Agricultural Microbes Genome 2 Conference Agricultural Microbes Genome 2 Conference
Poster: Microbial Genome Sequencing/Programs
P01_56.html
Spiroplasmas and phytoplasmas are Gram-positive bacteria and members of the Class Mollicutes. Mollicutes dramatically differ from other bacteria by their minute size (0.3 - 0.5 īm), total lack of cell wall and small genomes. Spiroplasmas establish an array of interactions with plants and insects, ranging from epiphytic to symbiotic to pathogenic. Plant-pathogenic spiroplasmas are transmitted by phloem-feeding insects, mainly leafhoppers, in circulative propagative manner to plants and, therefore, have two hosts for replication: insects and plants. To gain insight into the genetic basis of mollicute interaction with their hosts, we initiated the sequencing of the complete 1.6-Mb genome of the maize pathogen, corn stunt spiroplasma (CSS; Spiroplasma kunkelii). Genomic DNA was isolated from a CSS culture and used for the construction of both restriction and shotgun fragment libraries. Sequence contigs were obtained with PHRED-PHRAP software and searched against Genbank with the BLAST algorithm. An updated overview of the genome project is available at the spiroplasma web site (http://www.oardc.ohio-state.edu/spiroplasma/). Our data show that several spiroplasma genes have significant identity to genes from Gram-positive Bacillus spp, Streptococcus spp., and Clostridium spp., but are absent in other members of the Class Mollicutes, such as Mycoplasma genitalium and Mycoplasma pneumoniae. We expect that the CSS genome-sequencing project will provide the basis for comparative genomic studies among several spiroplasma species, and between spiroplasmas and the related vertebrate-pathogenic mycoplasmas. These studies should aid in identifying genes required for infection of plants and insects.