COMPARATIVE-STUDY OF PIG-RODENT SOMATIC-CELL HYBRIDS

The pig chromosome complement of six different types of pig-rodent hyb rid cell lines was examined by means of fluorescence in situ hybridiza tion with a porcine SINE probe. The cell lines were obtained by fusing pig lymphocytes with cells of the Chinese hamster cell lines wg3h, BK 14-150 and E36, and of the mouse cell lines NSO, PU and LMTK(-). The h ybrids were analysed with respect to: (1) the number of pig chromosome s, (2) the type of pig chromosomes, (3) the occurrence of pig-rodent c hromosome translocations, and (4) the presence of pig chromsome fragme nts. The results show that the number of pig chromosomes varied within and among hybrid cell lines. The pig-hamster hybrids mainly retained nontelocentric pig chromosomes, whereas the pig-mouse hybrids also ret ained telocentric pig chromosomes. Pig-rodent chromosome translocation s were found in all types of hybrids, but the incidence was in general low. Chromosome fragments were abundant in BK14-150 hybrids, and rare in most other hybrid cell lines. It is concluded that the SINE probe is a useful tool to make a preliminary characterization of the porcine chromosome complement of pig-rodent somatic cell hybrids. The results of this characterization can be used to select hybrids for further cy togenetic analysis. Furthermore, our data show that different rodent c ell lines will have to be used as fusion partners for the production o f hybrids when constructing a panel informative for all pig chromosome s.