Fig. 2. Working model for the signal network that controls meiotic initiation in S. cerevisiae. The three principal nutritional signals required to initiate meiosis are shown in boxes. The diagram shows some of the signal transduction pathways that control meiotic initiation and examples of where these pathways are connected (see text for details). The names of the proteins are abbreviated without the final `p' for brevity (e.g. Snf1 rather than Snf1p).