  Despite numerous studies, the origin of the gamma-ray emission from blazars
is still debated, in particular whether it is produced by leptonic or hadronic
processes. In this study, we are testing the leptonic scenario for the Flat
Spectrum Radio Quasar (FSRQ) 3C 279, assuming that the gamma-ray emission is
generated by inverse Compton scattering of external target photons from Broad
Line Region (IC-BLR scenario). For this purpose we use a 10-year data set of
the source consisting of the optical spectroscopy data from the Steward
Observatory blazar monitoring program and Fermi-LAT gamma-ray data. We search
for a possible correlation between the Compton dominance and the emission line
luminosity using the discrete correlation function (DCF) analysis. As a result,
we find no significant correlation between these two quantities at any time lag
value, while the emission line luminosity displays a moderate correlation with
the gamma-ray flux at a zero time lag. We also reveal that the optical
synchrotron continuum flux shows a pronounced correlation with the gamma-ray
flux, and therefore we interpret these results within the leptonic IC-BLR
scenario where the Compton dominance variations are primarily induced by
changes in the magnetic field, rather than in the emission line luminosity.
