CULTURE OF CELLS AND TISSUES DERIVED FROM XENOPUS LAEVIS 



629 



We have been able to maintain primary cultures derived from whole advanced 

 Xenopus embryos without subcultering them for almost four months now. In 

 thèse aging cultures certain cell varieties have undergone a process of degeneration 

 while the epithelioid cells which form the dense cell sheets have retained their 

 viability and their capacity for active prolifération. 



Fig. 1b 



b) colony of fully differentiated mela- 

 nophores (culture 1 month old), magni- 

 fication, 148 X. 



Fig. le 



c) fully developed melanophores in 1 

 month old culture, magnification 1480 X. 

 Fixed (Bouin) and stained (Hematoxylin- 

 eosin). 



Infections with fungi and with other micro-organisms of thèse primary- 

 explant cultures have been no problem at ail, yet their subculture has proved to 

 be very difficult. In order to establish normal-euploid cell strains from embryonic 

 Xenopus sources, our methods of subculturing must be substantially improved. 



REFERENCES 



Balls, M. and L. N. Ruben. 1966. Cultivation in vitro of normal and neoplastic cells 



of Xenopus laevis. Exptl. Cell Res. 43: 694-695. 

 Freed, J. J., 1962. Continuous cultivation of cells derived from haploid Rana pipiens 



embryos. Exptl. Cell Res. 26: 327-333. 



