Final answer:
Yeast retrotransposon Ty is capable of creating non-infectious virus-like particles (VLPs) in the cytoplasm which carry the necessary components for retrotransposition. These VLPs re-enter the nucleus for integration into the genomic DNA, differing from infectious retroviruses which lyse the host cell to release particles.
Step-by-step explanation:
The question revolves around the function of the yeast retrotransposon Ty, specifically whether it is capable of forming particles. Yeast Ty elements are a type of LTR retrotransposon which are similar to retroviruses in that they can transcribe genes necessary for their mobility such as reverse transcriptase (RT), integrase (Int), protease (Prt), and a structural protein called Gag.
However, unlike retroviruses, Ty elements do not form infectious particles that exit the host cell. Instead, their virus-like particles (VLPs) which consist of the copied RNA and proteins, re-enter the nucleus of the same yeast cell for integration into the genomic DNA.
In the process of retrotransposition, the Gag protein forms the VLP which encapsulates the retrotransposon RNA along with other proteins in the cytoplasm. The RT then creates double-stranded cDNAs within these VLPs. These cDNAs, still coated by VLPs, eventually enter the nucleus where they can integrate into the host's genome.
The key difference with pathogenic retroviruses is that Ty elements, despite creating VLPs, remain non-infectious and do not cause lysis of the host cell to release new particles.