Polyploidy

Polyploidy

Polyploidy is defined as an increase in genome DNA content. Throughout the plant and animal kingdoms specific cell types become polyploid as part of their differentiation programs. When this occurs in subsets of tissues within an organism it is termed somatic polyploidy, because it is distinct from the increase in ploidy that is inherited through the germline and present in every cell type of t...

Endoreplication: polyploidy with purpose.

A great many cell types are necessary for the myriad capabilities of complex, multicellular organisms. One interesting aspect of this diversity of cell type is that many cells in diploid organisms are polyploid. This is called endopolyploidy and arises from cell cycles that are often characterized as "variant," but in fact are widespread throughout nature. Endopolyploidy is essential for normal...

Polyploidy and Cancer

The average desoxypentosenucleic acid content of individual nuclei was determined for various normal and tumor tissues, and for livers showing precancerous changes, in the rat. With certain exceptions attributable to polyploidy, the values were practically indistinguishable from each other and from values reported for cell nuclei of other mammals. The amount of this nucleic acid in diploid cell...

Polyploidy and gender dimorphism.

Miller and Venable (1) claimed that polyploidy is a “trigger of unrecognized importance” for the evolution of gender dimorphism, an idea originally proposed by Jennings (2) and Baker (3). In our opinion, their phylogenetic analysis of North American Lycium (Solanaceae) does not support the claimed associations between polyploidy, self-fertility, and gender dimorphism. There is no support (boots...

Dermatoglyphs in human polyploidy.