Microsatellite mapping of Ae. speltoides and map-based comparative analysis of the S, G, and B genomes of Triticeae species.

The first microsatellite linkage map of Ae. speltoides Tausch (2n = 2x = 14, SS), which is a wild species with a genome closely related to the B and G genomes of polyploid wheats, was developed based on two F(2) mapping populations using microsatellite (SSR) markers from Ae. speltoides, wheat genomic SSRs (g-SSRs) and EST-derived SSRs. A total of 144 different microsatellite loci were mapped in the Ae. speltoides genome. The transferability of the SSRs markers between the related S, B, and G genomes allowed possible integration of new markers into the T. timopheevii G genome chromosomal maps and map-based comparisons. Thirty-one new microsatellite loci assigned to the genetic framework of the T. timopheevii G genome maps were composed of wheat g-SSR (genomic SSR) markers. Most of the used Ae. speltoides SSRs were mapped onto chromosomes of the G genome supporting a close relationship between the G and S genomes. Comparative microsatellite mapping of the S, B, and G genomes demonstrated colinearity between the chromosomes within homoeologous groups, except for intergenomic T6A(t)S.1G, T4AL.5AL.7BS translocations. A translocation between chromosomes 2 and 6 that is present in the T. aestivum B genome was found in neither Ae. speltoides nor in T. timopheevii. Although the marker order was generally conserved among the B, S, and G genomes, the total length of the Ae. speltoides chromosomal maps and the genetic distances between homoeologous loci located in the proximal regions of the S genome chromosomes were reduced compared with the B, and G genome chromosomes.

Comparative mapping of the wheat 5B short chromosome arm distal region with rice, relative to a crossability locus.

Colinearity between wheat and rice genomes is quite well established at the chromosome level, but less is known at a finer level. We tried to specify these relationships for the wheat 5BS chromosome-arm distal region, where a major locus for crossability was located. By developing AFLP markers, we succeeded to locate this major QTL more precisely. One cloned AFLP fragment mapped to rice chromosome 11, which was in agreement with a rice chromosome-11 linkage block reported in this region. However a second marker, a RFLP probe, showed a break in synteny because it mapped to rice long-arm chromosomes 1 and 5, while screening a rice BAC library with the same probe identified rice chromosomes 5 and 6. Therefore, we concluded that the syntenic relationships were more complex at the fine level. The observed results might indicate the presence of a linkage block carrying a crossability gene on wheat groups 1, 5 and 7, and also on rice chromosomes 5 and 6.

[Top-Forum: an interactive multimedia knowledge database to improve quality of care in pediatric oncology]. / Top-Forum: une base de connaissances multimédia interactive pour améliorer la qualité des soins en oncologie pédiatrique.

The treatment of pediatric cancer patients is characterised by complex and aggressive chemotherapy, difficult decision making, the numerous protocols available and the necessity of highly skilled caregivers. Quality of care is a major issue in all pediatric oncology units. We created an interactive multi-media database available to each caregiver to permit him/her to have easy access to information and thus increase his/her knowledge and participate in increasing their group's know-how. The computer database is available to all on a free-access basis in each ward. This is a novel approach to quality care, as it accords great importance to personal formation, allowing each caregiver to broaden his/her knowledge via easily obtained data which he/she can help enrich by permanent feedback. This database may become the backbone of department know-how.

Impact of the TOP-FORUM hypermedia system in a pediatric oncology care unit.

This paper describes our approach in analyzing the impact of the TOP-FORUM hypermedia in a pediatric oncology care unit. The impact of this technology is realized through the study of accommodation and assimilation adoption. Accommodation refers to the technological adoption and Assimilation refers to the professional adoption. Results show that accommodation depends on information and formation of the users. Assimilation is more difficult to evaluate because it depends on human, social and organizational problems.

Escherichia coli CS31A fimbriae: molecular cloning, expression and homology with the K88 determinant.

CS31A is a plasmid-encoded K88-related fimbrial antigen. A Sau3AI library was constructed from p31A, a 180 kb CS31A encoding plasmid, in the pSUP202 vector. Bacterial recombinant clones expressing CS31A were isolated. A 8.5 kb EcoRI-HinIII DNA fragment from one of them was subcloned in pBR322 and pHSG575 vectors, leading to pAG315 and pEH524 recombinant plasmids respectively. Escherichia coli harboring pAG315 or pEH524 expressed CS31A fimbrial antigens on their cell surface. Analysis of these plasmids in minicells showed that at least seven mature polypeptides were encoded by the EcoRI-HindIII DNA fragment, with apparent molecular masses of 76,000, 54,000, 30,000, 29,000, 28,000, 15,500 and 13,500 daltons respectively. The genetic organization of the CS31A gene cluster was determined and showed to be similar to that of the K88 operon. The nucleotide sequence homology between CS31A and K88 determinants was investigated by Southern blot hybridization at high stringency. This indicated that extensive nucleotide sequence homology exists throughout both gene clusters except for the subunit structural genes.

Structural organization of the group-1 chromosomes of two bread wheat sister lines.

Eureka and Renan are two French bread wheat cultivars derived from a 4-way cross. Using molecular markers (essentially RFLPs), we studied the structure of the group-1 chromosomes of these two genotypes, their parents and a doubled-haploid (DH) population derived from their F(1). Using the DH population (102 lines), a molecular map of the three homoeologous group-1 chromosomes was produced and compared with the map established on another intervarietal cross: Courtot x Chinese Spring (Cadalen et al. 1997). The polymorphic markers were mapped on the DH population and characterized on the four grand-parents, allowing us to compare the structural organization of the group-1 chromosomes of Eureka and Renan and determine their origin. These chromosomes were very different, except for small regions (1AL proximal and 1BL distal) which were identical.

Sequence analysis of the clpG gene, which codes for surface antigen CS31A subunit: evidence of an evolutionary relationship between CS31A, K88, and F41 subunit genes.

The clpG gene coding for the CS31A subunit was localized on a 0.9-kb SphI fragment from the recombinant plasmid pAG315. This was established by testing the ability of subclones to hybridize with a 17-meric oligonucleotide probe obtained from N-terminal analysis of the CS31A subunit. The nucleotide sequence of the region coding for CS31A was determined. From primer extension analysis, two initiation translation start sites were detected. Two possible promoterlike sequences were identified; the ribosome binding site and the translation terminator are proposed. Inverted repeat sequences leading to the formation of possible hairpin structures of the transcripts were found on the 5' untranslated region of clpG. The deduced amino acid composition was in close agreement with the chemical amino acid composition and sequence match with the first 25 N-terminal amino acids from the published N-terminal sequence of the purified CS31A subunit. The clpG gene codes for a mature protein of 257 amino acids with a molecular size of 26,777 Da. An obvious homology was observed when the amino acid sequence of CS31A was compared with those of K88 and F41. This homology includes five different conserved sequences of up to 19 identical amino acids, which is associated with conserved proline. An extensive change in the CS31A region homologous to that identified to contain the K88 receptor binding site might be responsible for the functional divergence between CS31A and K88.

An update of the Courtot x Chinese Spring intervarietal molecular marker linkage map for the QTL detection of agronomic traits in wheat.

We made an update of the intervarietal molecular marker linkage map of the wheat genome developed using a doubled-haploid (DH) population derived from the cross between the cultivars "Courtot" and "Chinese Spring". This map was constructed using 187 DH lines and 659 markers. The genome was well covered (more than 95%) except for chromosomes from homoeologous group 4 and chromosomes 5D and 7D, which had gaps slightly larger than 50 cM. A core-map based on a set of 200 anchor loci (one marker each 18.4 cM) was developed. The total length of this map was 3,685 cM which is similar to the size of the international reference map of the ITMI population (3,551 cM). Map coverage was identical for the three genomes (A, B and D) and for the number of anchor loci, as well as for the size of the map. Using this map, QTLs for several agronomic traits were detected on phenotypic data from the population grown in Clermont-Ferrand (France) under natural field conditions over 6 years, and in Norwich (UK) in controlled conditions and under natural field conditions in 1 year. Almost all of the 21 chromosomes were involved in at least one trait. However, several regions seemed to contain gene clusters either for grain traits (and thus bread-making quality) or plant development traits.