@article{mbs:/content/journal/micro/10.1099/00221287-146-4-893, author = "Padovan, Anna C. and Firrao, Giuseppe and Schneider, Bernd and Gibb, Karen S.", title = "Chromosome mapping of the sweet potato little leaf phytoplasma reveals genome heterogeneity within the phytoplasmasThe EMBL accession number for the sequence determined in this work is AJ245515.", journal= "Microbiology", year = "2000", volume = "146", number = "4", pages = "893-902", doi = "https://doi.org/10.1099/00221287-146-4-893", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-146-4-893", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "PFG, pulsed-field gels", keywords = "phytoplasma", keywords = "genome mapping", keywords = "gid gene", keywords = "TBB, tomato big bud", keywords = "SPLL, sweet potato little leaf", keywords = "2-D, two-dimensional", keywords = "WX, Western X", keywords = "pulsed-field gel electrophoresis", keywords = "ribosomal genes", abstract = "To further understand the genomic diversity and genetic architecture of phytoplasmas, a physical and genetic map of the sweet potato little leaf (SPLL) strain V4 phytoplasma chromosome was determined. PFGE was used to determine the size of the SPLL-V4 genome, which was estimated to be 622 kb. A physical map was prepared by two-dimensional reciprocal digestions using the restriction endonucleases BssHII, SmaI, EagI and I-CeuI. Sixteen cleavage sites were located on the map. Southern hybridizations of digested SPLL-V4 chromosomal DNA were done using random clones and PCR-amplified genes as probes. This confirmed fragment positions and located the two rRNA operons and the linked fus/tuf genes encoding elongation factors G and Tu, respectively, on the physical map. An inversion of one of the rRNA operons was observed from hybridization data. Sequence analysis of one of the random clones identified a gid gene encoding a glucose-inhibited division protein. Digestions of the tomato big bud (TBB) phytoplasma chromosome with the same four enzymes revealed genome heterogeneity when compared to the closely related SPLL-V4, and a preliminary chromosome size for the TBB phytoplasma of 662 kb was estimated. This mapping information has revealed that significant genome diversity exists within the phytoplasmas.", }