Copyright © 1997, Elsevier Science Ltd. All rights reserved. 0166 - 2236/97/$17.00 PII: S0166-2236(97)01082-5 TINS Vol. 20, No. 9, 1997 415 F. Battaini et al. – PKC activation and RACK1 in ageing R EVIEW Acknowledgements The authors wish to thank D. Mochly- Rosen for helpful comments, F.J. Van der Staay for providing the Wistar rats and W.C. Wetsel for the antisera to P.K.C. isoforms. This work was supported by the National Research Council (CNR) of Italy to F.B., the Ministry of University, Scientific and Technologic Research (MURST) to A.P., and by MURST and the Alzheimer Unit, Sacred Heart Hospital-FBF, Brescia, Italy to S.G. I N SCIENCE AND MYTHOLOGY the eye has always been an exciting topic. Many open questions still remain, particularly those concerning the evolution- ary aspects of how different organisms have solved the problem of forming and detecting an image. The iden- tification of various conserved genes among organisms as different as Drosophila and mice has challenged some of the previously accepted ideas regarding the origin of metazoan visual system. How much of the develop- ment pathway leading to eye formation has been con- served during evolution remains to be answered. Here, we focus on some of the most recent aspects of meta- zoan eye development, with a particular emphasis on the role of certain homeobox genes. Current views on eye development Guillermo Oliver and Peter Gruss Several genes involved in the regulation of eye development in different species have been identified. Structural and functional conservation have been found between some of these genes in organisms as diverse as Drosophila and mouse. One notable example is the relationship between the mouse Pax6 gene and eyeless of Drosophila. Ectopic expression of eyeless or mouse Pax6 in Drosophila results in the formation of additional eyes. Recently, another homeobox gene, Six3, was found to promote ectopic lens formation in fish embryos.The next step will be to unravel the associated regulatory pathways of these genes and assess the degree to which they display evolutionary conservation. This will be important in order to assimilate these findings with current anatomical and embryological models. It seems reasonable to believe that in the near future the characterization of the whole framework required for vertebrate eye development will be accomplished. Trends Neurosci. (1997) 20, 415–421 Guillermo Oliver is at the Dept of Genetics, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, TN 38105, USA. Peter Gruss is at the Dept of Molecular Cell Biology, Max- Planck Institute of Biophysical Chemistry, Am Fassberg, 37077 Göttingen, Germany. 7 Colley, P.A. and Routtenberg, A. (1993) Brain Res. Rev. 18, 115–122 8 Alkon, D.L. (1995) Behav. Brain Res. 66, 151–160 9 Nogues, X., Micheau, J. and Jaffard, R. (1996) Behav. Brain Res. 75, 139–146 10 Wehner, J.M., Sleight, S. and Upchurch, M. (1990) Brain Res. 523, 181–187 11 Pascale, A. et al. (1994) Eur. J. Pharmacol. 265, 1–7 12 Fordyce, D.E. et al. (1995) Brain Res. 672, 170–176 13 Sunayashiki-Kusuzaki, K. et al. (1993) Proc. Natl. Acad. Sci. U. S. A. 90, 4286–4289 14 Van der Zee, E.A. et al. (1992) J. Neurosci. 12, 4808–4815 15 Dekker, L.V. and Parker, P.J. (1994) Trends Biochem. Sci. 19, 73–77 16 Newton, A.C. (1995) J. Biol. Chem. 270, 28495–28498 17 Nishizuka, Y. (1995) FASEB J. 9, 484–496 18 Abeliovich, A. et al. (1993) Cell 75, 1253–1262 19 Chen, C. et al. (1996) Cell 83, 1233–1242 20 Leitges, M. et al. (1996) Science 273, 788–791 21 Prekeris, R. et al. (1996) J. Cell Biol. 132, 77–90 22 Ishii, H. et al. (1996) Science 272, 728–731 23 Conrad, R. et al. (1994) J. Biol. Chem. 269, 32051–32054 24 Bell, R.M. and Burns, D.J. (1991) J. Biol. Chem. 266, 4661–4664 25 Gopalakrishna, R. et al. (1986) J. Biol. Chem. 261, 16438–16445 26 Wolf, M. and Sahyoun, N. (1986) J. Biol. Chem. 261, 13327–13332 27 Chapline, C. et al. (1993) J. Biol. Chem. 268, 6858–6861 28 Staudiger, J. et al. (1995) J. Cell Biol. 128, 263–271 29 Klauck, T.M. et al. (1996) Science 271, 1589–1592 30 Mochly-Rosen, D., Khaner, H. and Lopez, J. (1991) Proc. Natl. Acad. Sci. U. S. A. 88, 3997–4000 31 Robles-Flores, M. and Garcia-Sainz, J.A. (1993) Biochem. J. 296, 467–472 32 Smith, B.L. and Mochly-Rosen, D. (1992) Biochem. Biophys. Res. Commun. 188, 1235–1240 33 Ron, D., Luo, J. and Mochly-Rosen, D. (1995) J. Biol. Chem. 270, 24180–24187 34 Kiley, S.C. and Jaken, S. (1994) Trends Cell Biol. 4, 223–227 35 Pascale, A. et al. (1996) J. Neurochem. 67, 2471–2477 36 Hashimoto, T. et al. (1988) J. Neurosci. 8, 1678–1683 37 Huang, F.L. et al. (1990) Dev. Brain Res. 52, 121–130 38 Hirata, M. et al. (1991) Dev. Brain Res. 62, 229–238 39 Tremblay, E., Ben-Ari, Y. and Roisin, M.P. (1995) J. Neurochem. 65, 863–870 40 Jiang, X. et al. (1994) Dev. Brain Res. 78, 291–295 41 Hunter, S.E., Seibenhener, M.L. and Wooten, M.W. (1995) Dev. Brain Res. 85, 239–248 42 Bothmer, J. and Jolles, J. (1994) Biochim. Biophys. Acta 1225, 111–124 43 Friedman, E. and Wang, H-Y. (1989) J. Neurochem. 52, 187–192 44 Meyer, M. et al. (1994) Neurobiol. Aging 15, 63–67 45 Battaini, F. et al. (1990) Neurobiol. Aging 11, 563–566 46 Battaini, F. et al. (1995) Neurobiol. Aging 16, 137–148 47 Fordyce, D.E. and Wehner, J.M. (1993) Neurobiol. Aging 14, 309–317 48 Narang, N. and Crews, F.T. (1995) Neurochem. Res. 20, 1119–1126 49 Pascale, A. et al. (1996) Neurosci. Lett. 214, 99–102 50 Battaini, F. et al. (1994) Biochem. Biophys. Res. Commun. 203, 1423–1431 51 Hrabetova, S. and Sacktor, T.C. (1996) J. Neurosci. 16, 5324–5333 52 Matsushima, H. et al. (1996) J. Neurochem. 67, 317–323 53 Battaini, F., Govoni, S. and Trabucchi, M. (1995) in Molecular Basis of Aging (Macieira-Coelho, A., ed.), pp. 269–291, CRC Press 54 Undie, A.S., Wang, H-Y. and Friedman, E. (1995) Neurobiol. Aging 16, 19–28 55 Pisano, M.R., Wang, H-Y. and Friedman, E. (1991) Biomed. Environ. Sci. 4, 173–181 56 Buchner, K. (1995) Eur. J. Biochem. 228, 211–221 57 Rogue, P.J., Ritz, M.F. and Malviya, A.N. (1993) FEBS Lett. 334, 351–354 58 Ron, D. et al. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 839–843 59 Gianotti, C. et al. (1993) Neurobiol. Aging 14, 401–406 60 Eckles, K.E. et al. (1995) Soc. Neurosci. Abstr. 21, 473 61 Mochly-Rosen, D. (1995) Science 268, 247–251 62 Jacken, S. (1994) in Protein Kinase C Current Concepts and Future Perspectives (Lester, D. and Epand, R.M., eds), pp. 237–254, Ellis Horwood 63 Faux, M.C. and Scott, J.D. (1996) Trends Biochem. Sci. 21, 312–315 64 Govoni, S. et al. (1992) Life Sci. 50, PL125–PL128 65 Lucchi, L. et al. (1993) Life Sci. 53, 1821–1832 66 Ron, D. and Mochly-Rosen, D. (1994) J. Biol. Chem. 269, 21395–21398 67 Krieger, C. et al. (1996) Trends Pharmacol. Sci. 17, 114–120 68 Manev, H. et al. (1990) FASEB J. 4, 2788–2797 69 Wang, H-J., Pisano, M.J. and Friedman, E. (1994) Neurobiol. Aging 15, 293–298 70 Masliah, E. et al. (1990) J. Neurosci. 10, 2113–2124 71 Nitsch, R.M. and Growdon, J.H. (1994) Biochem. Pharmacol. 47, 1275–1284 72 Govoni, S. et al. (1993) Neurology 43, 2581–2586 73 Bergamaschi, S. et al. (1995) Neurosci. Lett. 201, 1–4