Fig. 5

Expansion of NKRP1-Like genes and its ligand-like genes in duck MHC. a Maximum likelihood tree of NKC-like genes. Duck NKC-like genes clustered into two groups, namely groups II and V [54]. In group V, 15 duck NKC-like genes (referenced as NKRP1L-1 to NKRP1L-15) grouped with mammalian NKRP1 genes and 19 duck NKC-like genes (referenced as CLEC2L-1 to CLEC2L-19) grouped with mammalian NKRP1 ligands. Numbers of the tree branches are bootstrap percentages with 1000 iterations. Abbreviated information on species is in Additional file 1: Table S20. b,c Partial multiple sequence alignment of NKC-like proteins in duck MHC (see Additional file 2: Fig. S18 and Additional file 5: Fig. S19 for details). “·” and “-” represent the same amino acids and gap, respectively. d Distribution of 9 pairs of NKRP1-like/CLEC2-like genes in the duck MHC. e Expression of NKRP1-like genes in ducks. Total gene expression of activating and inhibitory NKRP1-like genes is shown in the bottom two rows. Detailed sample information is in Additional file 1: Table S9