During which stage of gene expression is mRNA produced?

The production of mRNA occurs during the transcription stage of gene expression. In this process, RNA polymerase synthesizes a strand of mRNA that is complementary to the DNA template strand. Transcription begins when RNA polymerase binds to a specific region of the gene known as the promoter. As the enzyme moves along the DNA, it unwinds the double helix and assembles nucleotides into a growing mRNA strand. This mRNA molecule then undergoes processing, including capping and polyadenylation, before it exits the nucleus and moves into the cytoplasm for translation into a protein.

The other processes mentioned do not involve the production of mRNA. Translation refers to the conversion of the mRNA sequence into a protein, replication is the process of duplicating DNA before cell division, and translocation usually refers to a movement of a segment of DNA or a part of the ribosome during translation, none of which are directly related to the synthesis of mRNA.