A number of studies have demonstrated the activation of phospholipase C-mediated hydrolysis of phosphatidylcholine (PC-PLC) both by growth factors and by the product of the ras oncogene, p21ras. Evidence has been presented indicating that the stimulation of this phospholipid degradative pathway is sufficient to activate mitogenesis in fibroblasts as well as that it is sufficient and necessary for induction of maturation in Xenopus laevis oocytes. However, the mechanism whereby PC-PLC transduces mitogenic signals triggered by growth factors or oncogenes remains to be elucidated. In this study, data are presented that show the involvement of protein kinase C zeta subspecies in the channelling of the mitogenic signal activated by insulin-p21ras-PC-PLC in Xenopus oocytes as well as the lack of a critical role of protein kinase C isotypes alpha, beta, gamma, delta, and epsilon in these pathways.

Objective-To perform genetic sex typing during the Barcelona Olympic Games using polymerase chain reaction (PCR) amplification of Y chromosome specific sequences.Methods-The assay consisted of the amplification of a specific sequence corresponding to the repeat DYZI element from buccal smears samples of 2406 female competitors. Positive samples were reanalysed for the presence of another Y chromosome specific gene, SRY. Results-The expression of these two elements did not always correlate; six samples were found where the presence of DYZI but not SRY was detected. This presence of DYZI sequence in female athletes is higher than in unselected females, where no DYZ1 amplification was observed in any of the 1629 samples analysed. Conclusions-Amplification of DYZI repeat should not be used as the only index for determining genetic sex, at least in sporting events. (Br 7 Sports Med 1996;30:310-312)

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