Development of myelofibrosis in the spleen of GATA-1^lowmice.

(A) Gomori reticulum staining of representative spleen sections from GATA-1^low mice at 1, 12, and 18 months of age that show the progressive appearance of fibers with age. Corresponding staining of a representative section from one 18-month-old wild-type mouse is also presented for comparison (original magnification, × 20). Similar results were obtained in at least 3 independent experiments per age group. In particular, 12 mice were analyzed for the 12- to 18-month-old age group. (B) Weight (in milligrams) of the spleen from wild-type (white bars) and GATA-1^low (gray bars) littermates arbitrarily divided into progressively older age groups (the same as used in Table 2). Results are presented as the mean (± SD) of at least 4 independent determinations per experimental group for a total of 12 wild-type and 18 mutant mice analyzed. **Values in the GATA-1^low age groups that are significantly (P < .01) different from those found in normal controls of the same age. (C) Total cellularity (TNC) of the spleen from wild-type (white bars) and GATA-1^low (gray bars) littermates arbitrarily divided into progressively older age groups. The same animals as those presented in panel B. See legend to panel B for further details.