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Letter from the editor | 76

From fossils to Xanthomonas

From fossils to Xanthomonas

The discovery of fossils that help to unveil one of the most important transitions in the lengthy evolution of the animal kingdom on the earth, which occurred around 210 million years ago, normally excites paleontologists from anywhere in the world excited. We are speaking of the transition of the reptiles into mammals, among which we find ourselves, the human species – and herein, perhaps, lies part of the enormous fascination of this topic even outside of the specialist field, since it alludes to ourselves, with an explanation about our own origin.

Well now, a new reason to shake up the paleontologists, and interestingly enough those who like new clues about the origin of different classes of the animal kingdom, comes from Brazil, more precisely from the Southern region. It was there that researchers from the Federal University of Rio Grande do Sul (UFRGS) and from the Argentinean Museum of Natural Sciences identified two new cynodonts with anatomical characteristics to be appointed as the closest ancestors to primordial mammals. Their provisional names: Brasiliterio, which means mammal of Brazil, and Brasilodonte, a word that is the result of the articulation between tooth (odon) and clearly, Brazil. No, they were not yet rigorously mammals, but their evolution is clearly orientated in that direction, hence their baptism.

The Brazilian cynodonts, according to the report of the journalist Marcos Pivetta, in the fine cover article of this edition, were identified through the analysis of fossil fragments of small reptiles, no larger than a pen, found over the last two years in the Southern Brazil region of Santa Maria. And if one of them is not an example of the species that was the final step towards the start of the mammal kingdom, their discoverers are convinced that both are important pieces in the phylogenetic challenging puzzle which they are poring over.

Another piece of good news on scientific research in Brazil, recently published by the national press, but which merits, because of its importance, a headline in this issue, has its origin in São Paulo: researchers who are part of the ONSA network of laboratories (Organization for Nucleotide Sequencing and Analysis ) – formed with the sequencing project of Xylella fastidiosa which, in 1997, gave origin to the FAPESP Genome program and internationally projected, three years later, Brazilian genomic research -, have pointed in a scientific paper published in the May 23rd edition of the scientifically respected magazineNature , ways for combating Xanthomonas citri. And furthermore they have presented the results of the sequencing of Xanthomonas campestri . What we now need to emphasize is that this new work, presented almost a year and a half after the conclusion of the sequencing of X. citri by the same group (Pesquisa FAPESP nº 60, December 2000), could have an impact on all agricultural pathogenic research, because the detailed study of one hundred genes of the X. citri to define ways to combat it in citrus farming – where it brings on citric canker – was done in comparison with its cousin X. campestri, which has a very favorable characteristic to the research, which is that of infecting the Arabdopsis thaliana, a model plant for genetic studies. Actually, the knowledge generated through this work could benefit not only citrus farming, but the main plants that serve as food for the human being, because the Xanthomonas gender is made up of twenty species that attack three hundred and ninety two vegetable plants, among them beans, rice, manioc, cotton, corn, sugarcane, wheat and the soybean.

In the technology section it is worth highlighting the advances obtained by a research group from the Federal University of São Carlos (UFSCar) in research into glass-ceramic materials, with extraordinarily broad possibilities for their use, from telescopes to artificial bones. However, there is lots more to discover in this edition which comes accompanied by a thoughtful special edition to commemorate the forty fruitful years of the life of FAPESP. Good reading.