  We study numerically the rheological properties of a slab of active gel close
o the isotropic-nematic transition. The flow behavior shows strong dependence
on sample size, boundary conditions, and on the bulk constitutive curve, which,
on entering the nematic phase, acquires an activity-induced discontinuity at
the origin. The precursor of this within the metastable isotropic phase for
contractile systems ({\em e.g.,} actomyosin gels) gives a viscosity divergence;
its counterpart for extensile ({\em e.g.,} {\em B. subtilis}) suspensions
admits instead a shear-banded flow with zero apparent viscosity.
