Supplemental Text

The Seat of Power: Nucleus or Cytoplasm?

Stephen L. Talbott

This article is supplemental to “Genes and the Central Fallacy of Evolutionary Theory”, and can best be read in conjunction with that essay. Both pieces are part of a larger work in progress entitled: Toward a Biology Worthy of Life. Original publication of this article: February 28, 2013. Date of last revision: February 28, 2013. Copyright 2013 The Nature Institute. All rights reserved.

In February 1997 the general public learned that a several-month-old sheep named “Dolly” had been produced by somatic cell nuclear transfer, a form of cloning. Dolly’s parentage involved a normal sheep’s ovum (egg cell) from which the nucleus had been removed. The nucleus was then replaced with one taken from a fully differentiated cell of a second female sheep, producing a viable zygote, which then began more or less normal development. Finally, the resulting embryo was carried to term by a surrogate mother, a third sheep.

The nucleus from the original egg cell was haploid — that is, like gametes in general, it had only half the number of chromosomes characteristic of sheep. But the nucleus replacing it was diploid, containing the number of chromosomes found in an egg after fertilization by a sperm cell. So instead of a union of two haploid gametes, there was a union of one enucleated gamete with the extracted nucleus of a somatic cell containing the full (diploid)