Analysis of Thioredoxin (TRX) protein family. (A) Phylogenetic tree based on maximum likelihood analysis of a Dermacentor variabilis midgut protein and published TRX sequences. The transcript identified in this analysis is in bold (DvM). Phylogenetic analysis was conducted on protein alignments using Tree Puzzle version 5.2. Values at nodes represent calculated internal branch node support (1000 replications). (B) Multiple sequence alignment (CLUSTALX) of protein sequences identified in a cDNA library of unfed/2 d fed or 6 d fed D. variabilis midguts (DvM) and published thiroredoxin-1 sequences found on genbank. Arrowheads indicate the catalytic cysteine motif. Shading represents 100% identity (black) or similarity (grey) among the sequences. Alignments were conducted using CLUSTALX. D. variabilis (Dv), Ixodes scapularis (Is), Mesobuthus cyprius (Mc), Aedes aegypti (As), Anopheles gambiae (Ag), Drosophila melanogaster (Dm), Bombyx mori (Bm), Manduca sexta (Ms), Tribolium castaneum (Tc), Maconellicoccus hirsutus (Mh), Drosophila pseudoobscura (Dp), Simulium jonesii (Sj), and Homo sapiens (Hs).