Thioflavin S binds non-amyloid protein structures in lampbrush chromosomes of Gallus gallus domesticus

Proteins that normally function in amyloid form are found in bacteria, yeast, plants and vertebrates, including humans. In particular, amyloid fibrils and amyloid-like structures are described in the germ cells of various organisms. Recently we showed that in chicken oocytes there are some nuclear structures that are stained by the amyloid-specific dye thioflavin S. Here we demonstrate that thioflavin S binds giant terminal RNP aggregates in chicken lampbrush chromosomes. However, these structures are not stained with Congo red and conformation-dependent anti-amyloid antibodies. Thus, thioflavin S stains chromosome-associated proteins that do not have amyloid properties. These data indicate that thioflavin S must be used with caution when identifying new functional and pathological amyloids.