Physical and genetic map of the Spiroplasma kunkelii CR2-3x chromosome.
Spiroplasma kunkelii (class Mollicutes) is the characteristically helical, wall-less bacterium that causes corn stunt disease. A combination of restriction enzyme analysis, pulsed-field gel electrophoresis (PFGE), and Southern hybridization analysis was used to construct a physical and genetic map of the S. kunkelii CR2-3x chromosome. The order of restriction fragments on the map was determined by analyses of reciprocal endonuclease double digests employing I-CeuI, AscI, ApaI, EagI, SmaI, BssHII, BglI, and SalI; adjacent fragments were identified on two-dimensional pulsed-field electrophoresis gels. The size of the chromosome was estimated at 1550 kb. Oligonucleotide pairs were designed to prime the amplification of 26 S. kunkelii gene sequences in the polymerase chain reaction (PCR). Using PCR amplicons as probes, the locations of 27 S. kunkelii putative single-copy genes were positioned on the map by Southern hybridization analyses of chromosomal fragments separated in PFGE. The nucleotide sequence of the single ribosomal RNA operon was determined and its location mapped to a chromosomal segment bearing recognition sites for SalI, SmaI, EagI, and I-CeuI.
Dally
Ellen L
EL
USDA, Agricultural Research Service, Molecular Plant Pathology Laboratory, Beltsville, MD 20705, USA.
Barros
Thereza S L
TS
Zhao
Yan
Y
Lin
ShaoPing
S
Roe
Bruce A
BA
Davis
Robert E
RE
D015139:Blotting, Southern; D002874:Chromosome Mapping / Q000379:methods*; D002876:Chromosomes, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D020161:Physical Chromosome Mapping / Q000379:methods*; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping / Q000379:methods; D013149:Spiroplasma / Q000235:genetics*