Fig. 6
Rhythmic expression of Daphnia immune system components. Numerous genes with putative immune functions were found to have rhythmic expression in D. pulex. a The Daphnia immune system can be separated into recognition proteins, signal transduction proteins, and attack proteins and processes. The cartoon illustrates the relationship between these categories. There were a number of rhythmically expressed pathogen recognition genes including two thioester-containing proteins (TEP), nineteen C-type lectins (CTLs), and three gram-negative bacteria-binding proteins (GNBP). Additionally, three membrane-bound toll-like receptors (TLRs) were rhythmically expressed. For signal transduction, four members of the IMD (Immune Deficiency) pathway were also found to be rhythmically expressed: IMD, Dredd, and two Relish paralogs. Expression is presented as raw florescence values for GNBPs (for visualization purposes). Two additional rhythmic CTLs were identified using network analysis and these are visualized in Fig. 3b. b 32 chitinase (CHT) genes, which may have direct immune functions (as a pathogen-chitinase) were found to have rhythmic expression. For visualization purposes, the 26 with peak phase between ZT4 – ZT6 are presented. Two additional rhythmic chitinases were identified using network analysis and these are visualized in Fig. 3b. c A scavenger (SVG) gene and three caspases genes (CAS), which may have immune recognition or signal transduction functions, respectably (but these gene classes also serve other roles), were also found to have rhythmic expression. Day and night for all plots in this figure are indicated by the horizontal white/black bars. Unless otherwise noted, expression in this figure is presented as log2 of median normalized expression