Crinivirus

Introduction
Crinivirus is a genus of viruses that belong to the family Closteroviridae. They are also known as the lettuce infectious yellows virus group. They are linear, single-stranded positive sense RNA viruses (and are therefore group IV). The viruses of the genus are plant viruses (1).

Examples of species whose entire genomes have been sequenced that are currently classified into the genus include ‘’Sweet potato chlorotic stunt virus’’ (SPCSV) and ‘’Lettuce infectious yellows virus’’ (LIYV) (2). Other examples of viruses belonging to that genus include ‘’Abutilon yellows virus; Cucurbit yellow stunting disorder virus; Lettuce chlorosis virus; Tomato chlorosis virus; Tomato infectious chlorosis virus; Beet pseudoyellows virus, Diodia vein chlorosis virus and Potato yellow vein virus’’ (1). Note that this is not an exhaustive list of all the viruses in the genus.

Virus particle structure
The Universal Virus Database describes that the virions of the genus each consists of a non-enveloped, filamentous capsid “with a length of 1200-2000 nm and a width of 10-13 nm” (1). The capsid is also described to have “helical symmetry.”

Genetics
The viruses of this genus have segmented, bipartite genomes that add up to 7,500 -19,500 nucleotides in length. The Universal Virus Database also describes that their genome sequences near their 3'-ends are capable of hairpin-loop formation and also believe that their 5'-ends may have methylated caps (1). Their genomes also code for proteins that do not form part of the virion particles as well as structural proteins.