incorporation in the course of evolution remains unsolved. Decoding this
key problem would provide the answer to some aspects of the origin of
life and its further development.
Multicellular organisms have emerged from the integration of single
cells, their interactions, and the formation of pores, channels and
cytoplasmic bridges among them. Besides somatic reproduction at the
initial stages of their development, sex reproduction appears and
gradually gets consolidated. It provides much greater opportunities for
genetic combinations and recombinations, the latter strongly increasing
living organism diversity.
At present the problem of the regeneration of multicellular
organisms from single somatic cells known as cloning is of exceptionally
great interest. In the animals it is accomplished by transplanting a
nucleus of a given somatic cell line into an enucleated unfertilized egg. It
is quite logical that this could also be achieved through somatic
embryogenesis which is a routine method in plant growing. This shows
that multicellular organisms are a product of cell integration. The degree
to which these independently existing before that cells are able to
preserve their autonomy and their relationships and interactions in the
framework of the multicellular systems built by them is one of the
numerous unclear problems of cell biology.
Discovered more than three centuries ago, the cell is still
inadequately elucidated by man. Such it will be in the hands of the
researchers at the beginning of the third millennium.