Glossaire Acheson, Julianna; Bley, Daniel; Boetsch, Gilles ...
Vers un Ailleurs Prometteur-: L'émigration, une Réponse Universelle à une Situation de Crise?,
06/2016
Journal Article
Il s’agit d’une part de rappeler ici la signification que prend la migration dans des cadres conceptuels très divers et, d’autre part, de préciser l’acception particulière selon laquelle un certain ...nombre de termes sont utilisés par les auteurs de cet ouvrage (en gras dans le texte qui suit). Le but n’est pas de fournir les définitions propres aux disciplines concernées, mais bien de proposer une explication qui soit accessible aux représentants d’autres domaines. Ces textes ont été rédigés p...
Choanoflagellates are the closest known relatives of metazoans. To discover potential molecular mechanisms underlying the evolution of metazoan multicellularity, we sequenced and analysed the genome ...of the unicellular choanoflagellate Monosiga brevicollis. The genome contains approximately 9,200 intron- rich genes, including a number that encode cell adhesion and signalling protein domains that are otherwise restricted to metazoans. Here we show that the physical linkages among protein domains often differ between M. brevicollis and metazoans, suggesting that abundant domain shuffling followed the separation of the choanoflagellate and metazoan lineages. The completion of the M. brevicollis genome allows us to reconstruct with increasing resolution the genomic changes that accompanied the origin of metazoans.
http://deepblue.lib.umich.edu/bitstream/2027.42/62649/1/nature06617.pdf
The involvement of the IGF system in the growth regulation of hormone-dependent (e.g. endometrial and breast) cancer cells was studied. We chose two opposing effects of tamoxifen: the paradoxical ...stimulation of Ishikawa endometrial cancer cells growth and its inhibitory effects on MCF-7 mammary cancer cells. The results clearly confirm our working hypothesis that the IGF system is involved in growth regulation of these cancer cells irrespective of the direction of the drug effect. The following par-ameters of the IGFs system were studied: IGF-I receptors, IGF-I stimulated protein tyrosine phosphorylation, and membrane-associated and secreted IGF-binding proteins (IGFBPs). In Ishikawa cells, tamoxifen, similar to estradiol, increased IGF-I stimulated tyrosine phosphorylation of cellular substrates in accordance with its effect on cell growth. This effect of tamoxifen was inverted in MCF-7 cells. Tamoxifen did not affect the number or affinity of IGF-I receptors in both Ishikawa and MCF-7 cells, however, it caused a three-fold decrease in membrane-associated IGFBPs in the endometrial cells but an increase in these proteins in breast cancer cells. Similar but much less pronounced changes in soluble IGFBPs were observed. Our results indicate that the opposing growth effects of tamoxifen on endometrial and mammary cancer cells are associated with modulation of the IGF system components, mainly with reciprocal changes in membrane-associated IGFBPs.
