Figure 1.
The immunoglobulin heavy chain locus of a panel of selected vertebrates from fish to humans.
The locus depicts every single gene as a block and without individual exons. The figure is not to scale and the genes have been color coded; IgM in black, IgD in dark green, IgA and IgX in light green, IgY in magenta, IgG in blue, IgE in purple, IgO in red, IgZ in yellow, IgF in orange and pseudogenes in shaded grey or purple.
Figure 2.
The major Fc receptor gene loci in a panel of different vertebrates.
Each horizontal line corresponds to a chromosome on which different Fc receptor genes are located. Genes are color coded. The Fc receptor-like (FcRL) genes are shown in yellow except the FcRLA and B that are in light green, classical IgG receptors in red (pseudogenes in striped red), IgE receptor in dark green, the IgM receptor in orange, the poly-Ig receptor (PIGR) and the IgA/IgM receptor in blue. The figure contains the genes identified for the following animal species: Zebrafish (Danio rerio), Western clawed frog (Xenopus silunarana and Xenopus tropicalis), Chicken (Gallus gallus), Turkey (Meleagris gallopovo), Zebra Finch (Taeniopygia guttata), Green anole (Anolis carolinennsis), Platypus (Ornithorhynchus anatinus), Opossum (Monodelphis domestica), Rat (Ratuus norvegius), Mouse (Mus musculus), Horse (Equus caballus), Rabbit (Oryctologus cunicullus), Pig (Sus scrofa), Dog (Canis lupus familaris), Cattle (Bos taurus), Orangutan (Pongo abelli), Chimpanzee (Pan troglodytes), Rhesus macaque (Macaca mulatta), Human (Homo sapiens).
Figure 3.
The FcαR locus and neighboring genes.
Panel A shows a schematic drawing of chromosome 19, panel B a schematic drawing of the LRC locus, panel C the domain structure of the LILRs of this locus (an ‘R’ represents arginine in the transmembrane region) and panel D the domain structure of the KIRs. In the detailed map of the region encoding the IgA receptor each horizontal line corresponds to a chromosome on which different Fc receptor genes are located. Genes are color coded. The IgA receptor in red, the KIRs and LILRs in yellow, the neighboring genes that are used as markers for the chromosomal region, NCR1 in dark green, the NACHT in orange, the NLRP7 in light blue, the PGRL1 in light green and the FQD1-FB1 in dark blue. The overall structure of the LRC locus and the protein domain structures have been adopted from Espeli et al 2010 and Brown et al 2004 [45], [68].
Figure 4.
A phylogenetic tree of Fc receptor sequences from a panel of vertebrates analyzed with the MrBayes program.
The Maximum-likelihood tree was based on the Bayesian methods of phylogenetic interference. Robustness of nodes was tested with the posterior probabilities based on MCMC analysis as implemented in the MrBayes program. Node supported posterior values are given in the phylogenetic tree. Groups of genes that are more closely related, thereby forming a sub-branch, are indicated by light or dark grey shading to make them more easily visible.
Figure 5.
A summary of domain structures and signaling motifs of the various vertebrate Fc receptors.
The Ig-like domains are depicted as filled circles with color-coding according to the similarities in sequence based on phylogenetic analyses [24], [58]. The domain type D1, D2, D3, D4 and D5 show a relatively conserved pattern in most tetrapods and have therefore been color-coded in red dark blue, yellow, light blue and green. A phylogenetic analysis of all the individual domains presented in figure 5 and a few additional receptors are presented in supplementary figure S4. The color-coding in figure 5 is based on this supplementary figure. The extracellular regions, the transmembrane regions and cytoplasmic tails are not to scale in order to show the positions of potential signaling motifs like ITAMs (green boxes) and ITIMs (red boxes), which regulate the biological function the Fc receptors. Non-consensus ITIMs are also indicated as boxes with half red half white. Some of the intracellular proteins contain C-terminal mucin-like regions that are depicted as blue triangles.