Dating origins polyploidy events
Polyploidy refers to a numerical change in a whole set of chromosomes.Organisms in which a particular chromosome, or chromosome segment, is under- or overrepresented are said to be aneuploid (from the Greek words meaning "not", "good", and "fold").Illustrating the broad impact of polyploidy, ancient WGD events have been documented in vertebrates (e.g., Cañestro, 2012; Braasch and Postlethwait, 2012), fungi (Kellis et al., 2004), and ciliates (Aury et al., 2006); both recent and ancient events occur extensively in plants, particularly in lineages such as the angiosperms.In fact, researchers have long recognized that polyploidy is an inseparable part of angiosperm biology.However, polyploidy is found in some organisms and is especially common in plants.
To date, taxonomy and phylogeny of the rice genus have been extensively investigated and the evolutionary framework has been well established at the genus level. Total DNA was isolated from fresh or silica-gel dried leaves using the cetyltrimethylammonium bromide method Table 1: Comprehensive list of the samples used in the present study including species name, genome type, source, abbreviation in figures, and accession numbers in the International Rice Research Institute (IRRI).
In the rice genus (Oryza), about one half of the species are allopolyploids. Our relaxed clock analyses suggest that all the BBCC species originated within the last one million years, which is coincident with the severe climate oscillations occurred during the last ice age, implying the potential impact of climate change on their formations and dispersals.
These species are not only important resources for rice breeding but also provide a unique opportunity for studying evolution of polyploid species. punctata being the maternal donors, whereas the diploid O. eichingeri (C-genome) were the progenitors of tetraploid O. In addition, our results support previous taxonomic arguments that the tetraploid O. minuta is distributed in Philippines and Papua New Guinea, and O.
Identifying and characterizing plant paleopolyploidies is ongoing research.
They are identified through whole genome comparisons using a combination of the data derived from genomic structure (e.g. As such, detecting these events and determining which lineages share what subset are continually changing.
Search for dating origins polyploidy events:
Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations.