Amyloid-mediated RNA uptake by sperm for embryonic delivery.

Area of Science:

• Reproductive biology
• Molecular biology
• Biophysics

Background:

• Extracellular RNA in seminal fluid is crucial for embryonic development.
• The mechanism of RNA transfer from seminal fluid to sperm is not well understood.

Purpose of the Study:

• To elucidate the mechanism of RNA trafficking from seminal fluid to sperm and zygotes.
• To investigate the role of functional amyloid fibrils in this process.

Main Methods:

• Cryo-electron tomography to visualize fibril internalization by sperm.
• Biophysical experiments to study RNA-fibril interactions.
• In vitro fertilization experiments to track RNA delivery to the zygote.

Main Results:

• Seminal fluid contains cationic peptides that form amyloid fibrils with RNA.
• Sperm internalize these amyloid-RNA fibrils.
• Amyloid-bound RNA is delivered to the zygote, where chaperones control RNA release for translation.

Conclusions:

• Functional amyloid fibrils mediate RNA transport from seminal fluid to sperm and zygotes.
• This mechanism is vital for embryonic development.
• Amyloid fibrils represent potential tools for RNA delivery in fertilization contexts.