Germline mutation
Encyclopedia
A germline mutation is any detectable and heritable variation in the lineage of germ cell
s. Mutation
s in these cells are transmitted to offspring
, while, on the other hand, those in somatic
cells are not. A germline mutation gives rise to a constitutional mutation in the offspring, that is, a mutation that is present in virtually every cell. A constitutional mutation can also occur very soon after fertilisation
, or continue from a previous constitutional mutation in a parent.
This distinction is most important in animal
s, where germ cells are distinct from somatic cells. However, in plant
s, the reproductive cells in a particular flower will be derived from the same meristem
as the cells in that flower
and on the stem
leading to the flower, which is a different population of cells than those that give rise to the other flowers on the plant. Single-celled
organism
s have no distinction between germline and somatic tissues.
In animals, mutations are more likely to occur in sperm
than in ova, because a larger number of cell divisions are involved in the production of sperm.
Mutations that are not germline are somatic mutations, which are also called acquired mutations.
Germ cell
A germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate near the gut of an embryo and migrate to the developing gonads. There, they undergo cell division of two types, mitosis and meiosis, followed by...
s. Mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s in these cells are transmitted to offspring
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
, while, on the other hand, those in somatic
Somatic
The term somatic means 'of the body',, relating to the body. In medicine, somatic illness is bodily, not mental, illness. The term is often used in biology to refer to the cells of the body in contrast to the germ line cells which usually give rise to the gametes...
cells are not. A germline mutation gives rise to a constitutional mutation in the offspring, that is, a mutation that is present in virtually every cell. A constitutional mutation can also occur very soon after fertilisation
Fertilisation
Fertilisation is the fusion of gametes to produce a new organism. In animals, the process involves the fusion of an ovum with a sperm, which eventually leads to the development of an embryo...
, or continue from a previous constitutional mutation in a parent.
This distinction is most important in animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s, where germ cells are distinct from somatic cells. However, in plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s, the reproductive cells in a particular flower will be derived from the same meristem
Meristem
A meristem is the tissue in most plants consisting of undifferentiated cells , found in zones of the plant where growth can take place....
as the cells in that flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
and on the stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
leading to the flower, which is a different population of cells than those that give rise to the other flowers on the plant. Single-celled
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s have no distinction between germline and somatic tissues.
In animals, mutations are more likely to occur in sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
than in ova, because a larger number of cell divisions are involved in the production of sperm.
Mutations that are not germline are somatic mutations, which are also called acquired mutations.