Sex pili

sex pili
(Science: cell biology) fine filamentous projections (pili) on the surface of a bacterium that are important in conjugation. Often seem to be coded for by plasmids that confer conjugative potential on the host, in the case of the f plasmid, the f pili are 8-9nm diameter and several microns long, composed of pilin. Whether the pili merely serve to establish and maintain adhesive contact between the partners in conjugation or whether dNA is actually transferred through the central core of the pilus is still unresolved, although a simple adhesion role is more generally accepted.