Project description:The data set submitted here contains the raw SNP genotyping data obtained from the analysis of 24 biparental segregating maize (Zea mays L.) populations and their respective parents. The processed and filtered data were used to construct genetic linkage maps which we used in our study of variation of recombination rate in maize. In sexually reproducing organisms, meiotic crossovers ensure the proper segregation of chromosomes and contribute to genetic diversity by shuffling allelic combinations. Such genetic reassortment is exploited in breeding to combine favorable alleles, and in genetic research to identify genetic factors underlying traits of interest via linkage or association-based approaches. Crossover numbers and distributions along chromosomes vary between species, but little is known about their intraspecies variation. In our study, we report on the variation of recombination rates between 22 European maize inbred lines that belong to the Dent and Flint gene pools. We genotyped 23 doubled-haploid populations derived from crosses between these lines with a 50k-SNP array and constructed high-density genetic maps, showing good correspondence with the maize B73 genome sequence assembly. By aligning each genetic map to the B73 sequence, we obtained the recombination rates along chromosomes specific to each population. We identified significant differences in recombination rates at the genome-wide, chromosome, and intrachromosomal levels between populations, as well as significant variation for genome-wide recombination rates among maize lines. Crossover interference analysis using a two-pathway modeling framework revealed a negative association between recombination rate and interference strength. To our knowledge, the present work provides the most comprehensive study on intraspecific variation of recombination rates and crossover interference strength in eukaryotes. Differences found in recombination rates will allow for selection of high or low recombining lines in crossing programs. Our methodology should pave the way for precise identification of genes controlling recombination rates in maize and other organisms.
Project description:The data set submitted here contains the raw SNP genotyping data obtained from the analysis of 24 biparental segregating maize (Zea mays L.) populations and their respective parents. The processed and filtered data were used to construct genetic linkage maps which we used in our study of variation of recombination rate in maize. In sexually reproducing organisms, meiotic crossovers ensure the proper segregation of chromosomes and contribute to genetic diversity by shuffling allelic combinations. Such genetic reassortment is exploited in breeding to combine favorable alleles, and in genetic research to identify genetic factors underlying traits of interest via linkage or association-based approaches. Crossover numbers and distributions along chromosomes vary between species, but little is known about their intraspecies variation. In our study, we report on the variation of recombination rates between 22 European maize inbred lines that belong to the Dent and Flint gene pools. We genotyped 23 doubled-haploid populations derived from crosses between these lines with a 50k-SNP array and constructed high-density genetic maps, showing good correspondence with the maize B73 genome sequence assembly. By aligning each genetic map to the B73 sequence, we obtained the recombination rates along chromosomes specific to each population. We identified significant differences in recombination rates at the genome-wide, chromosome, and intrachromosomal levels between populations, as well as significant variation for genome-wide recombination rates among maize lines. Crossover interference analysis using a two-pathway modeling framework revealed a negative association between recombination rate and interference strength. To our knowledge, the present work provides the most comprehensive study on intraspecific variation of recombination rates and crossover interference strength in eukaryotes. Differences found in recombination rates will allow for selection of high or low recombining lines in crossing programs. Our methodology should pave the way for precise identification of genes controlling recombination rates in maize and other organisms. Related publication: Bauer E, Falque M, Walter H, Bauland C, Camisan C, Campo L, Meyer N, Ranc N, Rincent R, Schipprack W, Altmann T, Flament P, Melchinger AE, Menz M, Moreno-González J, Ouzunova M, Revilla P, Charcosset A, Martin OC, Schön C-C (2013) Intraspecific variation of recombination rate in maize. Genome Biology (submitted) We genotyped 2233 maize DH lines from 24 biparental populations, and the 23 parents of these populations using the Illumina MaizeSNP50 BeadChip. We created two large half-sib panels, one each for the Dent and the Flint germplasm. The Dent populations have the prefix CFD, the Flint populations have the prefix CFF. In each panel, a common central parent was crossed to diverse founder lines, and doubled haploids were generated from the respective F1 plants. For a detailed description of the material, see Bauer et al. (2013) Genome Biology (submitted). We submit here three datasets: 1) Dataset Parents comprises all 23 parental lines. 2) Dataset CFD comprises all 1005 DH lines from Dent crosses, 3) Dataset CFF comprises all 1262 DH lines from Flint crosses.
Project description:affy_cellwall_maize - affy_cellwall_maize - Maize, Zea mays, is one of the most widely grown crops in the world as it provides cereal grain for human purposes and feedstock for cattle. Maize is increasingly used as a biomass fuel, such as ethanol. Studies have shown that maize stem is made up of different lignified cell types: epidermis, sclerenchyma (a few layers under the epidermis and surrounding vascular bundles in the rind), parenchyma (mostly lignified near the epidermis). One of the aims of this work is to find out if it is the proportion of these different cell types or their number (especially for vascular bundles) which influences the degree of digestibility of maize lines. For that the objective of our work is to develop a genomic strategic approach allowing an improvement of traits involved in cell wall degradability. The work will include the mapping of genes considered as strategic in the cell wall biosynthesis, the search of new genes of interest through bio-analysis, the functional analysis of genes suspected to be of importance in cell wall pathway, the search of candidate underlying QTL, and transcriptomic approaches in order to find genes co-regulation, transcription.-Comparison of internodes from 5 maize lines grown in field conditions
Project description:affy_en-tj_maize - affy_en_maize - Maize, Zea mays, is one of the most widely grown crops in the world as it provides cereal grain for human purposes and feedstock for cattle. Maize is increasingly used as a biomass fuel, such as ethanol. Studies have shown that maize stem is made up of different lignified cell types: epidermis, sclerenchyma (a few layers under the epidermis and surrounding vascular bundles in the rind), parenchyma (mostly lignified near the epidermis). One of the aims of this work is to find out if it is the proportion of these different cell types or their number (especially for vascular bundles) which influences the degree of digestibility of maize lines. For that the objective of our work is to develop a genomic strategic approach allowing an improvement of traits involved in cell wall degradability. The work will include the mapping of genes considered as strategic in the cell wall biosynthesis, the search of new genes of interest through bio-analysis, the functional analysis of genes suspected to be of importance in cell wall pathway, the search of candidate underlying QTL, and transcriptomic approaches in order to find genes co-regulation, transcription, and eQTL.-Comparison of 2 maize lines : Cm484: good digestibility F98902: bad digestibility) , at the following developmental stade 2: male flowering Keywords: genotype comparaison
Project description:affy_en-tj_maize - affy_tj_maize - Maize, Zea mays, is one of the most widely grown crops in the world as it provides cereal grain for human purposes and feedstock for cattle. Maize is increasingly used as a biomass fuel, such as ethanol. Studies have shown that maize stem is made up of different lignified cell types: epidermis, sclerenchyma (a few layers under the epidermis and surrounding vascular bundles in the rind), parenchyma (mostly lignified near the epidermis). One of the aims of this work is to find out if it is the proportion of these different cell types or their number (especially for vascular bundles) which influences the degree of digestibility of maize lines. For that the objective of our work is to develop a genomic strategic approach allowing an improvement of traits involved in cell wall degradability. The work will include the mapping of genes considered as strategic in the cell wall biosynthesis, the search of new genes of interest through bio-analysis, the functional analysis of genes suspected to be of importance in cell wall pathway, the search of candidate underlying QTL, and transcriptomic approaches in order to find genes co-regulation, transcription, and eQTL.-Comparison of 2 maize lines : Cm484: good digestibility F98902: bad digestibility at the following development stage : 21 days after sowing -7 leaves- Keywords: genotype comparaison
Project description:affy_diversity_maize - affy_diversity_maize - Maize, Zea mays, is one of the most widely grown crops in the world as it provides cereal grain for human purposes and feedstock for cattle. Maize is increasingly used as a biomass fuel, such as ethanol. Studies have shown that maize stem is made up of different lignified cell types: epidermis, sclerenchyma (a few layers under the epidermis and surrounding vascular bundles in the rind), parenchyma (mostly lignified near the epidermis). One of the aims of this work is to find out if it is the proportion of these different cell types or their number (especially for vascular bundles) which influences the degree of digestibility of maize lines. For that the objective of our work is to develop a genomic strategic approach allowing an improvement of traits involved in cell wall degradability. The work will include the mapping of genes considered as strategic in the cell wall biosynthesis, the search of new genes of interest through bio-analysis, the functional analysis of genes suspected to be of importance in cell wall pathway, the search of candidate underlying QTL, and transcriptomic approaches in order to find genes co-regulation, transcription, and eQTL.-Comparison of two maize lines Cm484 (line of good digestibility) and F98902 (line of bad digestibility) at the same developmental stage (male flowering). Keywords: organ comparison
Project description:The evolution of maize yields under drought is of particular concern in the context of climate change and human population growth. To better understand the mechanisms associated with the genetic polymorphisms underlying the variations of traits related to drought tolerance, we used a systems genetics approach integrating high-throughput phenotypic, proteomics and genomics data acquired on 254 maize hybrids grown under two watering conditions. We show that the genetic architecture of protein abundances depends on protein function and that water deficit strongly remodeled the proteome and induced a reprogramming of the genetic control of the abundances of proteins involved in drought and stress response. These findings bring several lines of evidence supporting candidate genes at many loci and provide novel insight into the molecular mechanisms of drought tolerance.
Project description:affy_cellwall_maize - affy_cellwall_maize - Maize, Zea mays, is one of the most widely grown crops in the world as it provides cereal grain for human purposes and feedstock for cattle. Maize is increasingly used as a biomass fuel, such as ethanol. Studies have shown that maize stem is made up of different lignified cell types: epidermis, sclerenchyma (a few layers under the epidermis and surrounding vascular bundles in the rind), parenchyma (mostly lignified near the epidermis). One of the aims of this work is to find out if it is the proportion of these different cell types or their number (especially for vascular bundles) which influences the degree of digestibility of maize lines. For that the objective of our work is to develop a genomic strategic approach allowing an improvement of traits involved in cell wall degradability. The work will include the mapping of genes considered as strategic in the cell wall biosynthesis, the search of new genes of interest through bio-analysis, the functional analysis of genes suspected to be of importance in cell wall pathway, the search of candidate underlying QTL, and transcriptomic approaches in order to find genes co-regulation, transcription.-Comparison of internodes from 5 maize lines grown in field conditions 10 arrays - maize; organ comparison