GENE-MAPPING IN THE COMMON SHREW (SOREX-APANEUS, INSECTIVORA) BY SHREW-RODENT CELL HYBRIDS - CHROMOSOME LOCALIZATION OF THE LOCI FOR HPRT, TK, LDHA, MDH1, G6PD, PGD, AND ADA

We selected the common shrew (Sorex araneus) to generate the first ins ectivore gene map. Shrew-Chinese hamster and shrew-mouse somatic cell hybrid cells were constructed. When the 119 shrew-rodent clones were c haracterized, only shrew chromosomes were found to have segregated. A panel of hybrid clones was selected for gene assignment. The genes for hypoxanthine phosphoribosyl transferase (HPRT), glucose-6-phosphate d ehydrogenase (G6PD), and malate dehydrogenase 1 (MDH1) were assigned t o shrew Chromosome (Chr) de [which is the product of a tandem fusion b etween the 'original' mammalian X Chromosome (Chr) and an autosome], t he genes for adenosine deaminase (ADA) and 6-phosphogluconate dehydrog enase (PGD) to Chromosome jl, the gene for thymidine kinase (TK) to Ch romosome hn, and the gene for lactate dehydrogenase (LDHA) to chromoso me ik. Further studies are in progress.