Introduction to the AMS Symposium “Phylogenomics of Mollusks,” 82nd Annual Meeting of the American Malacological Society

Abstract

70 If you search the NCBI nucleotide database for “Mollusca” and sort the entries by date modifi ed, the fi rst sequence to appear in the list is a 119 bp sequence from the 5.8S rRNA gene from the snail Helix pomatia Linnaeus, 1758, which was published by Fang and colleagues in 1982. Since then there has been, to put it lightly, signifi cant growth in the amount of available molecular sequence data from molluscs (3,371,221 sequences in the NCBI nucleotide database alone at the time of writing this manuscript). This growth has been punctuated by advances in DNA sequencing technology. I was born around the time that 5.8S sequence was uploaded and I’ve only ever seen discarded relics of the labor-intensive denaturing polyacrylamide-urea gel and autoradiography equipment that were used to generate it. When I began my Ph.D. dissertation research in 2007, my fi rst chapter was aimed at amplifying nuclear protein-coding genes via PCR from cDNA and sequencing them using Sanger sequencing on a capillary sequencer. We performed our own capillary sequencing and, although I imagine it was a breeze compared to running sequencing gels, every successful reaction felt like a personal victory. About a year after starting my dissertation research and before I was able to collect enough data using this approach to have anything remotely worthy of a publication, Roche 454 pyrosequencing came out and it became clear that it would be faster to start all over using this “cutting-edge” technology. In less than ten years, we have watched Roche 454 pyrosequencing rise and fall, Illumina sequencing soar in popularity and capability, and the cost of sequencing a human genome drop two orders of magnitude (Muir et al. 2016). Today, there are instruments that can generate about one billion sequences slightly longer than the aforementioned 5.8S rRNA sequence in 3 days for about USD $1,000 (Illumina 2016). Recent leaps forward in high-throughput DNA sequencing technology have made it feasible for single laboratories working on non-model organisms to conduct whole genome sequencing, sequence numerous transcriptomes, conduct targetcapture approaches to sequence pools of DNA enriched for genes of interest, etc. These exciting advances in highthroughput sequencing have led to a number of high profi le papers dealing with diverse aspects molluscan biology (e.g., Kocot et al. 2011, Smith et al. 2011, 2013, Zhang et al. 2012, Introduction to the AMS symposium “Phylogenomics of Mollusks,” 82 annual meeting of the American Malacological Society