  Assuming that a horizontal abelian (gauge) symmetry is at the origin of
texture zeros in the fermion mass matrices we show how realistic mass patterns
can be generated stepwise with a small number of effective operators from GUT's
and string theory. It is interesting to note that, in the minimal scenario, if
the up quark and the down quark mass matrices are generated simultaneously
their texture is formaquivalent and contains only two zeros. Textures with more
zeros (and thus more predictability) emerge if the up and down sectors are
generated stepwise. This last possibility leads to rather anomalous neutrino
patterns with mass degenerate neutrinos and large $\nu_{\mu} - \nu_{\tau}$ or
$\nu_e - \nu_{\tau}$ mixing even in the absence of hierarchy in $M_R$, the mass
matrix of the righthanded neutrinos, and as required by the LSND results if
they were to be confirmed by future experiments. In contrast if the quark mass
matrices have two zero entries (or less) the neutrino mass-mixing spectrum is
independent of the texture structure of $M_R$ -if the latter does not contain
any hierarchy of scales- and obeys the quadratic seesaw.
