Comptes Rendus de l'Académie des Sciences - Series III - Sciences de la Vie最新文献

During the last ten years, Arabidopsis thaliana has become the most favoured plant system for the study of many aspects of development and adaptation to adverse conditions and diseases. The sequencing of the Arabidopsis thaliana genome is nearly completed with more than 90 % of the sequence being released in public databases. This is the first plant genome to be analysed and it has revealed a tremendous amount of information about the nature of the genes it contains and its largely duplicated organisation. French groups have been involved in Arabidopsis genomics at several steps: EST (expressed sequence tags) sequencing, construction and ordering (physical mapping of chromosomes) of a YAC (yeast artificial chromosomes) library, genomic sequencing. In parallel an extensive programme of functional genomics is being undertaken through the systematic analysis of insertional mutants. This information provides a support for analysing other more economically important plant genomes such as the rice genome and constitutes the beginning of a systematic investigation on plant gene functions and will promote new strategies for plant improvement.

As a historical consequence of molecular biology, genomics provides a complete theory of information in the field of biology. Genomics through biotechnologies offers also for the first time in history the possibility to create a new living world. Genomics can be seen as a component of actual culture that is in close connection with the economic strategies with strong political implications especially for health care and environment. This article analyses the historical determinants of genomics culture and questions the sense of the interpretations given to life by genomists. It also underlines their responsibility in elaborating this new kind of knowledge.

In vitro, LSLCL is expressed by numerous myeloid, promyelocytic, and T or B lymphoblastoid cell lines. In vivo, LSLCL is strongly expressed in bone marrow and only faintly in lymphoid organs. We show here that, in bone marrow, LSLCL is detected: (i) concentrated in the cytoplasm of immature neutrophils but not in myeloblasts nor in mature neutrophils, (ii) in extracellular bone marrow fluid. Besides, numerous cDNAs, similar to LSLCL (identity of 93–99 %), are found in ‘expressed sequence tags’ databases from various origins, mostly fetal and undifferentiated tumour tissues. Since LSLCL and various closely related cDNAs are expressed at definite stages of cellular maturation processes, we hypothesize that this class of proteins could play an important role in the control of cellular differentiation.

Embryos and larvae of bivalves are frequently used in marine ecotoxicology for the purpose of assessing seawater quality, because they are very sensitive to pollutants and provide rapid responses. Laboratory studies, however, cannot accurately simulate natural conditions. We conducted bivalve embryo-larval studies in situ at the marina of Arcachon (southwest French Atlantic coast), in order to assess ‘biological quality’ of the water. One experiment conducted in winter 1999 (temperatures of 10 °C) with embryos of the Mediterranean mussel, Mytilus galloprovincialis, has shown that such tests are practicable in winter at low temperatures. This study did not show any deterioration in ‘biological quality’ of the water. Four series of experiments were subsequently performed during summer 2000 (ambient water temperatures of 19 to 22.4 °C) with embryos of the Japanese oyster, Crassostrea gigas. The results show that the ‘sea water biological quality’ deteriorates from the port entrance towards its inner part. To our knowledge, this is the first investigation of the marine environment in which bivalve embryos have been used in situ. They are very suitable for this type of study, because bivalve embryos and larvae are more sensitive to pollutants than the adults, and also because they belong to euryhaline species and the embryos tolerate summer temperatures (both species) as well as winter temperatures (mussels), allowing biomonitoring to be conducted all over the year.

The discovery of a functional division in T helper cells on the basis of their cytokine secretion patterns has changed our vision of immunological responses. This dichotomy has equally shown the complexity of immune responses since there is a well orchestrated cross-regulation of cytokine production induced by viral, bacterial or parasitic pathogens. In the context of type1–type 2 cytokine pattern, mice has been universally and extensively used to associate an infectious disease according to each category in order to better understand human infections. However, with respect to schistosomiasis, immunological observations in mice have not been confirmed in humans and particularly the nature of the protective immune response. This report will consider the relevance of extrapolating from immunological studies on schistosome in experimentally infected rats to studies on naturally infected humans.

A human being or person cannot be reduced to a set of human genes, or human genome. Genetic essentialism is wrong, because as a person the entity should have self-conscious and social interaction capacity which is grown in an interpersonal relationship. Genetic determinism is wrong too, the relationship between a gene and a trait is not a linear model of causation, but rather a non-linear one. Human genome is a complexity system and functions in a complexity system of human body and a complexity of systems of natural/social environment. Genetic determinism also caused the issue of how much responsibility an agent should take for her/his action, and how much degrees of freedom will a human being have. Human genome research caused several conceptual issues. Can we call a gene ‘good’ or ‘bad’, ‘superior’ of ‘inferior’? Is a boy who is detected to have the gene of Huntington’s chorea or Alzheimer disease a patient? What should the term ‘eugenics’ mean? What do the terms such as ‘gene therapy’, ‘treatment’ and ‘enhancement’ and ‘human cloning’ mean etc.? The research of human genome and its application caused and will cause ethical issues. Can human genome research and its application be used for eugenics, or only for the treatment and prevention of diseases? Must the principle of informed consent/choice be insisted in human genome research and its application? How to protecting gene privacy and combating the discrimination on the basis of genes? How to promote the quality between persons, harmony between ethnic groups and peace between countries? How to establish a fair, just, equal and equitable relationship between developing and developed countries in regarding to human genome research and its application?

Mammalian cytochrome c oxidase consists of thirteen subunits, ten encoded by the nuclear genome and three by the mitochondrial DNA. In several species, two isoforms have been isolated for nuclear-encoded subunits VIa, VIIa and VIII : an ubiquitous L (liver) form and a heart- and skeletal-muscle specific H form. The gene for murine cytochrome c oxidase subunit VIIa-L (Cox7aL) and its promoter region were isolated, sequenced and analysed. The coding region is split in four exons spanning 4.1 kbp and the promoter carries potential binding sites for Sp1, NRF1 and NRF2 transcription factors. Transcriptional activity of the promoter in reporter assays suggested an ubiquitous expression in mouse tissues.

Pollination and fertilization are key steps leading to seed and fruit formation. To obtain genes involved in pollination and fertilization in rice, an RNA fingerprinting technique, cDNA-AFLP (amplified fragment length polymorphism), was used to generate transcript profiles related to pollination. Of 15 000 cDNA fragments inspected, 2 100 showed altered expression in the pollinated pistil, of which about 1/5 were up-regulated (URP) and the rest down-regulated (DRP), suggesting that gene repression is a predominant mode of gene regulation in the pollinated pistil. Over 200 URP genes were sequenced and databank searches revealed that 70 % of them represented previously unnoticed rice genes. DNA blot analysis of 20 URP genes detected no restriction fragment length polymorphisms (RFLP) between two relatively distant rice varieties, suggesting that the URP genes are highly conserved and likely play important roles in pollination and fertilization. Furthermore, two genes, URP47 and URP63, probably encoding an ADP-ribosylation factor and a membrane transporter, respectively, in relation to pollination were discussed.

The risk of accident for a parisian pedestrian is of reduced frequency and of moderate severity (terrorism and natural disasters not included) according to the statistics of 1999. This is due to security measures and the excellent organisation of assistance to wounded persons. The improvement in protection of pedestrians, even the disabled and elderly persons will soon make Paris the best protected megalopolis of our continent. Pedestrians are involved in 28 % of accidents on public streets with a mortality of 1.2 %, with serious injuries in 12.6 % of the cases. Injuries without collision occur in 57 % of the cases. 18 % of the wounded older than 75 years with 1.8 % of deaths and 66 % of severe injury. Accidents related to public transportation represent a very slight risk of 0.00044 %. By modification of the concept of transportation and its materials over a five year period there is a decrease in the number of the victims (–3.75 %), in spite of the increase of accidents (3.5 %). For lone pedestrian being victims of aggression in public places, after a decrease of 10 % in 1999, there is in 2001 an increase which raises the question of police proximity again. Over a five year period the RATP (subway authority) has noticed  a 14.77 % decrease of thefts and a 54.78 % decrease in attacks… This makes the Parisian railnet (subway mostly) seven times less dangerous than the streets.