TDLacZ mouse, model for studying development and function of thymic microenvironment.

초록

In order to study thymic compartmentalization and organogenesis, Thymic Delta lacZ (TDLacZ) mouse model system was established by knocking-in the LacZ gene into the Thymic Stromal Co-transporter (TSCOT)/Ly110 locus. TDLacZ mouse was generated by use of 129 ES cell line. Mice were bred in clean IVC rack and set up for the timed pregnancy for obtaining fetal thymic tissues. PCR was applied for genotyping of mouse model. Immunohistochemistry and LacZ activity staining were used for identifying the expression of targeted gene in the tissues. In order to confirm the expression of LacZ message, RT-PCR method was applied. For the analyses of thymic development and thymic stromal cells population, flow cytometric analysis was used. Thymus-specific expression of lacZ was detected from embryonic day 11 when thymic organogensis initiated. In the new born thymus, LacZ expression was exclusively detected in the cortex. Moreover, their expression was also detected at the newborn thymus of TDLacZ and Nude double homozygote mice. Homozygote TDLacZ mouse exhibit slightly reduced levels of thymocyte when compared with heterozygote at the age of 6 weeks in early generation (N6) after back crossing to C57Bl/6. However, at the age of 6 month in later generation, there was no significant reduction in the thymocytes were observed. We are in the process of testing thymocyte development in fetal stage.