. Author manuscript; available in PMC: 2015 Sep 1.

Published in final edited form as: Dev Comp Immunol. 2014 Feb 15;46(1):24–34. doi: 10.1016/j.dci.2014.02.004

Table 1.

Sequence and structural characteristics of immunoglobulin domain-containing innate immune receptor families in zebrafish

Feature	NITR	DICP	PIGRL	NILT	LITR
Min. estimate of genes	39	29	29	>52^a	>23^a
Ig domains per molecule	1–2	1–2	2	1–2^b	1–6^b
Encoded by zebrafish chromosomes	7, 14	3, 14, 16	2	1	3, 7
Members with cytoplasmic ITAM	No	No	No	Yes^b	No^b
Members with charged residue in TM	Yes, + charge	Yes, − charge	Unknown	No^b	Yes, + charge^b
Adaptor protein	Dap12	Unknown	Unknown	Unknown	FcRγ, FcRγL^b
Members with cytoplasmic ITIM	Yes	Yes	Yes	Yes^b	Yes^b
Ig types	V, I	V-like	V	V-like	C2-like
C²³ to C¹⁰⁴ spacing	64–73	59–67	59–66	56–63^b	36, 40–52^b
Spacing of additional cysteine pairs	No internal C's in V domain^c	35–43	6, 7, 9^d	3, 6, 7^b	No internal C's^b
Notable Features	J domains; mediates allogeneic recognition^b	Poly-serine in D2	Conserved plgR motif	CX₃C motif^b	Putative MHC binding site^b
(I/V)(F/Y)X(L/V)X₄LX₅GXYXCX(I/V) motif	Yes	No	Yes	Yes^b	No^b
Ligands	Unknown	Phospholipids	Phospholipids	Unknown	Unknown

Approximate numbers of NILT and LITR genes were calculated by dividing the total number of Ig domains by two (NILTs) or six (LITRs)

Based on transcripts from catfish, carp, trout and/or salmon

NITR I domains contain six conserved cysteine residues and are excluded from this analysis

Not all Ig domains possess an extra cysteine pair