The second encodes a factor with considerable homologies (50% identical, 66% similar residues) to the human ‘metastasis-associated-protein’ MTA3 which is a component of the nucleosome-remodelling and histone-deacetylase complex (105) and, like the human protein, contains one BAH (bromo-adjacent homology) domain, one GATA-type zinc finger domain and one classical
zinc finger domain (data not shown). As previously suggested (72), the antigen B cluster is formed of one copy each of AgB1, AgB2, AgB4 and AgB5, two identical genes encoding AgB3 and one slightly altered AgB3 gene (AgB3’). The only difference to the previously suggested cluster organization (72) is that in the newest assembly version the AgB5 locus and R788 solubility dmso one AgB3 locus have changed position (Figure 2). All genes of the cluster display the typical organization (103) of two exons, with a signal peptide encoded by exon 1, separated by a small intron. Transcriptome analyses on in vitro
cultivated metacestode vesicles further indicate that AgB1 is, by far, the most abundantly expressed isoform, followed Selleck Metformin by AgB3’ (20% of the expression level of AgB1) and AgB3 (10%). Only marginal expression could be detected for AgB2, AgB4 and AgB5 in the metacestode, and likewise, almost no expression was measured for any AgB isoform in the protoscolex (data not shown). In E. granulosus, the situation appears to be highly similar to E. multilocularis (Figure 2). Within a region of approximately the same size as in E. multilocularis, close orthologs of EmLDLR (EgLDLR) and EmMTA (EgMTA) are present and are flanking a cluster of seven loci with one copy each of AgB1, AgB2, AgB4 and AgB5, as well as three slightly differing copies of AgB3 (AgB3-1, AgB3-2, Florfenicol AgB3-3). Although care has to be taken in suggesting complete synteny between both species in this region, because the single E. granulosus contigs (flanked by ‘N’ in Figure 2) have been assembled into supercontigs using the E. multilocularis sequence as a reference, at least the E. granulosus
copies of AgB1, AgB4 and AgB3-2 are clearly assembled into one contig and display the same gene order and transcriptional orientation as in E. multilocularis (Figure 2). This makes it highly likely that the genome arrangement as suggested for E. granulosus in Figure 2 reflects the true situation. Apart from the AgB cluster, we could not detect any AgB-related sequences elsewhere in the genomes of E. multilocularis and E. granulosus, with one notable exception of an AgB-like gene on E. multilocularis scaffold_7, that is, however, not represented in EST databases, does not show a detectable transcription profile in RNA-seq data, contains inactivating mutations within the reading frame (data not shown), and thus most likely represents a pseudogene.