TIBS 11 - February 1986 at 140 kDa and 150 kDa (Fig. 3). In this species, the 140 kDa component is the mem- braneassociated guanylate cyclase 7A°. The 150 kDa component is probably the unique flagellar creatine kinase that is a member of a phosphoryl-creatine shut- tle between sperm mitochondrion and flagellum 30. The sperm flagellum is an unusually rich source of creatine kinase. The abundance of creatine kinase and guanylate cyclase in flagellar membranes of sea urchin sperm suggests roles for the enzymes in motility. We must learn more about the membrane proteins of these fascinating cells before detailed know- ledge of the interaction of sperm with egg can be obtained. References Primary references to the work covered in thisarticle can befound in the reviewsand papers cited below. 1 Metz, C. B. and Monroy, A., (eds.) (1985) Biology of Fertilization, vols 1-3, Academic Press 2 Lopo, A. C. (1983) in Mechanism and Control of Animal Fertilization (J. F. Hartmann, ed.), pp. 270-311, Academic Press 3 Clapper, D. L., Davis, J. A., Lamothe, P. J., Patton, C. and Epel, D. (1985)J. CellBiol. 100, 1817-1824 4 Christen, R., Schackmann, R. W. and Shapiro, B. M. (1983) J. Biol. Chem. 258, 5392-5399 5 Bibring, T., Baxandall, J. and Harter, C. C. (1984) Dev. Biol. 101,425-435 6 Lee, H. C. (1985) J. Biol. Chem. 260, 10794-10799 7 Garbers, D. L., Bentley, J. K., Dangon, L. J., Ramarao, C. S., Shimomura, H., Suzuki, N. and Thorpe, D. in The Molecular and Cellular Biology of Fertilization (J. L. Hedrick, ed.), Plenum (in press) 8 Nomura, K. and Isaka, S. (1985) Biochem. Biophys. Res. Commun. 126, 974-982 9 Garbers, D. L. and Kopf, G. S. (1980) Adv. Cyclic Res. 13, 251-306 I0 Ramarao, C. S. and Garbers, D. L. (1985) J. Biol. Chem. 260, 8390~396 11 Ward, G. E. Garbers, D. L. and Vacquier, V. D. (1985) Science 227,768-770 12 Ward, G. E., Moy, G. W., Vacquier, V. D. in The Molecular and Cellular Biology of Fertiliza- tion (J. L. Hedrick, ed.), Plenum (in press) 13 Ward, G. E., Brokaw, C. J., Garbers, D. L. and VacquieL V. D. J. Cell Biol. (in press) 14 SeGall, G. K. and Lennarz, W. J. (1981). Dev. BioL 86, 87-93 15 Garbers, D. L., Kopf, G. S., Tubb, D. J. and Olson, G. (1983) Biol, Reprod. 29, 12t1-1220 16 Schackmann, R. W., Christen, R. and Shapiro, B. M. (1984) J. Biol. Chem. 259, 13914-13922 81 17 Shapiro, B. M. (1984) in Cell Fusion Ciba Foundation Symposium103, pp. 86-99, Pitman Books 18 Green, G. R. and Poccia, D. L. 0985) Dev. Biol. 108, 235-245 19 Porter, D. C. and Vacquier, V. D. (1985) J. Cell. Biol. 101,264a 20 Tilney, L. G., Kiehart, D. P., Sardet, C. and Tilney, M. (1978) J. Cell Biol. 77,536-550 21 Rossignol, D. P., Earles, B. J., Decker, G. L. and Lennarz, W. J. (1984) Dev. Biol. 104, 308-321 22 Vacquier, V. D. (1983) Anal. Biochem. 129, 497-502 23 Glabe, C. G. (1985) ,L Cell Biol. 100,794-799; 100, 800-806 24 Podell, S. B., Moy, G. W. and Vacquier, V. D. (1984) Biochim. Biophys. Acta 778, 25-37 25 Darszon, A., Gould, M., De La Torre, L. and Vargas, I. (1984) Eur. J. Biochem. 144, 515-522 26 Kazazoglou, T., Schackmann, R. W., Fosset, M. and Shapiro, B. M. (1985) Proc. NatlAcad. Sci. USA 82, 1460-1464 27 Podell, S. B. and Vacquier, V. D. (1984)J. Cell Biol. 99, 1598-1604 28 Podell, S. B. and Vacquier, V. D. (1985) J. Biol. Chem. 260, 2715-2718 29 Trimmer, J. S., Trowbridge, 1. S. and Vacquier, V. D. (1985) Cell 40,697-703 30 Tombes, R. M. and Shapiro, B. M. (1985) Cell 41,325-334 Fibroblast growth factors: broad spectrum mitogens with potent angiogenic activity Kenneth A. Thomas and GuiUermo Gimenez-Gallego Fibroblast growth factors (FGFs) are protein mitogens, found in brain and pituitary, that induce division of a wide variety of cells in culture. Interest has focused on FGF, in part, because of their mitogenic activity for vascular endothelial cells in culture and their ability to induce blood vessel growth in vivo. The discovery of substances that control the growth of animal cells and the mechanism by which they work is currently one of the major focuses of research in the biochemical sciences. With the recently discovered correlations between growth factors and oncogenes 1, this work is motivated in large part by the belief that lesions in K. A. Thomas and G. Gimenez-Gallego are at the Department of Biochemistry and Molecular Biol- ogy, Merck Institute for Therapeutic Research, Merck Sharp and Dohme Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA. G. Gimenez-Gallego is on sabbatical leave from the Consejo Superior de Investigaciones Cientificas, Centro de Investigaciones Biologicas, Madrid, Spain. these growth control systems are the underlying causes of cancers. Two of the recently purified mitogens, acidic and basic FGF, are the focus of attention of numerous research groups. The scientific origin of FGF is almost 50 years old. Around 1940, crude brain homogenates were reported to be a plentiful source of substances that stimulated primary fibroblasts to divide in culture2, 3. The activity was uniquely high in the central nervous system compared to a variety of other organs that wereexamined. In 1973, Armelin 4 found that pituitary extracts also had potent mitogenic activity for Balb/c 3T3 'fibroblasts', a cell line of uncertain differentiated state. In the 1970s, Gospodarowicz and colleagues 5 partially purified FGF activities from both pituitary and brain, based on mitogenic activity for the Balb/c 3T3 cell line. They showed that these presumably pure preparations induced division of a wide variety of cells of mesodermal origin including vascular endothelial cells, a phenotype that had previously been difficult to propagate in culture. Originally, only a single type of brain- derived FGF, proposed to arise from limited proteolysis of myelin basic protein in vivo, was thought to exist. The mitogen was claimed to be inactivated at its assumed basic isoelectric point, since no biological activity could be recovered with the myelin basic protein fragments after isoelectric focusing. By 1980, however, an active FGF with an acidic isoelectric point, clearly not a fragment of myelin basic protein, was identified in these partially purified preparations of FGF from brain 6. Shortly thereafter, the basic mitogen from pituitary also was shown to be distinct from the inactive contaminating protein that comprised the bulk of the partially purified pituitary preparations 7. In the past few years both acidic and basic FGF have been identified in brain and pituitary preparations. Once it was clear that these protein preparations were impure, efforts were renewed to obtain homogeneous FGF from both sources. (~)1986, Elsevier Science Publishers B.V., Amsterdam 0376 - 5067/86/$02.00