Spiroplasmas, members of Class Mollicutes,/ are scattered over wide host and geographic niches. Those which are plant pathogenic, such as Spiroplasma citri, / are transmitted from plant to plant by homopteran insect vectors, leafhoppers, and cause devastating damages to several crops world-wide. A variety of model systems are available to study the transmission of phytopathogenic spiroplasmas by leafhoppers, their predominant vectors. Spiroplasma citri-Circulifer tenellus/ is one such system. Because spiroplasmas can be cultured in artificial media, they offer an excellent means to investigate the complex molecular interactions underlying the transmission of S. citri/ by the insect vector C. tenellus./ Evidence suggests that an S. citri/ membrane protein, spiroplasma adhesion related protein 1 (SARP1), is involved in the adhesion of S. citri / cells to tissue-cultured C. tenellus/ cells and, thus, is thought to be a putative adhesin. The gene encoding SARP1 ( arp1/) has been isolated, cloned and characterizeDepartment of Biochemistry and Molecular Biolog
