  The condition of unification of gauge couplings in the minimal supersymmetric
standard model provides successful predictions for the weak mixing angle as a
function of the strong gauge coupling and the supersymmetric threshold scale.
In addition, in some scenarios, e.g.\ in the minimal SO(10) model, the tau
lepton and the bottom and top quark Yukawa couplings unify at the grand
unification scale. The condition of Yukawa unification leads naturally to large
values of $\tan\beta$, implying a proper top quark--bottom quark mass
hierarchy. In this work, we investigate the feasibility of unification of the
Yukawa couplings, in the framework of the minimal supersymmetric standard model
with (assumed) universal mass parameters at the unification scale and with
radiative breaking of the electroweak symmetry. We show that strong
correlations between the parameters $\mu_0$ and $M_{1/2}$ appear within this
scheme. These correlations have relevant implications for the sparticle
spectrum, which presents several characteristic features. In addition, we show
that due to large corrections to the running bottom quark mass induced through
the supersymmetry breaking sector of the theory, the predicted top quark mass
and $\tan\beta$ values are significantly lower than those previously estimated
in the literature.
