Germ line

In biology and genetics, the germline in a multicellular organism is the population of its bodily cells that are so differentiated or segregated that in the usual processes of reproduction they may pass on their genetic material to the progeny.

As a rule this passing-on happens via a process of sexual reproduction; typically it is a process that includes systematic changes to the genetic material, changes that arise during recombination, meiosis and fertilization or syngamy for example. However, there are many exceptions, including processes and concepts such as various forms of apomixis, autogamy, automixis, cloning, or parthenogenesis. The cells of the germline commonly are called germ cells.

For example, gametes such as the sperm or the egg are part of the germline. So are the cells that divide to produce the gametes, called , the cells that produce those, called gametogonia, and all the way back to the zygote, the cell from which the individual developed.

In sexually reproducing organisms, cells that are not in the germline are called somatic cells. The term refers to all of the cells of body apart from the gametes. According to this view mutations, recombinations and other genetic changes in the germline may be passed to offspring, but a change in a somatic cell will not be. This need not apply to somatically reproducing organisms, such as some Porifera and many plants. For example, many varieties of citrus, plants in the Rosaceae and some in the Asteraceae, such as Taraxacum produce seeds apomictically when somatic diploid cells displace the ovule or early embryo.

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