Figure 7: The atypical IMD pathway in Chelicerates/Myriapods.
From: Infection-derived lipids elicit an immune deficiency circuit in arthropods
(a) BLAST was used to survey arthropod sequences. The Drosophila IMD was used as a query sequence. Confounding factors, such as sparsely populated data matrices, sequence misalignment and biased statistical confidence were removed. *Trilobites are an extinct subphylum. (b) The Rel homology domain sequence from D. melanogaster Relish was used to search arthropod transcripts for relish (class I) and other Rel domain-containing targets (dorsal and dif; class II) with tBLASTn. Two human NF-κB molecules served as outgroups. (c) I. scapularis PGRP sequences include PGRP-1: XM_002411731.1, PGRP-2: XM_002433644.1, PGRP-3: XM_002410377.1 and PGRP-4: XM_002413046.1. PGRP-1 was used to search chelicerate proteomes for PGRPs. Bootstrap values greater than or equal to 70 are shown. Yellow shading indicates chelicerate PGRP sequences, with I. scapularis PGRPs highlighted in red. Insect PGRPs are coloured gray and light blue. Blue labels and asterisks denote probable amidase activity based on the residues HHC in the active site. (b,c) MUSCLE was used to generate the multiple sequence alignment. The maximum likelihood phylogenetic tree was calculated with RAxML and re-sampled 100 times to assess clade support. See also Supplementary Figs 6 and 7.
