Western blot assay of anti-FMRP on brain tissues from the mouse, rat, gerbil, chicken, and alligator. Molecular weight standards (left) were used to determine relative sizes of labeled protein bands. Arrows point to the bands of FMRP within predicted molecular weight range. The membrane was stripped and reblotted for β-actin to assess loading. Approximate amount of total protein loaded is 10 μg for the mouse, rat, and gerbil lanes and 30 μg for the chicken and alligator lanes.