrink)

Whether, and to what degree, do patents granted on human genes cast a shadow of uncertainty over genomics and its applications? Will owners of patents on individual genes or clusters of genes sue those performing whole-genome analyses on human samples for patent infringement? These are related questions that have haunted molecular diagnostics companies and services, coloring scientific, clinical, and business decisions. Can the profusion of whole-genome analysis methods proceed without fear of patent infringement liability?Whole-genome sequencing is (...) proceeding apace. Academic centers have been performing whole-genome and -exome sequencing in research for at least five years, and academic clinical laboratories with national reach have been doing sequencing for clinical applications for almost as long. Companies have also been offering WGS and WES as a clinical service for a few years now. So far as we know, no one has been sued for infringement of “gene patents” for performing WGS. (shrink)

In this post‐sequencing era, geneticists can focus on functional genomics on a much larger scale than ever before. One goal is the discovery and elucidation of the intricate genetic networks that co‐ordinate transcriptional activation in different regulatory circuitries. High‐throughput gene expression measurement using DNA arrays has thus become routine strategy. This approach, however, does not directly identify gene loci that belong to the same regulatory group; e.g., those that are bound by a common (set of) transcription factor(s). Working in yeast, (...) two groups have recently published an elegant method that could circumvent this problem, by combining chromatin immunoprecipitation and DNA microarrays.(1,2) The method is likely to provide a powerful tool for the dissection of global regulatory networks in eukaryotic cells. BioEssays 23:473–476, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Plastids and mitochondria arose through endosymbiotic acquisition of formerly free-living bacteria. During more than a billion years of subsequent concerted evolution, the three genomes of plant cells have undergone dramatic structural changes to optimize the expression of the compartmentalized genetic material and to fine-tune the communication between the nucleus and the organelles. The chimeric composition of many multiprotein complexes in plastids and mitochondria (one part of the subunits being nuclear encoded and another one being encoded in the organellar (...) class='Hi'>genome) provides a paradigm for co-evolution at the cellular level. In this paper, we discuss the co-evolution of nuclear and organellar genomes in the context of environmental adaptation in species and populations. We highlight emerging genetic model systems and new experimental approaches that are particularly suitable to elucidate the molecular basis of co-adaptation processes and describe how nuclear-cytoplasmic co-evolution can cause genetic incompatibilities that contribute to the establishment of hybridization barriers, ultimately leading to the formation of new species. (shrink)

The spatial organization of the genome is intimately linked to its biological function, yet our understanding of higher order genomic structure is coarse, fragmented and incomplete. In the nucleus of eukaryotic cells, interphase chromosomes occupy distinct.

The development of culture-independent strategies to study microbial diversity and function has led to a revolution in microbial ecology, enabling us to address fundamental questions about the distribution of microbes and their influence on Earth’s biogeochemical cycles. This article discusses some of the progress that scientists have made with the use of so-called “omic” techniques (metagenomics, metatranscriptomics, and metaproteomics) and the limitations and major challenges these approaches are currently facing. These ‘omic methods have been used to describe the taxonomic structure (...) of microbial communities in different environments and to discover new genes and enzymes of industrial and medical interest. However, microbial community structure varies in different spatial and temporal scales and none of the ‘omic techniques are individually able to elucidate the complex aspects of microbial communities and ecosystems. In this article we highlight the importance of a spatiotemporal sampling design, together with a multilevel ‘omic approach and a community analysis strategy (association networks and modeling) to examine and predict interacting microbial communities and their impact on the environment. (shrink)

A clear, introductory overview of the issues surrounding gene patenting.

Human heritable genome editing (HHGE) involves editing the genes of human gametes and/or early human embryos. Whilst ‘identity’ is a key concept underpinning the current HHGE debate, there is a lack of inclusive analysis on different concepts of ‘identity’ which renders the overall debate confusing at times. This paper first contributes to reviewing the existing literature by consolidating how ‘identity’ has been discussed in the HHGE debate. Essentially, the discussion will reveal an ontological and empirical understanding of identity (...) when different types of identity are involved. Here, I discuss genetic, numerical, qualitative and narrative and how each of them is relevant in the HHGE context. Secondly, given the different types of identity, the paper explores how we could navigate these different interpretations of identity in a way that promotes an inclusive and informed discussion between primary stakeholders and the general public in the HHGE debate. Here, I argue for and refine a multi-faceted concept of identity as a suitable framework for discussing the ethical and societal implications of HHGE because it not only could integrate different understandings of identity but also highlight the interconnectedness between these different understandings. (shrink)

Whole-genome analysis and whole-exome analysis generate many more clinically actionable findings than traditional targeted genetic analysis. These findings may be relevant to research participants themselves as well as for members of their families. Though researchers performing genomic analyses are likely to find medically significant genetic variations for nearly every research participant, what they will find for any given participant is unpredictable. The ubiquity and diversity of these findings complicate questions about disclosing individual genetic test results. We (...) outline an approach for disclosing a select range of genetic results to the relatives of research participants who have died, developed in response to relatives? requests during a pilot study of large-scale medical genetic sequencing. We also argue that studies that disclose individual research results to participants should, at a minimum, passively disclose individual results to deceased participants? relatives. (shrink)

The power of the scientific enterprise presents multiple avenues for harnessing and increasingly controlling biological phenomena and instituting interventions in different areas of biomedicine (Af...

I analyze Ojibway objections to genomics and genetics research on wild rice. Although key academic and industry participants in this research have dismissed their objections out of hand, my analysis supports the conclusion that the objections merit serious consideration, even by those who do not share the Ojibway’s religious beliefs.

New techniques in genome editing have led to a controversial debate about the opportunities and uncertainties they present for agricultural food production and consumption. In July 2018, the Court of Justice of the European Union defined genome editing as a new process of mutagenesis, which implies that the resulting organisms count as genetically modified and are subject, in principle, to the obligations of EU Directive 2001/18/EG. This paper examines how key protagonists from academia, politics, and the economy strategically (...) framed the debate around genome editing in agriculture in Germany prior to its legal classification by the Court of Justice. It is based on an analysis of 96 official statements, including position papers, press releases, and information brochures. Our study reveals eight strategic frames used in the discourse on genome editing and uncovers the strategies used to disconnect from or connect with the previous discourse on green genetic engineering in the 1970s, 1980s and 1990s. Building on competitive framing theory, the study provides explanations for the use and emergence of counter-framing strategies and their success or failure in the debate around genome editing. (shrink)

The vast majority (> 95%) of single-gene mutations in yeast affect not only the expression of the mutant gene, but also the expression of many other genes. These data suggest the presence of a previously uncharacterized ‘gene expression network’—a set of interactions between genes which dictate gene expression in the native cell environment. Here, we quantitatively analyze the gene expression network revealed by microarray expression data from 273 different yeast gene deletion mutants.(1) We find that gene expression interactions form a (...) robust, error-tolerant ‘scale-free’ network, similar to metabolic pathways(2) and artificial networks such as power grids and the internet.(3-5) Because the connectivity between genes in the gene expression network is unevenly distributed, a scale-free organization helps make organisms resistant to the deleterious effects of mutation, and is thus highly adaptive. The existence of a gene expression network poses practical considerations for the study of gene function, since most mutant phenotypes are the result of changes in the expression of many genes. Using principles of scale-free network topology, we propose that fragmenting the gene expression network via ‘genome-engineering’ may be a viable and practical approach to isolating gene function. BioEssays 24:267–274, 2002. © 2002 Wiley Periodicals, Inc.; DOI 10.1002/bies.10054. (shrink)

Increasing interest has been paid to applications of fluorescence measurements to analyze physiological mechanisms in living cells. However, few studies have taken advantage of DNA quantification by fluorometry for dynamic assessment of chromatin organization as well as cell motion during the cell cycle. This approach involves both optimal conditions for DNA staining and cell tracking methods. In this context, this report describes a stoichiometric method for nuclear DNA specific staining, using the bisbenzimidazole dye Hoechst 33342 associated with verapamil, a (...) calcium membrane channel blocker. This method makes it possible to correlate variations of nuclear DNA content with cell motion in cells that are maintained alive. Motion measurement is the second goal of this paper and it explains the snake-spline method, and the associated cell following method. (shrink)

Genomic research results and incidental findings with health implications for a research participant are of potential interest not only to the participant, but also to the participant's family. Yet investigators lack guidance on return of results to relatives, including after the participant's death. In this paper, a national working group offers consensus analysis and recommendations, including an ethical framework to guide investigators in managing this challenging issue, before and after the participant's death.