Geminiviridae

Maize streak virus is the type member of the Mastrevirus genus of the taxonomic family Geminiviridae: the genera of this family were recently renamed; the next (7th) version of "Virus Taxonomy" from the International Committee on Taxonomy of Viruses (ICTV) will reflect the changes described below. Geminiviruses are plant viruses with a circular ssDNA genome, with characteristic "geminate" virions;

Mastreviruses have single-component genomes of about 2.7 kilobases and are obligately leafhopper transmitted;

Begomoviruses (type member bean golden mosaic virus, BGMV) usually have a two-component genome (A and B; B dependent on A for replication, both +/- 2.6 kb in size) and are obligately transmitted by Bemisia tabaci whiteflies;

Curtoviruses (type member: beet curly top virus) are single component and leafhopper or treehopper transmitted, and appear to be the result of an ancient recombination event between a Mastre- and a Begomovirus.

(Briddon and Markham, 1995; Rybicki, 1994; Padidam et al., 1995). There is a Geminiviridae home page, maintained by Claude Fauquet, for further information on the family.

A relationship dendrogram - derived from whole-genome alignments and neighbour-joining phylogenetic analysis, and drawn using TreeView - is shown below: this illustrates the groupings within the genera, and generic groupings within the family.

This is copyrighted by Academic Press, SanDiego, and appears in "The Molecular Biology of the Mastreviruses", by KE Palmer and EP Rybicki, in "Advances in Virus Research", Volume 50, 1998.