ABSTRACT
High resolution physical maps of two adjacent regions of MMU19 were constructed in order to establish a comparative map between the pericentromeric region of MMU19 and its human counterpart on HSA11q13. These two physical maps span 2.5 and 0.5 megabases on MMU19. Long range restriction analysis and YAC contigs have been built, five genes were located on MMU19 and eight new STSs were generated. The 0.5-Mb map which has been positioned close to the centromere of MMU19, based on dual-color FISH experiments and genetic data, includes eight genes (Type I markers), three microsatellites (Type II markers) and five new STSs. The 2.5-Mb map is located more telomeric and contains seven genes, four microsatellites and four new STSs. Gene order and physical distances appear to be similar in human and in mouse in this 2.5-Mb region. Strikingly, the 0.5-Mb region has a similar size in human but gene order is shuffled. The overall comparative map shows that these two regions are inverted on MMU19 when compared with HSA11q13.
Subject(s)
Chromosome Mapping , Chromosomes, Human, Pair 11 , Mice/genetics , Animals , Centromere/genetics , Chromosomes, Artificial, Yeast , Electrophoresis, Gel, Pulsed-Field , Gene Library , Genetic Linkage , Genetic Markers , Humans , In Situ Hybridization, Fluorescence , Mice, Inbred C57BL , Mice, Inbred Strains , Microsatellite Repeats , Polymerase Chain ReactionABSTRACT
We have developed a genetic screen for the isolation of larger or smaller recombinant yeast artificial chromosomes derived from overlapping YACs. Integration plasmids were used to modify the TRP1 and URA3 auxotrophic markers present respectively on the left and right vector arms of one of the parental YACs. Diploids containing the two parental YACs were studied through meiosis and mitosis. Tetrad analysis revealed the presence of meiotic recombinant YACs at a frequency comparable with what is expected for yeast DNA (about 3 kb/cM). More direct genetic selection of diploids on -TRP-LYS synthetic media in the presence of 5-fluoro-orotic acid (5-FOA), led to the isolation of mitotic recombinant YACs at a high frequency. Analysis of these yeast cells by pulsed-field gel electrophoresis, confirmed the loss of both parental artificial chromosomes, and the specific retention of a larger or smaller recombinant YAC.
