[Theory of the continuity of germ plasma according to the findings of modern biology].
The main principles on the theory of germ plasma by A. Weismann are briefly presented; a number of his genetic-embryological hypotheses proved to be prophetic. Modern notions on the germ plasma are critically discussed, as well as the resulting from them the conception on continuity of totipotent cells (the source of germ cells) in the line of generations, that is historically connected with M. Nussbaum--A. Weismann's notions on continuity of the embryonic pathway. The term totipotency is sometimes used inaccurately; it means ability to formation of a whole organism. In Metazoa zygota and isolated blastomeres, at a regulative type of development, and groups of somatic cells or fragments of the organism, at an asexual reproduction and somatic embryogenesis, possess this ability. In ontogenesis totipotency is lost both by the somatic and by the germ cells because of their specialization and is recreated with the beginning of every ontogenesis when zygota is formed. The germ cells are always a product of the organism--unicellular or multicellular, and their specialization in all its manifestations is the result of integrative influences of the organism as a whole of them. Certain reasons are presented for supporting ideas on germ cells as one of the lines of cell differentiation. The main, if not the only contradiction in the problem concerning relation of the germ and somatic cells is, at the present time, the thesis on continuity of totipotent cells in the line of generations.
Gabaeva
N S
NS
D005075:Biological Evolution; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000502:physiology; D002970:Cleavage Stage, Ovum; D003593:Cytoplasm / Q000502:physiology; D056890:Eukaryota / Q000502:physiology; D005823:Genetics; D005854:Germ Cells / Q000166:cytology*; D006066:Gonads / Q000196:embryology; D013045:Species Specificity
Teoriia nepreryvnosti zarodyshevoĭ plazmy po dannym sovremennoĭ biologii.