  We study the evolution of galaxy satellites with high resolution N-body
simulations. Satellites are modeled as replicas of typical low and high surface
brightness galaxies (LSBs and HSBs). Encounters on high eccentricity orbits (as
typical in hierarchical models of galaxy formation) strip LSBs of most of their
stars and tend to decrease their surface brightness. On the contrary, bar
instability in HSBs leads to substantial loss of angular momentum of the
stellar component and to an increase of central surface brightness. In both
cases the remnant resembles a spheroidal galaxy with an exponential surface
brightness profile. A simple modeling of color evolution and interactions
driven star formation gives M/L ratios for the remnants that are roughly
consistent with observations. These results suggest an evolutionary scenario
for the dwarf galaxies in our Local Group, faint dSphs being the descendents of
LSBs and brighter dSphs/dEs being the final state of HSB satellites.
