Development of new genetic resources for faba bean (Vicia faba L.) breeding through the discovery of gene-based SNP markers and the construction of a high-density consensus map.

Faba bean (Vicia faba L.) is a pulse crop of high nutritional value and high importance for sustainable agriculture and soil protection. With the objective of identifying gene-based SNPs, transcriptome sequencing was performed in order to reduce faba bean genome complexity. A set of 1,819 gene-based SNP markers polymorphic in three recombinant line populations was selected to enable the construction of a high-density consensus genetic map encompassing 1,728 markers well distributed in six linkage groups and spanning 1,547.71 cM with an average inter-marker distance of 0.89 cM. Orthology-based comparison of the faba bean consensus map with legume genome assemblies highlighted synteny patterns that partly reflected the phylogenetic relationships among species. Solid blocks of macrosynteny were observed between faba bean and the most closely-related sequenced legume species such as pea, barrel medic or chickpea. Numerous blocks could also be identified in more divergent species such as common bean or cowpea. The genetic tools developed in this work can be used in association mapping, genetic diversity, linkage disequilibrium or comparative genomics and provide a backbone for map-based cloning. This will make the identification of candidate genes of interest more efficient and will accelerate marker-assisted selection (MAS) and genomic-assisted breeding (GAB) in faba bean.

Effects of chamber depth on the motion pattern of human spermatozoa in semen or in capacitating medium.

The computer-aided sperm analysis system (CASA) permits precise calculation of the trajectory characteristics of human spermatozoa. Comparison between different chamber depths (10, 20 and 100 microns) revealed variations in the results, which were more evident as the magnitude of the spermatozoon flagellar beat increased. In seminal spermatozoa, the reduced amplitude of movement, linked to the relatively short flagellum and high viscosity of seminal plasma, indicates that the 10 microns-deep chamber can be used for motion analysis without involving extensive modifications. On the other hand, analysis of quicker movement, such as in capacitated spermatozoa, revealed large variations; in particular the proportion of non-progressive hyperactivated spermatozoa was higher in the 20 microns than in the 10 microns chamber (17.9 +/- 14% and 6.9 +/- 4.5% respectively, P < 0.01). In fact the distribution of non-progressive and progressive hyperactivated spermatozoa is depth-dependent. It is therefore necessary to use a chamber of at least 20 microns in depth for sperm analysis in capacitated medium.

[Value of computer processing of data acquired by cytofluorometry for biological analyses]. / Intérêt pour l'analyse biologique du traitement informatique des données acquises par cytofluorométrie.

The amount of informations relative to cell analysis generated on a flow cytometer must often be processed on a computer so that accurate and efficient analysis can be performed on the stored data, and have the power to consider complex signal distributions. A Ortho 50H flow cytometer was complemented with a Persona 1600 microcomputer (LogAbax) via an acquisition system directly connected to the photomultiplier assemblies. In the configuration we used, three primary signals are processed and stored simultaneously, thus providing six parameters for each cell. The analysis of the data can be delayed or operated immediately after each acquisition. Turbo Pascal was used for all programming. The implanted programs are available for the processing of histograms relative to immunofluorescence or DNA analyses. They allow the user to operate on data obtained after selecting the cells on a two-parameter basis. Examples of immunofluorescence and DNA analyses obtained on experimental preparations are presented.