http://en.wikipedia.org/wiki/Regional_specification http://en.wikipedia.org/wiki/Regional_specification http://en.wikipedia.org/wiki/R.....cification http://en.wikipedia.org/wiki/Regional_specification http://en.wikipedia.org/wiki/Regional_specification http://en.wikipedia.org/wiki/Regional_specification http://en.wikipedia.org/wiki/Regional_specification http://en.wikipedia.org/wiki/Regional_specification dorsoventral patterning http://en.wikipedia.org/wiki/Regional_specification