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A somatic cell surrounding an oocyte. In Drosophila melanogaster, ovarian follicle cells interpret oocyte signals and contribute to eggshell pattern and later embryonic positional information.

A germ cell belongs to the cell lineage that produces gametes and transmits a genome to the next generation. The term includes immature precursors, so a germ cell need not already be a sperm or an ovum, or already be haploid. In a mammal, proliferating precursors precede meiosis and subsequent gamete differentiation. The distinction from a somatic cell concerns developmental fate and ancestry, not simply where a cell is located. ^[ref]

Germ cell specification can depend on signals from neighbouring tissues. In a mouse experiment, embryos lacking functional BMP4 lacked primordial germ cells; the study used mutants and chimaeras to identify an essential contribution from extraembryonic tissue. This makes the inherited lineage an outcome of developmental signalling, rather than a compartment that must always be isolated at the first cleavage. ^[ref]

An ovary is a female gonad supporting oocyte development and reproductive hormone production. In mammalian anatomy, an ovarian follicle combines the developing germ cell with supporting somatic cells; ovulation releases the oocyte from this structure. The animal organ is distinct from an ovary in a flower.

Variation among plants regenerated from cultured somatic cells; it can have genetic or epigenetic causes.

A somatic cell belongs to the body of a multicellular organism rather than its germline. Keratinocytes and cardiomyocytes are examples. The distinction concerns contribution to reproduction rather than a universal difference in chromosome number: many somatic cells are diploid, but specialized exceptions occur. A mutation in a somatic cell can spread through its descendants within the body without necessarily being inherited by offspring. ^[ref]

Researcher in Drosophila development. Schüpbach studied cooperation between germline and somatic cells during oogenesis, connecting communication between tissues with dorsal–ventral patterning of the egg and embryo.^[ref]