Fig. 1. Pcm heterozygotes are characterized by external ruddiness and transient polycythemia mapping to proximal chromosome 1. (A) Ears and hindpaws show increased redness in 7-week-old heterozygous mice, particularly in vasculature (arrowheads). (B) Microcapillary hematocrits measured at several postnatal timepoints demonstrate transient polycythemia in Pcm/+ mice, and a transient anemia in Pcm/Pcm mice. Asterisk, P<0.001 for mutant classes when compared with wild-type mice per timepoint. (C) Pcm critical region. Phenotype co-segregates with microsatellite marker D1Mit236; n represents ratio of Pcm/+ mutant progeny (Hct > 55%) retaining heterozygosity for parental alleles (101/HeH) of markers. Physical map position (Mb) as per the Sanger Centre mouse genome assembly (NCBI Build 30).