1 - Insect Genomics

Abstract

This chapter discusses the insect genome sequencing and analysis of sequenced genomes using “omics” and high-throughput sequencing technologies. It also provides an overview of proteomics and structural genomics of insect systems biology. Research on insects, especially in the areas of physiology, biochemistry, and molecular biology, has undergone notable transformations during the last two decades. Almost all insect genomes sequenced to date employed the whole-genome shotgun sequencing (WGS) method. Shotgun genome sequencing begins with isolation of high molecular weight genomic DNA from nuclei isolated from isogenic lines of insects. The genomic DNA is then randomly sheared, end-polished with Bal31 nuclease/ T4 DNA polymerase primers, and, finally, the DNA is size-selected. The size-selected, sheared DNA is then ligated to restriction enzyme adaptors such as the BstX1 adaptors. Subsequently, the genomic fragments are inserted into restriction enzyme-linearized plasmid vectors. Most genomes sequenced to date employed this technology. Sanger sequencing must be distinguished from next generation sequencing technology, which has entered the marketplace during the last four years and is rapidly changing the approaches used to sequence genomes. Genomes sequenced by NGS technologies will be completed more quickly and at a lower price than those from the first few insect genomes.