Mice Lacking Expression of Secondary Lymphoid Organ Chemokine Have Defects in Lymphocyte Homing and Dendritic Cell Localization

Gunn, Michael D.; Kyuwa, Shigeru; Tam, Carmen; Kakiuchi, Terutaka; Matsuzawa, Akio; Williams, Lewis T.; Nakano, Hideki

SLC Introns and Exons Are Intact in plt Mice. Although the plt mutation (29) and the SLC gene (Gunn, M.D., un- published data) map to the same genetic locus on mouse chromosome 4, the molecular basis of the plt mutation has not been identified. To identify the genetic abnormality that leads to a loss of SLC expression in plt mice, we have initiated a search for the plt mutation at the DNA level. The murine SLC gene contains four exons spanning a total of 1 kb (Gunn, M.D., unpublished data). To determine if the plt mutation occurs within SLC introns or exons, overlapping PCR fragments were generated from genomic DNA of both plt and Ï©/Ï© mice. Comparison of plt and Ï©/Ï© sequence over a 3-kb region extending from 1 kb upstream of the transcriptional start site to 1 kb downstream of the polyadenylation signal revealed several single base changes but no mutation that would account for a loss of SLC expression (data not shown). Thus, while the plt mutation is located in the proximity of the SLC gene, it is not within SLC introns or exons.