Generation of TREM2 Transgenic Mice

A forward primer (5′-GAA TTC GCC CTT GGC TGG CTG CTG GCA-3′) and reverse primer for the mouse TREM2 nucleotide sequence (5′-GTA CGT GAG AGA ATT C-3′) were used to amplify TREM2 cDNA by RT-PCR. The amplified cDNA was cloned into the pGEM (Professional Group on Engineering Management)-T vector (Promega, Madison, WI), digested with the EcoRI restriction enzyme and then cloned into the pcDNA3.1 expression vector (Invitrogen, Carlsbad, CA, USA) to construct the recombinant expression vector pcDNA3.1/TREM2. Pure isolated recombinant TREM-2 cDNA was microinjected into fertilized eggs (0.5 days) from C57BL/6J mice, and the eggs were then implanted into the oviducts of pseudopregnant C57BL/6J female mice that had been mated with vasectomized male mice of the same strain 1 day before. TREM2-TG mice highly expressed TREM2 in the various tissues, such as the liver, lung, brain, heart, thymus, spleen, colon and bone marrow compared with WT mice [39 (link)]. However, no specific difference in phenotypes and behaviors between WT and TREM2-TG mice was observed [40 (link)].