DETAILED COMPARATIVE MAP OF HUMAN-CHROMOSOME 19Q AND RELATED REGIONS OF THE MOUSE GENOME

One of the larger contiguous blocks of mouse-human genomic homology in cludes the proximal portion of mouse chromosome 7 and the long arm of human chromosome 19. Previous studies have demonstrated the close rela tionship between the two regions, but have also indicated significant rearrangements in the relative orders of homologous mouse and human ge nes. Here we present the genetic locations of the homologs of 42 human chromosome 19q markers in the mouse, with an emphasis on genes also i ncluded in the human chromosome 19 physical map. Our results demonstra te that despite an overall inversion of sequences relative to the cent romere, apparent ''transpositions'' of three gene-rich segments, and a local inversion of markers mapping near the 19q telomere, gene conten t, order, and spacing are remarkably well conserved throughout the len gths of these related mouse and human regions. Although most human 19q markers have remained genetically linked in mouse, one small human se gment forms a separate region of homology between human chromosome 19q and mouse chromosome 17. Three of the four rearrangements of mouse ve rsus human 19q sequences involve segments that are located directly ad jacent to each other in 19q13.3-q13.4, suggesting either the coinciden t occurrence of these events or their common association with unstable DNA sequences. These data permit an unusually in-depth examination of this large region of mouse-human genomic homology and provide an impo rtant new tool to aid in the mapping of genes and associated phenotype s in both species. (C) 1996 Academic Press, Inc.