P0029 Whole genome shotgun sequencing and assembly to access the gene rich portion of the genome of Lolium perenne L

Linda Cardle , The James Hutton Institute, Dundee, United Kingdom
Dan Milbourne , Teagasc, Carlow, Ireland
David Marshall , The James Hutton Institute, Dundee, United Kingdom
Janaki Velmurugan , Teagasc, Carlow, Ireland
Micha Bayer , The James Hutton Institute, Dundee, United Kingdom
Chris Creevey , Teagasc, Dunsany, Ireland
Matthew McCabe , Teagasc, Dunsany, Ireland
Susanne Barth , Teagasc , Carlow, Ireland
High throughput next generation sequencing technologies are leading to dramatic new approaches to directly sequence and characterise the genomes of crop species. It is now possible to whole genome shotgun (WGS) sequence even the large genomes of grasses and cereals. When such WGS data sets are assembled the gene-rich, low-copy-number regions, typically containing 1-3 genes in islands surrounded by high-copy number retroelement “debris”, assemble fairly readily in sequence contigs up to about 25 kb.   Such a resource provides the ideal template for the identification and characterisation of key gene families using comparative data from well annotated cereal/grass species such as rice, sorghum, Brachypodium and maize. So we have obtained ~38x  sequence coverage of the an inbred Lolium perenne genotype. This is based on Illumina paired-end coverage (mean fragment size approximately 450nt and up to 150 of sequence read at either end). Assembly of this Lolium WGS data results in the formation of approximately 1 million contigs. Initial analysis using a series of genes and genes families which have already been characterised in the Bowman and Morex barley assemblies have shown that even at this stage of progress it is possible to obtain a very significant proportion of the Lolium gene complement as intact contigs spanning both the coding and promoter regions of the gene.