Sea food consumption is an important component of healthy diet. Increase in aquaculture production is required to compensate rarefaction of sea food from wild fisheries. A challenge facing aquaculture industry is to increase fish flesh production while maintaining nutritional value and quality of the product. Hyperplasia, a process by which small new fibres are added into the fish myotome is an important determinant of muscle growth rate (flesh production) in fish. Also a high number of small fibres resulting from hyperplasia is correlated with a high collagen content that positively influence texture. However, so far, almost nothing is known regarding the genetic circuits controlling the continuous muscle fibre production, a trait linked to productivity and profitability of fish enterprise. Therefore, the aim of this project is to provide the genetic basis for hyperplastic growth in fish. This includes (i) an idenfication of genes specifically expressed in hyperplastic area of the myotome using transcriptomic tools and in situ hybridization screen and a functional analysis of hyperplasia candidate genes by means of antisens morpholinonucleotides and transgenic approaches.

Rapeseed is the oilseed crop most widely cultivated in Europe.The cultivated surface kept growing since 2003 as a consequence of the development of non-food uses of rapeseed oil while the demand for human feeding remained high. Recently the demand for arable products and vegetable oil in particular, has increased dramatically. This is mainly due to the growing world population and the related demand for food and to the increasing demand for bioenergy. It is also becoming clear that to satisfy demand, productivity of arable crops, and more precisely oil crop, will need to be improved. At the same time inputs need to be reduced for both economic and ecological reasons. Genetic progress is of major interest in the context of low input-systems/sustainable agriculture During the last years a technological breakthrough was observed in the domain of plant genetic improvement with the development of high throughput sequencing and genotyping technologies. Very promising results were also recently obtained using genetic association approaches to analyse traits. Association of new genotyping technologies and new methodologies for genetic data analysis, allow successful analysis of complex traits. Recently, the field of plant association genetics pioneered the use of a new type of association populations, designed to incorporate advantages of both linkage based and linkage disequilibrium based quantitative trait dissection approaches, in association studies. This population named NAM for Nested Association Mapping, was successfully developed in maize and is being developed in wheat. This kind of population is of great interest to validate quickly and at a large scale, candidate genes and to deeply characterize QTL in plants The aim of the OSR_NAM project is to develop a NAM population in oilseed rape which will give to scientific and breeders involved in oilseed rape improvement, a major tool for high resolution genetic mapping. This resource will be developed by two laboratories leader in genetics, genomics and genotyping. The project will gather public and private research. This secures the use of the resource at once for basic and applied research, to put in the market new varieties with improved agronomical traits.

Crossovers (COs) lead to the reciprocal exchange of large fragments of genetic material between homologous chromosomes occurring during meiosis. Data from various model organisms show that the distribution of COs is not random along chromosomes. The current view is that the final distribution of COs is the result of several constraints that can be summarized as follows: (i) The density of DNA double strand breaks that initiate meiotic recombination varies along chromosomes. (ii) Their individual penchant to become a CO or a NCO is probably variable. (iii) Interference strength varies within and from chromosome to chromosome and probably acts on several levels. (iv) Some COs are insensitive to interference, their proportion differing from species to species. (v) There may be more than two pathways controlling CO formation. (vi) Density of COs on a bivalent may be modulated by a global cellular control. To obtain a coherent view of molecular components and mechanisms involved in CO formation and distribution, we propose to study in parallel the actors and the distribution of this process using Arabidopsis thaliana as model. We will study the different steps and pathways of meiotic recombination through (i) the isolation and characterization of meiotic mutants, (ii) the description of CO density and distribution genome-wide in wild-type, (iii) the analysis of the effect of different mutations on CO distribution, and (iv) the use of modeling approaches to integrate results obtained from the previous points. Studies in the closest crop relatives of Arabidopsis thaliana, diploid and tetraploid Brassica species, will allow us to investigate the effect of adding one or several supplementary chromosomes on the final CO distribution. The integration of the results obtained by these approaches will provide a genomic-wide understanding of the constraints on meiotic COs formation and localization. ...