Polarizing and maintenance activities in two polydactylous mutants of the fowl: <i>diplopodia</i> <i>1</i> and <i>talpid</i> <i>2</i>

Abstract

ABSTRACT In two polydactylous mutants, talpid2 and diplopodia1, polarizing activity appears to be present only in the normal location in the posterior corner of the limb-bud. There is, thus, a preaxial extension of maintenance activity without an accompanying extension of demon-strable polarizing activity. Experiments involving apex exchanges between normal and talpid2 wing-buds suggest that the movement of ‘maintenance factor’ per se from preaxial talpid2 limb tissue into a normal apex does not occur.