REPORTS Chinese Science Bulletin Vol. 48 No. 5 March 2003 465 300. 9. Stone, J., Dixon, J. E., Protein tyrosine phosphatases, J. Biol. Chem., 1994, 269: 31323 3132. 10. Stone, J. M., Walker, J. C., Plant protein kinase families and signal transmission, Plant Physiol., 1999, 108: 451 457. 11. Guo, Y. L., Roux, S. J., Partial purification and characterization of an enzyme from pea nuclei with protein tyrosine phosphtase ac- tivity, Plant Physiol., 1995, 107: 167 173. 12. Huyer, G., Liu, S., Kelly, J. et al., Mechanism of inhibition of pro- tein-tyrosine phosphatases by vanafate and pervanadate, J. Bio. Chem., 1997, 272: 843 851. 13. Chiarugi, P., Fiaschi, T., Taddei, M. L. et al., Two vicinal cysteines confer a peculiar redox regulation to low molecular weight protein tyrosine phophatases in response to platelet-derived growth factor receptor stimulation, J. Bio. Chem., 2001, 276: 33478 33487. 14. Frost, S, C., Lane, M. D., Evidence for the involvement of vicinal sulfhydrl groups in insulin-activated hexose transport by 3T3-L1 adipocytes, J. Bio. Chem., 1985, 260: 2646 2652. 15. Guo, Y, L,, Terry, M. E., Roux, S. J., Characterization of a cytoso- lic phosphatase from pea plumules having significant protein ty- rosine phosphatase activity, Plant Physiol. Biochem., 1998, 36: 269 278. 16. Xu, Q., Fu, H. H, Gupta, R. et al., Molecular characterization of a tyrosine-specific protein phosphatase encoded by a stress-re- sponse gene in arabidopsis, Plant Cell, 1998, 10: 849 857. 17. Tassoni, A., Antognoni, F., Bagni, N., Polyamine binding to plasma membrane vesicles isolated from zucchini hypocotyls, Plant Physiol., 1996, 110: 817 824. 18. Chen, P. S., Toribara, T. Y., Warner, H., Microdetermination of phosphorus, Analytical Chem. 1956, 28: 1756 1758. 19. Quarrie, S. A., Whitford, P. N., Appleford, N. E. J. et al., A mono- clonal antibody to (S)-abscisic acid: Its characterization and use in a radio immunoassay for measuring abscisic acid in crude extracts of cereal and lupin leaves, Planta, 1988, 173: 330 339. 20. Ng, D. H. W., Harder, K. W., Clark-Lewis, I. et al., Non- radioactive method to measure CD45 protein tyrosine phosphatase activity isolated directly from cells, J. Immunol. Methods, 1994, 179: 177 185. 21. Sheen, J., Ca 2+ -dependent protein kinases and stress signal trans- duction in plants, Science, 1996, 274: 1900 1902. 22. Stone, J. M., Walker, J. C., Plant protein kinase families and signal transmission, Plant Physiol., 1995, 108: 451 457. 23. Chang, C., Stewart, R. C., The two -component system, Plant Physiol., 1998, 117: 723 731. 24. Urao, T., Yakubov, B., Satoh, R. et al., A transmembrane hy- brid-type histidine kinase in arabidopsis function as an osmosen- sor, Plant Cell, 1999, 11: 1743 1754. (Received November 25, 2002) Chinese Science Bulletin 2003 Vol. 48 No.5 465 468 PCR-RFLP analysis of mitochondrial DNA ND5/6 region among 3 subspecies of common carp (Cyprinus carpio L.) and its application to genetic discrimination of subspecies ZHOU Jianfeng, WANG Zhongwei, YE Yuzhen & WU Qingjiang State Key Laboratory of Freshwater Ecology and Biotechnology, Insti- tute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China Correspondence should be addressed to Wu Qingjiang (e-mail: qjwu@ihb.ac.cn) Abstract Mitochondrial DNA ND5/6 region was studied by PCR-RFLP analysis among ten representative strains belonging to three subspecies ( Cyprinus carpio carpio, Cypri- nus carpio haematopterus and Cyprinus carpio rubrofuscus ) of common carp ( Cyprinus carpio L.). A total of 2.4 kb frag- ment was amplified and subjected to restriction endonucle- ase analysis with nine restriction endonucleases subsequently. The results indicated that each subspecies owned one hyplo- type and four restriction enzymes ( Dde , Hae , Taq and Mbo ) produced diagnostic restriction sites which could be used for discriminating the three subspecies and as molecu- lar genetic markers for assistant selective breeding of com- mon carp. Keywords: Cyprinus carpio , subspecies, ND5/6, PCR-RFLP, mo- lecular marker. Common carp is the most extensive cultivation fish species and perhaps the best-known teleost that owned the longest cultivation history in all freshwater species in the world [1 3] . It has been suggested that common carp mainly consisted of three subspecies: Cyprinus carpio carpio, mainly distributed from Danube River to Volga River and minor distributed in the northwest of the Xinjiang Uygur Autonomous Region of China; Cyprinus carpio haemato pterus, mainly distributed in the north of Nanling Moun- tains in China; and Cyprinus carpio rubrofuscus , mainly distributed in the south of Nanling Mountains in China except Cyprinus carpio chilia in the lakes of Yunnan pla- teau of China [4] . Many of distinctive domestic strains, such as Xingguo red carp, Purse red carp and Big-belly carp in China, German mirror carp and Russian scattered scaled mirror carp in Europe, were obtained in a long cultivation history of common carp in Asia and Europe. For