NEW GENE ASSIGNMENTS USING A COMPLETE, CHARACTERIZED SHEEP-HAMSTER SOMATIC-CELL HYBRID PANEL

The generation and characterization of new sheep-hamster cell hybrids is reported from the fusion of sheep white blood cells with six differ ent hamster auxotrophs. Selection from these and previously generated cell hybrids has led to the production of a panel of 30 hybrids coveri ng the complete sheep genome of 28 chromosomes. Over half of the cell hybrids in this panel contain single sheep chromosomes. By complementa tion, the following new assignments have been made using the panel: ph osphoribosyl N-formylglycinamide amidotransferase (PRFGA) to sheep chr omosome (chr) 11; adenylosuccinate synthetase (ADSS) to sheep chr 12; adenylosuccinate lyase (ADSL) to sheep chr 3q; 3-hydroxy-3-methylgluta ryl-coenzyme A synthase (HMGCS) to sheep chr 16; dihydrofolate reducta se (DHFR) to sheep chr 5; and adenine phosphoribosyltransferase (APRT) to sheep chr 14. The gene phosphoribosylaminoinidazole-carboxamide fo rmyltransferase/Inosinicase (PRACFT) has now been regionally assigned to chr 2q. By isozyme analysis, phosphogluconate dehydrogenase (PGD) w as assigned to sheep chr 12, anchoring the sheep syntenic group U1 to this chromosome, and mannose phosphate isomerase (MPI) was assigned to sheep chr 18. Furthermore, the chromosomal assignment of 110 microsat ellites was confirmed using this cell panel.