What is an Endocycle?
The endocycle is a common cell cycle variant in which cells successively duplicate genomic DNA without segregating their chromosomes during mitosis.
What is Endopolyploidy plant?
Endopolyploidy is a general term describing the multiplication of nuclear DNA within the cell. In plants, this takes place via several mechanisms but mainly through the process of endoreduplication.
What is endopolyploidy what is its biological significance?
Endopolyploidy is essential for normal development and physiology in many different organisms. Here we review how both plants and animals use variations of the cell cycle, termed collectively as endoreplication, resulting in polyploid cells that support specific aspects of development.
What is the role of endoreduplication in plants?
Endoreduplication is the major source of endopolyploidy in higher plants. The process of endoreduplication results from the ability of cells to modify their classical cell cycle into a partial cell cycle where DNA synthesis occurs independently from mitosis.
How is Endopolyploidy important to some species?
In particular, we argue that endopolyploidy is likely to play a central role in key traits such as gene expression, body and cell size, and growth rate, and in a variety of cell types, including those responsible for tissue regeneration, nutrient storage, and inducible anti-predator defences.
What is the meaning of Allopolyploid?
Definition of allopolyploid : a polyploid individual or strain having a chromosome set composed of two or more chromosome sets derived more or less complete from different species.
What crops are polyploids?
Introduction to Polyploidy Examples of important polyploid plants used for human food include, Triticum aestivum (wheat), Arachis hypogaea (peanut), Avena sativa (oat), Musa sp. (banana), many agricultural Brassica species, Solanum tuberosum (potato), Fragaria ananassa (strawberry), and Coffea arabica (coffee).
Why do plants become polyploid?
How does an organism become polyploid? Polyploids arise when a rare mitotic or meiotic catastrophe, such as nondisjunction, causes the formation of gametes that have a complete set of duplicate chromosomes. Diploid gametes are frequently formed in this way.
What is produced by endoreduplication?
Endoreduplication is a form of nuclear polyploidization that results in multiple, uniform copies of chromosomes. This process is common in plants and animals, especially in tissues with high metabolic activity, and it generally occurs in cells that are terminally differentiated.
How does endoreduplication occur?
Endoreplication occurs when a cell exits the mitotic cell cycle in G2 phase and undergoes multiple S phases without entering mitosis and undergoing cytokinesis. The result is a giant cell with a single, enlarged, polyploid nucleus.
What are examples of allopolyploidy?
Wheat is an example of an allopolyploid with six chromosome sets. For instance, a cross between tetraploid wheat Triticum (AAAA) and rye Secale (BB) would produce a hybrid progeny with a chromosomal composition of AAB. Allopolyploidy can be artificially induced by colchicine treatment of the seedlings.
What is allopolyploidy give an example?
Allopolyploidy occurs when an organism has more than two sets of chromosomes from different species. An example of allopolyploidy is Gossypium, a species of cotton, which are hybrids formed from two diploid species of cotton.
What is Autopolyploids and allopolyploids?
Autopolyploidy appears when an individual has more than two sets of chromosomes, both of which from the same parental species. Allopolyploidy, on the other hand, occurs when the individual has more than two copies but these copies, come from different species.
How do polyploids arise?