An integrated high-density RFLP-AFLP map of tomato based on two Lycopersicon esculentum x L. pennellii F2 populations

Two independent F2 populations of Lycopersicon esculentum×L. pennellii which have previously been investigated in RFLP mapping studies were used for construction of a highly saturated integrated AFLP map. This map spanned 1482 cM and contained 67 RFLP markers, 1078 AFLP markers obtained with 22 EcoRI+MseI primer combinations and 97 AFLP markers obtained with five PstI+MseI primer combinations, 231 AFLP markers being common to both populations. The EcoRI+MseI AFLP markers were not evenly distributed over the chromosomes. Around the centromeric region, 848 EcoRI+ MseI AFLP markers were clustered and covered a genetic distance of 199 cM, corresponding to one EcoRI+ MseI AFLP marker per 0.23 cM; on the distal parts 1283 cM were covered by 230 EcoRI+MseI AFLP markers, corresponding to one marker per 5.6 cM. The PstI/MseI AFLP markers showed a more even distribution with 16 PstI/MseI AFLP markers covering a genetic distance of 199 cM around the centromeric regions and 81 PstI/MseI AFLP markers covering a genetic distance of 1283 cM on the more distal parts, corresponding to one marker per 12 and 16 cM respectively. In both populations a large number of loci showed a significant skewed segregation, but only chromosome 10 loci showed skewness that was similar for both populations. This ultra-dense molecular-marker map provides good perspectives for genetic and breeding purposes and map-based cloning.<br/

PCR-based characterization of Yersinia enterocolitica: comparison with biotyping and serotyping.

PCR-based DNA fingerprinting was used to characterize 48 clinical isolates of Yersinia enterocolitica. The samples were examined by random amplified polymorphic DNA (RAPD-PCR) and inter-repeat PCR (IR-PCR). IR-PCR with two enterobacterial repetitive intergenic consensus primers resulted in patterns which were poorly discriminated; 2 of 11 arbitrary primers (RAPD-PCR) provided sufficient discriminatory power. In comparisons with serotyping and biotyping, RAPD-fingerprinting was the most discriminatory technique and may therefore be a valuable epidemiological tool for the study of Y. enterocolitica infections

An integrated high-density RFLP-AFLP map of tomato based on two Lycopersicon esculentum x L. pennellii F2 populations

 Two independent F2 populations of Lycopersicon esculentum×L. pennellii which have previously been investigated in RFLP mapping studies were used for construction of a highly saturated integrated AFLP map. This map spanned 1482 cM and contained 67 RFLP markers, 1078 AFLP markers obtained with 22 EcoRI+MseI primer combinations and 97 AFLP markers obtained with five PstI+MseI primer combinations, 231 AFLP markers being common to both populations. The EcoRI+MseI AFLP markers were not evenly distributed over the chromosomes. Around the centromeric region, 848 EcoRI+ MseI AFLP markers were clustered and covered a genetic distance of 199 cM, corresponding to one EcoRI+ MseI AFLP marker per 0.23 cM; on the distal parts 1283 cM were covered by 230 EcoRI+MseI AFLP markers, corresponding to one marker per 5.6 cM. The PstI/MseI AFLP markers showed a more even distribution with 16 PstI/MseI AFLP markers covering a genetic distance of 199 cM around the centromeric regions and 81 PstI/MseI AFLP markers covering a genetic distance of 1283 cM on the more distal parts, corresponding to one marker per 12 and 16 cM respectively. In both populations a large number of loci showed a significant skewed segregation, but only chromosome 10 loci showed skewness that was similar for both populations. This ultra-dense molecular-marker map provides good perspectives for genetic and breeding purposes and map-based cloning.<br/

In situ localisation of Yersinia enterocolitica by catalysed reported deposition signal amplification.

AIM: The sensitive detection of pathogenic Yersinia enterocolitica in paraffin embedded tissue sections by in situ hybridisation (ISH). METHODS: Y enterocolitica infected cell lines, rat spleens, and patient biopsy specimens were used to compare conventional ISH, immune fluorescence assay (IFA) detection, and catalysed reporter deposition (CARD) signal amplification ISH. RESULTS: CARD-ISH was shown to be more sensitive then conventional ISH and had a comparable sensitivity to IFA. In contrast to IFA, CARD-ISH preserved good tissue morphology. CONCLUSIONS: CARD-ISH appeared to be a fast and sensitive ISH method for detecting Y enterocolitica in routinely processed tissue sections. Application of this method allows the combination of routine detection and cellular localisation of the pathogen within the infected tissue