  The experimentally observed $\Delta I = 1$ doublet bands in some odd-odd
nuclei are analyzed within the orthosymplectic extension of the Interacting
Vector Boson Model (IVBM). A new, purely collective interpretation of these
bands is given on the basis of the obtained boson-fermion dynamical symmetry of
the model. It is illustrated by its application to three odd-odd nuclei from
the $A\sim 130$ region, namely $^{126}Pr$, $^{134}Pr$ and $^{132}La$. The
theoretical predictions for the energy levels of the doublet bands as well as
$E2$ and $M1$ transition probabilities between the states of the yrast band in
the last two nuclei are compared with experiment and the results of other
theoretical approaches. The obtained results reveal the applicability of the
orthosymplectic extension of the IVBM.
