SPATIAL REDISTRIBUTION OF POLY(A)(+) RNA DURING POLARIZATION OF THE FUCUS ZYGOTE IS DEPENDENT UPON MICROFILAMENTS

Asymmetrical distribution of mRNA has been associated with polarizatio n and cell fate determination during early development of animal embry os. In this report we determine the distribution pattern of poly(A)(+) RNA during early embryogenesis of the brown alga Fucus. Poly(A)(+) RN A is symmetrically distributed in the egg and early zygote. Shortly af ter the polar axis is established, poly(A)(+) RNA becomes segregated t o the thallus pole of the zygote. Following cytokinesis, most of poly( A)(+) RNA is partitioned into the thallus cell. We show that the spati al redistribution of poly(A)(+) RNA requires intact microfilaments and the fixation of the polar axis, but is not dependent upon polarized g rowth of the rhizoid, intact microtubules, or orientation of the divis ion plane. (C) 1995 Academic Press, Inc.