FIG. 3.

Pb99 maps in the central region of mouse chromosome 8. Pb99 was placed on mouse chromosome 8 by interspecific backcross analysis. The segregation patterns of Pb99 and flanking genes in 174 backcross animals that were typed for all loci are shown at the top. For individual pairs of loci, more than 174 animals were typed (see text). Each column represents the chromosome identified in the backcross progeny that was inherited from the (C57BL/6J × M. spretus)F₁ parent. The black boxes represent the presence of a C57BL/6J allele, and the white boxes represent the presence of an M. spretus allele. The number of offspring inheriting each type of chromosome is listed at the bottom of each column. A partial chromosome 8 linkage map showing the location of Pb99 in relation to linked genes is shown at the bottom. Recombination distances between loci, in centimorgans, are shown to the left of the chromosome, and the positions of the loci in human chromosomes, where known, are shown to the right. References for the human map positions of loci cited in this study can be obtained from the GDB (Genome Data Base), a computerized database of human linkage information maintained by The William H. Welch Medical Library of The Johns Hopkins University (Baltimore, Md.).