THE ROLE OF THE NUCLEUS IN ORGANOGENESIS .2.

In a previous paper, it was proposed that the spatial orientation of s tem cells was dependent on nucleus/nucleus contact. This proposition i s discussed in more detail here. The correct spatial orientation of th e cells making up the organs of the adult demands a molecular plan of some type to be encoded in the DNA, and it is suggested that the plan is encoded in the nontranscribed DNA. This DNA is present in the form of loops and folds, giving rise to a spatial array of enormous complex ity, and the general belief is that the spatial array is dependent on sequence-specific proteins which firmly bind to the DNA. It is propose d that the binding proteins can also join the DNA of two adjacent stem -cell nuclei once nucleus/nucleus contact has been made, and in this w ay determine the spatial orientation of the future specialized cells. There is enough information encoded in the spatial arrays to correctly position the myriad of cells that make up the adult organism. If cell alignment is carried out by nuclear union, then the development of th e neuron can be better understood. It is suggested that malignancy may be due to a fault in either the nontranscribed DNA responsible for sp atial orientation or in the sequence-specific binding proteins.