Sequence divergence and putative recombination sites at the MAT locus in serotype D strains. The chromosomal coordinates are shown at the top and the annotated genes in the region are indicated as boxes. Putative recombination sites are marked with arrows. Specific genes that are known to have high sequence similarity between the MAT a and MATα alleles , and that exhibit a corresponding Log2 ratio close to zero are labelled with letters: a, RPO41 (XM_570485.1; The Institute for Genomic Research [TIGR] locus tag CND05820); b, BSP2 (XM_570482.1; TIGR locus tag CND05830); c, LPD1 (XM_570114.1; TIGR locus tag CND05840); d, CID1 (XM_570548.1; TIGR locus tag CND05850); and e, GEF1 (XM_570546.1; TIGR locus tag CND05860). The gap in the hybridization signal for NIH12 and NIH433 centered on position 1,610,000 resulted from the presence of repeated sequences in this region that reduced probe density .