The germline is the cell lineage running from the fertilized oocyte via the primordial germ cells to the eggs and sperm of the human being who arose from it. Through it genetic information is passed to subsequent generations; interventions upon it are therefore heritable.
Ontological classification
- is not a category of cells but a relation of descent among cells
- comprises as cells: primordial germ cell, oogonium and spermatogonium, oocyte and spermatocyte, and the mature gametes
- is the site of meiosis and of the establishment of genomic imprinting
Why the concept is legally decisive
German law defines germline cells as all cells forming a lineage from the fertilized egg to the eggs and sperm of the human being who arose from it — together with the egg from the entry of the sperm until the completion of fertilization.
This definition prohibits nothing. But it decides to what the prohibition on artificially altering germline cells is applicable at all. And from it follows a result regularly overlooked in the debate: a skin cell is not a germline cell. It does not lie on this lineage. Procedures seeking to turn a body cell into a germ cell — in vitro gametogenesis and mitomeiosis — are therefore not caught by the germline prohibition.
One observation on the statutory text itself is notable: an exemption presupposes that from a cell “a germ cell arises.” In 1990 the legislator therefore already had in view the in vitro emergence of germ cells from germline cells — but not from somatic cells. The gap is not negligence but the distance of thirty-five years.
The question of continuity
In personal ontology the germline is where continuity between generations runs bodily. The argument from germline continuity is occasionally invoked for determining the beginning of human existence — though it carries only limited weight there: the germline is a lineage of cells, whereas personhood begins with the coming-to-be of an individual. The two do not coincide. An embryo’s primordial germ cells belong to the germline of its future children but are not persons.
See also
- Gamete, Oocyte
- Meiosis, Genomic Imprinting
- In Vitro Gametogenesis, Mitomeiosis
- Somatic Cell Nuclear Transfer (SCNT)
- Genetic Technology
- Fertilization
Sources: Generated by querying the Personhood ontology. Research as of 27 July 2026.
Further sources:
- German Embryo Protection Act of 13 December 1990, ss. 5 and 8(3).
- German Ethics Council (2019): Intervening in the Human Germline. Opinion of 9 May 2019.