Effect of the fungicide captafol on the survival and symbiotic properties of Rhizobium trifolii

The fungicide captafol is toxic to Rhizobium trifolii at concentrations greater than 75 μg/ml, and at lower concentrations it affects growth adversely. Captafol-resistant mutants were isolated and all were found to have lost the same plasmid and the ability to nodulate clovers. Nodulation plasmids transferred from a R. leguminosarum or R. trifolii donor to the resistant mutants conferred the ability to nodulate peas and clover plants, respectively. The rhizobia remained resistant to captafol indicating that the genetic alteration leading to captafol resistance was not necessarily detrimental to the ability of the bacteria to form nitrogen fixing nodules. These results indicate that captafol may act as a plasmid-curing agent in R. trifolii.     

The effect of colony age on PCR fingerprinting

The pattern of DNA fragments produced by the polymerase chain reaction using arbitrary primers is strongly influenced by the age of the colonies sampled. We show that the number, clarity and reproducibility of the bands produced is optimal when very young colonies are sampled.
This work was supported by European Community grants (EEC CI1* 0545-UK, JEB and HC; BIOT-CT91-0283, JEB and HK), the AFRC (PG7 586, JEB and BH) and the SERC Biotechnology Directorate and Zeneca Ltd through a CASE studentship to LS.     

Proposed follow up programme after curative resection for lower third oesophageal cancer

Cyclins are indispensable elements of the cell cycle and derangement of their function can lead to cancer formation. Recent studies have also revealed more mechanisms through which cyclins can express their oncogenic potential. This review focuses on the aberrant expression of G1/S cyclins and especially cyclin D and cyclin E; the pathways through which they lead to tumour formation and their involvement in different types of cancer. These elements indicate the mechanisms that could act as targets for cancer therapy.