Efficient Genome Locus Identification Using Non-Gridded BAC Library Strategy

Plant genomes are complexes regarding many aspects, their large size, their polyploidy and the high percentage of repetitive elements. Next-generation DNA sequencing technologies have revolutionized the genomic research by offering the capacity to obtain large amount of sequences in a short time. However, this approach is not sufficient to decipher the high complexity of plant genomes. Bacterial Artificial Chromosome (BAC) libraries are still invaluable tools for plant genome analysis.

The French Plant Genomic Resource Center (INRA - CNRGV) is in charge of more than 10 millions unique BAC samples belonging to more than 150 model and crop plant genomic libraries (http://cnrgv.toulouse.inra.fr/en/Library) and is a leader in the development of approaches involving BAC libraries to study plant genomes.

In order to efficiently focus on genomic region of interest, we have developed a non-gridded BAC library strategy that avoids BAC clones massive picking steps and lightens screening effort.

In this poster, we present the non-gridded BAC library strategy that we have developed in order to identify the GER4 locus in 7 barley varieties, a locus involved in the response of  barley against the powdery mildew fungus Blumeria graminis f. sp hordei (Bgh) attack.  The barley GER4 is encoded by a dense  cluster of tandemly duplicated genes (GER4a-h) that underwent several cycles of gene duplication. The 7 barley varieties showed different GER4 expression and different B.graminis  resistance pattern and the goal of the project is to analyse the GER4 locus sequences diversity of those varieties.