Figure 1.

Ribosomal profiles are altered in SDS patient cells. (A) Bone marrow stromal cell lysates from healthy controls or SDS patients were fractionated through 7%-47% sucrose gradients by ultracentrifugation. Representative polysome profiles are shown. Relative 80S:40S ratios were quantified for 3 healthy controls versus 5 SDS patients (DF259, FHCRC18, FHCRC30, FHCRC32, UW1) of different SBDS genotypes (listed in supplemental Table 1). (B) Ribosomes were dissociated with 0.5M KCl or 0.25mM MgCl₂ into 40S and 60S subunits, followed by sucrose density centrifugation. Representative polysome gradients are shown. 60S:40S ratios in 0.5M KCl were quantified for 3 healthy controls versus 3 SDS patients (DF259, FHCRC32, UW1) and the aggregate results are graphed; *P < .05. For 2 controls and 2 patients, the assay was repeated up to 3 times with consistent results (methods to quantitate the 40S, 60S, and 80S peaks are illustrated in supplemental Figure 1).