Follicle stimulating hormone (FSH) is a glycoprotein hormone with subunits α and β, and is required for gamete development. Differential glycosylation may produce diglycosylated FSH with higher biological activity, and is suspected to be generated via the action of oligosaccharyltransferase(OST) isoforms. Signal peptide hydrophobicity of α and β maycontribute to selective usage of OST, and hence modulate N-glycosylation. We hypothesize that N-glycosylation of FSH subunits is regulated via differential interactions between OST isoforms and subunit signal peptides and modulated by estrogen. To test our hypothesis, we will engineer chimeric hFSH subunits by swapping the signal peptide sequences of α and β. Constructs with the chimeric sequences will be transfected into cell lines, and expressed FSH will be examined.