Generating Transgenic GFP/RFP Mice for Microglial and Monocyte Tracking

C57BL/10SnJ mice were obtained from an in-house breeding colony, these mice are noted as C57BL/10 throughout the paper. TgGFP/RFP mice were generated by crossbreeding Cx3cr1 knockout mice homozygous for the Cx3cr1-GFP targeted mutation (B6.129P-Cx3cr1^tm1Litt/J,The Jackson Laboratory, Stock No: 005582) with Ccr2 knockout mice homozygous for the Ccr2-RFP targeted mutation (B6.129(Cg)-Ccr2^tm2.1Ifc/J,The Jackson Laboratory, Stock No:017586) [21 (link), 34 (link)]. Resultant offspring had heterozygous expression of both Cx3cr1 and Ccr2. In addition, green fluorescent protein (GFP) was expressed under promoter for Cx3cr1, prominently expressed by microglia in the CNS and red fluorescent protein (RFP) was expressed under the promoter for Ccr2, prominently expressed by monocytes [33 (link)]. All mice were group housed in transparent cages in a 12 h light (250-300 lx) /12 h dark cycle and food and water were available ad libitium.