Figure 1.

Association of FMRP with polyribosomes in extracts from brain cortex of mice at different ages. Cytoplasmic extracts were prepared from brain cortices of 9-d-old (A), 5-month-old (B), and 53-d-old (C) mice and centrifuged on a 20-50% w/w linear sucrose gradient. Fractions were collected and analyzed by Western blot with antibodies against FMRP and ribosomal S6 protein (rS6). Extracts treated with 30 mm EDTA or RNase (C) were analyzed in parallel. Fractions from the top to the bottom of the gradient are shown from left to right. The positions of the 80 S ribosome monomer and 60 S subunit are indicated.