Figure 2.

Map of the Y chromosome long arm. (a) Map of the Y chromosome long arm (Yq) showing the position of deletion intervals 4–7 (12) and the centromere (black circle). The positions of the BITRA and HORIS deletion breakpoints are shown as arrows (with map locations in parentheses), which result in the deletion of the entire Y chromosome distal to this point (i.e., the rest of interval 5 and intervals 6 and 7). Regions of the Y chromosome long arm frequently microdeleted in infertile men are labeled b and c, and these are shown in more detail in b and c, respectively. (b) More detailed map of the subintervals 5B–5D of the Y chromosome, which contain the AZFa locus (13), showing underneath the extent of microdeletions in patients missing this region of the Y chromosome alongside the name of each patient, and a summary of both RBM and Sm expression in the germ cells of these men. The size of the microdeletion shown corresponds to the number of missing STSs (see Table 1 and ref. 12). The rest of the Y chromosome outside the region indicated to be deleted is intact in these men. Neither JOLAR or ELTOR have germ cells, and so RBM expression cannot be visualized (labeled N/A). Testes sections not probed for Sm are labeled ND. (c) Detail of distal interval 5/interval 6 showing the the locations of the mapped RBM and DAZ/SPGY genes and the position of microdeletions in this region, along with the names of the corresponding patients. The NICKEI microdeletion defines the AZFc locus, while the H139 and ER66 microdeletions define the AZFb locus (13). The expression of RBM and Sm in germ cells in each of these patients is summarized alongside the name of the patient, and the minimum critical region for RBM expression is indicated underneath. BITRA and HORIS are cytological deletions which remove this entire region (see a).