• CLEC1A is a type 2 transmembrane protein that belongs to the Dectin-1 family of C-type lectins, consists of a 52 amino acid (aa) cytoplasmic domain, a 21 aa transmembrane segment, and a 207 aa extracellular domain (ECD).
• CLEC1A is a nonclassical C-type lectin in that its CRD lacks consensus amino acids which mediate calcium dependent carbohydrate binding in other C-type lectins. The cytoplasmic domain contains one tyrosine, multiple serine and threonine, and a cluster of aspartic acid residues. The CLEC1A is involved in regulating NK cell activation.
• CLEC1A is most highly expressed in heart, lung, kidney, small intestine, thymus and lymph nodes.
• The exons 3~6 of mouse Clec1a gene that encodes the extracellular domain was replaced by human CLEC1A exons 3~6 in B-hCLEC1A mice.

Gene targeting strategy for B-hCLEC1A mice.
The exons 3~6 of mouse Clec1a gene that encodes the extracellular domain was replaced by human CLEC1A exons 3~6 in B-hCLEC1A mice.

Western blot analysis of CLEC1A protein expression in homozygous B-hCLEC1A mice. Various tissue lysates were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCLEC1A mice (H/H), and then analyzed by western blot with anti-CLEC1A antibody. 40 μg total proteins were loaded for western blotting analysis. hCLEC1A was detected in heart, lung, kidney, small intestine, thymus and lymph node (red arrow).

Strain specific analysis of CLEC1A mRNA expression in wild-type C57BL/6 mice and B-hCLEC1A mice by RT-PCR. Lung RNA were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hCLEC1A mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CLEC1A primers. Mouse Clec1a mRNA were detectable only in wild-type C57BL/6 mice. Human CLEC1A mRNA was detectable only in homozygous B-hCLEC1A mice but not in wild-type mice.