The Establishment Of Hybrid Assembly Pipeline Combining With Illumina&Pacbio SMRT Sequencing Technology And The Acquisition Of The Lentinus Edodes Accurate Genome

The genome sequences contain the genetic information essential for the growth and development for every organism.The acquisition of such a sequence information has to be relied on the sequencing technologies.The final destination of sequencing is to achieve the complete sequence of a target genome.Sequencing technologies started from the 1970s,which went through three periods.In 1977,Sanger and Coulson developed the first generation of sequencing technology based on the double deoxidizing terminal end method.The advantage of this technology is the long length of reads and the high accuracy.The first human draft genome was accomplished using this method.The drawback of this method is its low efficiency and high cost,for example,the human genome was accomplished at a cost of billions of dollars and took more than ten years.In 2005,the next generation sequencing technologies came to the world,of which Illumina Sequencing Platform is the most representative one.Compared with the Sanger sequencing it has much low costs,high speed and high throughput,As a result,it has been put into use and quickly occupied the sequencing market.However,the reads length produced by Illumina Hiseq Platform are shorter than 300 bp,which bring difficulties for the genome assembly.Meanwhile,it could not overcome the GC bias and thus limits the use of this technology.Recently,the third generation sequencing technology represented by Single Molecule Real-time Sequencing has developed quickly.The characteristic of the SMRT sequencing is its long reads length,high throughput and no GC bias.Compared with the traditional sequencing,however,the SMRT sequencing has low accuracy rate.In this study,we selected the Lentinus edodes genome to combine the SMRT and NGS sequencing technologies,and make full use the long reads length advantage of SMRT and high accuracy of NGS to overcome the assemble difficulties of such a high repetitive and heterozygous genome.By using this pipeline we generated a high-quality reference genome of Lentinus edodes.Future efforts will put to improve this assembly pipeline that would help to assemble the complicated genomes in the future.