Somatic Mutation

Somatic mutation occurs in the body cells. It is undetectable if recessive, unless the individual is heterozygous. The mutation is manifested by sector formation. This procedure for testing mutability is particularly effective if multiple-marker heterozygotes are treated. It is not inherited to generative progeny unless it occurs or expands also to the germline. It has been successfully used for studies of mutation in the stamen hairs of the plant Tradescantia. In fungal cultures mutation in mitotic cells may appear as sectorial colonies. Somatic mutation can be studied in in vitro cell cultures. Recessive mutations are detectable for X-linked genes in hemizygous cells such as those of the male. The procedure is effective if it is directed toward loci with selectable products. If loxP is introduced into mammalian cells in a near centromeric region and if neo is inserted distal to the selectable marker, after random mutagenesis the Creexpressing cells—through recombination—produce...