Identification of molecular motors in the Woods Hole squid, Loligo pealei: An expressed sequence tag approach

Abstract

The squid giant axon and synapse are unique systems for studying neuronal function. While a few nucleotide and amino acid sequences have been obtained from squid, large scale genetic and proteomic information is lacking. We have been particularly interested in motors present in axons and their roles in transport processes. Here, to obtain genetic data and to identify motors expressed in squid, we initiated an expressed sequence tag project by single-pass sequencing mRNAs isolated from the stellate ganglia of the Woods Hole Squid, Loligo pealei. A total of 22,689 high quality expressed sequence tag (EST) sequences were obtained and subjected to basic local alignment search tool analysis. Seventy six percent of these sequences matched genes in the National Center for Bioinformatics databases. By CAP3 analysis this library contained 2459 contigs and 7568 singletons. Mining for motors successfully identified six kinesins, six myosins, a single dynein heavy chain, as well as components of the dynactin complex, and motor light chains and accessory proteins. This initiative demonstrates that EST projects represent an effective approach to obtain sequences of interest.