Tomato (Solanum lycopersicum) is a major crop plant and a model system for fruit development. Solanum is one of the largest angiosperm genera(1) and includes annual and perennial plants from diverse habitats. Here we present a high-quality genome sequence of domesticated tomato, a draft sequence of its closest wild relative, Solanum pimpinellifolium(2), and compare them to each other and to the potato genome (Solanum tuberosum). The two tomato genomes show only 0.6% nucleotide divergence and signs of recent admixture, but show more than 8% divergence from potato, with nine large and several smaller inversions. In contrast to Arabidopsis, but similar to soybean, tomato and potato small RNAs map predominantly to gene-rich chromosomal regions, including gene promoters. The Solanum lineage has experienced two consecutive genome triplications: one that is ancient and shared with rosids, and a more recent one. These triplications set the stage for the neofunctionalization of genes controlling fruit characteristics, such as colour and fleshiness

The polymerase chain reaction (PCR) after a short enrichment culture was used to detect Campylobacter spp. in chicken products. After the 16S rRNA gene sequence of Campylobacterjejuni was determined and compared with known sequences from other enterobacteria, a primer and probe combination was selected from the region before V3 and the variable regions V3 and V5. With this primer set and probe, 426-bp fragments from C. jejuni, Campylobacter coli, and Campylobacter lari could be amplified. The detection limit of the PCR was 12.5 CFU. Chicken samples inoculated with 25 CFU of Campylobacter spp. per g were PCR positive after an 18-h enrichment, which resulted in 500 CFU/ml of culture broth. This PCR-culture assay was compared with the

The application of polymerase chain reaction (PCR) fingerprinting assays enables discrimination between species and strains of microorganisms. PCR primers aiming at arbitrary sequences in combination with primers directed against the repetitive extragenic palindrome (REP) or enterobacterial repetitive intergenic consensus (ERIC) motifs generate isolate-specific DNA banding patterns. Analysis of these PCR fingerprints obtained for 33 isolates of Campylobacter jejuni, 30 isolates of Campylobacter coli, and 8 isolates of Campylobacter lari revealed that besides generation of isolate-specific fragments, species-specific DNA fragments of identical size were synthesized. It appeared that these DNA fragments could be used as species-specific probes, since they are unique for the pattern which they are deriving from. The probes do not cross-react with amplified DNA originating from a large panel of nonrelated microorganisms. Moreover, these probes displayed species specificity, as they reacted with a single restriction fragment on Southern blots containing DNA from C. jejuni, C. coli, and C. lari and other Campylobacter species. This combination of PCR fingerprinting and probe hybridization results in a highly specific identification assay and provides an example of specific test development without the prior need for DNA sequence information. The principle of the procedure holds great promise for the rapid isolation of DNA probes which, in combination with a general PCR assay, may lead to efficient typing and detection procedures for a multitude of medically important nonviral microorganisms.

No abstract

No abstract