Colorectal cancer: mutations in a signalling pathway

Protein kinases are enzymes that are important for controlling cellular growth and invasion, and their malfunction is implicated in the development of some tumours. We analysed human colorectal cancers for genetic mutations in 340 serine/threonine kinases and found mutations in eight genes, including in three members of the phosphatidylinositol-3-OH kinase (PI(3)K) pathway. The discovery of this mutational activation of a key cell-signalling pathway may provide new targets for therapeutic intervention.     

The determination of mating speeds inDrosophila melanogaster for various combinations of inbred lines

Résumé Il ressort de nos expériences portant sur cinq souches pures deDrosophila melanogaster que la souche d'origine du mâle influe sur la durée de l'accouplement (jusqu'à 40 min) de l'une de ces souches avec d'autres. Toutefois, il n'y a pas d'interactions significatives, de ce point de vue, entre les souches.     

The genotypic control of the duration of copulation inDrosophila melanogaster

Résumé Une série d'expériences tend à montrer que chezDrosophila melanogaster la structure génétique joue un rÔle déterminant dans la durée de l'accouplement.     

Polymorphism in natural populations ofDrosophila for the ability to withstand temperature shocks

Résumé Chaque femelleDrosophila melanogaster sauvage, inséminée, isolée de son milieu naturel, a donné des descendances qui présentaient des différences génétiques concernant leur capacité à supporter le choc provoqué par de hautes températures. On peut donc émettre l'hypothèse que la population originelle de ces femelles est polymorphique quant aux gênes contrôlant cette aptitude.

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Supported by a Commonwealth of Australia Postgraduate Award

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The work was partly supported by a grant from the Australian Research Grants Committee.     

Local degradation of fibronectin at sites of expression of the transforming gene product pp60src

Local degradation of extracellular fibronectin, a major extracellular adhesive protein, is believed to play an important part in the migration of cells through the extracellular matrix during tumour invasion, morphogenetic movement and trophoblast implantation. Fibronectin is lost from the cell surface after transformation with Rous sarcoma virus (RSV). By using fluorescent and radiolabelled probes covalently coupled to the surface of substrata, we have recently identified a proteolytic activity that is expressed in RSV-transformed cells and is involved in the local degradation of fibronectin at cell-substratum contact sites. Here, we extend the relevance of these findings and gain some insight into the cellular functions of pp60src, the transforming gene product of RSV. We show that newly expressed viral pp60src is localized at the cytoplasmic surface of the cell membrane, corresponding to the cell contact sites where degradation of extracellular fibronectin occurs.