The molecular fingerprints of 1,349 isolates of Mycobacterium bovis received between 1979 and August 2000 at Agence Française de Sécurité Sanitaire des Aliments (Afssa) have been obtained by spoligotyping. The majority of the isolates (1,266) were obtained from cattle living in France. An apparently high level of heterogeneity was observed between isolates. One hundred sixty-one spoligotypes were observed in total, of which 153 were from French isolates. The two predominant spoligotypes, designated BCG-like and GB54, accounted for 26 and 12% of the isolates, respectively. In addition, 84% of the spoligotypes were found fewer than 10 times. Analysis of the results by clustering and parsimony-based algorithms revealed that the majority of the spoligotypes were closely related. The predominant spoligotype was identical to that of the vaccine strain Mycobacterium bovis BCG, which was isolated in France at the end of the 19th century. Some spoligotypes were closely associated with restricted geographical areas. Interestingly, some spoligotypes, which were frequently observed in France, were also observed in neighboring countries. Conversely, few spoligotypes were common to France and England, and those that were shared were observed at very different frequencies. This last point illustrates the potential role for an international data bank, which could help trace the spread of M. bovis across national borders.Bovine tuberculosis (TB) was endemic in France until the 1960s, with herd prevalence rates of 25% in 1955 (9). From this time onwards, a national program for TB control based on tuberculin skin testing with control of animal movements and total slaughter of infected herds was implemented. This control strategy resulted in a dramatic decrease in bovine tuberculosis leading to a herd prevalence rate of 0.09% in 1998 (2), suggesting that cattle are the most important reservoir, or even the sole reservoir, for Mycobacterium bovis in France. Due to the success of this control strategy, France was declared "officially free of bovine TB" by the European Commission (3).The very low level of TB in cattle has resulted in the introduction of new control strategies. Consequently, there has been a progressive reduction in the use of skin testing, with an increasing emphasis on systematic sampling of suspect lesions identified at slaughterhouses for M. bovis isolate identification and molecular typing. New laboratory tools were therefore required in order to improve the traceability of the infections and identification of the origin of the outbreak (i.e

The conifers, which traditionally comprise seven families, are the largest and most diverse group of living gymnosperms. Efforts to systematize this diversity without a cladistic phylogenetic framework have often resulted in the segregation of certain genera and/or families from the conifers. In order to understand better the relationships between the families, we performed cladistic analyses using a new data set obtained from 28S rRNA gene sequences. These analyses strongly support the monophyly of conifers including Taxaceae. Within the conifers, the Pinaceae are the first to diverge, being the sister group of the rest of conifers. A recently discovered Australian genus Wollemia is confirmed to be a natural member of the Araucariaceae. The Taxaceae are nested within the conifer clade, being the most closely related to the Cephalotaxaceae. The Taxodiaceae and Cupressaceae together form a monophyletic group. Sciadopitys should be considered as constituting a separate family. These relationships are consistent with previous cladistic analyses of morphological and molecular (18S rRNA, rbcL) data. Furthermore, the well-supported clade linking the Araucariaceae and Podocarpaceae, which has not been previously reported, suggests that the common ancestor of these families, both having the greatest diversity in the Southern Hemisphere, inhabited Gondwanaland.

We present a new method using nucleic acid secondary structure to assess phylogenetic relationships among species. In this method, which we term "molecular morphometrics," the measurable structural parameters of the molecules (geometrical features, bond energies, base composition, etc.) are used as specific characters to construct a phylogenetic tree. This method relies both on traditional morphological comparison and on molecular sequence comparison. Applied to the phylogenetic analysis of Cirripedia, molecular morphometrics supports the most recent morphological analyses arguing for the monophyly of Cirripedia sensu stricto (Thoracica + Rhizocephala + Acrothoracica). As a proof, a classical multiple alignment was also performed, either using or not using the structural information to realign the sequence segments considered in the molecular morphometrics analysis. These methods yielded the same tree topology as the direct use of structural characters as a phylogenetic signal. By taking into account the secondary structure of nucleic acids, the new method allows investigators to use the regions in which multiple alignments are barely reliable because of a large number of insertions and deletions. It thus appears to be complementary to classical primary sequence analysis in phylogenetic studies.

No abstract