Genetics is a science without object

La genética es la ciencia de los caracteres hereditarios; por lo menos ésta es su definición. Pero un análisis histórico de las nociones de gen y herencia pone en entredicho la aparente evidencia de estos términos. Antes de creer en las “promesas” de la genética, es necesario volver sobre algunas falsas certidumbres de la biología.Genetics is the science of hereditary traits; at least this is its definition. But a historical gene and inheritance notion analysis questions the apparent evidence of these terms. Before believing in genetics “promises”, it is necessary to revisit some false certainties of biology

An alternative to Kitcher's theory of conceptual progress and his account of the change of the gene concept

The present paper discusses Kitcher’s framework for studying conceptual change and progress. Kitcher’s core notion of reference potential is hard to apply to concrete cases. In addition, an account of conceptual change as change in reference potential misses some important aspects of conceptual change and conceptual progress. I propose an alternative framework that focuses on the inferences and explanations supported by scientific concepts. The application of my approach to the history of the gene concept offers a better account of the conceptual progress that occurred in the transition from the Mendelian to the molecular gene than Kitcher’s theory

Similarity and categorisation: getting dissociations in perspective

Dissociations between similarity and categorization have constituted critical counter-evidence to the view that categorization is similarity-based. However, there have been difficulties in replicating such dissociations. This paper reports three experiments. The first provides evidence of a double dissociation between similarity and categorization. The second and third show that by asking participants to make their judgments from particular perspectives, this dissociation disappears or is much reduced. It is argued that these data support a perspectival view of concepts, in which categorization is similarity-based, but where the dimensions used to make similarity and categorization judgments are partially fixed by perspective

Public understanding of science and common sense: Social representations of the human microbiome among the expert and non-expert public

The aim of this investigation is to examine the structure and the content of different social groups’ representations of the human microbiome. We employed a non-probabilistic sample comprising two groups of participants. The first group (n = 244) included university students. The second group included lay people (n = 355). We chose a mixed-method approach. The data obtained were processed using IRaMuTeQ software. The results allow us to identify the anchoring and objectification processes activated by the two different groups of interviewees. The results could be useful to those in charge of implementing campaigns aimed at promoting health literac

The search for the Jew's gene : science, spectacle, and the ethnic other

This paper considers the collision of spectacle, science, and racial-ethnic identifications in the contemporary scientific search for a "Jewish gene." It aims not so much to distinguish the "line between ‘real’ and ‘fabled’ aspects of the Jew" (as cited in the passage by Gilman above), but to consider the inextricability of both as composite elements, mutually constituting "difference" as racial-ethnic identification. Thus I am concerned with the specular economies of science as well as the knowledge capital of its mediatisation as they come together, troubled, over the Jew’s body. The essay takes as its case study the National Geographic (NOVA/PBS) television documentary, The Sons of Abraham, a film that follows the progress of anthropologist Tudor Parfitt through the Lemba communities of South Africa in a quest to obtain genetic evidence in order to authenticate (or falsify) their claims to Jewish identity

Combined flow cytometry and high-throughput image analysis for the study of essential genes in Caenorhabditis elegans

Background: Advances in automated image-based microscopy platforms coupled with high-throughput liquid workflows have facilitated the design of large-scale screens utilising multicellular model organisms such as Caenorhabditis elegans to identify genetic interactions, therapeutic drugs or disease modifiers. However, the analysis of essential genes has lagged behind because lethal or sterile mutations pose a bottleneck for high-throughput approaches, and a systematic way to analyse genetic interactions of essential genes in multicellular organisms has been lacking. Results: In C. elegans, non-conditional lethal mutations can be maintained in heterozygosity using chromosome balancers, commonly expressing green fluorescent protein (GFP) in the pharynx. However, gene expression or function is typically monitored by the use of fluorescent reporters marked with the same fluorophore, presenting a challenge to sort worm populations of interest, particularly at early larval stages. Here, we develop a sorting strategy capable of selecting homozygous mutants carrying a GFP stress reporter from GFP-balanced animals at the second larval stage. Because sorting is not completely error-free, we develop an automated high-throughput image analysis protocol that identifies and discards animals carrying the chromosome balancer. We demonstrate the experimental usefulness of combining sorting of homozygous lethal mutants and automated image analysis in a functional genomic RNA interference (RNAi) screen for genes that genetically interact with mitochondrial prohibitin (PHB). Lack of PHB results in embryonic lethality, while homozygous PHB deletion mutants develop into sterile adults due to maternal contribution and strongly induce the mitochondrial unfolded protein response (UPR mt ). In a chromosome-wide RNAi screen for C. elegans genes having human orthologues, we uncover both known and new PHB genetic interactors affecting the UPR mt and growth. Conclusions: The method presented here allows the study of balanced lethal mutations in a high-throughput manner. It can be easily adapted depending on the user's requirements and should serve as a useful resource for the C. elegans community for probing new biological aspects of essential nematode genes as well as the generation of more comprehensive genetic networks.European Research Council ERC-2011-StG-281691Ministerio de Economía y Competitividad BFU2012–3550