ESTABLISHMENT OF PERMANENT WILD-MOUSE CELL-LINES WITH READILY IDENTIFIABLE MARKER CHROMOSOMES

Physical gene mapping by in situ hybridization is a difficult task in an all-acrocentric mouse karyotype, because all of the chromosomes are morphologically very similar. These difficulties can be overcome by u sing the many different metacentric Robertsonian translocation (Rb) ch romosomes derived from wild mice. Here we describe the establishment o f two Moloney murine leukemia virus-transformed suspension cell lines, WMP-1 and WMP-2, derived from wild mice of the strain WMP/WMP. These mice carry nine pairs of metacentric Rb chromosomes containing chromos omes 1 to 18. Chromosome 19 and the sex chromosomes are the only acroc entric chromosomes. Furthermore, a heterozygous reciprocal translocati on between chromosomes 13 and 17 involved in two Rb chromosomes is pre sent in this stock and provides additional marker chromosomes. The chr omosome designation of these mice is Rb(10.17)9Mp1 Rb(13.15)10Mp1 T(13 .17)1Lub.