RT Journal Article SR Electronic T1 Identification of immediate early genes in the nervous system of snail Helix lucorum JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0416-18.2019 DO 10.1523/ENEURO.0416-18.2019 A1 Chuan Xu A1 Qian Li A1 Olga Efimova A1 Xi Jiang A1 Marina Petrova A1 Alia Kh. Vinarskaya A1 Peter Kolosov A1 Nikolay Aseyev A1 Kira Koshkareva A1 Victor N. Ierusalimsky A1 Pavel M. Balaban A1 Philipp Khaitovich YR 2019 UL http://www.eneuro.org/content/early/2019/05/03/ENEURO.0416-18.2019.abstract AB Immediate early genes (IEGs) are useful markers of neuronal activation and essential components of neuronal response. While studies of gastropods have provided many insights into the basic learning and memory mechanisms, the genome-wide assessment of IEGs has been mainly restricted to vertebrates. In this study we identified IEGs in the terrestrial snail Helix lucorum. In the absence of the genome, we conducted de novo transcriptome assembly using reads with short and intermediate lengths cumulatively covering more than 98 billion nucleotides. Based on this assembly, we identified 37 proteins corresponding to contigs differentially expressed in either the parietal ganglia or two giant interneurons located within the parietal ganglia of the snail in response to the neuronal stimulation. These proteins included homologues of well-known mammalian IEGs, such as c-jun/jund, C/EBP, c-fos/fosl2 and Egr1, as well as homologues of genes not yet implicated in the neuronal response.Significance Statement Gastropods, which include snails and slugs, are widely used in studies of basic neuronal activity mechanisms. The first step of the transcriptional response to neuronal stimulation requires the activation of immediate early genes (IEGs). The identification of IEGs is important for the understanding of neuronal response mechanisms and for the visualization of activated neurons. However, genome-wide studies of IEGs have thus far been mainly restricted to vertebrates. Furthermore, a study of activity-regulated genes, a gene group that includes IEGs, conducted in fruit flies did not reveal a clear overlap with vertebrate IEGs. In this study we present a transcriptome-wide study of snail IEGs, which reveals multiple homologues of well-known mammalian IEGs, as well as a number of novel IEG candidates.