Oryza sativa Oryza sativa Oryza sativa, commonly known as Asian rice, is the plant species most commonly referred to in English as rice. "Oryza sativa" is a grass with a genome consisting of 430Mb across 12 chromosomes. It is renowned for being easy to genetically modify, and is a model organism for cereal biology. "Oryza sativa" contains two major subspecies: the sticky, short-grained "japonica or sinica" variety, and the nonsticky, long-grained "" variety. "Japonica" varieties are usually cultivated in dry fields, in temperate East Asia, upland areas of Southeast Asia, and high elevations in South Asia, while "indica" varieties are mainly lowland
Helitron (biology) Helitron (biology) Helitrons are one of the three groups of eukaryotic class 2 transposable elements (TEs) so far described. They are the eukaryotic rolling-circle transposable elements which are hypothesized to transpose by a rolling circle replication mechanism via a single-stranded DNA intermediate. They were first discovered in plants ("Arabidopsis thaliana" and "Oryza sativa") and in the nematode "Caenorhabditis elegans", and now they have been identified in a diverse range of species, from protists to mammals. Helitrons make up a substantial fraction of many genomes where non-autonomous elements frequently outnumber the putative autonomous partner. Helitrons seem to have a major role