Considerably expanded the dataset of recognized MACIT sequences and identified MACITs in several phyla in which MACITs were previously unknown. Accession numbers for MACITs from species representative of all the phyla in which MACITs had been identified are provided in Table 1. MACIT sequences had been identified in multiple lineages of bilaterians, but not in any in the earlydiverging metazoan phyla (Ctenophora, Porifera, Placazoa, Cnidaria), or quite a few major protostome phyla (Annelida, Mollusca). Within deuterostomes, MACITs were not identified in the readily available species of Echinodermata (Stronglyocentrus purpuratus), Cephalochordata (Branchiostoma floridae or Branchiostoma belcheri), or Cyclostomata (Petromyzon marinus and Lethenteron japonicum) (Fig. two). MACITs had been not identified in non-metazoan species. Within protostomes, single MACIT-encoding genes had been identified in C. elegans and numerous other nematodes and in species from all classes of arthropods (Table 1, Fig. 2). In C. elegans the predicted MACIT protein (Fig. 1c), ORF F29C4.8, has been named COL-99 (Putative cuticle collagen 99) (wormbase.org). Expression on the gene has been confirmed at the mRNA level, but not established by protein data [29]. 5 option splicing variants have already been predicted, although as however without experimental confirmation (uniprot.org). We investigate COL-99 more deeply inside the experimental sections of the Results. In D. melanogaster, one particular predicted MACIT homologue was identified (Table 1 and Fig. 1c). Collagen chain CG43342 is composed of 822 amino acids including a single transmembrane domain close towards the N-terminus and four interruptions within the collagenous ectodomain (Fig. 1c). The existence of a protein has not however been established but there’s evidence in the amount of transcription (uniprot.org). 4 alternatively spliced isoforms have already been predicted but these are however to be confirmed experimentally [30]. Inside the modENCODE Temporal Expression Profile, peak expression of CG43342 has been detected at the 6-12 h embryonic stage via microarray studies [30]. Single MACIT-encoding genes were also identified in other Hexapoda (Table 1). The predicted MACITs of T. castaneum, B. impatiens and N. vitripennis MACITs are shorter proteins than D. melanogasterTu et al. BMC Evolutionary Biology (2015) 15:Web page four ofTable 1 The dataset of MACIT protein sequences from protostomes and deuterostomes analysed in this study. Essential: + sequence corrected versus expressed sequence tagPhylum/Species/protein name Nematoda Caenorhabditis elegans MACIT/Col-99 C briggsae MACIT Arthropoda Drosophila melanogaster MACIT Nasonia vitripennis MACIT Tribolium castaneum MACIT Ixodes scapularis MACIT Bombus impatiens MACIT Daphnia pulex MACIT (incomplete N-end) Hemichordata Saccoglossus kowalevskii MACIT Urochordata Ciona intestinalis MACIT Vertebrata: Fish Callorhinchus milii XIII Callorhinchus milii XXIII Callorhinchus milii XXV Salmo salar collagen XIII Danio rerio collagen XIII (partial) Danio rerio collagen XXIII Danio rerio collagen XXV Maylandia zebra collagen XIII Takifugu rubripes collagen XXIII Takifugu rubripes collagen XXV Oryzias latipes collagen XIII Oreochromis niloticus collagen XXV Latimeria chalumnae collagen XXIII Latimeria chalumnae collagen XXV Vertebrata: Amphibians Xenopus tropicalis collagen XIII Xenopus tropicalis collagen XXV Vertebrata: Reptiles XP_002935816+ NP_001123747 XtXIII XtXXV XP_007896149 XP_007899591 XP_007887363 NP_001167092 XP_009305408 XP_009305980 XP_009301819 XP_0045.GFP Protein Molecular Weight IGF2R, Human (Domain 1-7, HEK293, His-Avi) PMID:24275718