Hello Group, Definition of endoreduplication: Modified cell cycle in which alternating S (DNA synthesis) phases occur with G (Gap periods) in the absence of a mitotic period. This cycle type leads to the production of chromosomes with 2 to the n chromatids. The maize endosperm endoreduplication case is a dramatic example of DNA content changes in plant development (endosperm is a triploid tissue, 3C- C= haploid DNA content), values of 386C (7 endocycles) have been recorded). This process is known to occur in in both plants and animals in a variety of tissue types. For example, leaf epidermal cells of Triticum durum (Cavallini et al. 1995) go through endoreduplication cycles in response to light signals from the external environment. Another example, in addition to plant endosperm types, include silk gland cells of dipterans. -John On Sun, 21 Mar 1999, Robert Pyle wrote: > > > We too see the unexpected 8N etc. cell ploidies in some of our cell cultures and > haven't had a good explanation for same. The "endoduplication" explanation > seemed popular. Sorry to seem daft and ignorant but I surveyed a number of our > cell culture people and molecular types here and no one could define > endoduplication for me. In fact, no one had heard the term before. The mail > camel has not yet arrived with my latest copy of cytometry so I am at a loss for > an explanation of what endoduplication is. Could someone help this poor soul? > > Thanks > > Haywood Pyle > KFSH, MBC#3 > Box 3354 > Riyadh 11211 > Saudi Arabia > e:pyle@kfshrc.edu.sa > > >
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