Does the Nucleus Have a Monopoly on Inheritance?

Abstract

Today we know for certain that the Mendelian heritable factors (genes) are localized in the chromosomes of the cell nucleus. And yet we also know that the nucleus cannot function by itself, but only in cooperation with the cytoplasm. The question which now poses itself is: can we locate the boundaries of the nuclear and cytoplasmic spheres of influence? Theodor Boveri designed an experiment which he believed must provide the answer. He combined merogone formation with interspecific hybridization: eggs of one sea urchin species were inseminated by sperm of another species. Having first fragmented the eggs by shaking them (p. 15), Boveri was able to follow the development of egg pieces containing only paternal nuclear material. Would such hybrid merogones resemble the maternal species which supplied the cytoplasm or the paternal species which provided the nucleus?