The exon 13 duplication in the BRCA1 gene is a founder mutation present in geographicaly diverse populations

Recently, a 6-kb duplication of exon 13, which creates a frameshift in the coding sequence of the BRCA1 gene, has been described in three unrelated U.S. families of European ancestry and in one Portuguese family. Here, our goal was to estimate the frequency and geographic diversity of carriers of this duplication. To do this, a collaborative screening study was set up that involved 39 institutions from 19 countries and included 3,580 unrelated individuals with a family history of the disease and 934 early-onset breast and/or ovarian cancer cases. A total of 11 additional families carrying this mutation were identified in Australia (1), Belgium (1), Canada (1), Great Britain (6), and the United States (2). Haplotyping showed that they are likely to derive from a common ancestor, possibly of northern British origin. Our results demonstrate that it is strongly advisable, for laboratories carrying out screening either in English-speaking countries or in countries with historical links with Britain, to include within their BRCA1 screening protocols the polymerase chain reaction-based assay described in this report

Le potager familial méditerranéen

National audienc

Le potager tropical

National audienc

Is it Possible to Find a Third Way Between "Green Revolution" and Traditional Systems of Agriculture?

Traditional systems of agriculture still feed millions of people in tropical countries. There is probably a superior limit to their yield potentials, especially in over-populated situations. However, many things can be learned about the biological mechanisms which explain their productivity, and perhaps it is possible to imagine ameliorated systems in which productivity would be ameliorated by minimal inputs of chemical aid, and adequate plant breeding

L’intérêt de lignées collectées en Haïti pour l’amélioration variétale du haricot grain (Phaseolus vulgaris L)

Parmi d’autres légumineuses, les grains secs de haricots (Phaseolus vulgaris) tiennent une grande place dans l’alimentation haïtienne. Les types de haricots cultivés en Haïti sont très variés, mais ont une tendance générale à la précocité et à l’indifférence photopériodique. Les paysans cultivent des mélanges de gros grains produits par des plantes naines et de grains moyens et petits produits par des plantes à croissance indéterminée : économie de l’investissement en semences et assurance de meilleure régularité de récolte. Les principaux types variétaux cultivés en Haïti sont décrits, ainsi que les meilleures lignées qui en ont été tirées. Des croisements simples ou complexes faisant intervenir soit exclusivement des lignées haïtiennes, soit aussi des variétés provenant d’autres pays, ont permis d’obtenir des lignées améliorées, intéressant non seulement Haïti, mais cultivables également en Afrique et dans le Midi de la France.Dry beans and peas belonging to Phaseolus, Vigna, Cajanus and Lablab spp are an important constituent of the diet in Haiti. Of these, the common bean (Phaseolus vulgaris L) is cultivated on a widespread scale and is the most popular legume. No doubt for historic, sociological and agricultural reasons common beans grown in Haiti are extremely heterogeneous as regards growth habit, seed size and color, but have in common earliness and indifference to photoperiodicity. Haitian farmers grow mixtures of large beans (produced by dwarf plants), and medium-sized or small beans (produced by plants with indeterminate growth) for seed input saving, and to ensure yield regularity. From beans bought in the markets, or from superior plants chosen in the fields several hundred lines were extracted, 50 of which were preserved after severe elimination had been carried out in Guadeloupe (FWI) for powdery mildew susceptibility at the seedling stage or in southern France for summer heat or common mosaic susceptibility. The principal common bean categories grown in Haiti and the best lines found in each category are described: - large kidney-shaped beans (most of them mottled red) produced by dwarf plants (4 lines are described); - large ovoid beans (most of them mottled red) produced by dwarf plants (1 line described); - medium-sized black beans, produced by plants with indeterminate growth (4 lines described); - small-sized beans of various colors, produced by plants with indeterminate growth (4 lines described); - small-sized uniform red beans produced by plants which become climbing under good fertilization (one line described). Crosses were made in order to obtain still better lines for use in Haiti (and other countries), with tolerance to leaf diseases (such as powdery mildew, rust, and Isariopsis, Chaetoseptoria, Cercospora and Entyloma leaf spots), which in Haiti could result in a yield of 1 t/ha instead of 0.5, with 0.30.30 fertilization, but without fungicide sprays. The general objective was to propose to the farmers a "superior mixture" of the best lines. The programs were as follows: large mottled red-kidney-shaped beans; black beans; small pink or red-mottled beans (the best lines obtained, such as "Salagnac 90" for the first program, have been described). A fourth program aimed at obtaining fresh shell-beans for the FWI: red beans, red or red-striated pods (dwarf or climbing lines following the use in various seasons). Most of these breeding programs involved breeding generations alternated between different climates: Haiti/southern France, Haiti/Guadeloupe, or Haiti/southern France/Guadeloupe. As a consequence of the earliness and day-neutral behaviour of the germplasm used, and also possibly the alternated generations system utilized, the lines resulting from these programs show a wide climatic adaptation. Good results were obtained in some parts of Africa (the highlands of Comoro and the Réunion islands; Burkina-Faso), and southern France where most of them are easily grown and have a satisfactory yield

Les maladies de la canne a sucre en Guadeloupe

National audienc

Une nouvelle source de résistance au flétrissement bactérien obtenue à partir d’un croisement entre Solanum aethiopicum L et Solanum melongena L

International audienceAs the eggplant hybrid F1 Kalenda no longer showed enough resistance to Pseudomonas solanacearum EF Smith in Guadeloupe and Martinique (French West Indies), a new breeding program was undertaken using Solanum aethiopicum as source of resistance. Despite sterility problems encountered during the first generations, selection was conducted under an artificial inoculation test according to a recurrent selection scheme including backcrosses by Solanum melongena. From the second backcross it was possible to obtain families with a high level of resistance to bacterial wilt, as well as a wide variation in the shape and colour of the fruits.Un nouveau programme de sélection d’aubergines utilisant Solanum aethiopicum L comme source de résistance à Pseudomonas solanacearum EF Smith a été lancé en Guadeloupe et en Martinique; l’hybride F1 Kalenda ne manifestant plus une résistance suffisante. La sélection a pu être réalisée malgré d’importants problèmes de stérilité rencontrés pendant les premières générations. Elle fut conduite généralement sous inoculation artificielle selon un modèle de sélection récurrente avec des phases de backcross par Solanum melongena L. Après le second backcross, il fut possible de sélectionner des familles manifestant un haut degré de résistance à la bactérie et possédant une très large variabilité pour la forme et la coloration du fruit